TY - JOUR A1 - Noonan, Michael J. A1 - Tucker, Marlee A. A1 - Fleming, Christen H. A1 - Akre, Thomas S. A1 - Alberts, Susan C. A1 - Ali, Abdullahi H. A1 - Altmann, Jeanne A1 - Antunes, Pamela Castro A1 - Belant, Jerrold L. A1 - Beyer, Dean A1 - Blaum, Niels A1 - Boehning-Gaese, Katrin A1 - Cullen Jr, Laury A1 - de Paula, Rogerio Cunha A1 - Dekker, Jasja A1 - Drescher-Lehman, Jonathan A1 - Farwig, Nina A1 - Fichtel, Claudia A1 - Fischer, Christina A1 - Ford, Adam T. A1 - Goheen, Jacob R. A1 - Janssen, Rene A1 - Jeltsch, Florian A1 - Kauffman, Matthew A1 - Kappeler, Peter M. A1 - Koch, Flavia A1 - LaPoint, Scott A1 - Markham, A. Catherine A1 - Medici, Emilia Patricia A1 - Morato, Ronaldo G. A1 - Nathan, Ran A1 - Oliveira-Santos, Luiz Gustavo R. A1 - Olson, Kirk A. A1 - Patterson, Bruce D. A1 - Paviolo, Agustin A1 - Ramalho, Emiliano Estero A1 - Rosner, Sascha A1 - Schabo, Dana G. A1 - Selva, Nuria A1 - Sergiel, Agnieszka A1 - da Silva, Marina Xavier A1 - Spiegel, Orr A1 - Thompson, Peter A1 - Ullmann, Wiebke A1 - Zieba, Filip A1 - Zwijacz-Kozica, Tomasz A1 - Fagan, William F. A1 - Mueller, Thomas A1 - Calabrese, Justin M. T1 - A comprehensive analysis of autocorrelation and bias in home range estimation JF - Ecological monographs : a publication of the Ecological Society of America. N2 - Home range estimation is routine practice in ecological research. While advances in animal tracking technology have increased our capacity to collect data to support home range analysis, these same advances have also resulted in increasingly autocorrelated data. Consequently, the question of which home range estimator to use on modern, highly autocorrelated tracking data remains open. This question is particularly relevant given that most estimators assume independently sampled data. Here, we provide a comprehensive evaluation of the effects of autocorrelation on home range estimation. We base our study on an extensive data set of GPS locations from 369 individuals representing 27 species distributed across five continents. We first assemble a broad array of home range estimators, including Kernel Density Estimation (KDE) with four bandwidth optimizers (Gaussian reference function, autocorrelated‐Gaussian reference function [AKDE], Silverman's rule of thumb, and least squares cross‐validation), Minimum Convex Polygon, and Local Convex Hull methods. Notably, all of these estimators except AKDE assume independent and identically distributed (IID) data. We then employ half‐sample cross‐validation to objectively quantify estimator performance, and the recently introduced effective sample size for home range area estimation ( N̂ area ) to quantify the information content of each data set. We found that AKDE 95% area estimates were larger than conventional IID‐based estimates by a mean factor of 2. The median number of cross‐validated locations included in the hold‐out sets by AKDE 95% (or 50%) estimates was 95.3% (or 50.1%), confirming the larger AKDE ranges were appropriately selective at the specified quantile. Conversely, conventional estimates exhibited negative bias that increased with decreasing N̂ area. To contextualize our empirical results, we performed a detailed simulation study to tease apart how sampling frequency, sampling duration, and the focal animal's movement conspire to affect range estimates. Paralleling our empirical results, the simulation study demonstrated that AKDE was generally more accurate than conventional methods, particularly for small N̂ area. While 72% of the 369 empirical data sets had >1,000 total observations, only 4% had an N̂ area >1,000, where 30% had an N̂ area <30. In this frequently encountered scenario of small N̂ area, AKDE was the only estimator capable of producing an accurate home range estimate on autocorrelated data. KW - animal movement KW - kernel density estimation KW - local convex hull KW - minimum convex polygon KW - range distribution KW - space use KW - telemetry KW - tracking data Y1 - 2018 U6 - https://doi.org/10.1002/ecm.1344 SN - 0012-9615 SN - 1557-7015 VL - 89 IS - 2 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Schurr, Frank Martin A1 - Dean, W. R. J. A1 - Milton, Sue J. A1 - Jeltsch, Florian T1 - A conceptual model linking demography of the shrub species Grewia flava to the dynamics of Kalahari savannas N2 - Environmental heterogeneity is a major determinant of plant population dynamics. In semi-arid Kalahari savannas, heterogeneity is created by savanna structure, i.e. by the spatial arrangement and temporal dynamics of woody plant and open grassland microsites. We formulate a conceptual model describing the effects of savanna dynamics on the population dynamics of the animal-dispersed shrub Grewia flava. From empirical results we derive model rules describing effects of savanna structure on several processes in Grewia's life cycle. By formulating the model, we summarise existing information on Grewia demography and identify gaps in this knowledge. Despite a number of such gaps, the model can be used to make certain quantitative predictions. As an example, we apply the model to investigate the role of seed dispersal in Grewia encroachment on rangelands. Model results show that cattle promote encroachment by depositing substantial numbers of seeds in open areas, where Grewia is otherwise dispersal-limited. Finally, we draw some general conclusions about Grewia's life history and population dynamics. Under natural conditions, concentrated seed deposition under woody plants appears to be a key process causing the observed association between Grewia and other woody plants. Furthermore, low rates of recruitment and high adult survival result in slow-motion dynamics of Grewia populations. As a consequence, Grewia populations interact with savanna dynamics on long temporal and short to intermediate spatial scales. Y1 - 2004 ER - TY - JOUR A1 - Reeg, Jette A1 - Heine, Simon A1 - Mihan, Christine A1 - McGee, Sean A1 - Preuss, Thomas G. A1 - Jeltsch, Florian T1 - A graphical user interface for the plant community model IBC-grass JF - Plos One N2 - Plants located adjacent to agricultural fields are important for maintaining biodiversity in semi-natural landscapes. To avoid undesired impacts on these plants due to herbicide application on the arable fields, regulatory risk assessments are conducted prior to registration to ensure proposed uses of plant protection products do not present an unacceptable risk. The current risk assessment approach for these non-target terrestrial plants (NTTPs) examines impacts at the individual-level as a surrogate approach for protecting the plant community due to the inherent difficulties of directly assessing population or community level impacts. However, modelling approaches are suitable higher tier tools to upscale individual-level effects to community level. IBC-grass is a sophisticated plant community model, which has already been applied in several studies. However, as it is a console application software, it was not deemed sufficiently user-friendly for risk managers and assessors to be conveniently operated without prior expertise in ecological models. Here, we present a user-friendly and open source graphical user interface (GUI) for the application of IBC-grass in regulatory herbicide risk assessment. It facilitates the use of the plant community model for predicting long-term impacts of herbicide applications on NTTP communities. The GUI offers two options to integrate herbicide impacts: (1) dose responses based on current standard experiments (acc. to testing guidelines) and (2) based on specific effect intensities. Both options represent suitable higher tier options for future risk assessments of NTTPs as well as for research on the ecological relevance of effects. Y1 - 2020 U6 - https://doi.org/10.1371/journal.pone.0230012 SN - 1932-6203 VL - 15 IS - 3 PB - Plos 1 CY - San Francisco ER - TY - JOUR A1 - Geyer, Juliane A1 - Strixner, Lena A1 - Kreft, Stefan A1 - Jeltsch, Florian A1 - Ibisch, Pierre L. T1 - Adapting conservation to climate change: a case study on feasibility and implementation in Brandenburg, Germany JF - Regional environmental change N2 - Conservation actions need to account for global climate change and adapt to it. The body of the literature on adaptation options is growing rapidly, but their feasibility and current state of implementation are rarely assessed. We discussed the practicability of adaptation options with conservation managers analysing three fields of action: reducing the vulnerability of conservation management, reducing the vulnerability of conservation targets (i.e. biodiversity) and climate change mitigation. For all options, feasibility, current state of implementation and existing obstacles to implementation were analysed, using the Federal State of Brandenburg, Germany, as a case study. Practitioners considered a large number of options useful, most of which have already been implemented at least in part. Those options considered broadly implemented resemble mainly conventional measures of conservation without direct relation to climate change. Managers are facing several obstacles for adapting to climate change, including political reluctance to change, financial and staff shortages in conservation administrations and conflictive EU funding schemes in agriculture. A certain reluctance to act, due to the high degree of uncertainty with regard to climate change scenarios and impacts, is widespread. A lack of knowledge of appropriate methods such as adaptive management often inhibits the implementation of adaptation options in the field of planning and management. Based on the findings for Brandenburg, we generally conclude that it is necessary to focus in particular on options that help to reduce vulnerability of conservation management itself, i.e. those that enhance management effectiveness. For instance, adaptive and proactive risk management can be applied as a no-regrets option, independently from specific climate change scenarios or impacts, strengthening action under uncertainty. KW - Climate change KW - Adaptation options KW - Nature conservation management KW - Vulnerability Y1 - 2015 U6 - https://doi.org/10.1007/s10113-014-0609-9 SN - 1436-3798 SN - 1436-378X VL - 15 IS - 1 SP - 139 EP - 153 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Romero-Mujalli, Daniel A1 - Rochow, Markus A1 - Kahl, Sandra M. A1 - Paraskevopoulou, Sofia A1 - Folkertsma, Remco A1 - Jeltsch, Florian A1 - Tiedemann, Ralph T1 - Adaptive and nonadaptive plasticity in changing environments: Implications for sexual species with different life history strategies JF - Ecology and Evolution N2 - Populations adapt to novel environmental conditions by genetic changes or phenotypic plasticity. Plastic responses are generally faster and can buffer fitness losses under variable conditions. Plasticity is typically modeled as random noise and linear reaction norms that assume simple one-to- one genotype–phenotype maps and no limits to the phenotypic response. Most studies on plasticity have focused on its effect on population viability. However, it is not clear, whether the advantage of plasticity depends solely on environmental fluctuations or also on the genetic and demographic properties (life histories) of populations. Here we present an individual-based model and study the relative importance of adaptive and nonadaptive plasticity for populations of sexual species with different life histories experiencing directional stochastic climate change. Environmental fluctuations were simulated using differentially autocorrelated climatic stochasticity or noise color, and scenarios of directiona climate change. Nonadaptive plasticity was simulated as a random environmental effect on trait development, while adaptive plasticity as a linear, saturating, or sinusoidal reaction norm. The last two imposed limits to the plastic response and emphasized flexible interactions of the genotype with the environment. Interestingly, this assumption led to (a) smaller phenotypic than genotypic variance in the population (many-to- one genotype–phenotype map) and the coexistence of polymorphisms, and (b) the maintenance of higher genetic variation—compared to linear reaction norms and genetic determinism—even when the population was exposed to a constant environment for several generations. Limits to plasticity led to genetic accommodation, when costs were negligible, and to the appearance of cryptic variation when limits were exceeded. We found that adaptive plasticity promoted population persistence under red environmental noise and was particularly important for life histories with low fecundity. Populations produing more offspring could cope with environmental fluctuations solely by genetic changes or random plasticity, unless environmental change was too fast. KW - developmental canalization KW - environmental change KW - genetic accommodation KW - Individual-based models KW - limits KW - many-to-one genotype–phenotype map KW - noise color KW - phenotypic plasticity KW - reaction norms KW - stochastic fluctuations Y1 - 2020 SN - 2045-7758 VL - 11 IS - 11 PB - John Wiley & Sons, Inc. CY - New Jersey ER - TY - GEN A1 - Romero-Mujalli, Daniel A1 - Rochow, Markus A1 - Kahl, Sandra M. A1 - Paraskevopoulou, Sofia A1 - Folkertsma, Remco A1 - Jeltsch, Florian A1 - Tiedemann, Ralph T1 - Adaptive and nonadaptive plasticity in changing environments: Implications for sexual species with different life history strategies T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Populations adapt to novel environmental conditions by genetic changes or phenotypic plasticity. Plastic responses are generally faster and can buffer fitness losses under variable conditions. Plasticity is typically modeled as random noise and linear reaction norms that assume simple one-to- one genotype–phenotype maps and no limits to the phenotypic response. Most studies on plasticity have focused on its effect on population viability. However, it is not clear, whether the advantage of plasticity depends solely on environmental fluctuations or also on the genetic and demographic properties (life histories) of populations. Here we present an individual-based model and study the relative importance of adaptive and nonadaptive plasticity for populations of sexual species with different life histories experiencing directional stochastic climate change. Environmental fluctuations were simulated using differentially autocorrelated climatic stochasticity or noise color, and scenarios of directiona climate change. Nonadaptive plasticity was simulated as a random environmental effect on trait development, while adaptive plasticity as a linear, saturating, or sinusoidal reaction norm. The last two imposed limits to the plastic response and emphasized flexible interactions of the genotype with the environment. Interestingly, this assumption led to (a) smaller phenotypic than genotypic variance in the population (many-to- one genotype–phenotype map) and the coexistence of polymorphisms, and (b) the maintenance of higher genetic variation—compared to linear reaction norms and genetic determinism—even when the population was exposed to a constant environment for several generations. Limits to plasticity led to genetic accommodation, when costs were negligible, and to the appearance of cryptic variation when limits were exceeded. We found that adaptive plasticity promoted population persistence under red environmental noise and was particularly important for life histories with low fecundity. Populations produing more offspring could cope with environmental fluctuations solely by genetic changes or random plasticity, unless environmental change was too fast. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1170 KW - developmental canalization KW - environmental change KW - genetic accommodation KW - Individual-based models KW - limits KW - many-to-one genotype–phenotype map KW - noise color KW - phenotypic plasticity KW - reaction norms KW - stochastic fluctuations Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-523201 SN - 1866-8372 IS - 1170 ER - TY - JOUR A1 - Reeg, Jette A1 - Strigl, Lea A1 - Jeltsch, Florian T1 - Agricultural buffer zone thresholds to safeguard functional bee diversity BT - Insights from a community modeling approach JF - Ecology and Evolution N2 - Wild bee species are important pollinators in agricultural landscapes. However, population decline was reported over the last decades and is still ongoing. While agricultural intensification is a major driver of the rapid loss of pollinating species, transition zones between arable fields and forest or grassland patches, i.e., agricultural buffer zones, are frequently mentioned as suitable mitigation measures to support wild bee populations and other pollinator species. Despite the reported general positive effect, it remains unclear which amount of buffer zones is needed to ensure a sustainable and permanent impact for enhancing bee diversity and abundance. To address this question at a pollinator community level, we implemented a process-based, spatially explicit simulation model of functional bee diversity dynamics in an agricultural landscape. More specifically, we introduced a variable amount of agricultural buffer zones (ABZs) at the transition of arable to grassland, or arable to forest patches to analyze the impact on bee functional diversity and functional richness. We focused our study on solitary bees in a typical agricultural area in the Northeast of Germany. Our results showed positive effects with at least 25% of virtually implemented agricultural buffer zones. However, higher amounts of ABZs of at least 75% should be considered to ensure a sufficient increase in Shannon diversity and decrease in quasi-extinction risks. These high amounts of ABZs represent effective conservation measures to safeguard the stability of pollination services provided by solitary bee species. As the model structure can be easily adapted to other mobile species in agricultural landscapes, our community approach offers the chance to compare the effectiveness of conservation measures also for other pollinator communities in future. KW - agricultural landscape KW - buffer zones KW - community model KW - functional traits KW - solitary bees KW - spatially explicit Y1 - 2022 U6 - https://doi.org/10.1002/ece3.8748 SN - 2045-7758 VL - 12 SP - 1 EP - 17 PB - Wiley Online Library CY - Hoboken, New Jersey, USA ET - 3 ER - TY - GEN A1 - Reeg, Jette A1 - Strigl, Lea A1 - Jeltsch, Florian T1 - Agricultural buffer zone thresholds to safeguard functional bee diversity: Insights from a community modeling approach T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Wild bee species are important pollinators in agricultural landscapes. However, population decline was reported over the last decades and is still ongoing. While agricultural intensification is a major driver of the rapid loss of pollinating species, transition zones between arable fields and forest or grassland patches, i.e., agricultural buffer zones, are frequently mentioned as suitable mitigation measures to support wild bee populations and other pollinator species. Despite the reported general positive effect, it remains unclear which amount of buffer zones is needed to ensure a sustainable and permanent impact for enhancing bee diversity and abundance. To address this question at a pollinator community level, we implemented a process-based, spatially explicit simulation model of functional bee diversity dynamics in an agricultural landscape. More specifically, we introduced a variable amount of agricultural buffer zones (ABZs) at the transition of arable to grassland, or arable to forest patches to analyze the impact on bee functional diversity and functional richness. We focused our study on solitary bees in a typical agricultural area in the Northeast of Germany. Our results showed positive effects with at least 25% of virtually implemented agricultural buffer zones. However, higher amounts of ABZs of at least 75% should be considered to ensure a sufficient increase in Shannon diversity and decrease in quasi-extinction risks. These high amounts of ABZs represent effective conservation measures to safeguard the stability of pollination services provided by solitary bee species. As the model structure can be easily adapted to other mobile species in agricultural landscapes, our community approach offers the chance to compare the effectiveness of conservation measures also for other pollinator communities in future. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1281 KW - agricultural landscape KW - buffer zones KW - community model KW - functional traits KW - solitary bees KW - spatially explicit Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-570800 SN - 1866-8372 IS - 1281 ER - TY - JOUR A1 - Buchmann, Carsten M. A1 - Schurr, Frank Martin A1 - Nathan, Ran A1 - Jeltsch, Florian T1 - An allometric model of home range formation explains the structuring of animal communities exploiting heterogeneous resources JF - Oikos N2 - Understanding and predicting the composition and spatial structure of communities is a central challenge in ecology. An important structural property of animal communities is the distribution of individual home ranges. Home range formation is controlled by resource heterogeneity, the physiology and behaviour of individual animals, and their intra- and interspecific interactions. However, a quantitative mechanistic understanding of how home range formation influences community composition is still lacking. To explore the link between home range formation and community composition in heterogeneous landscapes we combine allometric relationships for physiological properties with an algorithm that selects optimal home ranges given locomotion costs, resource depletion and competition in a spatially-explicit individual-based modelling framework. From a spatial distribution of resources and an input distribution of animal body mass, our model predicts the size and location of individual home ranges as well as the individual size distribution (ISD) in an animal community. For a broad range of body mass input distributions, including empirical body mass distributions of North American and Australian mammals, our model predictions agree with independent data on the body mass scaling of home range size and individual abundance in terrestrial mammals. Model predictions are also robust against variation in habitat productivity and landscape heterogeneity. The combination of allometric relationships for locomotion costs and resource needs with resource competition in an optimal foraging framework enables us to scale from individual properties to the structure of animal communities in heterogeneous landscapes. The proposed spatially-explicit modelling concept not only allows for detailed investigation of landscape effects on animal communities, but also provides novel insights into the mechanisms by which resource competition in space shapes animal communities. Y1 - 2011 U6 - https://doi.org/10.1111/j.1600-0706.2010.18556.x SN - 0030-1299 VL - 120 IS - 1 SP - 106 EP - 118 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Jeltsch, Florian A1 - Tews, Jörg A1 - Brose, Ulrich A1 - Grimm, Volker A1 - Tielbörger, Katja A1 - Wichmann, Matthias A1 - Schwager, Monika T1 - Animal species diversity driven by habitat heterogeneity/diversity : the importance of keystone structures N2 - In a selected literature survey we reviewed studies on the habitat heterogeneity-animal species diversity relationship and evaluated whether there are uncertainties and biases in its empirical support. We reviewed 85 publications for the period 1960-2003. We screened each publication for terms that were used to define habitat heterogeneity, the animal species group and ecosystem studied, the definition of the structural variable, the measurement of vegetation structure and the temporal and spatial scale of the study. The majority of studies found a positive correlation between habitat heterogeneity/diversity and animal species diversity. However, empirical support for this relationship is drastically biased towards studies of vertebrates and habitats under anthropogenic influence. In this paper we show that ecological effects of habitat heterogeneity may vary considerably between species groups depending on whether structural attributes are perceived as heterogeneity or fragmentation. Possible effects may also vary relative to the structural variable measured. Based upon this, we introduce a classification framework that may be used for across-studies comparisons. Moreover, the effect of habitat heterogeneity for one species group may differ in relation to the spatial scale. In several studies, however, different species groups are closely linked to 'keystone structures' that determine animal species diversity by their presence. Detecting crucial keystone structures of the vegetation has profound implications for nature conservation and biodiversity management. Y1 - 2004 ER - TY - JOUR A1 - Jeltsch, Florian A1 - Stephan, T. A1 - Wiegand, T. A1 - Weber, G. E. T1 - Arid rangeland management supported by dynamic spatially-explicit simulation models Y1 - 2001 ER - TY - JOUR A1 - Geyer, Juliane A1 - Kreft, Stefan A1 - Jeltsch, Florian A1 - Ibisch, Pierre L. T1 - Assessing climate change-robustness of protected area management plans-The case of Germany JF - PLoS one N2 - Protected areas are arguably the most important instrument of biodiversity conservation. To keep them fit under climate change, their management needs to be adapted to address related direct and indirect changes. In our study we focus on the adaptation of conservation management planning, evaluating management plans of 60 protected areas throughout Germany with regard to their climate change-robustness. First, climate change-robust conservation management was defined using 11 principles and 44 criteria, which followed an approach similar to sustainability standards. We then evaluated the performance of individual management plans concerning the climate change-robustness framework. We found that climate change-robustness of protected areas hardly exceeded 50 percent of the potential performance, with most plans ranking in the lower quarter. Most Natura 2000 protected areas, established under conservation legislation of the European Union, belong to the sites with especially poor performance, with lower values in smaller areas. In general, the individual principles showed very different rates of accordance with our principles, but similarly low intensity. Principles with generally higher performance values included holistic knowledge management, public accountability and acceptance as well as systemic and strategic coherence. Deficiencies were connected to dealing with the future and uncertainty. Lastly, we recommended the presented principles and criteria as essential guideposts that can be used as a checklist for working towards more climate change-robust planning. Y1 - 2017 U6 - https://doi.org/10.1371/journal.pone.0185972 SN - 1932-6203 VL - 12 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Esther, Alexandra A1 - Groeneveld, Jürgen A1 - Enright, Neal J. A1 - Miller, Ben P. A1 - Lamont, Byron B. A1 - Perry, George L. W. A1 - Schurr, Frank Martin A1 - Jeltsch, Florian T1 - Assessing the importance of seed immigration on coexistence of plant functional types in a species-rich ecosystem N2 - Modelling and empirical studies have shown that input from the regional seed pool is essential to maintain local species diversity. However, most of these studies have concentrated on simplified, if not neutral, model systems, and focus on a limited subset of species or on aggregated measures of diversity only (e.g., species richness or Shannon diversity). Thus they ignore more complex species interactions and important differences between species. To gain a better understanding of how seed immigration affects community structure at the local scale in real communities we conducted computer simulation experiments based on plant functional types (PFTs) for a species-rich, fire-prone Mediterranean-type shrubland in Western Australia. We developed a spatially explicit simulation model to explore the community dynamics of 38 PFTs, defined by seven traits - regeneration mode, seed production, seed size, maximum crown diameter, drought tolerance, dispersal mode and seed bank type - representing 78 woody species. Model parameterisation is based on published and unpublished data on the population dynamics of shrub species collected over 18 years. Simulation experiments are based on two contrasting seed immigration scenarios: (1) the 'equal seed input number' scenario, where the number of immigrant seeds is the same for all PFTs, and (2) the 'equal seed input mass' scenario, where the cumulative mass of migrating seeds is the same for all PFTs. Both scenarios were systematically tested and compared for different overall seed input values. Without immigration the local community drifts towards a state with only 13 coexisting PFTs. With increasing immigration rates in terms of overall mass of seeds the simulated number of coexisting PFTs and Shannon diversity quickly approaches values observed in the field. The equal seed mass scenario resulted in a more diverse community than did the seed number scenario. The model successfully approximates the frequency distributions (relative densities) of all individual plant traits except seed size for scenarios associated with equal seed input mass and high immigration rate. However, no scenario satisfactorily approximated the frequency distribution for all traits in combination. Our results show that regional seed input can explain the more aggregated measures of local community structure, and some, but not all, aspects of community composition. This points to the possible importance of other (untested) processes and traits (e.g., dispersal vectors) operating at the local scale. Our modelling framework can readily allow new factors to be systematically investigated, which is a major advantage compared to previous simulation studies, as it allows us to find structurally realistic models, which can address questions pertinent to ecological theory and to conservation management. Y1 - 2008 UR - http://www.sciencedirect.com/science/journal/03043800 U6 - https://doi.org/10.1016/j.ecolmodel.2008.01.014 SN - 0304-3800 ER - TY - JOUR A1 - Rossmanith, Eva A1 - Grimm, Volker A1 - Blaum, Niels A1 - Jeltsch, Florian T1 - Behavioural flexibility in the mating system buffers population extinction: lessons from the Lesser Spotted Woodpecker (Picoides minor) N2 - In most stochastic models addressing the persistence of small populations, environmental noise is included by imposing a synchronized effect of the environment on all individuals. However, buffer mechanisms are likely to exist that may counteract this synchronization to some degree. We have studied whether the flexibility in the mating system, which has been observed in some bird species, is a potential mechanism counteracting the synchronization of environmental fluctuations. Our study organism is the lesser spotted woodpecker Picoides minor (Linnaeus), a generally monogamous species. However, facultative polyandry, where one female mates with two males with separate nests, was observed in years with male-biased sex ratio. We constructed an individual-based model from data and observations of a population in Taunus, Germany. We tested the impact of three behavioural scenarios on population persistence: (1) strict monogamy; (2) polyandry without costs; and (3) polyandry assuming costs in terms of lower survival and reproductive success for secondary males. We assumed that polyandry occurs only in years with male-biased sex ratio and only for females with favourable breeding conditions. Even low rates of polyandry had a strong positive effect on population persistence. The increase of persistence with carrying capacity was slower in the monogamous scenario, indicating strong environmental noise. In the polyandrous scenarios, the increase of persistence was stronger, indicating a buffer mechanism. In the polyandrous scenarios, populations had a higher mean population size, a lower variation in number of individuals, and recovered faster after a population breakdown. Presuming a realistic polyandry rate and costs for polyandry, there was still a strong effect of polyandry on persistence. The results show that polyandry and in general flexibility in mating systems is a buffer mechanism that can significantly reduce the impact of environmental and demographic noise in small populations. Consequently, we suggest that even behaviour that seems to be exceptional should be considered explicitly when predicting the persistence of populations Y1 - 2006 U6 - https://doi.org/10.1111/j.1365-2656.2006.01074.x ER - TY - JOUR A1 - Wasiolka, Bernd A1 - Blaum, Niels A1 - Jeltsch, Florian A1 - Henschel, Joh T1 - Behavioural responses of the lizard "Pedioplanis l. lineoocellata" to overgrazing N2 - We studied the effects of overgrazing on the foraging behaviour of the lizard Pedioplanis l. lineoocellata (Spotted Sand Lizard), a sit-and-wait forager, in habitats of differing vegetation states to determine the effects of habitat degradation on this species. At high grazing intensity where vegetation cover and diversity is low, the lizard P. lineoocellata moves more frequently, spends more time moving and covers larger distances than in habitats where vegetation cover and diversity is high. These behavioural changes in movement patterns can be explained by less abundant prey in habitats with low vegetation cover and diversity. Although morphology, phylogeny and physiology of P. lineoocellata should constrain the change in foraging behaviour, the species has modified its foraging strategy from sit- and-wait to actively foraging. We assume that this behavioural flexibility of P. lineoocellata is a buffer mechanism enabling the species to use and survive in degraded (unfavourable) habitats. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/1146609X U6 - https://doi.org/10.1016/j.actao.2008.09.009 SN - 1146-609X ER - TY - JOUR A1 - Jeltsch, Florian A1 - Weber, Gisela A1 - Paruelo, J. A1 - Dean, W. R. J. A1 - Milton, Sue J. A1 - VanRooyen, N. T1 - Beweidung als Degradationsfaktor in ariden und semiariden Weidesystemen Y1 - 2000 ER - TY - JOUR A1 - Seifan, Merav A1 - Seifan, Tal A1 - Schiffers, Katja A1 - Jeltsch, Florian A1 - Tielboerger, Katja T1 - Beyond the competition-colonization trade-off - linking multiple trait response to disturbance characteristics JF - The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences N2 - Disturbances' role in shaping communities is well documented but highly disputed. We suggest replacing the overused two-trait trade-off approach with a functional group scheme, constructed from combinations of four key traits that represent four classes of species' responses to disturbances. Using model results and field observations from sites affected by two highly different disturbances, we demonstrated that popular dichotomous trade-offs are not sufficient to explain community dynamics, even if some emerge under certain conditions. Without disturbances, competition was only sufficient to predict species survival but not relative success, which required some escape mechanism (e.g., long-term dormancy). With highly predictable and large-scale disturbances, successful species showed a combination of high individual tolerance to disturbance and, more surprisingly, high competitive ability. When disturbances were less predictable, high individual tolerance and long-term seed dormancy were favored, due to higher environmental uncertainty. Our study demonstrates that theories relying on a small number of predefined trade-offs among traits (e.g., competition-colonization trade-off) may lead to unrealistic results. We suggest that the understanding of disturbance-community relationships can be significantly improved by employing sets of relevant trait assemblies instead of the currently common approach in which trade-offs are assumed in advance. KW - competition resistance trade-off KW - functional types KW - intermediate disturbance hypothesis KW - plant communities KW - species assemblies Y1 - 2013 U6 - https://doi.org/10.1086/668844 SN - 0003-0147 VL - 181 IS - 2 SP - 151 EP - 160 PB - Univ. of Chicago Press CY - Chicago ER - TY - JOUR A1 - Nathan, Ran A1 - Monk, Christopher T. A1 - Arlinghaus, Robert A1 - Adam, Timo A1 - Alós, Josep A1 - Assaf, Michael A1 - Baktoft, Henrik A1 - Beardsworth, Christine E. A1 - Bertram, Michael G. A1 - Bijleveld, Allert A1 - Brodin, Tomas A1 - Brooks, Jill L. A1 - Campos-Candela, Andrea A1 - Cooke, Steven J. A1 - Gjelland, Karl O. A1 - Gupte, Pratik R. A1 - Harel, Roi A1 - Hellstrom, Gustav A1 - Jeltsch, Florian A1 - Killen, Shaun S. A1 - Klefoth, Thomas A1 - Langrock, Roland A1 - Lennox, Robert J. A1 - Lourie, Emmanuel A1 - Madden, Joah R. A1 - Orchan, Yotam A1 - Pauwels, Ine S. A1 - Riha, Milan A1 - Röleke, Manuel A1 - Schlägel, Ulrike A1 - Shohami, David A1 - Signer, Johannes A1 - Toledo, Sivan A1 - Vilk, Ohad A1 - Westrelin, Samuel A1 - Whiteside, Mark A. A1 - Jaric, Ivan T1 - Big-data approaches lead to an increased understanding of the ecology of animal movement JF - Science N2 - Understanding animal movement is essential to elucidate how animals interact, survive, and thrive in a changing world. Recent technological advances in data collection and management have transformed our understanding of animal "movement ecology" (the integrated study of organismal movement), creating a big-data discipline that benefits from rapid, cost-effective generation of large amounts of data on movements of animals in the wild. These high-throughput wildlife tracking systems now allow more thorough investigation of variation among individuals and species across space and time, the nature of biological interactions, and behavioral responses to the environment. Movement ecology is rapidly expanding scientific frontiers through large interdisciplinary and collaborative frameworks, providing improved opportunities for conservation and insights into the movements of wild animals, and their causes and consequences. Y1 - 2022 U6 - https://doi.org/10.1126/science.abg1780 SN - 0036-8075 SN - 1095-9203 VL - 375 IS - 6582 SP - 734 EP - + PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Meyer, Jork A1 - Raudnitschka, Dorit A1 - Steinhauser, J. A1 - Jeltsch, Florian A1 - Brandl, Roland T1 - Biology and ecology of "Thallomys nigricauda" (Rodentia, Muridae) in the Thornveld savannah of South Africa Y1 - 2008 UR - http://www.sciencedirect.com/science/journal/16165047 U6 - https://doi.org/10.1016/j.mambio.2006.11.002 SN - 1616-5047 ER - TY - JOUR A1 - Ni, Jian A1 - Cao, Xianyong A1 - Jeltsch, Florian A1 - Herzschuh, Ulrike T1 - Biome distribution over the last 22,000 yr in China JF - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences N2 - Patterns of past vegetation changes over time and space can help facilitate better understanding of the interactions among climate, ecosystem, and human impact. Biome changes in China over the last 22,000 yr (calibrated radiocarbon date, a BP) were numerically reconstructed by using a standard approach of pollen-plant functional type-biome assignment (biomization). The biomization procedure involves pollen data from 2434 surface sites and 228 fossil sites with a high quality of pollen count and C-14 dating, 51 natural and three anthropogenic plant functional types (PFTs), as well as 19 natural and one anthropogenic biome. Surface pollen-based reconstruction of modern natural biome patterns is in good agreement (74.4%) with actual vegetation distribution in China. However, modem large-scale anthropogenic biome reconstruction has not been successful based on the current setup of three anthropogenic PFTs (plantation, secondary, and disturbed PFT) because of the limitation of non-species level pollen identification and the difficulty in the clear assignment of disturbed PFTs. The non-anthropogenic biome distributions of 44 time slices at 500-year intervals show large-scale discrepant and changed vegetation patterns from the last glacial maximum (LGM) to the Holocene throughout China. From 22 ka BP to 19 ka BP, temperate grassland, xerophytic shrubland, and desert dominated northern China, whereas cold or cool forests flourished in central China. Warm-temperate evergreen forests were restricted to far southern China, and tropical forests were absent During 18.5 ka BP to 12 ka BP, cold, cool, and dry biomes extended to some parts of northern, westem, and eastern China. Warm-temperate evergreen and mixed forests gradually expanded to occupy the whole of southern China. A slight northward shift of forest biomes occurred from 15 ka BP to 12 lea BP. During 11.5 ka BP to 9 ka BP, temperate grassland and shrubland gradually stretched to northern and western China. Cold and cool forests widely expanded into northern and central China, as well as in the northern margin of South China along with temperate deciduous forest. Since the early mid-Holocene (approximately 8.5 ka BP to 5.5 ka BP), all forest biomes shifted northward at the expense of herbaceous and shrubby biomes. Simultaneously, cold and cool forest biomes occupied the marginal areas of the Tibetan Plateau and the high mountains in western China. During the middle to late Holocene, from 5 ka to the present, temperate grassland and xerophytic shrubland expanded to the south and east, whereas temperate deciduous forests slightly shifted southward. After 3 lea BP, forest biomes were absent in western China and on the Tibetan plateau surface. Dramatic biome shifts from the LGM to the Holocene were observed in the forest-grassland ecotone and transitional zones between temperate and subtropical climates, between subtropical and tropical regions, and in the mountainous margins of the eastern Tibetan Plateau. Evidence showed more human disturbances during the late Holocene. More pollen records and historical documents are therefore further needed to understand fully the human disturbance-induced large-scale forest changes. In addition, more classifications of anthropogenic biome or land cover, more distinct assignment of pollen taxa to anthropogenic PFTs, and more effective numerical and/or mechanistic techniques in building large-scale human disturbances are required. (C) 2014 Elsevier B.V. All rights reserved. KW - Anthropogenic biome KW - Biomization KW - Holocene KW - Last glacial maximum KW - Plant functional types KW - Pollen dataset Y1 - 2014 U6 - https://doi.org/10.1016/j.palaeo.2014.04.023 SN - 0031-0182 SN - 1872-616X VL - 409 SP - 33 EP - 47 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Blaum, Niels A1 - Seymour, Colleen A1 - Rossmanith, Eva A1 - Schwager, Monika A1 - Jeltsch, Florian T1 - Changes in arthropod diversity along a land use driven gradient of shrub cover in savanna rangelands : identifcation of suitable indicators N2 - Shrub encroachment linked to heavy grazing has dramatically changed savanna landscapes, and is a major form of rangeland degradation. Our understanding of how shrub encroachment affects arthropod communities is poor, however. Here, we investigate the effects of shrub encroachment on abundance and diversity of ground-dwelling (wingless) arthropods at varying levels of shrub cover in the southern Kalahari. We also ascertain if invertebrate assemblage composition changes with habitat structure and identify which aspects of habitat structure (e.g., grass cover, herbaceous plant cover, shrub density) correlate most strongly with these changes. Ant, scorpion and dung beetle abundance increased with shrub cover, whereas grasshoppers and solifuges declined. Spider and beetle abundance exhibited hump-shaped relationships with shrub cover. RTU richness within orders either mirrored abundances, or exhibited no trend. Shrub density was the habitat component most correlated with similarities between invertebrate assemblages. Ground-dwelling arthropods showed clear shifts in species assemblage composition at a similarity level of 65% according to shrub density. Changes in indicator species showed that within the Tenebrionidae (darkling beetles), certain species respond positively to shrub thickening, replacing other species within the Family. Small-bodied, wingless Scarabaeidae (dung beetles) tended to increase with increased shrub density and three species emerged as significant indicators of more thickened habitats, although this might be a response to greater dung availability, rather than habitat structure itself. We conclude that because ground- dwelling invertebrates showed such clear responses in species assemblage composition, they present excellent candidates for use as indicator species in further studies into bush encroachment. Y1 - 2009 UR - http://www.springerlink.com/content/100125 U6 - https://doi.org/10.1007/s10531-008-9498-x SN - 0960-3115 ER - TY - JOUR A1 - Geyer, Juliane A1 - Kiefer, Iris A1 - Kreft, Stefan A1 - Chavez, Veronica A1 - Salafsky, Nick A1 - Jeltsch, Florian A1 - Ibisch, Pierre L. T1 - Classification of climate-change-induced stresses on biological diversity JF - Conservation biology : the journal of the Society for Conservation Biology N2 - Conservation actions need to account for and be adapted to address changes that will occur under global climate change. The identification of stresses on biological diversity (as defined in the Convention on Biological Diversity) is key in the process of adaptive conservation management. We considered any impact of climate change on biological diversity a stress because such an effect represents a change (negative or positive) in key ecological attributes of an ecosystem or parts of it. We applied a systemic approach and a hierarchical framework in a comprehensive classification of stresses to biological diversity that are caused directly by global climate change. Through analyses of 20 conservation sites in 7 countries and a review of the literature, we identified climate-change-induced stresses. We grouped the identified stresses according to 3 levels of biological diversity: stresses that affect individuals and populations, stresses that affect biological communities, and stresses that affect ecosystem structure and function. For each stress category, we differentiated 3 hierarchical levels of stress: stress class (thematic grouping with the coarsest resolution, 8); general stresses (thematic groups of specific stresses, 21); and specific stresses (most detailed definition of stresses, 90). We also compiled an overview of effects of climate change on ecosystem services using the categories of the Millennium Ecosystem Assessment and 2 additional categories. Our classification may be used to identify key climate-change-related stresses to biological diversity and may assist in the development of appropriate conservation strategies. The classification is in list format, but it accounts for relations among climate-change-induced stresses. KW - adaptation of conservation strategies KW - adaptive management KW - climate change KW - conservation planning KW - conservation targets KW - hierarchical framework KW - threats to biological diversity Y1 - 2011 U6 - https://doi.org/10.1111/j.1523-1739.2011.01676.x SN - 0888-8892 VL - 25 IS - 4 SP - 708 EP - 715 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Jeltsch, Florian A1 - Tews, Jörg T1 - Climate change impacts woody plant population dynamics in arid savanna Y1 - 2004 ER - TY - JOUR A1 - Seifan, Merav A1 - Seifan, Tal A1 - Jeltsch, Florian A1 - Tielboerger, Katja T1 - Combined disturbances and the role of their spatial and temporal properties in shaping community structure JF - Perspectives in plant ecology, evolution and systematics N2 - Disturbances are characteristic for many ecosystems. However, we still lack generalizations concerning their role in shaping communities, particularly when disturbances co-occur. To study such effects, we used a novel modeling approach that is unrestricted by a priori tradeoffs among specific plant traits, except for those generated by allocation principles. Thus, trait combinations were emergent properties associated with biotic and abiotic constraints. Specifically, we asked which traits dominate under specific disturbance regimes, whether single and combined disturbance regimes promote similar trait tradeoffs and how complex disturbance regimes affect species richness and functional diversity. Overall, disturbances' temporal properties governed the outcome of combined disturbances and were a stronger assortative force than spatial disturbance properties: low temporal predictability decreased seed-dispersability and dormancy, but increased competitive ability and disturbance tolerance. Evidence for tradeoffs between different colonization modes and between dormancy and disturbance tolerance were found, while surprisingly, the widely accepted colonization-competition tradeoff was not generated. Diversity was highest at intermediate disturbance intensity, but decreased monotonically with increasing unpredictability. In accordance with our results, future models should avoid restrictive assumptions about tradeoffs to generate robust and more general predictions about the role of disturbances for community dynamics. KW - Intermediate disturbance hypothesis KW - Coexistence KW - Environmental heterogeneity KW - Competition-colonization KW - Plant community KW - Individual-based model Y1 - 2012 U6 - https://doi.org/10.1016/j.ppees.2011.11.003 SN - 1433-8319 VL - 14 IS - 3 SP - 217 EP - 229 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Geissler, Katja A1 - Fiedler, Sebastian A1 - Ni, Jian A1 - Herzschuh, Ulrike A1 - Jeltsch, Florian T1 - Combined effects of grazing and climate warming drive shrub dominance on the Tibetan Plateau JF - The Rangeland journal N2 - Encroachment of shrubs into the unique pastoral grassland ecosystems of the Tibetan Plateau has significant impact on ecosystem services, especially forage production. We developed a process-based ecohydrological model to identify the relative importance of the main drivers of shrub encroachment for the alpine meadows within the Qinghai province. Specifically, we explored the effects of summer livestock grazing (intensity and type of livestock) together with the effects of climate warming, including interactions between herbaceous and woody vegetation and feedback loops between soil, water and vegetation. Under current climatic conditions and a traditional herd composition, an increasing grazing intensity above a threshold value of 0.32 +/- 0.10 large stock units (LSU) ha(-1) day(-1) changes the vegetation composition from herbaceous towards a woody and bare soil dominated system. Very high grazing intensity (above 0.8 LSU ha(-1) day(-1)) leads to a complete loss of any vegetation. Under warmer conditions, the vegetation showed a higher resilience against livestock farming. This resilience is enhanced when the herd has a higher browser : grazer ratio. A cooler climate has a shrub encroaching effect, whereas warmer conditions increase the cover of the herbaceous vegetation. This effect was primarily due to season length and an accompanied competitive loss of slower growing shrubs, rather than evaporative water loss leading to less soil water in deeper soil layers for deeper rooting shrubs. If climate warming is driving current shrub encroachment, we conclude it is only indirectly so. It would be manifest by an advancing shrubline and could be regarded as a climatic escape of specific shrub species such as Potentilla fruticosa. Under the recent high intensity of grazing, only herding by more browsing animals can potentially prevent both shrub encroachment and the complete loss of herbaceous vegetation. KW - alpine grassland degradation KW - herd composition KW - rangeland management KW - shrub encroachment KW - shrubline KW - simulation model Y1 - 2019 U6 - https://doi.org/10.1071/RJ19027 SN - 1036-9872 SN - 1834-7541 VL - 41 IS - 5 SP - 425 EP - 439 PB - CSIRO Publishing CY - Collingwood ER - TY - JOUR A1 - Teckentrup, Lisa A1 - Grimm, Volker A1 - Kramer-Schadt, Stephanie A1 - Jeltsch, Florian T1 - Community consequences of foraging under fear JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Non-consumptive effects of predators within ecosystems can alter the behavior of individual prey species, and have cascading effects on other trophic levels. In this context, an understanding of non-consumptive predator effects on the whole prey community is crucial for predicting community structure and composition, hence biodiversity patterns. We used an individual-based, spatially-explicit modelling approach to investigate the consequences of landscapes of fear on prey community metrics. The model spans multiple hierarchical levels from individual home range formation based on food availability and perceived predation risk to consequences on prey community structure and composition. This mechanistic approach allowed us to explore how important factors such as refuge availability and foraging strategy under fear affect prey community metrics. Fear of predators affected prey space use, such as home range formation. These adaptations had broader consequences for the community leading to changes in community structure and composition. The strength of community responses to perceived predation risk was driven by refuge availability in the landscape and the foraging strategy of prey animals. Low refuge availability in the landscape strongly decreased diversity and total biomass of prey communities. Additionally, body mass distributions in prey communities facing high predation risk were shifted towards small prey animals. With increasing refuge availability the consequences of non-consumptive predator effects were reduced, diversity and total biomass of the prey community increased. Prey foraging strategies affected community composition. Under medium refuge availability, risk-averse prey communities consisted of many small animals while risk-taking prey communities showed a more even body mass distribution. Our findings reveal that non-consumptive predator effects can have important implications for prey community diversity and should therefore be considered in the context of conservation and nature management. KW - Predator-prey interactions KW - Individual-based model KW - Landscape of fear KW - Home range KW - Biodiversity KW - Foraging Y1 - 2018 U6 - https://doi.org/10.1016/j.ecolmodel.2018.05.015 SN - 0304-3800 SN - 1872-7026 VL - 383 SP - 80 EP - 90 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Pfestorf, H. A1 - Weiss, L. A1 - Müller, J. A1 - Boch, Steffen A1 - Socher, S. A. A1 - Prati, Daniel A1 - Schöning, Ingo A1 - Weisser, W. A1 - Fischer, M. A1 - Jeltsch, Florian T1 - Community mean traits as additional indicators to monitor effects of land-use intensity On grassland plant diversity JF - Perspectives in plant ecology, evolution and systematics N2 - Semi-natural grasslands, biodiversity hotspots in Central-Europe, suffer from the cessation of traditional land-use. Amount and intensity of these changes challenge current monitoring frameworks typically based on classic indicators such as selected target species or diversity indices. Indicators based on plant functional traits provide an interesting extension since they reflect ecological strategies at individual and ecological processes at community levels. They typically show convergent responses to gradients of land-use intensity over scales and regions, are more directly related to environmental drivers than diversity components themselves and enable detecting directional changes in whole community dynamics. However, probably due to their labor- and cost intensive assessment in the field, they have been rarely applied as indicators so far. Here we suggest overcoming these limitations by calculating indicators with plant traits derived from online accessible databases. Aiming to provide a minimal trait set to monitor effects of land-use intensification on plant diversity we investigated relationships between 12 community mean traits, 2 diversity indices and 6 predictors of land-use intensity within grassland communities of 3 different regions in Germany (part of the German 'Biodiversity Exploratory' research network). By standardization of traits and diversity measures, use of null models and linear mixed models we confirmed (i) strong links between functional community composition and plant diversity, (ii) that traits are closely related to land-use intensity, and (iii) that functional indicators are equally, or even more sensitive to land-use intensity than traditional diversity indices. The deduced trait set consisted of 5 traits, i.e., specific leaf area (SLA), leaf dry matter content (LDMC), seed release height, leaf distribution, and onset of flowering. These database derived traits enable the early detection of changes in community structure indicative for future diversity loss. As an addition to current monitoring measures they allow to better link environmental drivers to processes controlling community dynamics. KW - Biodiversity Exploratories KW - Biological conservation KW - (Semi-natural) Grasslands KW - Plant functional traits KW - Indicators KW - Land-use intensity Y1 - 2013 U6 - https://doi.org/10.1016/j.ppees.2012.10.003 SN - 1433-8319 VL - 15 IS - 1 SP - 1 EP - 11 PB - Elsevier CY - Jena ER - TY - GEN A1 - Sonnemann, Ilja A1 - Pfestorf, Hans A1 - Jeltsch, Florian A1 - Wurst, Susanne T1 - Community- weighted mean plant traits predict small scale distribution of insect root herbivore abundance T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Small scale distribution of insect root herbivores may promote plant species diversity by creating patches of different herbivore pressure. However, determinants of small scale distribution of insect root herbivores, and impact of land use intensity on their small scale distribution are largely unknown. We sampled insect root herbivores and measured vegetation parameters and soil water content along transects in grasslands of different management intensity in three regions in Germany. We calculated community-weighted mean plant traits to test whether the functional plant community composition determines the small scale distribution of insect root herbivores. To analyze spatial patterns in plant species and trait composition and insect root herbivore abundance we computed Mantel correlograms. Insect root herbivores mainly comprised click beetle (Coleoptera, Elateridae) larvae (43%) in the investigated grasslands. Total insect root herbivore numbers were positively related to community-weighted mean traits indicating high plant growth rates and biomass (specific leaf area, reproductive-and vegetative plant height), and negatively related to plant traits indicating poor tissue quality (leaf C/N ratio). Generalist Elaterid larvae, when analyzed independently, were also positively related to high plant growth rates and furthermore to root dry mass, but were not related to tissue quality. Insect root herbivore numbers were not related to plant cover, plant species richness and soil water content. Plant species composition and to a lesser extent plant trait composition displayed spatial autocorrelation, which was not influenced by land use intensity. Insect root herbivore abundance was not spatially autocorrelated. We conclude that in semi-natural grasslands with a high share of generalist insect root herbivores, insect root herbivores affiliate with large, fast growing plants, presumably because of availability of high quantities of food. Affiliation of insect root herbivores with large, fast growing plants may counteract dominance of those species, thus promoting plant diversity. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 494 KW - Diabrotica Virgifera Virgifera KW - land-use intensity KW - functional traits KW - wireworms coloptera KW - spatial-distribution KW - Agriotes Ustulatus KW - population-dynamics KW - grassland diversity KW - european flora KW - arable land Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-408161 SN - 1866-8372 IS - 494 ER - TY - JOUR A1 - Sonnemann, Ilja A1 - Pfestorf, Hans A1 - Jeltsch, Florian A1 - Wurst, Susanne T1 - Community-Weighted Mean Plant Traits Predict Small Scale Distribution of Insect Root Herbivore Abundance JF - PLoS one N2 - Small scale distribution of insect root herbivores may promote plant species diversity by creating patches of different herbivore pressure. However, determinants of small scale distribution of insect root herbivores, and impact of land use intensity on their small scale distribution are largely unknown. We sampled insect root herbivores and measured vegetation parameters and soil water content along transects in grasslands of different management intensity in three regions in Germany. We calculated community-weighted mean plant traits to test whether the functional plant community composition determines the small scale distribution of insect root herbivores. To analyze spatial patterns in plant species and trait composition and insect root herbivore abundance we computed Mantel correlograms. Insect root herbivores mainly comprised click beetle (Coleoptera, Elateridae) larvae (43%) in the investigated grasslands. Total insect root herbivore numbers were positively related to community-weighted mean traits indicating high plant growth rates and biomass (specific leaf area, reproductive-and vegetative plant height), and negatively related to plant traits indicating poor tissue quality (leaf C/N ratio). Generalist Elaterid larvae, when analyzed independently, were also positively related to high plant growth rates and furthermore to root dry mass, but were not related to tissue quality. Insect root herbivore numbers were not related to plant cover, plant species richness and soil water content. Plant species composition and to a lesser extent plant trait composition displayed spatial autocorrelation, which was not influenced by land use intensity. Insect root herbivore abundance was not spatially autocorrelated. We conclude that in semi-natural grasslands with a high share of generalist insect root herbivores, insect root herbivores affiliate with large, fast growing plants, presumably because of availability of high quantities of food. Affiliation of insect root herbivores with large, fast growing plants may counteract dominance of those species, thus promoting plant diversity. Y1 - 2015 U6 - https://doi.org/10.1371/journal.pone.0141148 SN - 1932-6203 VL - 10 IS - 10 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Jeltsch, Florian A1 - Moloney, Kirk A. A1 - Schwager, Monika A1 - Körner, Katrin A1 - Blaum, Niels T1 - Consequences of correlations between habitat modifications and negative impact of climate change for regional species survival JF - Agriculture, ecosystems & environment : an international journal for scientific research on the relationship of agriculture and food production to the biosphere N2 - While several empirical and theoretical studies have clearly shown the negative effects of climate or landscape changes on population and species survival only few of them addressed combined and correlated consequences of these key environmental drivers. This also includes positive landscape changes such as active habitat management and restoration to buffer the negative effects of deteriorating climatic conditions. In this study, we apply a conceptual spatial modelling approach based on functional types to explore the effects of both positive and negative correlations between changes in habitat and climate conditions on the survival of spatially structured populations. We test the effect of different climate and landscape change scenarios on four different functional types that represent a broad spectrum of species characterised by their landscape level carrying capacity, the local population turnover rates at the patch level (K-strategies vs. r-strategies) and dispersal characterstics. As expected, simulation results show that correlated landscape and climatic changes can accelerate (in case of habitat loss or degradation) or slow down (in case of habitat gain or improvement) regional species extinction. However, the strength of the combined changes depends on local turnover at the patch level, the overall landscape capacity of the species, and its specific dispersal characteristics. Under all scenarios of correlated changes in habitat and climate conditions we found the highest sensitivity for functional types representing species with a low landscape capacity but a high population growth rate and a strong density regulation causing a high turnover at the local patch level. The relative importance of habitat loss or habitat degradation, in combination with climate deterioration, differed among the functional types. However, an increase in regional capacity revealed a similar response pattern: For all types, habitat improvement led to higher survival times than habitat gain, i.e. the establishment of new habitat patches. This suggests that improving local habitat quality at a regional scale is a more promising conservation strategy under climate change than implementing new habitat patches. This conceptual modelling study provides a general framework to better understand and support the management of populations prone to complex environmental changes. KW - Functional types KW - Spatially explicit modelling KW - Dynamic landscapes KW - Species conservation KW - Habitat fragmentation KW - Habitat management Y1 - 2011 U6 - https://doi.org/10.1016/j.agee.2010.12.019 SN - 0167-8809 VL - 145 IS - 1 SP - 49 EP - 58 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Jeltsch, Florian A1 - Hansen, Frank A1 - Tackmann, K. A1 - Wissel, Christian A1 - Thulke, Hans-Hermann T1 - Controlling Echinococcus multilocularis - ecological implications of field trials Y1 - 2003 ER - TY - JOUR A1 - Pfestorf, Hans A1 - Körner, Katrin A1 - Sonnemann, Ilja A1 - Wurst, Susanne A1 - Jeltsch, Florian T1 - Coupling experimental data with individual-based modelling reveals differential effects of root herbivory on grassland plant co-existence along a resource gradient JF - Journal of vegetation science N2 - QuestionThe empirical evidence of root herbivory effects on plant community composition and co-existence is contradictory. This originates from difficulties connected to below-ground research and confinement of experimental studies to a small range of environmental conditions. Here we suggest coupling experimental data with an individual-based model to overcome the limitations inherent in either approach. To demonstrate this, we investigated the consequences of root herbivory, as experimentally observed on individual plants, on plant competition and co-existence in a population and community context under different root herbivory intensities (RHI), fluctuating and constant root herbivore activity and grazing along a resource gradient. LocationBerlin, Germany, glasshouse; Potsdam, Germany, high performance cluster computer. MethodsThe well-established community model IBC-Grass was adapted to allow for a flexible species parameterization and to include annual species. Experimentally observed root herbivory effects on performance of eight common grassland plant species were incorporated into the model by altering plant growth rates. We then determined root herbivore effects on plant populations, competitive hierarchy and consequences for co-existence and community diversity. ResultsRoot herbivory reduced individual biomass, but temporal fluctuation allowed for compensation of herbivore effects. Reducing resource availability strongly shifted competitive hierarchies, with, however, more similar hierarchies along the gradient under root herbivory, pointing to reduced ecological species differences. Consequently, negative effects on co-existence and diversity prevailed, with the exception of a few positive effects on co-existence of selected species pairs. Temporal fluctuation alleviated but did not remove negative root herbivore effects, despite of the stronger influence of intra- compared to interspecific competition. Grazing in general augmented co-existence. Most interestingly, grazing interacted with RHI and resource availability by promoting positive effects of root herbivory. ConclusionsThrough integrating experimental data on the scale of individual plants with a simulation model we verified that root herbivory could affect plant competition with consequences for species co-existence. Our approach demonstrates the benefit that accrues when empirical and modelling approaches are brought more closely together, and that gathering data on distinct processes and under specific conditions, combined with appropriate models, can be used to answer challenging research questions in a more general way. KW - Above-/below-ground interactions KW - Below-ground resources KW - Competitive hierarchies KW - Grassland KW - Greenhouse experiment KW - Simulation experiment KW - Species co-existence KW - Wireworms Y1 - 2016 U6 - https://doi.org/10.1111/jvs.12357 SN - 1100-9233 SN - 1654-1103 VL - 27 SP - 269 EP - 282 PB - Wiley-Blackwell CY - Hoboken ER - TY - GEN A1 - Sieck, Mungla A1 - Ibisch, Pierre L. A1 - Moloney, Kirk A. A1 - Jeltsch, Florian T1 - Current models broadly neglect specific needs of biodiversity conservation in protected areas under climate change N2 - Background Protected areas are the most common and important instrument for the conservation of biological diversity and are called for under the United Nations' Convention on Biological Diversity. Growing human population densities, intensified land-use, invasive species and increasing habitat fragmentation threaten ecosystems worldwide and protected areas are often the only refuge for endangered species. Climate change is posing an additional threat that may also impact ecosystems currently under protection. Therefore, it is of crucial importance to include the potential impact of climate change when designing future nature conservation strategies and implementing protected area management. This approach would go beyond reactive crisis management and, by necessity, would include anticipatory risk assessments. One avenue for doing so is being provided by simulation models that take advantage of the increase in computing capacity and performance that has occurred over the last two decades. Here we review the literature to determine the state-of-the-art in modeling terrestrial protected areas under climate change, with the aim of evaluating and detecting trends and gaps in the current approaches being employed, as well as to provide a useful overview and guidelines for future research. Results Most studies apply statistical, bioclimatic envelope models and focus primarily on plant species as compared to other taxa. Very few studies utilize a mechanistic, process-based approach and none examine biotic interactions like predation and competition. Important factors like land-use, habitat fragmentation, invasion and dispersal are rarely incorporated, restricting the informative value of the resulting predictions considerably. Conclusion The general impression that emerges is that biodiversity conservation in protected areas could benefit from the application of modern modeling approaches to a greater extent than is currently reflected in the scientific literature. It is particularly true that existing models have been underutilized in testing different management options under climate change. Based on these findings we suggest a strategic framework for more effectively incorporating the impact of climate change in models exploring the effectiveness of protected areas. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 368 Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400894 ER - TY - JOUR A1 - Schiffers, Katja A1 - Schurr, Frank Martin A1 - Tielbörger, Katja A1 - Urbach, Carsten A1 - Moloney, Kirk A. A1 - Jeltsch, Florian T1 - Dealing with virtual aggregation : a new index for analysing heterogeneous point patterns Y1 - 2008 UR - http://www3.interscience.wiley.com/journal/117966123/home U6 - https://doi.org/10.1111/j.0906-7590.2008.05374.x SN - 0906-7590 ER - TY - JOUR A1 - Körner, Katrin A1 - Jeltsch, Florian T1 - Detecting general plant functional type responses in fragmented landscapes using spatially-explicit simulations Y1 - 2008 UR - http://www.sciencedirect.com/science/journal/03043800 U6 - https://doi.org/10.1016/j.ecolmodel.2007.08.002 SN - 0304-3800 ER - TY - JOUR A1 - Lohmann, Dirk A1 - Falk, Thomas A1 - Geissler, Katja A1 - Blaum, Niels A1 - Jeltsch, Florian T1 - Determinants of semi-arid rangeland management in a land reform setting in Namibia JF - Journal of arid environments N2 - To assess the ecological and economic implications of the redistributive land reform in semi-arid Namibia, we investigated to what extent land reform beneficiaries adjust herd size and herd composition according to environmental (rainfall, vegetation) and economic variables (herd size, financial assets, running costs). We performed model-based role-plays with Namibian land reform beneficiaries, simulating 10 years of rangeland management. Our study revealed that the farmers surveyed mainly manage their herds according to their economic situation (herd size and account balance) but do not take environmental variability (rainfall and vegetation) into account. Further, our results indicate that, due to financial pressure, farmers are not able to apply their desired management strategies, and that owners of small farms face a higher risk of economic failure. However, farmers apply rather conservative and constant stocking rates and will thus, given the current economic limitations, likely not contribute to semi-arid savanna degradation. We conclude that land reform beneficiaries need support to be able to apply straightforward and efficient management strategies. This could be achieved by facilitating cooperation between small farming businesses and by supporting initial investment in productive cattle herds at the time of redistribution of the land. KW - Dry land degradation KW - Semi-arid savanna KW - Land reform KW - Rangeland management KW - Simulation model KW - Role-play Y1 - 2014 U6 - https://doi.org/10.1016/j.jaridenv.2013.10.005 SN - 0140-1963 SN - 1095-922X VL - 100 SP - 23 EP - 30 PB - Elsevier CY - London ER - TY - JOUR A1 - Luft, Laura A1 - Neumann, C. A1 - Itzerott, S. A1 - Lausch, A. A1 - Doktor, D. A1 - Freude, M. A1 - Blaum, Niels A1 - Jeltsch, Florian T1 - Digital and real-habitat modeling of Hipparchia statilinus based on hyper spectral remote sensing data JF - International journal of environmental science and technology N2 - The abandonment of military areas leads to succession processes affecting valuable open-land habitats and is considered to be a major threat for European butterflies. We assessed the ability of hyper spectral remote sensing data to spatially predict the occurrence of one of the most endangered butterfly species (Hipparchia statilinus) in Brandenburg (Germany) on the basis of habitat characteristics at a former military training area. Presence-absence data were sampled on a total area of 36 km(2), and N = 65 adult individuals of Hipparchia statilinus could be detected. The floristic composition within the study area was modeled in a three-dimensional ordination space. Occurrence probabilities for the target species were predicted as niches between ordinated floristic gradients by using Regression Kriging of Indicators. Habitat variance could be explained by up to 81 % with spectral variables at a spatial resolution of 2 x 2 m by transferring PLSR models to imagery. Ordinated ecological niche of Hipparchia statilinus was tested against environmental predictor variables. N = 6 variables could be detected to be significantly correlated with habitat preferences of Hipparchia statilinus. They show that Hipparchia statilinus can serve as a valuable indicator for the evaluation of the conservation status of Natura 2000 habitat type 2330 (inland dunes with open Corynephorus and Agrostis grasslands) protected by the Habitat Directive (Council Directive 92/43/EEC). The authors of this approach, conducted in August 2013 at Doberitzer Heide Germany, aim to increase the value of remote sensing as an important tool for questions of biodiversity research and conservation. KW - Habitat gradients KW - Military areas KW - Natura 2000 KW - hyper spectral KW - Vegetation continuum KW - Kriging Y1 - 2016 U6 - https://doi.org/10.1007/s13762-015-0859-1 SN - 1735-1472 SN - 1735-2630 VL - 13 SP - 187 EP - 200 PB - Springer CY - New York ER - TY - JOUR A1 - May, Felix A1 - Giladi, Itamar A1 - Ziv, Yaron A1 - Jeltsch, Florian T1 - Dispersal and diversity - unifying scale-dependent relationships within the neutral theory JF - Oikos N2 - The response of species diversity to dispersal capability is inherently scale-dependent: increasing dispersal capability is expected to increase diversity at the local scale, while decreasing diversity at the metacommunity scale. However, these expectations are based on model formulations that neglect dispersal limitation and species segregation at the local scale. We developed a unifying framework of dispersaldiversity relationships and tested the generality of these expectations. For this purpose we used a spatially-explicit neutral model with various combinations of survey area (local scale) and landscape size (metacommunity scale). Simulations were conducted using landscapes of finite and of conceptually infinite size. We analyzed the scale-dependence of dispersal-diversity relationships for exponentially-bounded versus fat-tailed dispersal kernels, several levels of speciation rate and contrasting assumptions on recruitment at short dispersal distances. We found that the ratio of survey area to landscape size is a major determinant of dispersaldiversity relationships. With increasing survey-to-landscape area ratio the dispersaldiversity relationship switches from monotonically increasing through a U-shaped pattern (with a local minimum) to a monotonically decreasing pattern. Therefore, we provide a continuous set of dispersaldiversity relationships, which contains the response shapes reported previously as extreme cases. We suggest the mean dispersal distance with the minimum of species diversity (minimizing dispersal distance) for a certain scenario as a key characteristic of dispersaldiversity relationships. We show that not only increasing mean dispersal distances, but also increasing variances of dispersal can enhance diversity at the local scale, given a diverse species pool at the metacommunity scale. In conclusion, the response of diversity to variations of dispersal capability at spatial scales of interest, e.g. conservation areas, can differ more widely than expected previously. Therefore, land use and conservation activities, which manipulate dispersal capability, need to consider the landscape context and potential species pools carefully. Y1 - 2012 U6 - https://doi.org/10.1111/j.1600-0706.2011.20078.x SN - 0030-1299 VL - 121 IS - 6 SP - 942 EP - 951 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Wieczorek, Mareike A1 - Kruse, Stefan A1 - Epp, Laura Saskia A1 - Kolmogorov, Alexei A1 - Nikolaev, Anatoly N. A1 - Heinrich, Ingo A1 - Jeltsch, Florian A1 - Pestryakova, Luidmila Agafyevna A1 - Zibulski, Romy A1 - Herzschuh, Ulrike T1 - Dissimilar responses of larch stands in northern Siberia to increasing temperatures-a field and simulation based study JF - Ecology : a publication of the Ecological Society of America N2 - Arctic and alpine treelines worldwide differ in their reactions to climate change. A northward advance of or densification within the treeline ecotone will likely influence climate-vegetation feedback mechanisms. In our study, which was conducted in the Taimyr Depression in the North Siberian Lowlands, w present a combined field-and model-based approach helping us to better understand the population processes involved in the responses of the whole treeline ecotone, spanning from closed forest to single-tree tundra, to climate warming. Using information on stand structure, tree age, and seed quality and quantity from seven sites, we investigate effects of intra-specific competition and seed availability on the specific impact of recent climate warming on larch stands. Field data show that tree density is highest in the forest-tundra, and average tree size decreases from closed forest to single-tree tundra. Age-structure analyses indicate that the trees in the closed forest and forest-tundra have been present for at least similar to 240 yr. At all sites except the most southerly ones, past establishment is positively correlated with regional temperature increase. In the single-tree tundra, however, a change in growth form from krummholz to erect trees, beginning similar to 130 yr ago, rather than establishment date has been recorded. Seed mass decreases from south to north, while seed quantity increases. Simulations with LAVESI (Larix Vegetation Simulator) further suggest that relative density changes strongly in response to a warming signal in the forest-tundra while intra-specific competition limits densification in the closed forest and seed limitation hinders densification in the single-tree tundra. We find striking differences in strength and timing of responses to recent climate warming. While forest-tundra stands recently densified, recruitment is almost non-existent at the southern and northern end of the ecotone due to autecological processes. Palaeo-treelines may therefore be inappropriate to infer past temperature changes at a fine scale. Moreover, a lagged treeline response to past warming will, via feedback mechanisms, influence climate change in the future. KW - climate change KW - closed forest KW - dendroecology KW - forest change KW - latitude KW - recruitment KW - tundra KW - vegetation model Y1 - 2017 U6 - https://doi.org/10.1002/ecy.1887 SN - 0012-9658 SN - 1939-9170 VL - 98 SP - 2343 EP - 2355 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Wiegand, K. A1 - Jeltsch, Florian A1 - Ward, D. T1 - Do spatial effects play a role in the spatial distribution of desert dwelling Acacias? Y1 - 2000 ER - TY - JOUR A1 - Wichmann, Matthias A1 - Jeltsch, Florian A1 - Dean, Richard A1 - Moloney, Kirk A. A1 - Wissel, Christian T1 - Does climate change in arid savanna affect the population persistence of raptors? Y1 - 2002 ER - TY - JOUR A1 - Schwager, Monika A1 - Johst, Karin A1 - Jeltsch, Florian T1 - Does red noise increase or decrease extinction risk? Single extreme events versus series of unfavorable conditions N2 - Recent theoretical studies have shown contrasting effects of temporal correlation of environmental fluctuations ( red noise) on the risk of population extinction. It is still debated whether and under which conditions red noise increases or decreases extinction risk compared with uncorrelated ( white) noise. Here, we explain the opposing effects by introducing two features of red noise time series. On the one hand, positive autocorrelation increases the probability of series of poor environmental conditions, implying increasing extinction risk. On the other hand, for a given time period, the probability of at least one extremely bad year ("catastrophe") is reduced compared with white noise, implying decreasing extinction risk. Which of these two features determines extinction risk depends on the strength of environmental fluctuations and the sensitivity of population dynamics to these fluctuations. If extreme ( catastrophic) events can occur ( strong noise) or sensitivity is high ( overcompensatory density dependence), then temporal correlation decreases extinction risk; otherwise, it increases it. Thus, our results provide a simple explanation for the contrasting previous findings and are a crucial step toward a general understanding of the effect of noise color on extinction risk Y1 - 2006 ER - TY - JOUR A1 - Popp, Alexander A1 - Blaum, Niels A1 - Jeltsch, Florian T1 - Ecohydrological feedback mechanisms in arid rangelands : simulating the impacts of topography and land use N2 - The interaction between ecological and hydrological processes is particularly important in arid and semi-arid regions. Often the interaction between these processes is not completely understood and they are studied separately. We developed a grid-based computer model simulating the dynamics of the four most common vegetation types (perennial grass, annuals, dwarf shrubs and shrubs) and related hydrological processes in the region studied. Eco-hydrological interactions gain importance in rangelands with increasing slope, where vegetation cover obstructs run-off and decreases evaporation from the soil. Overgrazing can influence these positive feedback mechanisms. In this study, we first show that model predictions of cover and productivity of the vegetation types are realistic by comparing them with estimates obtained from field surveys. Then, we apply a realistic range in slope angle combined with two land use regimes (light versus heavy grazing intensity). Our simulation results reveal that hydrological processes and associated productivity are strongly affected by slope, whereas the magnitude of this impact depends on overgrazing. Under low stocking rates, undisturbed vegetation is maintained and run-off and evaporation remain low on flat plains and gentle slope. On steep slopes, run-off and evaporation become larger, while water retention potential decreases, which leads to reduced productivity. Overgrazing, however, reduces vegetation cover and biomass production and the landscape"s ability to conserve water decreases even on flat plains and gentle slopes. Generally, the abundance of perennial grasses and shrubs decreases with increasing slope and grazing. Dominance is shifted towards shrubs and annuals. As a management recommendation we suggest that different vegetation growth forms should not only be regarded as forage producers but also as regulators of ecosystem functioning. Particularly on sloping range lands, a high percentage of cover by perennial vegetation insures that water is retained in the system. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/14391791 U6 - https://doi.org/10.1016/j.baae.2008.06.002 SN - 1439-1791 ER - TY - JOUR A1 - Jeltsch, Florian A1 - Weber, Gisela A1 - Grimm, Volker T1 - Ecological buffering mechanisms in savannas : a unifying theory of long-term tree-grass coexistence Y1 - 2000 ER - TY - GEN A1 - Jeltsch, Florian A1 - Grimm, Volker T1 - Editorial BT - thematic series "Integrating movement ecology with biodiversity research" T2 - Movement Ecology Y1 - 2020 U6 - https://doi.org/10.1186/s40462-020-00210-0 SN - 2051-3933 VL - 8 IS - 1 PB - BioMed Central CY - London ER - TY - JOUR A1 - Tietjen, Britta A1 - Jeltsch, Florian A1 - Zehe, Erwin A1 - Classen, Nikolaus A1 - Groengroeft, Alexander A1 - Schiffers, Katja A1 - Oldeland, Jens T1 - Effects of climate change on the coupled dynamics of water and vegetation in drylands N2 - Drylands worldwide are exposed to a highly variable environment and face a high risk of degradation. The effects of global climate change such as altered precipitation patterns and increased temperature leading to reduced water availability will likely increase this risk. At the same time, an elevated atmospheric CO2 level could mitigate the effects of reduced water availability by increasing the water use efficiency of plants. To prevent degradation of drylands, it is essential to understand the underlying processes that affect water availability and vegetation cover. Since water and vegetation are strongly interdependent in water-limited ecosystems, changes can lead to highly non- linear effects. We assess these effects by developing an ecohydrological model of soil moisture and vegetation cover. The water component of the model simulates the daily dynamics of surface water and water contents in two soil layers. Vegetation is represented by two functional types: shrubs and grasses. These compete for soil water and strongly influence hydrological processes. We apply the model to a Namibian thornbush savanna and evaluate the separate and combined effects of decreased annual precipitation, increased temperature, more variable precipitation and elevated atmospheric CO2 on soil moisture and on vegetation cover. The results show that two main factors control the response of plant types towards climate change, namely a change in water availability and a change in water allocation to a specific plant type. Especially, reduced competitiveness of grasses can lead to a higher risk of shrub encroachment in these systems. Y1 - 2010 UR - http://www3.interscience.wiley.com/journal/114209870/home U6 - https://doi.org/10.1002/Eco.70 SN - 1936-0584 ER - TY - CHAP A1 - Jeltsch, Florian A1 - Schröder-Esselbach, Boris A1 - Blaum, Niels A1 - Badeck, Franz-Werner T1 - Einsatz der Fernerkundung in der Ökologie BT - Beispiele, Synergien und mögliche Verknüpfungen N2 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006 Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7075 ER - TY - JOUR A1 - Romero-Mujalli, Daniel A1 - Jeltsch, Florian A1 - Tiedemann, Ralph T1 - Elevated mutation rates are unlikely to evolve in sexual species, not even under rapid environmental change JF - BMC Evolutionary Biology N2 - Background Organisms are expected to respond to changing environmental conditions through local adaptation, range shift or local extinction. The process of local adaptation can occur by genetic changes or phenotypic plasticity, and becomes especially relevant when dispersal abilities or possibilities are somehow constrained. For genetic changes to occur, mutations are the ultimate source of variation and the mutation rate in terms of a mutator locus can be subject to evolutionary change. Recent findings suggest that the evolution of the mutation rate in a sexual species can advance invasion speed and promote adaptation to novel environmental conditions. Following this idea, this work uses an individual-based model approach to investigate if the mutation rate can also evolve in a sexual species experiencing different conditions of directional climate change, under different scenarios of colored stochastic environmental noise, probability of recombination and of beneficial mutations. The color of the noise mimicked investigating the evolutionary dynamics of the mutation rate in different habitats. Results The results suggest that the mutation rate in a sexual species experiencing directional climate change scenarios can evolve and reach relatively high values mainly under conditions of complete linkage of the mutator locus and the adaptation locus. In contrast, when they are unlinked, the mutation rate can slightly increase only under scenarios where at least 50% of arising mutations are beneficial and the rate of environmental change is relatively fast. This result is robust under different scenarios of stochastic environmental noise, which supports the observation of no systematic variation in the mutation rate among organisms experiencing different habitats. Conclusions Given that 50% beneficial mutations may be an unrealistic assumption, and that recombination is ubiquitous in sexual species, the evolution of an elevated mutation rate in a sexual species experiencing directional climate change might be rather unlikely. Furthermore, when the percentage of beneficial mutations and the population size are small, sexual species (especially multicellular ones) producing few offspring may be expected to react to changing environments not by adaptive genetic change, but mainly through plasticity. Without the ability for a plastic response, such species may become – at least locally – extinct. KW - Individual-based models KW - sexual species KW - Beneficial mutations KW - Recombination KW - Directional climate change KW - Mutator locus KW - Mutation rate Y1 - 2019 U6 - https://doi.org/10.1186/s12862-019-1494-0 SN - 1471-2148 VL - 19 PB - BioMed Central CY - London ER - TY - GEN A1 - Romero-Mujalli, Daniel A1 - Jeltsch, Florian A1 - Tiedemann, Ralph T1 - Elevated mutation rates are unlikely to evolve in sexual species, not even under rapid environmental change T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Background Organisms are expected to respond to changing environmental conditions through local adaptation, range shift or local extinction. The process of local adaptation can occur by genetic changes or phenotypic plasticity, and becomes especially relevant when dispersal abilities or possibilities are somehow constrained. For genetic changes to occur, mutations are the ultimate source of variation and the mutation rate in terms of a mutator locus can be subject to evolutionary change. Recent findings suggest that the evolution of the mutation rate in a sexual species can advance invasion speed and promote adaptation to novel environmental conditions. Following this idea, this work uses an individual-based model approach to investigate if the mutation rate can also evolve in a sexual species experiencing different conditions of directional climate change, under different scenarios of colored stochastic environmental noise, probability of recombination and of beneficial mutations. The color of the noise mimicked investigating the evolutionary dynamics of the mutation rate in different habitats. Results The results suggest that the mutation rate in a sexual species experiencing directional climate change scenarios can evolve and reach relatively high values mainly under conditions of complete linkage of the mutator locus and the adaptation locus. In contrast, when they are unlinked, the mutation rate can slightly increase only under scenarios where at least 50% of arising mutations are beneficial and the rate of environmental change is relatively fast. This result is robust under different scenarios of stochastic environmental noise, which supports the observation of no systematic variation in the mutation rate among organisms experiencing different habitats. Conclusions Given that 50% beneficial mutations may be an unrealistic assumption, and that recombination is ubiquitous in sexual species, the evolution of an elevated mutation rate in a sexual species experiencing directional climate change might be rather unlikely. Furthermore, when the percentage of beneficial mutations and the population size are small, sexual species (especially multicellular ones) producing few offspring may be expected to react to changing environments not by adaptive genetic change, but mainly through plasticity. Without the ability for a plastic response, such species may become – at least locally – extinct. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 776 KW - Individual-based models KW - sexual species KW - Beneficial mutations KW - Mutation rate KW - Mutator locus KW - Directional climate change KW - Recombination Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439058 SN - 1866-8372 IS - 776 ER - TY - JOUR A1 - Treydte, Anna C. A1 - Riginos, Corinna A1 - Jeltsch, Florian T1 - Enhanced use of beneath-canopy vegetation by grazing ungulates in African savannahs N2 - The cover of large trees in African savannahs is rapidly declining, mainly due to human land-use practices. Trees improve grass nutrient quality and contribute to species and structural diversity of savannah vegetation. However, the response of herbivores to trees as habitat features is unknown We quantified the habitat use of wild and domestic ungulates in two eastern and southern African savannahs. We assessed grazing intensities and quantified dung depositions beneath and around canopies of different sized trees. Grasses were eaten and dung was deposited twice as frequently beneath large (ca. 5 m in height) and very large trees (7-10 m) than in open grasslands. Small trees (<2.5 m) did not show this trend. Grazing intensity and dung deposition decreased with distance away from trees at both study sites. These results suggest that large trees represent essential habitat features for domestic and wild herbivores. Increased dung depositions beneath large trees may further promote the maintenance of a patchy nutrient distribution in savannahs. Small trees cannot provide the same structural and functional advantages as large trees do. We recommend that land-use practices be promoted which conserve large single-standing trees to benefit the flora and fauna of African savannahs. Y1 - 2010 UR - http://www.sciencedirect.com/science/journal/01401963 U6 - https://doi.org/10.1016/j.jaridenv.2010.07.003 SN - 0140-1963 ER - TY - JOUR A1 - Jeltsch, Florian A1 - Weber, Gisela A1 - Dean, W. R. J. A1 - Milton, Sue J. A1 - VanRooyen, N. A1 - O'Connor, Terry A1 - Moloney, Kirk A. T1 - Entstehung und Bedeutung räumlicher Vegetationsstrukturen in Trockensavannen : Baum-Graskoexistenz und Artenvielfalt Y1 - 2000 ER - TY - JOUR A1 - Bergholz, Kolja A1 - May, Felix A1 - Giladi, Itamar A1 - Ristow, Michael A1 - Ziv, Yaron A1 - Jeltsch, Florian T1 - Environmental heterogeneity drives fine-scale species assembly and functional diversity of annual plants in a semi-arid environment JF - Perspectives in plant ecology, evolution and systematics N2 - Spatial environmental heterogeneity is considered a fundamental factor for the maintenance of plant species richness. However, it still remains unclear whether heterogeneity may also facilitate coexistence at fine grain sizes or whether other processes, like mass effects and source sink dynamics due to dispersal, control species composition and diversity at these scales. In this study, we used two complimentary analyses to identify the role of heterogeneity within 15 m x 15 m plots for the coexistence of species-rich annual communities in a semi-arid environment along a steep precipitation gradient. Specifically, we: (a) analyzed the effect of environmental heterogeneity on species, functional and phylogenetic diversity within microsites (alpha diversity, 0.06 m(2) and 1 m(2)), across microsites (beta diversity), and diversity at the entire plot (gamma diversity); (b) further we used two null models to detect non-random trait and phylogenetic patterns in order to infer assembly processes, i.e. whether co-occurring species tend to share similar traits (trait convergence) or dissimilar traits (trait divergence). In general, our results showed that heterogeneity had a positive effect on community diversity. Specifically, for alpha diversity, the effect was significant for functional diversity, and not significant for either species or phylogenetic diversities. For beta diversity, all three measures of community diversity (species, functional, and phylogenetic) increased significantly, as they also did for gamma diversity, where functional measures were again stronger than for species or phylogenetic measures. In addition, the null model approach consistently detected trait convergence, indicating that species with similar traits tended to co-occur and had high abundances in a given microsite. While null model analysis across the phylogeny partly supported these trait findings, showing phylogenetic underdispersion at the 1m(2) grain size, surprisingly when species abundances in microsites were analyzed they were more evenly distributed across the phylogenetic tress than expected (phylogenetic overdispersion). In conclusion, our results provide compelling support that environmental heterogeneity at a relatively fine scale is an important factor for species co-existence as it positively affects diversity as well as influences species assembly. Our study underlines the need for trait-based approaches conducted at fine grain sizes in order to better understand species coexistence and community assembly. (C) 2017 Elsevier GmbH. All rights reserved. KW - Community assembly KW - Plant functional trait KW - Habitat heterogeneity KW - Limiting similarity KW - Environmental filtering KW - Heterogeneity species diversity relationship Y1 - 2017 U6 - https://doi.org/10.1016/j.ppees.2017.01.001 SN - 1433-8319 VL - 24 SP - 138 EP - 146 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Schlägel, Ulrike E. A1 - Signer, Johannes A1 - Herde, Antje A1 - Eden, Sophie A1 - Jeltsch, Florian A1 - Eccard, Jana A1 - Dammhahn, Melanie T1 - Estimating interactions between individuals from concurrent animal movements JF - Methods in ecology and evolution : an official journal of the British Ecological Society N2 - Animal movements arise from complex interactions of individuals with their environment, including both conspecific and heterospecific individuals. Animals may be attracted to each other for mating, social foraging, or information gain, or may keep at a distance from others to avoid aggressive encounters related to, e.g., interference competition, territoriality, or predation. With modern tracking technology, more datasets are emerging that allow to investigate fine‐scale interactions between free‐ranging individuals from movement data, however, few methods exist to disentangle fine‐scale behavioural responses of interacting individuals when these are highly individual‐specific. In a framework of step‐selection functions, we related movements decisions of individuals to dynamic occurrence distributions of other individuals obtained through kriging of their movement paths. Using simulated data, we tested the method's ability to identify various combinations of attraction, avoidance, and neutrality between individuals, including asymmetric (i.e. non‐mutual) behaviours. Additionally, we analysed radio‐telemetry data from concurrently tracked small rodents (bank vole, Myodes glareolus) to test whether our method could detect biologically plausible behaviours. We found that our method was able to successfully detect and distinguish between fine‐scale interactions (attraction, avoidance, neutrality), even when these were asymmetric between individuals. The method worked best when confounding factors were taken into account in the step‐selection function. However, even when failing to do so (e.g. due to missing information), interactions could be reasonably identified. In bank voles, responses depended strongly on the sexes of the involved individuals and matched expectations. Our approach can be combined with conventional uses of step‐selection functions to tease apart the various drivers of movement, e.g. the influence of the physical and the social environment. In addition, the method is particularly useful in studying interactions when responses are highly individual‐specific, i.e. vary between and towards different individuals, making our method suitable for both single‐species and multi‐species analyses (e.g. in the context of predation or competition). KW - attraction-avoidance KW - fine-scale interactions KW - individual variability KW - inter-specific interactions KW - movement behaviour KW - occurrence estimates KW - social environment KW - step-selection function Y1 - 2019 U6 - https://doi.org/10.1111/2041-210X.13235 SN - 2041-210X SN - 2041-2096 VL - 10 IS - 8 SP - 1234 EP - 1245 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Weiss, Lina A1 - Schalow, Linda A1 - Jeltsch, Florian A1 - Geissler, Katja T1 - Experimental evidence for root competition effects on community evenness in one of two phytometer species JF - Journal of plant ecology N2 - Aims Plant-plant interactions, being positive or negative, are recognized to be key factors in structuring plant communities. However, it is thought that root competition may be less important than shoot competition due to greater size symmetry belowground. Because direct experimental tests on the importance of root competition are scarce, we aim at elucidating whether root competition may have direct or indirect effects on community structure. Indirect effects may occur by altering the overall size asymmetry of competition through root-shoot competitive interactions. Methods We used a phytometer approach to examine the effects of root, shoot and total competition intensity and importance on evenness of experimental plant communities. Thereby two different phytometer species, Festuca brevipila and Dianthus carthusianorum, were grown in small communities of six grassland species over three levels of light and water availability, interacting with neighbouring shoots, roots, both or not at all. Important Findings We found variation in community evenness to be best explained if root and shoot (but not total) competition were considered. However, the effects were species specific: in Dianthus communities increasing root competition increased plant community evenness, while in Festuca communities shoot competition was the driving force of this evenness response. Competition intensities were influenced by environmental conditions in Dianthus, but not in Festuca phytometer plants. While we found no evidence for root-shoot interactions for neither phytometer species root competition in Dianthus communities led to increased allocation to shoots, thereby increasing the potential ability to perform in size-asymmetric competition for light. Our experiment demonstrates the potential role of root competition in structuring plant communities. KW - plant-plant interactions KW - root and shoot competition KW - intensity vs KW - importance KW - experimental plant communities KW - asymmetry of competition Y1 - 2018 U6 - https://doi.org/10.1093/jpe/rty021 SN - 1752-9921 SN - 1752-993X VL - 12 IS - 2 SP - 281 EP - 291 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Jeltsch, Florian A1 - Wichmann, Matthias A1 - Johst, J. A1 - Moloney, Kirk A. A1 - Wissel, Christian T1 - Extinction risk in periodically fluctuating environments Y1 - 2003 ER - TY - JOUR A1 - Wichmann, Matthias A1 - Johst, Karin A1 - Schwager, Monika A1 - Jeltsch, Florian A1 - Blasius, Bernd T1 - Extinction risk, coloured noise and the scaling of variance N2 - The impact of temporally correlated fluctuating environments (coloured noise) on the extinction risk of populations has become a main focus in theoretical population ecology. In this study we particularly focus on the extinction risk in strongly autocorrelated environments. Here, in contrast to moderate autocorrelation, we found the extinction risk to be highly dependent on the process of noise generation, in particular on the method of variance scaling. Such variance scaling is commonly applied to avoid variance-driven biases when comparing the extinction risk for white and coloured noise. In this study we found an often-used scaling technique to lead to high variability in the resulting variances of different time series for strong auto-correlation eventually leading to deviations in the projected extinction risk. Therefore, we present an alternative method that always delivers the target variance, even in the case of strong temporal correlation. Furthermore, in contrast to the earlier method, our very intuitive method is not bound to auto-regressive processes but can be applied to all types of coloured noises. We recommend the method introduced here to be used when the target of interest is the effect of noise colour on extinction risk not obscured by any variance effects. Y1 - 2005 UR - http://www.agnld.uni-potsdam.de/~bernd/papers/tpb1.pdf ER - TY - JOUR A1 - Turjeman, Sondra Feldman A1 - Centeno-Cuadros, Alejandro A1 - Eggers, Ute A1 - Rotics, Shay A1 - Blas, Julio A1 - Fiedler, Wolfgang A1 - Kaatz, Michael A1 - Jeltsch, Florian A1 - Wikelski, Martin A1 - Nathan, Ran T1 - Extra-pair paternity in the socially monogamous white stork (Ciconia ciconia) is fairly common and independent of local density JF - Scientific reports N2 - Although many birds are socially monogamous, most (>75%) studied species are not strictly genetically monogamous, especially under high breeding density. We used molecular tools to reevaluate the reproductive strategy of the socially monogamous white stork (Ciconia ciconia) and examined local density effects. DNA samples of nestlings (Germany, Spain) were genotyped and assigned relationships using a two-program maximum likelihood classification. Relationships were successfully classified in 79.2% of German (n = 120) and 84.8% of Spanish (n = 59) nests. For each population respectively, 76.8% (n = 73) and 66.0% (n = 33) of nests contained only full-siblings, 10.5% (n = 10) and 18.0% (n = 9) had half-siblings (at least one nestling with a different parent), 3.2% (n = 3) and 10.0% (n = 5) had unrelated nestlings (at least two nestlings, each with different parents), and 9.5% (n = 9) and 6.0% (n = 3) had “not full-siblings” (could not differentiate between latter two cases). These deviations from strict monogamy place the white stork in the 59th percentile for extra-pair paternity among studied bird species. Although high breeding density generally increases extra-pair paternity, we found no significant association with this species’ mating strategies. Thus although genetic monogamy is indeed prominent in the white stork, extra-pair paternity is fairly common compared to other bird species and cannot be explained by breeding density. Y1 - 2016 U6 - https://doi.org/10.1038/srep27976 SN - 2045-2322 VL - 6 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Synodinos, Alexios D. A1 - Tietjen, Britta A1 - Jeltsch, Florian T1 - Facilitation in drylands: Modeling a neglected driver of savanna dynamics JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Our current understanding regarding the functioning of the savanna ecosystem describes savannas as either competition- or disturbance-dependent. Within this generalized view, the role and importance of facilitation have been mostly neglected. This study presents a mathematical model of savannas with coupled soil moisture-vegetation dynamics, which includes interspecific competition and environmental disturbance. We find that there exist environmental and climatic conditions where grass facilitation toward trees plays an important role in supporting tree cover and by extension preserving the savanna biome. We, therefore, argue that our theoretical results in combination with the first empirical studies on the subject should stimulate further research into the role of facilitation in the savanna ecosystem, particularly when analyzing the impact of past and projected climatic changes on it. (C) 2015 Elsevier B.V. All rights reserved. KW - Ecohydrological modeling KW - ODE model KW - Coexistence KW - Biome shifts KW - Fire KW - Grazing Y1 - 2015 U6 - https://doi.org/10.1016/j.ecolmodel.2015.02.015 SN - 0304-3800 SN - 1872-7026 VL - 304 SP - 11 EP - 21 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Lauterbach, D. A1 - Roemermann, C. A1 - Jeltsch, Florian A1 - Ristow, Michael T1 - Factors driving plant rarity in dry grasslands on different spatial scales: a functional trait approach JF - BIODIVERSITY AND CONSERVATION N2 - In European dry grasslands land-use changes affect plant species performance and frequency. Potential driving forces are eutrophication and habitat fragmentation. The importance of these factors is presumably scale dependent. We used a functional trait approach to detect processes that influence species frequency and endangerment on different spatial scales. We tested for associations between functional traits and (1) frequency and (2) degree of endangerment on local, regional and national scales. We focussed on five selected traits that describe the life-history of plant species and that are related to competition, dispersal ability and habitat specificity. Trait data on plant height, SLA, plant coverage, peak of flowering and diaspore mass were measured for 28 perennials from common to rare and endangered to non-endangered on 59 dry grassland sites in north-eastern Germany. Multiple regression models revealed that species frequency is positively and species endangerment negatively related to plant height, plant coverage and SLA on more than one spatial scale. On the local scale, diaspore mass has a negative effect on species frequency. More frequent and less endangered species show a later peak of flowering on nationwide and regional scales. We concluded that competition traits are more important on larger scales, whereas dispersal traits are more important for species frequency on the smaller scale. On national and regional scales, eutrophication and habitat loss may be the main drivers of species threat, whereas on the local scale fragmentation plays a crucial role for the performance of dry grassland species. KW - Species frequency KW - Species endangerment KW - Fragmentation KW - Eutrophication KW - SLA Y1 - 2013 U6 - https://doi.org/10.1007/s10531-013-0455-y SN - 0960-3115 VL - 22 IS - 10 SP - 2337 EP - 2352 PB - SPRINGER CY - DORDRECHT ER - TY - JOUR A1 - Bergholz, Kolja A1 - Jeltsch, Florian A1 - Weiß, Lina A1 - Pottek, Janine A1 - Geißler, Katja A1 - Ristow, Michael T1 - Fertilization affects the establishment ability of species differing in seed mass via direct nutrient addition and indirect competition effects JF - Oikos N2 - Fertilization causes species loss and species dominance changes in plant communities worldwide. However, it still remains unclear how fertilization acts upon species functional traits, e.g. seed mass. Seed mass is a key trait of the regeneration strategy of plants, which influences a range of processes during the seedling establishment phase. Fertilization may select upon seed mass, either directly by increased nutrient availability or indirectly by increased competition. Since previous research has mainly analyzed the indirect effects of fertilization, we disentangled the direct and indirect effects to examine how nutrient availability and competition influence the seed mass relationships on four key components during seedling establishment: seedling emergence, time of seedling emergence, seedling survival and seedling growth. We conducted a common garden experiment with 22 dry grassland species with a two-way full factorial design that simulated additional nutrient supply and increased competition. While we found no evidence that fertilization either directly by additional nutrient supply or indirectly by increased competition alters the relationship between seed mass and (time of) seedling emergence, we revealed that large seed mass is beneficial under nutrient-poor conditions (seedlings have greater chances of survival, particularly in nutrient-poor soils) as well as under competition (large-seeded species produced larger seedlings, which suffered less from competition than small-seeded species). Based on these findings, we argue that both factors, i.e. nutrient availability and competition intensity, ought to be considered to understand how fertilization influences seedling establishment and species composition with respect to seed mass in natural communities. We propose a simple conceptual model, in which seed mass in natural communities is determined by competition intensity and nutrient availability. Here, we hypothesize that seed mass shows a U-shaped pattern along gradients of soil fertility, which may explain the contrasting soil fertility-seed mass relationships found in the recent literature. Y1 - 2015 U6 - https://doi.org/10.1111/oik.02193 SN - 0030-1299 SN - 1600-0706 VL - 124 IS - 11 SP - 1547 EP - 1554 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Milles, Alexander Benedikt A1 - Dammhahn, Melanie A1 - Jeltsch, Florian A1 - Schlägel, Ulrike A1 - Grimm, Volker T1 - Fluctuations in density-dependent selection drive the evolution of a pace-of-life syndrome within and between populations JF - The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences N2 - The pace-of-life syndrome (POLS) hypothesis posits that suites of traits are correlated along a slow-fast continuum owing to life history trade-offs. Despite widespread adoption, environmental conditions driving the emergence of POLS remain unclear. A recently proposed conceptual framework of POLS suggests that a slow-fast continuum should align to fluctuations in density-dependent selection. We tested three key predictions made by this framework with an ecoevolutionary agent-based population model. Selection acted on responsiveness (behavioral trait) to interpatch resource differences and the reproductive investment threshold (life history trait). Across environments with density fluctuations of different magnitudes, we observed the emergence of a common axis of trait covariation between and within populations (i.e., the evolution of a POLS). Slow-type (fast-type) populations with high (low) responsiveness and low (high) reproductive investment threshold were selected at high (low) population densities and less (more) intense and frequent density fluctuations. In support of the predictions, fast-type populations contained a higher degree of variation in traits and were associated with higher intrinsic reproductive rate (r(0)) and higher sensitivity to intraspecific competition (gamma), pointing to a universal trade-off. While our findings support that POLS aligns with density-dependent selection, we discuss possible mechanisms that may lead to alternative evolutionary pathways. KW - pace-of-life syndrome KW - density dependence KW - life history KW - trait KW - variation KW - model KW - personality Y1 - 2022 U6 - https://doi.org/10.1086/718473 SN - 0003-0147 SN - 1537-5323 VL - 199 IS - 4 SP - E124 EP - E139 PB - Univ. of Chicago Press CY - Chicago ER - TY - CHAP A1 - Popp, Alexander A1 - Blaum, Niels A1 - Domptail, Stephanie A1 - Herpel, Nicole A1 - Gröngröft, Alexander A1 - Hoffman, T. T. A1 - Jürgens, Norbert A1 - Milton, Sue A1 - Nuppenau, Ernst-August A1 - Rossmanith, Eva A1 - Schmidt, Michael A1 - Vogel, Melanie A1 - Vohland, Katrin A1 - Jeltsch, Florian T1 - From satellite imagery to soil-plant interactions BT - integrating disciplines and scales in process based simulation models N2 - Decisions for the conservation of biodiversity and sustainable management of natural resources are typically related to large scales, i.e. the landscape level. However, understanding and predicting the effects of land use and climate change on scales relevant for decision-making requires to include both, large scale vegetation dynamics and small scale processes, such as soil-plant interactions. Integrating the results of multiple BIOTA subprojects enabled us to include necessary data of soil science, botany, socio-economics and remote sensing into a high resolution, process-based and spatially-explicit model. Using an example from a sustainably-used research farm and a communally used and degraded farming area in semiarid southern Namibia we show the power of simulation models as a tool to integrate processes across disciplines and scales. Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7302 N1 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006. [Poster] ER - TY - JOUR A1 - Wiegand, K. A1 - Ward, D. A1 - Thulke, Hans-Hermann A1 - Jeltsch, Florian T1 - From snap-shot information to long-term population dynamics of Acacias by a simulation model Y1 - 2000 ER - TY - GEN A1 - Jeltsch, Florian A1 - Grimm, Volker A1 - Reeg, Jette A1 - Schlägel, Ulrike E. T1 - Give chance a chance BT - from coexistence to coviability in biodiversity theory T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - A large part of biodiversity theory is driven by the basic question of what allows species to coexist in spite of a confined number of niches. A substantial theoretical background to this question is provided by modern coexistence theory (MCT), which rests on mathematical approaches of invasion analysis to categorize underlying mechanisms into factors that reduce either niche overlap (stabilizing mechanisms) or the average fitness differences of species (equalizing mechanisms). While MCT has inspired biodiversity theory in the search for these underlying mechanisms, we feel that the strong focus on coexistence causes a bias toward the most abundant species and neglects the plethora of species that are less abundant and often show high local turnover. Given the more stochastic nature of their occurrence, we advocate a complementary cross-level approach that links individuals, small populations, and communities and explicitly takes into account (1) a more complete inclusion of environmental and demographic stochasticity affecting small populations, (2) intraspecific trait variation and behavioral plasticity, and (3) local heterogeneities, interactions, and feedbacks. Focusing on mechanisms that drive the temporary coviability of species rather than infinite coexistence, we suggest a new approach that could be dubbed coviability analysis (CVA). From a modeling perspective, CVA builds on the merged approaches of individual-based modeling and population viability analysis but extends them to the community level. From an empirical viewpoint, CVA calls for a stronger integration of spatiotemporal data on variability and noise, changing drivers, and interactions at the level of individuals. The resulting large volumes of data from multiple sources could be strongly supported by novel techniques tailored to the discovery of complex patterns in high-dimensional data. By complementing MCT through a stronger focus on the coviability of less common species, this approach can help make modern biodiversity theory more comprehensive, predictive, and relevant for applications. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 742 KW - behavioral plasticity KW - biodiversity KW - coexistence KW - community theory KW - coviability analysis KW - demographic noise KW - environmental noise KW - heterogeneity KW - individual-based modeling KW - intraspecific trait variation KW - modern coexistence theory KW - population viability analysis Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-435320 SN - 1866-8372 IS - 742 ER - TY - JOUR A1 - Jeltsch, Florian A1 - Grimm, Volker A1 - Reeg, Jette A1 - Schlägel, Ulrike E. T1 - Give chance a chance BT - from coexistence to coviability in biodiversity theory JF - Ecosphere N2 - A large part of biodiversity theory is driven by the basic question of what allows species to coexist in spite of a confined number of niches. A substantial theoretical background to this question is provided by modern coexistence theory (MCT), which rests on mathematical approaches of invasion analysis to categorize underlying mechanisms into factors that reduce either niche overlap (stabilizing mechanisms) or the average fitness differences of species (equalizing mechanisms). While MCT has inspired biodiversity theory in the search for these underlying mechanisms, we feel that the strong focus on coexistence causes a bias toward the most abundant species and neglects the plethora of species that are less abundant and often show high local turnover. Given the more stochastic nature of their occurrence, we advocate a complementary cross-level approach that links individuals, small populations, and communities and explicitly takes into account (1) a more complete inclusion of environmental and demographic stochasticity affecting small populations, (2) intraspecific trait variation and behavioral plasticity, and (3) local heterogeneities, interactions, and feedbacks. Focusing on mechanisms that drive the temporary coviability of species rather than infinite coexistence, we suggest a new approach that could be dubbed coviability analysis (CVA). From a modeling perspective, CVA builds on the merged approaches of individual-based modeling and population viability analysis but extends them to the community level. From an empirical viewpoint, CVA calls for a stronger integration of spatiotemporal data on variability and noise, changing drivers, and interactions at the level of individuals. The resulting large volumes of data from multiple sources could be strongly supported by novel techniques tailored to the discovery of complex patterns in high-dimensional data. By complementing MCT through a stronger focus on the coviability of less common species, this approach can help make modern biodiversity theory more comprehensive, predictive, and relevant for applications. KW - behavioral plasticity KW - biodiversity KW - coexistence KW - community theory KW - coviability analysis KW - demographic noise KW - environmental noise KW - heterogeneity KW - individual-based modeling KW - intraspecific trait variation KW - modern coexistence theory KW - population viability analysis Y1 - 2019 U6 - https://doi.org/10.1002/ecs2.2700 SN - 2150-8925 VL - 10 IS - 5 PB - ESA CY - Ithaca, NY ER - TY - JOUR A1 - Jeltsch, Florian A1 - Wichmann, Matthias A1 - Dean, W. R. J. T1 - Global change challenges the Tawny Eagle (Aquila rapax) : modelling extinction risk with respect to predicted climate and land use changes Y1 - 2004 ER - TY - JOUR A1 - Dengler, Jürgen A1 - Wagner, Viktoria A1 - Dembicz, Iwona A1 - Garcia-Mijangos, Itziar A1 - Naqinezhad, Alireza A1 - Boch, Steffen A1 - Chiarucci, Alessandro A1 - Conradi, Timo A1 - Filibeck, Goffredo A1 - Guarino, Riccardo A1 - Janisova, Monika A1 - Steinbauer, Manuel J. A1 - Acic, Svetlana A1 - Acosta, Alicia T. R. A1 - Akasaka, Munemitsu A1 - Allers, Marc-Andre A1 - Apostolova, Iva A1 - Axmanova, Irena A1 - Bakan, Branko A1 - Baranova, Alina A1 - Bardy-Durchhalter, Manfred A1 - Bartha, Sandor A1 - Baumann, Esther A1 - Becker, Thomas A1 - Becker, Ute A1 - Belonovskaya, Elena A1 - Bengtsson, Karin A1 - Benito Alonso, Jose Luis A1 - Berastegi, Asun A1 - Bergamini, Ariel A1 - Bonini, Ilaria A1 - Bruun, Hans Henrik A1 - Budzhak, Vasyl A1 - Bueno, Alvaro A1 - Antonio Campos, Juan A1 - Cancellieri, Laura A1 - Carboni, Marta A1 - Chocarro, Cristina A1 - Conti, Luisa A1 - Czarniecka-Wiera, Marta A1 - De Frenne, Pieter A1 - Deak, Balazs A1 - Didukh, Yakiv P. A1 - Diekmann, Martin A1 - Dolnik, Christian A1 - Dupre, Cecilia A1 - Ecker, Klaus A1 - Ermakov, Nikolai A1 - Erschbamer, Brigitta A1 - Escudero, Adrian A1 - Etayo, Javier A1 - Fajmonova, Zuzana A1 - Felde, Vivian A. A1 - Fernandez Calzado, Maria Rosa A1 - Finckh, Manfred A1 - Fotiadis, Georgios A1 - Fracchiolla, Mariano A1 - Ganeva, Anna A1 - Garcia-Magro, Daniel A1 - Gavilan, Rosario G. A1 - Germany, Markus A1 - Giladi, Itamar A1 - Gillet, Francois A1 - Giusso del Galdo, Gian Pietro A1 - Gonzalez, Jose M. A1 - Grytnes, John-Arvid A1 - Hajek, Michal A1 - Hajkova, Petra A1 - Helm, Aveliina A1 - Herrera, Mercedes A1 - Hettenbergerova, Eva A1 - Hobohm, Carsten A1 - Huellbusch, Elisabeth M. A1 - Ingerpuu, Nele A1 - Jandt, Ute A1 - Jeltsch, Florian A1 - Jensen, Kai A1 - Jentsch, Anke A1 - Jeschke, Michael A1 - Jimenez-Alfaro, Borja A1 - Kacki, Zygmunt A1 - Kakinuma, Kaoru A1 - Kapfer, Jutta A1 - Kavgaci, Ali A1 - Kelemen, Andras A1 - Kiehl, Kathrin A1 - Koyama, Asuka A1 - Koyanagi, Tomoyo F. A1 - Kozub, Lukasz A1 - Kuzemko, Anna A1 - Kyrkjeeide, Magni Olsen A1 - Landi, Sara A1 - Langer, Nancy A1 - Lastrucci, Lorenzo A1 - Lazzaro, Lorenzo A1 - Lelli, Chiara A1 - Leps, Jan A1 - Loebel, Swantje A1 - Luzuriaga, Arantzazu L. A1 - Maccherini, Simona A1 - Magnes, Martin A1 - Malicki, Marek A1 - Marceno, Corrado A1 - Mardari, Constantin A1 - Mauchamp, Leslie A1 - May, Felix A1 - Michelsen, Ottar A1 - Mesa, Joaquin Molero A1 - Molnar, Zsolt A1 - Moysiyenko, Ivan Y. A1 - Nakaga, Yuko K. A1 - Natcheva, Rayna A1 - Noroozi, Jalil A1 - Pakeman, Robin J. A1 - Palpurina, Salza A1 - Partel, Meelis A1 - Paetsch, Ricarda A1 - Pauli, Harald A1 - Pedashenko, Hristo A1 - Peet, Robert K. A1 - Pielech, Remigiusz A1 - Pipenbaher, Natasa A1 - Pirini, Chrisoula A1 - Pleskova, Zuzana A1 - Polyakova, Mariya A. A1 - Prentice, Honor C. A1 - Reinecke, Jennifer A1 - Reitalu, Triin A1 - Pilar Rodriguez-Rojo, Maria A1 - Rolecek, Jan A1 - Ronkin, Vladimir A1 - Rosati, Leonardo A1 - Rosen, Ejvind A1 - Ruprecht, Eszter A1 - Rusina, Solvita A1 - Sabovljevic, Marko A1 - Maria Sanchez, Ana A1 - Savchenko, Galina A1 - Schuhmacher, Oliver A1 - Skornik, Sonja A1 - Sperandii, Marta Gaia A1 - Staniaszek-Kik, Monika A1 - Stevanovic-Dajic, Zora A1 - Stock, Marin A1 - Suchrow, Sigrid A1 - Sutcliffe, Laura M. E. A1 - Swacha, Grzegorz A1 - Sykes, Martin A1 - Szabo, Anna A1 - Talebi, Amir A1 - Tanase, Catalin A1 - Terzi, Massimo A1 - Tolgyesi, Csaba A1 - Torca, Marta A1 - Torok, Peter A1 - Tothmeresz, Bela A1 - Tsarevskaya, Nadezda A1 - Tsiripidis, Ioannis A1 - Tzonev, Rossen A1 - Ushimaru, Atushi A1 - Valko, Orsolya A1 - van der Maarel, Eddy A1 - Vanneste, Thomas A1 - Vashenyak, Iuliia A1 - Vassilev, Kiril A1 - Viciani, Daniele A1 - Villar, Luis A1 - Virtanen, Risto A1 - Kosic, Ivana Vitasovic A1 - Wang, Yun A1 - Weiser, Frank A1 - Went, Julia A1 - Wesche, Karsten A1 - White, Hannah A1 - Winkler, Manuela A1 - Zaniewski, Piotr T. A1 - Zhang, Hui A1 - Ziv, Yaron A1 - Znamenskiy, Sergey A1 - Biurrun, Idoia T1 - GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands JF - Phytocoenologia N2 - GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database " sPlot". Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board. KW - biodiversity KW - European Vegetation Archive (EVA) KW - Eurasian Dry Grassland Group (EDGG) KW - grassland vegetation KW - GrassPlot KW - macroecology KW - multi-taxon KW - nested plot KW - scale-dependence KW - species-area relationship (SAR) KW - sPlot KW - vegetation-plot database Y1 - 2018 U6 - https://doi.org/10.1127/phyto/2018/0267 SN - 0340-269X VL - 48 IS - 3 SP - 331 EP - 347 PB - Cramer CY - Stuttgart ER - TY - JOUR A1 - Weiss, Lina A1 - Pfestorf, Hans A1 - May, Felix A1 - Körner, Katrin A1 - Boch, Steffen A1 - Fischer, Markus A1 - Müller, Jörg A1 - Prati, Daniel A1 - Socher, Stephanie A. A1 - Jeltsch, Florian T1 - Grazing response patterns indicate isolation of semi-natural European grasslands JF - Oikos N2 - Identifying drivers of species diversity is a major challenge in understanding and predicting the dynamics of species-rich semi-natural grasslands. In particular in temperate grasslands changes in land use and its consequences, i.e. increasing fragmentation, the on-going loss of habitat and the declining importance of regional processes such as seed dispersal by livestock, are considered key drivers of the diversity loss witnessed within the last decades. Y1 - 2014 U6 - https://doi.org/10.1111/j.1600-0706.2013.00957.x SN - 0030-1299 SN - 1600-0706 VL - 123 IS - 5 SP - 599 EP - 612 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Buchmann, Carsten M. A1 - Schurr, Frank Martin A1 - Nathan, Ran A1 - Jeltsch, Florian T1 - Habitat loss and fragmentation affecting mammal and bird communities-The role of interspecific competition and individual space use JF - Ecological informatics : an international journal on ecoinformatics and computational ecolog N2 - Fragmentation and loss of habitat are major threats to animal communities and are therefore important to conservation. Due to the complexity of the interplay of spatial effects and community processes, our mechanistic understanding of how communities respond to such landscape changes is still poor. Modelling studies have mostly focused on elucidating the principles of community response to fragmentation and habitat loss at relatively large spatial and temporal scales relevant to metacommunity dynamics. Yet, it has been shown that also small scale processes, like foraging behaviour, space use by individuals and local resource competition are also important factors. However, most studies that consider these smaller scales are designed for single species and are characterized by high model complexity. Hence, they are not easily applicable to ecological communities of interacting individuals. To fill this gap, we apply an allometric model of individual home range formation to investigate the effects of habitat loss and fragmentation on mammal and bird communities, and, in this context, to investigate the role of interspecific competition and individual space use. Results show a similar response of both taxa to habitat loss. Community composition is shifted towards higher frequency of relatively small animals. The exponent and the 95%-quantile of the individual size distribution (ISD, described as a power law distribution) of the emerging communities show threshold behaviour with decreasing habitat area. Fragmentation per se has a similar and strong effect on mammals, but not on birds. The ISDs of bird communities were insensitive to fragmentation at the small scales considered here. These patterns can be explained by competitive release taking place in interacting animal communities, with the exception of bird's buffering response to fragmentation, presumably by adjusting the size of their home ranges. These results reflect consequences of higher mobility of birds compared to mammals of the same size and the importance of considering competitive interaction, particularly for mammal communities, in response to landscape fragmentation. Our allometric approach enables scaling up from individual physiology and foraging behaviour to terrestrial communities, and disentangling the role of individual space use and interspecific competition in controlling the response of mammal and bird communities to landscape changes. KW - Allometry KW - Body size KW - Fractal landscapes KW - Foraging movement KW - Individual-based model KW - Locomotion costs Y1 - 2013 U6 - https://doi.org/10.1016/j.ecoinf.2012.11.015 SN - 1574-9541 VL - 14 SP - 90 EP - 98 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Reeg, Jette A1 - Heine, Simon A1 - Mihan, Christine A1 - McGee, Sean A1 - Preuss, Thomas G. A1 - Jeltsch, Florian T1 - Herbicide risk assessments of non-target terrestrial plant communities BT - A graphical user interface for the plant community model IBC-grass T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Plants located adjacent to agricultural fields are important for maintaining biodiversity in semi-natural landscapes. To avoid undesired impacts on these plants due to herbicide application on the arable fields, regulatory risk assessments are conducted prior to registration to ensure proposed uses of plant protection products do not present an unacceptable risk. The current risk assessment approach for these non-target terrestrial plants (NTTPs) examines impacts at the individual-level as a surrogate approach for protecting the plant community due to the inherent difficulties of directly assessing population or community level impacts. However, modelling approaches are suitable higher tier tools to upscale individual-level effects to community level. IBC-grass is a sophisticated plant community model, which has already been applied in several studies. However, as it is a console application software, it was not deemed sufficiently user-friendly for risk managers and assessors to be conveniently operated without prior expertise in ecological models. Here, we present a user-friendly and open source graphical user interface (GUI) for the application of IBC-grass in regulatory herbicide risk assessment. It facilitates the use of the plant community model for predicting long-term impacts of herbicide applications on NTTP communities. The GUI offers two options to integrate herbicide impacts: (1) dose responses based on current standard experiments (acc. to testing guidelines) and (2) based on specific effect intensities. Both options represent suitable higher tier options for future risk assessments of NTTPs as well as for research on the ecological relevance of effects. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 874 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459997 SN - 1866-8372 IS - 874 ER - TY - JOUR A1 - Lozada-Gobilard, Sissi Donna A1 - Jeltsch, Florian A1 - Zhu, Jinlei T1 - High matrix vegetation decreases mean seed dispersal distance but increases long wind dispersal probability connecting local plant populations in agricultural landscapes JF - Agriculture, ecosystems & environment : an international journal for scientific research on the relationship of agriculture and food production to the biosphere N2 - Seed dispersal plays an important role in population dynamics in agricultural ecosystems, but the effects of surrounding vegetation height on seed dispersal and population connectivity on the landscape scale have rarely been studied. Understanding the effects of surrounding vegetation height on seed dispersal will provide important information for land-use management in agricultural landscapes to prevent the spread of undesired weeds or enhance functional connectivity. We used two model species, Phragmites australis and Typha latifolia, growing in small natural ponds known as kettle holes, in an agricultural landscape to evaluate the effects of surrounding vegetation height on wind dispersal and population connectivity between kettle holes. Seed dispersal distance and the probability of long-distance dispersal (LDD) were simulated with the mechanistic WALD model under three scenarios of "low", "dynamic" and "high" surrounding vegetation height. Connectivity between the origin and target kettle holes was quantified with a connectivity index adapted from Hanski and Thomas (1994). Our results show that mean seed dispersal distance decreases with the height of surrounding matrix vegetation, but the probability of long-distance dispersal (LDD) increases with vegetation height. This indicates an important vegetation-based trade-off between mean dispersal distance and LDD, which has an impact on connectivity. Matrix vegetation height has a negative effect on mean seed dispersal distance but a positive effect on the probability of LDD. This positive effect and its impact on connectivity provide novel insights into landscape level (meta-)population and community dynamics - a change in matrix vegetation height by land-use or climatic changes could strongly affect the spread and connectivity of wind-dispersed plants. The opposite effect of vegetation height on mean seed dispersal distance and the probability of LDD should therefore be considered in management and analyses of future land-use and climate change effects. KW - Seed dispersal by wind KW - Long-distance seed dispersal KW - Matrix vegetation KW - Kettle holes KW - Agricultural landscapes KW - Metapopulation dynamics Y1 - 2021 U6 - https://doi.org/10.1016/j.agee.2021.107678 SN - 0167-8809 SN - 1873-2305 VL - 322 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Fer, Istem A1 - Tietjen, Britta A1 - Jeltsch, Florian T1 - High-resolution modelling closes the gap between data and model simulations for Mid-Holocene and present-day biomes of East Africa JF - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences N2 - East Africa hosts a striking diversity of terrestrial ecosystems, which vary both in space and time due to complex regional topography and a dynamic climate. The structure and functioning of these ecosystems under this environmental setting can be studied with dynamic vegetation models (DVMs) in a spatially explicit way. Yet, regional applications of DVMs to East Africa are rare and a comprehensive validation of such applications is missing. Here, we simulated the present-day and mid-Holocene vegetation of East Africa with the DVM, LPJ-GUESS and we conducted an exhaustive comparison of model outputs with maps of potential modern vegetation distribution, and with pollen records of local change through time. Overall, the model was able to reproduce the observed spatial patterns of East African vegetation. To see whether running the model at higher spatial resolutions (10′ × 10′) contribute to resolve the vegetation distribution better and have a better comparison scale with the observational data (i.e. pollen data), we run the model with coarser spatial resolution (0.5° × 0.5°) for the present-day as well. Both the area- and point-wise comparison showed that a higher spatial resolution allows to better describe spatial vegetation changes induced by the complex topography of East Africa. Our analysis of the difference between modelled mid-Holocene and modern-day vegetation showed that whether a biome shifts to another is best explained by both the amount of change in precipitation it experiences and the amount of precipitation it received originally. We also confirmed that tropical forest biomes were more sensitive to a decrease in precipitation compared to woodland and savanna biomes and that Holocene vegetation changes in East Africa were driven not only by changes in annual precipitation but also by changes in its seasonality. KW - Dynamic vegetation models KW - Biome KW - Mid-Holocene KW - Leaf area index KW - Climate change KW - East Africa Y1 - 2016 U6 - https://doi.org/10.1016/j.palaeo.2015.12.001 SN - 0031-0182 SN - 1872-616X VL - 444 SP - 144 EP - 151 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Zurell, Damaris A1 - von Wehrden, Henrik A1 - Rotics, Shay A1 - Kaatz, Michael A1 - Gross, Helge A1 - Schlag, Lena A1 - Schäfer, Merlin A1 - Sapir, Nir A1 - Turjeman, Sondra A1 - Wikelski, Martin A1 - Nathan, Ran A1 - Jeltsch, Florian T1 - Home range size and resource use of breeding and non-breeding white storks along a land use gradient JF - Frontiers in Ecology and Evolution N2 - Biotelemetry is increasingly used to study animal movement at high spatial and temporal resolution and guide conservation and resource management. Yet, limited sample sizes and variation in space and habitat use across regions and life stages may compromise robustness of behavioral analyses and subsequent conservation plans. Here, we assessed variation in (i) home range sizes, (ii) home range selection, and (iii) fine-scale resource selection of white storks across breeding status and regions and test model transferability. Three study areas were chosen within the Central German breeding grounds ranging from agricultural to fluvial and marshland. We monitored GPS-locations of 62 adult white storks equipped with solar-charged GPS/3D-acceleration (ACC) transmitters in 2013-2014. Home range sizes were estimated using minimum convex polygons. Generalized linear mixed models were used to assess home range selection and fine-scale resource selection by relating the home ranges and foraging sites to Corine habitat variables and normalized difference vegetation index in a presence/pseudo-absence design. We found strong variation in home range sizes across breeding stages with significantly larger home ranges in non-breeding compared to breeding white storks, but no variation between regions. Home range selection models had high explanatory power and well predicted overall density of Central German white stork breeding pairs. Also, they showed good transferability across regions and breeding status although variable importance varied considerably. Fine-scale resource selection models showed low explanatory power. Resource preferences differed both across breeding status and across regions, and model transferability was poor. Our results indicate that habitat selection of wild animals may vary considerably within and between populations, and is highly scale dependent. Thereby, home range scale analyses show higher robustness whereas fine-scale resource selection is not easily predictable and not transferable across life stages and regions. Such variation may compromise management decisions when based on data of limited sample size or limited regional coverage. We thus recommend home range scale analyses and sampling designs that cover diverse regional landscapes and ensure robust estimates of habitat suitability to conserve wild animal populations. KW - 3D-acceleration sensor KW - biotelemetry KW - Ciconia ciconia KW - home range selection KW - resource selection Y1 - 2018 U6 - https://doi.org/10.3389/fevo.2018.00079 SN - 2296-701X VL - 6 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Jeltsch, Florian A1 - Blaum, Niels A1 - Brose, Ulrich A1 - Chipperfield, Joseph D. A1 - Clough, Yann A1 - Farwig, Nina A1 - Geissler, Katja A1 - Graham, Catherine H. A1 - Grimm, Volker A1 - Hickler, Thomas A1 - Huth, Andreas A1 - May, Felix A1 - Meyer, Katrin M. A1 - Pagel, Jörn A1 - Reineking, Björn A1 - Rillig, Matthias C. A1 - Shea, Katriona A1 - Schurr, Frank Martin A1 - Schroeder, Boris A1 - Tielbörger, Katja A1 - Weiss, Lina A1 - Wiegand, Kerstin A1 - Wiegand, Thorsten A1 - Wirth, Christian A1 - Zurell, Damaris T1 - How can we bring together empiricists and modellers in functional biodiversity research? JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - Improving our understanding of biodiversity and ecosystem functioning and our capacity to inform ecosystem management requires an integrated framework for functional biodiversity research (FBR). However, adequate integration among empirical approaches (monitoring and experimental) and modelling has rarely been achieved in FBR. We offer an appraisal of the issues involved and chart a course towards enhanced integration. A major element of this path is the joint orientation towards the continuous refinement of a theoretical framework for FBR that links theory testing and generalization with applied research oriented towards the conservation of biodiversity and ecosystem functioning. We further emphasize existing decision-making frameworks as suitable instruments to practically merge these different aims of FBR and bring them into application. This integrated framework requires joint research planning, and should improve communication and stimulate collaboration between modellers and empiricists, thereby overcoming existing reservations and prejudices. The implementation of this integrative research agenda for FBR requires an adaptation in most national and international funding schemes in order to accommodate such joint teams and their more complex structures and data needs. KW - Biodiversity theory KW - Biodiversity experiments KW - Conservation management KW - Decision-making KW - Ecosystem functions and services KW - Forecasting KW - Functional traits KW - Global change KW - Monitoring programmes KW - Interdisciplinarity Y1 - 2013 U6 - https://doi.org/10.1016/j.baae.2013.01.001 SN - 1439-1791 VL - 14 IS - 2 SP - 93 EP - 101 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Blaum, Niels A1 - Mosner, Eva A1 - Schwager, Monika A1 - Jeltsch, Florian T1 - How functional is functional?Ecological groupings in terrestrial animal ecology - towards an animal functional type approach JF - Biodiversity and conservation N2 - Understanding mechanisms to predict changes in plant and animal communities is a key challenge in ecology. The need to transfer knowledge gained from single species to a more generalized approach has led to the development of categorization systems where species' similarities in life strategies and traits are classified into ecological groups (EGs) like functional groups/types or guilds. While approaches in plant ecology undergo a steady improvement and refinement of methodologies, progression in animal ecology is lagging behind. With this review, we aim to initiate a further development of functional classification systems in animal ecology, comparable to recent developments in plant ecology. We here (i) give an overview of terms and definitions of EGs in animal ecology, (ii) discuss existing classification systems, methods and application areas of EGs (focusing on terrestrial vertebrates), and (iii) provide a "roadmap towards an animal functional type approach" for improving the application of EGs and classifications in animal ecology. We found that an animal functional type approach requires: (i) the identification of core traits describing species' dependency on their habitat and life history traits, (ii) an optimization of trait selection by clustering traits into hierarchies, (iii) the assessment of "soft traits" as substitute for hardly measurable traits, e.g. body size for dispersal ability, and (iv) testing of delineated groups for validation including experiments. KW - Ecological classification KW - Functional type KW - Guild KW - Functional trait KW - Trait selection KW - Effect group KW - Response group KW - Environmental relationships Y1 - 2011 U6 - https://doi.org/10.1007/s10531-011-9995-1 SN - 0960-3115 VL - 20 IS - 11 SP - 2333 EP - 2345 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Luft, Laura A1 - Neumann, Carsten A1 - Freude, Matthias A1 - Blaum, Niels A1 - Jeltsch, Florian T1 - Hyperspectral modeling of ecological indicators - A new approach for monitoring former military training areas JF - Ecological indicators : integrating monitoring, assessment and management N2 - Military areas are valuable habitats and refuges for rare and endangered plants and animals. We developed a new approach applying innovative methods of hyperspectral remote sensing to bridge the existing gap between remote sensing technology and the demands of the nature conservation community. Remote sensing has already proven to be a valuable monitoring instrument. However, the approaches lack the consideration of the demands of applied nature conservation which includes the legal demands of the EU Habitat Directive. Following the idea of the Vital Signs Monitoring in the USA, we identified a subset of the highest priority monitoring indicators for our study area. We analyzed continuous spectral response curves and tested the measurability of N=19 indicators on the basis of complexity levels aggregated from extensive vegetation assemblages. The spectral differentiability for the floristic as well as faunistic indicators revealed values up to 100% accuracy. We point out difficulties when it comes to distinguishing faunistic habitat requirements of several species adapted to dry open landscapes, which in this case results in OVERALL ACCURACY of 67, 87-95, and 35% in the error matrix. In summary, we provide an applicable and feasible method to facilitating monitoring military areas by hyperspectral remote sensing in the following. (C) 2014 Elsevier Ltd. All rights reserved. KW - Ecological health KW - Fauna KW - Flora KW - Hyperspectral remote sensing KW - Military conversion KW - Natura 2000 monitoring Y1 - 2014 U6 - https://doi.org/10.1016/j.ecolind.2014.06.025 SN - 1470-160X SN - 1872-7034 VL - 46 SP - 264 EP - 285 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Sarmento, Juliano Sarmento A1 - Jeltsch, Florian A1 - Thuiller, Wilfried A1 - Higgins, Steven A1 - Midgley, Guy F. A1 - Rebelo, Anthony G. A1 - Rouget, Mathieu A1 - Schurr, Frank Martin T1 - Impacts of past habitat loss and future climate change on the range dynamics of South African Proteaceae JF - Diversity & distributions : a journal of biological invasions and biodiversity N2 - Aim To assess how habitat loss and climate change interact in affecting the range dynamics of species and to quantify how predicted range dynamics depend on demographic properties of species and the severity of environmental change. Location South African Cape Floristic Region. Methods We use data-driven demographic models to assess the impacts of past habitat loss and future climate change on range size, range filing and abundances of eight species of woody plants (Proteaceae). The species-specific models employ a hybrid approach that simulates population dynamics and long-distance dispersal on top of expected spatio-temporal dynamics of suitable habitat. Results Climate change was mainly predicted to reduce range size and range filling (because of a combination of strong habitat shifts with low migration ability). In contrast, habitat loss mostly decreased mean local abundance. For most species and response measures, the combination of habitat loss and climate change had the most severe effect. Yet, this combined effect was mostly smaller than expected from adding or multiplying effects of the individual environmental drivers. This seems to be because climate change shifts suitable habitats to regions less affected by habitat loss. Interspecific variation in range size responses depended mostly on the severity of environmental change, whereas responses in range filling and local abundance depended mostly on demographic properties of species. While most surviving populations concentrated in areas that remain climatically suitable, refugia for multiple species were overestimated by simply overlying habitat models and ignoring demography. Main conclusions Demographic models of range dynamics can simultaneously predict the response of range size, abundance and range filling to multiple drivers of environmental change. Demographic knowledge is particularly needed to predict abundance responses and to identify areas that can serve as biodiversity refugia under climate change. These findings highlight the need for data-driven, demographic assessments in conservation biogeography. KW - biodiversity refugia KW - CFR Proteaceae KW - climate change KW - demographic properties KW - habitat loss KW - local abundances KW - process-based range models KW - range filling KW - range size KW - species distribution models Y1 - 2013 U6 - https://doi.org/10.1111/ddi.12011 SN - 1366-9516 VL - 19 IS - 4 SP - 363 EP - 376 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Jeltsch, Florian A1 - Wichmann, Matthias A1 - Dean, W. R. J. A1 - Moloney, Kirk A. A1 - Wissel, Christian T1 - Implications of climate change for the persistence of raptors in arid savannah Y1 - 2003 ER - TY - JOUR A1 - Grimm, Volker A1 - Revilla, Eloy A1 - Groeneveld, Jürgen A1 - Kramer-Schadt, Stephanie A1 - Schwager, Monika A1 - Tews, Jörg A1 - Wichmann, Matthias A1 - Jeltsch, Florian T1 - Importance of buffer mechanisms for population viability analysis Y1 - 2005 ER - TY - JOUR A1 - Thiele, T. A1 - Jeltsch, Florian A1 - Blaum, Niels T1 - Importance of woody vegetation for foraging site selection in the Southern Pied Babbler (Turdoides bicolor) under two different land use regimes Y1 - 2008 SN - 0140-1963 ER - TY - JOUR A1 - Romero-Mujalli, Daniel A1 - Jeltsch, Florian A1 - Tiedemann, Ralph T1 - Individual-based modeling of eco-evolutionary dynamics BT - state of the art and future directions JF - Regional environmental change N2 - A challenge for eco-evolutionary research is to better understand the effect of climate and landscape changes on species and their distribution. Populations of species can respond to changes in their environment through local genetic adaptation or plasticity, dispersal, or local extinction. The individual-based modeling (IBM) approach has been repeatedly applied to assess organismic responses to environmental changes. IBMs simulate emerging adaptive behaviors from the basic entities upon which both ecological and evolutionary mechanisms act. The objective of this review is to summarize the state of the art of eco-evolutionary IBMs and to explore to what degree they already address the key responses of organisms to environmental change. In this, we identify promising approaches and potential knowledge gaps in the implementation of eco-evolutionary mechanisms to motivate future research. Using mainly the ISI Web of Science, we reveal that most of the progress in eco-evolutionary IBMs in the last decades was achieved for genetic adaptation to novel local environmental conditions. There is, however, not a single eco-evolutionary IBM addressing the three potential adaptive responses simultaneously. Additionally, IBMs implementing adaptive phenotypic plasticity are rare. Most commonly, plasticity was implemented as random noise or reaction norms. Our review further identifies a current lack of models where plasticity is an evolving trait. Future eco-evolutionary models should consider dispersal and plasticity as evolving traits with their associated costs and benefits. Such an integrated approach could help to identify conditions promoting population persistence depending on the life history strategy of organisms and the environment they experience. KW - Modeling KW - Individual-based models KW - Ecology KW - Evolution KW - Eco-evolutionary dynamics Y1 - 2018 U6 - https://doi.org/10.1007/s10113-018-1406-7 SN - 1436-3798 SN - 1436-378X VL - 19 IS - 1 SP - 1 EP - 12 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Zurell, Damaris A1 - Eggers, Ute A1 - Kaatz, Michael A1 - Rotics, Shay A1 - Sapir, Nir A1 - Wikelski, Martin A1 - Nathan, Ran A1 - Jeltsch, Florian T1 - Individual-based modelling of resource competition to predict density-dependent population dynamics: a case study with white storks JF - Oikos N2 - Density regulation influences population dynamics through its effects on demographic rates and consequently constitutes a key mechanism explaining the response of organisms to environmental changes. Yet, it is difficult to establish the exact form of density dependence from empirical data. Here, we developed an individual-based model to explore how resource limitation and behavioural processes determine the spatial structure of white stork Ciconia ciconia populations and regulate reproductive rates. We found that the form of density dependence differed considerably between landscapes with the same overall resource availability and between home range selection strategies, highlighting the importance of fine-scale resource distribution in interaction with behaviour. In accordance with theories of density dependence, breeding output generally decreased with density but this effect was highly variable and strongly affected by optimal foraging strategy, resource detection probability and colonial behaviour. Moreover, our results uncovered an overlooked consequence of density dependence by showing that high early nestling mortality in storks, assumed to be the outcome of harsh weather, may actually result from density dependent effects on food provision. Our findings emphasize that accounting for interactive effects of individual behaviour and local environmental factors is crucial for understanding density-dependent processes within spatially structured populations. Enhanced understanding of the ways animal populations are regulated in general, and how habitat conditions and behaviour may dictate spatial population structure and demographic rates is critically needed for predicting the dynamics of populations, communities and ecosystems under changing environmental conditions. Y1 - 2015 U6 - https://doi.org/10.1111/oik.01294 SN - 0030-1299 SN - 1600-0706 VL - 124 IS - 3 SP - 319 EP - 330 PB - Wiley-Blackwell CY - Hoboken ER - TY - GEN A1 - Jeltsch, Florian A1 - Bonte, Dries A1 - Pe'er, Guy A1 - Reineking, Björn A1 - Leimgruber, Peter A1 - Balkenhol, Niko A1 - Schröder-Esselbach, Boris A1 - Buchmann, Carsten M. A1 - Müller, Thomas A1 - Blaum, Niels A1 - Zurell, Damaris A1 - Böhning-Gaese, Katrin A1 - Wiegand, Thorsten A1 - Eccard, Jana A1 - Hofer, Heribert A1 - Reeg, Jette A1 - Eggers, Ute A1 - Bauer, Silke T1 - Integrating movement ecology with biodiversity research BT - exploring new avenues to address spatiotemporal biodiversity dynamics N2 - Movement of organisms is one of the key mechanisms shaping biodiversity, e.g. the distribution of genes, individuals and species in space and time. Recent technological and conceptual advances have improved our ability to assess the causes and consequences of individual movement, and led to the emergence of the new field of ‘movement ecology’. Here, we outline how movement ecology can contribute to the broad field of biodiversity research, i.e. the study of processes and patterns of life among and across different scales, from genes to ecosystems, and we propose a conceptual framework linking these hitherto largely separated fields of research. Our framework builds on the concept of movement ecology for individuals, and demonstrates its importance for linking individual organismal movement with biodiversity. First, organismal movements can provide ‘mobile links’ between habitats or ecosystems, thereby connecting resources, genes, and processes among otherwise separate locations. Understanding these mobile links and their impact on biodiversity will be facilitated by movement ecology, because mobile links can be created by different modes of movement (i.e., foraging, dispersal, migration) that relate to different spatiotemporal scales and have differential effects on biodiversity. Second, organismal movements can also mediate coexistence in communities, through ‘equalizing’ and ‘stabilizing’ mechanisms. This novel integrated framework provides a conceptual starting point for a better understanding of biodiversity dynamics in light of individual movement and space-use behavior across spatiotemporal scales. By illustrating this framework with examples, we argue that the integration of movement ecology and biodiversity research will also enhance our ability to conserve diversity at the genetic, species, and ecosystem levels. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 401 KW - mobile links KW - species coexistence KW - community dynamics KW - biodiversity conservation KW - long distance movement KW - landscape genetics KW - individual based modeling Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-401177 ER - TY - JOUR A1 - Jeltsch, Florian A1 - Bonte, Dries A1 - Peer, Guy A1 - Reineking, Björn A1 - Leimgruber, Peter A1 - Balkenhol, Niko A1 - Schröder-Esselbach, Boris A1 - Buchmann, Carsten M. A1 - Müller, Thomas A1 - Blaum, Niels A1 - Zurell, Damaris A1 - Böhning-Gaese, Katrin A1 - Wiegand, Thorsten A1 - Eccard, Jana A1 - Hofer, Heribert A1 - Reeg, Jette A1 - Eggers, Ute A1 - Bauer, Silke T1 - Integrating movement ecology with biodiversity research - exploring new avenues to address spatiotemporal biodiversity dynamics Y1 - 2013 UR - http://download.springer.com/static/pdf/827/art%253A10.1186%252F2051-3933-1- 6.pdf?auth66=1394891271_f1a4cb74d6be42ee3f8872ef2ca22c24&ext=.pdf U6 - https://doi.org/10.1186/2051-3933-1-6 ER - TY - JOUR A1 - Crawford, Michael A1 - Jeltsch, Florian A1 - May, Felix A1 - Grimm, Volker A1 - Schlägel, Ulrike E. T1 - Intraspecific trait variation increases species diversity in a trait-based grassland model JF - Oikos N2 - Intraspecific trait variation (ITV) is thought to play a significant role in community assembly, but the magnitude and direction of its influence are not well understood. Although it may be critical to better explain population persistence, species interactions, and therefore biodiversity patterns, manipulating ITV in experiments is challenging. We therefore incorporated ITV into a trait‐ and individual‐based model of grassland community assembly by adding variation to the plants’ functional traits, which then drive life‐history tradeoffs. Varying the amount of ITV in the simulation, we examine its influence on pairwise‐coexistence and then on the species diversity in communities of different initial sizes. We find that ITV increases the ability of the weakest species to invade most, but that this effect does not scale to the community level, where the primary effect of ITV is to increase the persistence and abundance of the competitively‐average species. Diversity of the initial community is also of critical importance in determining ITV's efficacy; above a threshold of interspecific diversity, ITV does not increase diversity further. For communities below this threshold, ITV mainly helps to increase diversity in those communities that would otherwise be low‐diversity. These findings suggest that ITV actively maintains diversity by helping the species on the margins of persistence, but mostly in habitats of relatively low alpha and beta diversity. KW - community assembly KW - individual-based model KW - intraspecific trait variation Y1 - 2018 U6 - https://doi.org/10.1111/oik.05567 SN - 0030-1299 SN - 1600-0706 VL - 128 IS - 3 SP - 441 EP - 455 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Jeltsch, Florian A1 - Hansen, Frank A1 - Tackmann, K. A1 - Thulke, Hans-Hermann T1 - Köderauslageintervalle und Dauer der Bekämpfung des Kleinen Fuchsbandwurms : eine Modellierstudie Y1 - 2003 ER - TY - JOUR A1 - Popp, Alexander A1 - Domptail, Stephanie A1 - Blaum, Niels A1 - Jeltsch, Florian T1 - Landuse experience does not qualify for adaptation to climate change N2 - The need to implement sustainable resource management regimes for semi-arid and arid rangelands is acute as non- adapted grazing strategies lead to irreversible environmental problems such as desertification and associated loss of economic support to society. In these sensitive ecosystems, traditional sectoral, disciplinary approaches will not work to attain sustainability: achieving a collective vision of how to attain sustainability requires interactive efforts among disciplines in a more integrated approach. Therefore, we developed an integrated ecological-economic approach that consists of an ecological and an economic module and combines relevant processes on either level. Parameters for both modules are adjusted for an arid dwarf shrub savannah in southern Namibia. The economic module is used to analyse decisions of different virtual farmer types on annual stocking rates depending on their knowledge how the ecosystem works and climatic conditions. We used a dynamic linear optimisation model to simulate farm economics and livestock dynamics. The ecological module is used to simulate the impact of the farmers' land-use decision, derived by the economic module, on ecosystem dynamics and resulting carrying capacity of the system for livestock. Vegetation dynamics, based on the concept of State-and-transition models, and forage productivity for both modules is derived by a small- scale and spatially explicit vegetation model. This mechanistic approach guarantees that data collected and processes estimated at smaller scales are included in our application. Simulation results of the ecological module were successfully compared to simulation results of the optimisation model for a time series of 30 years. We revealed that sustainable management of semi-arid and arid rangelands relies strongly on rangeland managers' understanding of ecological processes. Furthermore, our simulation results demonstrate that the projected lower annual rainfall due to climate change adds an additional layer of risk to these ecosystems that are already prone to land degradation. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/03043800 U6 - https://doi.org/10.1016/j.ecolmodel.2008.11.015 SN - 0304-3800 ER - TY - JOUR A1 - Petru, Martina A1 - Tielbörger, Katja A1 - Belkin, Ruthie A1 - Sternberg, Marcelo A1 - Jeltsch, Florian T1 - Life history variation in an annual plant under two opposing environmental constraints along an aridity gradient N2 - Environmental gradients represent an ideal framework for studying adaptive variation in the life history of plant species. However, on very steep gradients, largely contrasting conditions at the two gradient ends often limit the distribution of the same species across the whole range of environmental conditions. Here, we study phenotypic variation in a winter annual crucifer Biscutella didyma persisting along a steep gradient of increasing rainfall in Israel. In particular, we explored whether the life history at the arid end of the gradient indicates adaptations to drought and unpredictable conditions, while adaptations to the highly competitive environment prevail at the mesic Mediterranean end. We examined several morphological and reproductive traits in four natural populations and in populations cultivated in standard common environment. Plants from arid environments were faster in phenological development, more branched in architecture and tended to maximize reproduction, while the Mediterranean plants invested mainly in vertical vegetative growth. Differences between cultivation and field in diaspore production were very large for arid populations as opposed to Mediterranean ones, indicating a larger potential to increase reproduction under favorable conditions. Our overall findings indicate two strongly opposing selective forces at the two extremes of the aridity gradient, which result in contrasting strategies within the studied annual plant species Y1 - 2006 UR - http://www3.interscience.wiley.com/journal/117966123/home U6 - https://doi.org/10.1111/j.2005.0906-7590.04310.x ER - TY - JOUR A1 - Schwager, Monika A1 - Covas, Rita A1 - Blaum, Niels A1 - Jeltsch, Florian T1 - Limitations of population models in predicting climate change effects : a simulation study of sociable weavers in southern Africa Y1 - 2008 UR - http://www3.interscience.wiley.com/journal/118531693/home U6 - https://doi.org/10.1111/j.0030-1299.2008.16464.x SN - 0030-1299 ER - TY - JOUR A1 - Tews, Jörg A1 - Esther, Alexandra A1 - Milton, Sue J. A1 - Jeltsch, Florian T1 - Linking a population model with an ecosystem model : assessing the impact of land use and climate change on savanna shrub cover dynamics N2 - In semiarid savannas of Southern Africa current land use practices and climate change may lead to substantial changes of vegetation structure in the near future, however uncertainty remains about the potential consequences and the magnitude of change. In this paper we study the impact of climate change, cattle grazing, and wood cutting on shrub cover dynamics in savannas of the southern Kalahari. We use an established savanna ecosystem model to simulate landscape dynamics in terms of rainfall, fire and distribution of the dominant tree Acacia erioloba. We then incorporate these data into a spatial population model of the common, fleshy-fruited shrub Grewia flava and investigate shrub cover dynamics for a period of 100 years. Depending on the intensity of commercial wood cutting practices tree removal of A. erioloba led to a strong decline of the G. flava population, as shrub recruitment is concentrated in tree sub-canopies due to bird-mediated seed dispersal. Under climate change shrub cover slightly decreased with decreasing precipitation and was unchanged with increase in precipitation variability. Contrarily, grazing by cattle strongly increased shrub cover and facilitated shrub encroachment because of cattle-induced distribution of G. flava seeds into the matrix vegetation. Knowledge of the latter process is particularly important because shrub invasion is a major concern for conservation and savanna rangeland management as a result of its adverse effects on livestock carrying capacity and biodiversity Y1 - 2006 UR - http://www.mendeley.com/research/linking-a-population-model-with-an-ecosystem-model-assessing-the-impact- of-land-use-and-climate-change-on-savanna-shrub-cover-dynamics/#page-1 U6 - https://doi.org/10.1016/j.ecolmodel.2005.11.025 ER - TY - JOUR A1 - Wiegand, K. A1 - Schmidt, H. A1 - Jeltsch, Florian A1 - Ward, D. T1 - Linking a spatially-explicit model of acacias to GIS and remotely-sensed data Y1 - 2000 ER - TY - JOUR A1 - Wiegand, T. A1 - Jeltsch, Florian T1 - Long-term dynamics in arid and semi-arid ecosystems : synthesis of a workshop Y1 - 2000 ER - TY - JOUR A1 - Weber, Gisela A1 - Jeltsch, Florian T1 - Long-term impacts of livestock herbivory on herbaceous and woody vegetation in semiarid savannas Y1 - 2000 ER - TY - JOUR A1 - Moustakas, Aristides A1 - Günther, Matthias A1 - Wiegand, Kerstin A1 - Müller, Karl-Heinz A1 - Ward, David A1 - Meyer, Katrin M. A1 - Jeltsch, Florian T1 - Long-term mortality patterns of the deep-rooted Acacia erioloba BT - The middle class shall die! JF - Journal of vegetation science N2 - Question: Is there a relationship between size and death in the Iona-lived, deep-rooted tree, Acacia erioloba, in a semi-arid savanna? What is the size-class distribution of A. erioloba mortality? Does the mortality distribution differ from total tree size distribution? Does A. erioloba mortality distribution match the mortality distributions recorded thus far in other environments? Location: Dronfield Ranch, near Kimberley, Kalahari, South Africa. Methods: A combination of aerial photographs and a satellite image covering 61 year was used to provide long-term spatial data on mortality. We used aerial photographs of the study area from 1940, 1964, 1984, 1993 and a satellite image from 2001 to follow three plots covering 510 ha. We were able to identify and individually follow ca. 3000 individual trees from 1940 till 2001. Results: The total number of trees increased over time. No relationship between total number of trees and mean tree size was detected. There were no trends over time in total number of deaths per plot or in size distributions of dead trees. Kolmogorov-Smirnov tests showed no differences in size class distributions for living trees through time. The size distribution of dead trees was significantly different from the size distribution of all trees present on the plots. Overall, the number of dead trees was low in small size classes, reached a peak value when canopy area was 20 - 30 m(2), and declined in lamer size-classes. Mortality as a ratio of dead vs. total trees peaked at intermediate canopy sizes too. Conclusion: A. erioloba mortality was size-dependent, peaking at intermediate sizes. The mortality distribution differs from all other tree mortality distributions recorded thus far. We suggest that a possible mechanism for this unusual mortality distribution is intraspecific competition for water in this semi-arid environment. KW - competition KW - long-term data KW - remote sensing KW - savanna KW - size dependent mortality KW - size distribution KW - tree death Y1 - 2006 U6 - https://doi.org/10.1111/j.1654-1103.2006.tb02468.x SN - 1100-9233 VL - 17 SP - 473 EP - 480 PB - Blackwell CY - Malden ER - TY - JOUR A1 - Esther, Alexandra A1 - Groeneveld, Jürgen A1 - Enright, Neal J. A1 - Miller, Ben P. A1 - Lamont, Byron B. A1 - Perry, George L. W. A1 - Tietjen, Britta A1 - Jeltsch, Florian T1 - Low-dimensional trade-offs fail to explain richness and structure in species-rich plant communities JF - Theoretical ecology N2 - Mathematical models and ecological theory suggest that low-dimensional life history trade-offs (i.e. negative correlation between two life history traits such as competition vs. colonisation) may potentially explain the maintenance of species diversity and community structure. In the absence of trade-offs, we would expect communities to be dominated by 'super-types' characterised by mainly positive trait expressions. However, it has proven difficult to find strong empirical evidence for such trade-offs in species-rich communities. We developed a spatially explicit, rule-based and individual-based stochastic model to explore the importance of low-dimensional trade-offs. This model simulates the community dynamics of 288 virtual plant functional types (PFTs), each of which is described by seven life history traits. We consider trait combinations that fit into the trade-off concept, as well as super-types with little or no energy constraints or resource limitations, and weak PFTs, which do not exploit resources efficiently. The model is parameterised using data from a fire-prone, species-rich Mediterranean-type shrubland in southwestern Australia. We performed an exclusion experiment, where we sequentially removed the strongest PFT in the simulation and studied the remaining communities. We analysed the impact of traits on performance of PFTs in the exclusion experiment with standard and boosted regression trees. Regression tree analysis of the simulation results showed that the trade-off concept is necessary for PFT viability in the case of weak trait expression combinations such as low seed production or small seeds. However, species richness and diversity can be high despite the presence of super-types. Furthermore, the exclusion of super-types does not necessarily lead to a large increase in PFT richness and diversity. We conclude that low-dimensional trade-offs do not provide explanations for multi-species co-existence contrary to the prediction of many conceptual models. KW - Plant diversity KW - Plant functional types KW - Co-existence KW - Spatially explicit model KW - Individual-based model KW - CART KW - Regression tree analysis KW - Boosted regression tree Y1 - 2011 U6 - https://doi.org/10.1007/s12080-010-0092-y SN - 1874-1738 VL - 4 IS - 4 SP - 495 EP - 511 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Scherer, Cedric A1 - Jeltsch, Florian A1 - Grimm, Volker A1 - Blaum, Niels T1 - Merging trait-based and individual-based modelling: An animal functional type approach to explore the responses of birds to climatic and land use changes in semi-arid African savannas JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Climate change and land use management practices are major drivers of biodiversity in terrestrial ecosystems. To understand and predict resulting changes in community structures, individual-based and spatially explicit population models are a useful tool but require detailed data sets for each species. More generic approaches are thus needed. Here we present a trait-based functional type approach to model savanna birds. The aim of our model is to explore the response of different bird functional types to modifications in habitat structure. The functional types are characterized by different traits, in particular body mass, which is related to life-history traits (reproduction and mortality) and spatial scales (home range area and dispersal ability), as well as the use of vegetation structures for foraging and nesting, which is related to habitat quality and suitability. We tested the performance of the functional types in artificial landscapes varying in shrub:grass ratio and clumping intensity of shrub patches. We found that an increase in shrub encroachment and a decrease in habitat quality caused by land use mismanagement and climate change endangered all simulated bird functional types. The strength of this effect was related to the preferred habitat. Furthermore, larger-bodied insectivores and omnivores were more prone to extinction due to shrub encroachment compared to small-bodied species. Insectivorous and omnivorous birds were more sensitive to clumping intensity of shrubs whereas herbivorous and carnivorous birds were most affected by a decreasing amount of grass cover. From an applied point of view, our findings emphasize that policies such as woody plant removal and a reduction in livestock stocking rates to prevent shrub encroachment should prioritize the enlargement of existing grassland patches. Overall, our results show that the combination of an individual-based modelling approach with carefully defined functional types can provide a powerful tool for exploring biodiversity responses to environmental changes. Furthermore, the increasing accumulation of worldwide data sets on species’ core and soft traits (surrogates to determine core traits indirectly) on one side and the refinement of conceptual frameworks for animal functional types on the other side will further improve functional type approaches which consider the sensitivities of multiple species to climate change, habitat loss, and fragmentation. KW - IBM KW - Functional types KW - Trait-based approach KW - Shrub encroachment KW - Birds Y1 - 2016 U6 - https://doi.org/10.1016/j.ecolmodel.2015.07.005 SN - 0304-3800 SN - 1872-7026 VL - 326 SP - 75 EP - 89 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - May, Felix A1 - Giladi, Itamar A1 - Ristow, Michael A1 - Ziv, Yaron A1 - Jeltsch, Florian T1 - Metacommunity, mainland-island system or island communities? : assessing the regional dynamics of plant communities in a fragmented landscape JF - Ecography : pattern and diversity in ecology ; research papers forum N2 - Understanding the regional dynamics of plant communities is crucial for predicting the response of plant diversity to habitat fragmentation. However, for fragmented landscapes the importance of regional processes, such as seed dispersal among isolated habitat patches, has been controversially debated. Due to the stochasticity and rarity of among-patch dispersal and colonization events, we still lack a quantitative understanding of the consequences of these processes at the landscape-scale. In this study, we used extensive field data from a fragmented, semi-arid landscape in Israel to parameterize a multi-species incidence-function model. This model simulates species occupancy pattern based on patch areas and habitat configuration and explicitly considers the locations and the shapes of habitat patches for the derivation of patch connectivity. We implemented an approximate Bayesian computation approach for parameter inference and uncertainty assessment. We tested which of the three types of regional dynamics - the metacommunity, the mainland-island, or the island communities type - best represents the community dynamics in the study area and applied the simulation model to estimate the extinction debt in the investigated landscape. We found that the regional dynamics in the patch-matrix study landscape is best represented as a system of highly isolated island' communities with low rates of propagule exchange among habitat patches and consequently low colonization rates in local communities. Accordingly, the extinction rates in the local communities are the main drivers of community dynamics. Our findings indicate that the landscape carries a significant extinction debt and in model projections 33-60% of all species went extinct within 1000 yr. Our study demonstrates that the combination of dynamic simulation models with field data provides a promising approach for understanding regional community dynamics and for projecting community responses to habitat fragmentation. The approach bears the potential for efficient tests of conservation activities aimed at mitigating future losses of biodiversity. Y1 - 2013 U6 - https://doi.org/10.1111/j.1600-0587.2012.07793.x SN - 0906-7590 VL - 36 IS - 7 SP - 842 EP - 853 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Wiegand, K. A1 - Jeltsch, Florian A1 - Ward, D. T1 - Minimum recruitment frequency in plants with episodic recruitment N2 - There is concern about the lack of recruitment of Acacia trees in the Negev desert of Israel. We have developed three models to estimate the frequency of recruitment necessary for long-term population survival (i.e. positive average population growth for 1,000 years and <10% probability of extinction). Two models assume purely episodic recruitment based on the general notion that recruitment in and environments is highly episodic. They differ in that the deterministic model investigates average dynamics while the stochastic model does not. Studies indicating that recruitment episodes in and environments have been overemphasized motivated the development of the third model. This semi-stochastic model simulates a mixture of continuous and episodic recruitment. Model analysis was done analytically for the deterministic model and via running model simulations for the stochastic and semi-stochastic models. The deterministic and stochastic models predict that, on average, 2.2 and 3.7 recruitment events per century, respectively, are necessary to sustain the population. According to the semi-stochastic model, 1.6 large recruitment events per century and an annual probability of 50% that a small recruitment event occurs are needed. A consequence of purely episodic recruitment is that all recruitment episodes produce extremely large numbers of recruits (i.e. at odds with field observations), an evaluation that holds even when considering that rare events must be large. Thus, the semi- stochastic model appears to be the most realistic model. Comparing the prediction of the semi-stochastic model to field observations in the Negev desert shows that the absence of observations of extremely large recruitment events is no reason for concern. However, the almost complete absence of small recruitment events is a serious reason for concern. The lack of recruitment may be due to decreased densities of large mammalian herbivores and might be further exacerbated by possible changes in climate, both in terms of average precipitation and the temporal distribution of rain Y1 - 2004 ER - TY - JOUR A1 - Wichmann, Matthias A1 - Groeneveld, Jürgen A1 - Jeltsch, Florian A1 - Grimm, Volker T1 - Mitigation of climate change impacts on raptors by behavioural adaptation : ecological buffering mechanisms N2 - The predicted climate change causes deep concerns on the effects of increasing temperatures and changing precipitation patterns on species viability and, in turn, on biodiversity. Models of Population Viability Analysis (PVA) provide a powerful tool to assess the risk of species extinction. However, most PVA models do not take into account the potential effects of behavioural adaptations. Organisms might adapt to new environmental situations and thereby mitigate negative effects of climate change. To demonstrate such mitigation effects, we use an existing PVA model describing a population of the tawny eagle (Aquila rapax) in the southern Kalahari. This model does not include behavioural adaptations. We develop a new model by assuming that the birds enlarge their average territory size to compensate for lower amounts of precipitation. Here, we found the predicted increase in risk of extinction due to climate change to be much lower than in the original model. However, this "buffering" of climate change by behavioural adaptation is not very effective in coping with increasing interannual variances. We refer to further examples of ecological "buffering mechanisms" from the literature and argue that possible buffering mechanisms should be given due consideration when the effects of climate change on biodiversity are to be predicted. (c) 2004 Elsevier B.V. All rights reserved Y1 - 2005 SN - 0921-8181 ER - TY - JOUR A1 - Wichmann, Matthias A1 - Groeneveld, Jürgen A1 - Jeltsch, Florian A1 - Grimm, Volker T1 - Mitigation of climate change impacts on raptors by behavioural adaption : ecological buffering mechanism Y1 - 2005 ER -