@article{BinzerBroseCurtsdotteretal.2011, author = {Binzer, Amrei and Brose, Ulrich and Curtsdotter, Alva and Ekloef, Anna and Rall, Bjoern C. and Riede, Jens O. and de Castro, Francisco}, title = {The susceptibility of species to extinctions in model communities}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {12}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, number = {7}, publisher = {Elsevier}, address = {Jena}, issn = {1439-1791}, doi = {10.1016/j.baae.2011.09.002}, pages = {590 -- 599}, year = {2011}, abstract = {Despite the fact that the loss of a species from a community has the potential to cause a dramatic decline in biodiversity, for example through cascades of secondary extinctions, little is known about the factors contributing to the extinction risk of any particular species. Here we expand earlier modeling approaches using a dynamic food-web model that accounts for bottom-up as well as top-down effects. We investigate what factors influence a species' extinction risk and time to extinction of the non-persistent species. We identified three basic properties that affect a species' risk of extinction. The highest extinction risk is born by species with (1) low energy input (e.g. high trophic level), (2) susceptibility to the loss of energy pathways (e.g. specialists with few prey species) and (3) dynamic instability (e.g. low Hill exponent and reliance on homogeneous energy channels when feeding on similarly sized prey). Interestingly, and different from field studies, we found that the trophic level and not the body mass of a species influences its extinction risk. On the other hand, body mass is the single most important factor determining the time to extinction of a species, resulting in small species dying first. This suggests that in the field the trophic level might have more influence on the extinction risk than presently recognized.}, language = {en} } @article{PennekampIlesGarlandetal.2019, author = {Pennekamp, Frank and Iles, Alison C. and Garland, Joshua and Brennan, Georgina and Brose, Ulrich and Gaedke, Ursula and Jacob, Ute and Kratina, Pavel and Matthews, Blake and Munch, Stephan and Novak, Mark and Palamara, Gian Marco and Rall, Bjorn C. and Rosenbaum, Benjamin and Tabi, Andrea and Ward, Colette and Williams, Richard and Ye, Hao and Petchey, Owen L.}, title = {The intrinsic predictability of ecological time series and its potential to guide forecasting}, series = {Ecological monographs : a publication of the Ecological Society of America.}, volume = {89}, journal = {Ecological monographs : a publication of the Ecological Society of America.}, number = {2}, publisher = {Wiley}, address = {Hoboken}, issn = {0012-9615}, doi = {10.1002/ecm.1359}, pages = {17}, year = {2019}, language = {en} } @article{RyserHaeusslerStarketal.2019, author = {Ryser, Remo and H{\"a}ussler, Johanna and Stark, Markus and Brose, Ulrich and Rall, Bj{\"o}rn C. and Guill, Christian}, title = {The biggest losers: habitat isolation deconsructs complex food webs from top to bottom}, series = {Proceedings of the Royal Society of London : B, Biological sciences}, volume = {286}, journal = {Proceedings of the Royal Society of London : B, Biological sciences}, number = {1908}, publisher = {Royal Society}, address = {London}, issn = {0962-8452}, doi = {10.1098/rspb.2019.1177}, pages = {8}, year = {2019}, abstract = {Habitat fragmentation threatens global biodiversity. To date, there is only limited understanding of how the different aspects of habitat fragmentation (habitat loss, number of fragments and isolation) affect species diversity within complex ecological networks such as food webs. Here, we present a dynamic and spatially explicit food web model which integrates complex food web dynamics at the local scale and species-specific dispersal dynamics at the landscape scale, allowing us to study the interplay of local and spatial processes in metacommunities. We here explore how the number of habitat patches, i.e. the number of fragments, and an increase of habitat isolation affect the species diversity patterns of complex food webs (alpha-,beta-,gamma-, diversities). We specifically test whether there is a trophic dependency in the effect of these two factors on species diversity. In our model, habitat isolation is the main driver causing species loss and diversity decline. Our results emphasize that large-bodied consumer species at high trophic positions go extinct faster than smaller species at lower trophic levels, despite being superior dispersers that connect fragmented landscapes better. We attribute the loss of top species to a combined effect of higher biomass loss during dispersal with increasing habitat isolation in general, and the associated energy limitation in highly fragmented landscapes, preventing higher trophic levels to persist. To maintain trophic-complex and species-rich communities calls for effective conservation planning which considers the interdependence of trophic and spatial dynamics as well as the spatial context of a landscape and its energy availability.}, language = {en} } @article{BroseTielboerger2005, author = {Brose, Ulrich and Tielb{\"o}rger, Katja}, title = {Subtle differences in environmental stress along a flooding gradient affect the importance of inter-specific competition in an annual plant community}, issn = {1385-0237}, year = {2005}, abstract = {Empirical evidence suggests that the direction and intensity of plant-plant interactions may depend on the favourability of the environment. Previous studies have mainly focused on steep gradients of environmental stress or disturbance, while the interplay of competition and environment has not been tested for subtle environmental differences. Here, we present results from a study on plant communities of temporary wetlands in East-German farmland. Due to yearly ploughing in autumn, the vegetation is composed of annual species. Flooding does not affect adult plants and the elevation on the gradient expresses differences in the length of the growing season rather than in disturbance intensity or severe environmental stress. We tested whether such subtle differences in environmental stress may affect the importance of interspecific competition by the dominant species. Two treatments were applied at two elevations: removal of the dominant species (Matricaria maritima ssp. inodora) and reciprocal transplants of the seed-bank of the two elevations. At both elevations, removal of Matricaria inodora led to an increase in total species richness and number of wetland species, but the effects were substantially stronger at high elevations. Removal and the elevation on the flooding gradient significantly influenced the plant community composition. In particular, the weed communities became more similar to the wetland communities after the removal. Transplanted weed species did not emerge at low elevations. While two of four target species had significantly higher densities after the removal at high elevations, none of them was influenced by removal at low elevations. This indicates that, consistent with previous studies from other habitat types, competition by the dominant species was more intense under conditions of low environmental stress. The overall results suggest that both flooding as well as interspecific competition are important in structuring the plant communities along the freshwater gradient studied}, language = {en} } @article{RiedeBinzerBroseetal.2011, author = {Riede, Jens O. and Binzer, Amrei and Brose, Ulrich and de Castro, Francisco and Curtsdotter, Alva and Rall, Bjoern C. and Ekloef, Anna}, title = {Size-based food web characteristics govern the response to species extinctions}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {12}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, number = {7}, publisher = {Elsevier}, address = {Jena}, issn = {1439-1791}, doi = {10.1016/j.baae.2011.09.006}, pages = {581 -- 589}, year = {2011}, abstract = {How ecological communities react to species extinctions is a long-standing yet current question in ecology. The species constituting the basic units of ecosystems interact with each other forming complex networks of trophic relationships and the characteristics of these networks are highly important for the consequences of species extinction. Here we take a more general approach and analyze a broad range of network characteristics and their role in determining food web susceptibility to secondary extinctions. We extend previous studies, that have focused on the consequences of topological and dynamical food web parameters for food web robustness, by also defining network-wide characteristics depending on the relationships between the distribution of species body masses and other species characteristics. We use a bioenergetic dynamical model to simulate realistically structured model food webs that differ in their structural and dynamical properties as well as their size structure. In order to measure food web robustness we calculated the proportion of species going secondarily extinct. A multiple regression analysis was then used to fit a general model relating the proportion of species going secondarily extinct to the measured food web properties. Our results show that there are multiple factors from all three groups of food web characteristics that affect food web robustness. However, we find the most striking effect was related to the body mass abundance relationship which points to the importance of body mass relationships for food web stability.}, language = {en} } @article{CurtsdotterBinzerBroseetal.2011, author = {Curtsdotter, Alva and Binzer, Amrei and Brose, Ulrich and de Castro, Francisco and Ebenman, Bo and Ekloef, Anna and Riede, Jens O. and Thierry, Aaron and Rall, Bjoern C.}, title = {Robustness to secondary extinctions comparing trait-based sequential deletions in static and dynamic food webs}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {12}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, number = {7}, publisher = {Elsevier}, address = {Jena}, issn = {1439-1791}, doi = {10.1016/j.baae.2011.09.008}, pages = {571 -- 580}, year = {2011}, abstract = {The loss of species from ecological communities can unleash a cascade of secondary extinctions, the risk and extent of which are likely to depend on the traits of the species that are lost from the community. To identify species traits that have the greatest impact on food web robustness to species loss we here subject allometrically scaled, dynamical food web models to several deletion sequences based on species' connectivity, generality, vulnerability or body mass. Further, to evaluate the relative importance of dynamical to topological effects we compare robustness between dynamical and purely topological models. This comparison reveals that the topological approach overestimates robustness in general and for certain sequences in particular. Top-down directed sequences have no or very low impact on robustness in topological analyses, while the dynamical analysis reveals that they may be as important as high-impact bottom-up directed sequences. Moreover, there are no deletion sequences that result, on average, in no or very few secondary extinctions in the dynamical approach. Instead, the least detrimental sequence in the dynamical approach yields an average robustness similar to the most detrimental (non-basal) deletion sequence in the topological approach. Hence, a topological analysis may lead to erroneous conclusions concerning both the relative and the absolute importance of different species traits for robustness. The dynamical sequential deletion analysis shows that food webs are least robust to the loss of species that have many trophic links or that occupy low trophic levels. In contrast to previous studies we can infer, albeit indirectly, that secondary extinctions were triggered by both bottom-up and top-down cascades.}, language = {en} } @article{KefiBerlowWietersetal.2012, author = {Kefi, Sonia and Berlow, Eric L. and Wieters, Evie A. and Navarrete, Sergio A. and Petchey, Owen L. and Wood, Spencer A. and Boit, Alice and Joppa, Lucas N. and Lafferty, Kevin D. and Williams, Richard J. and Martinez, Neo D. and Menge, Bruce A. and Blanchette, Carol A. and Iles, Alison C. and Brose, Ulrich}, title = {More than a meal ... integrating non-feeding interactions into food webs}, series = {Ecology letters}, volume = {15}, journal = {Ecology letters}, number = {4}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1461-023X}, doi = {10.1111/j.1461-0248.2011.01732.x}, pages = {291 -- 300}, year = {2012}, abstract = {Organisms eating each other are only one of many types of well documented and important interactions among species. Other such types include habitat modification, predator interference and facilitation. However, ecological network research has been typically limited to either pure food webs or to networks of only a few (<3) interaction types. The great diversity of non-trophic interactions observed in nature has been poorly addressed by ecologists and largely excluded from network theory. Herein, we propose a conceptual framework that organises this diversity into three main functional classes defined by how they modify specific parameters in a dynamic food web model. This approach provides a path forward for incorporating non-trophic interactions in traditional food web models and offers a new perspective on tackling ecological complexity that should stimulate both theoretical and empirical approaches to understanding the patterns and dynamics of diverse species interactions in nature.}, language = {en} } @article{GrossAllhoffBlasiusetal.2020, author = {Gross, Thilo and Allhoff, Korinna Theresa and Blasius, Bernd and Brose, Ulrich and Drossel, Barbara and Fahimipour, Ashkaan K. and Guill, Christian and Yeakel, Justin D. and Zeng, Fanqi}, title = {Modern models of trophic meta-communities}, series = {Philosophical transactions of the Royal Society of London : B, Biological sciences}, volume = {375}, journal = {Philosophical transactions of the Royal Society of London : B, Biological sciences}, number = {1814}, publisher = {Royal Society}, address = {London}, issn = {0962-8436}, doi = {10.1098/rstb.2019.0455}, pages = {12}, year = {2020}, abstract = {Dispersal and foodweb dynamics have long been studied in separate models. However, over the past decades, it has become abundantly clear that there are intricate interactions between local dynamics and spatial patterns. Trophic meta-communities, i.e. meta-foodwebs, are very complex systems that exhibit complex and often counterintuitive dynamics. Over the past decade, a broad range of modelling approaches have been used to study these systems. In this paper, we review these approaches and the insights that they have revealed. We focus particularly on recent papers that study trophic interactions in spatially extensive settings and highlight the common themes that emerged in different models. There is overwhelming evidence that dispersal (and particularly intermediate levels of dispersal) benefits the maintenance of biodiversity in several different ways. Moreover, some insights have been gained into the effect of different habitat topologies, but these results also show that the exact relationships are much more complex than previously thought, highlighting the need for further research in this area. This article is part of the theme issue 'Integrative research perspectives on marine conservation'.}, language = {en} } @article{BinzerGuillRalletal.2016, author = {Binzer, Amrei and Guill, Christian and Rall, Bj{\"o}rn C. and Brose, Ulrich}, title = {Interactive effects of warming, eutrophication and size structure: impacts on biodiversity and food-web structure}, series = {Global change biology}, volume = {22}, journal = {Global change biology}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1354-1013}, doi = {10.1111/gcb.13086}, pages = {220 -- 227}, year = {2016}, abstract = {Warming and eutrophication are two of the most important global change stressors for natural ecosystems, but their interaction is poorly understood. We used a dynamic model of complex, size-structured food webs to assess interactive effects on diversity and network structure. We found antagonistic impacts: Warming increases diversity in eutrophic systems and decreases it in oligotrophic systems. These effects interact with the community size structure: Communities of similarly sized species such as parasitoid-host systems are stabilized by warming and destabilized by eutrophication, whereas the diversity of size-structured predator-prey networks decreases strongly with warming, but decreases only weakly with eutrophication. Nonrandom extinction risks for generalists and specialists lead to higher connectance in networks without size structure and lower connectance in size-structured communities. Overall, our results unravel interactive impacts of warming and eutrophication and suggest that size structure may serve as an important proxy for predicting the community sensitivity to these global change stressors.}, language = {en} } @article{JeltschBlaumBroseetal.2013, author = {Jeltsch, Florian and Blaum, Niels and Brose, Ulrich and Chipperfield, Joseph D. and Clough, Yann and Farwig, Nina and Geissler, Katja and Graham, Catherine H. and Grimm, Volker and Hickler, Thomas and Huth, Andreas and May, Felix and Meyer, Katrin M. and Pagel, J{\"o}rn and Reineking, Bj{\"o}rn and Rillig, Matthias C. and Shea, Katriona and Schurr, Frank Martin and Schroeder, Boris and Tielb{\"o}rger, Katja and Weiss, Lina and Wiegand, Kerstin and Wiegand, Thorsten and Wirth, Christian and Zurell, Damaris}, title = {How can we bring together empiricists and modellers in functional biodiversity research?}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {14}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, number = {2}, publisher = {Elsevier}, address = {Jena}, issn = {1439-1791}, doi = {10.1016/j.baae.2013.01.001}, pages = {93 -- 101}, year = {2013}, abstract = {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.}, language = {en} } @phdthesis{Brose2000, author = {Brose, Ulrich}, title = {Artendiversit{\"a}t der Pflanzen- und Laufk{\"a}fergemeinschaften (Coleoptera, Carabidae) von Naßstelle auf mehreren r{\"a}umlichen Skalenebenen}, pages = {146, LXI S.}, year = {2000}, language = {de} } @article{JeltschTewsBroseetal.2004, author = {Jeltsch, Florian and Tews, J{\"o}rg and Brose, Ulrich and Grimm, Volker and Tielb{\"o}rger, Katja and Wichmann, Matthias and Schwager, Monika}, title = {Animal species diversity driven by habitat heterogeneity/diversity : the importance of keystone structures}, year = {2004}, abstract = {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.}, language = {en} } @article{SchneiderBroseRalletal.2016, author = {Schneider, Florian D. and Brose, Ulrich and Rall, Bj{\"o}rn C. and Guill, Christian}, title = {Animal diversity and ecosystem functioning in dynamic food webs}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, publisher = {Nature Publ. Group}, address = {London}, issn = {2041-1723}, doi = {10.1038/ncomms12718}, pages = {3129 -- 3138}, year = {2016}, abstract = {Species diversity is changing globally and locally, but the complexity of ecological communities hampers a general understanding of the consequences of animal species loss on ecosystem functioning. High animal diversity increases complementarity of herbivores but also increases feeding rates within the consumer guild. Depending on the balance of these counteracting mechanisms, species-rich animal communities may put plants under top-down control or may release them from grazing pressure. Using a dynamic food-web model with body-mass constraints, we simulate ecosystem functions of 20,000 communities of varying animal diversity. We show that diverse animal communities accumulate more biomass and are more exploitative on plants, despite their higher rates of intra-guild predation. However, they do not reduce plant biomass because the communities are composed of larger, and thus energetically more efficient, plant and animal species. This plasticity of community body-size structure reconciles the debate on the consequences of animal species loss for primary productivity.}, language = {en} }