TY - JOUR A1 - Leins, Johannes A. A1 - Banitz, Thomas A1 - Grimm, Volker A1 - Drechsler, Martin T1 - High-resolution PVA along large environmental gradients to model the combined effects of climate change and land use timing BT - lessons from the large marsh grasshopper JF - Ecological modelling : international journal on ecological modelling and systems ecology N2 - Both climate change and land use regimes affect the viability of populations, but they are often studied separately. Moreover, population viability analyses (PVAs) often ignore the effects of large environmental gradients and use temporal resolutions that are too coarse to take into account that different stages of a population's life cycle may be affected differently by climate change. Here, we present the High-resolution Large Environmental Gradient (HiLEG) model and apply it in a PVA with daily resolution based on daily climate projections for Northwest Germany. We used the large marsh grasshopper (LMG) as the target species and investigated (1) the effects of climate change on the viability and spatial distribution of the species, (2) the influence of the timing of grassland mowing on the species and (3) the interaction between the effects of climate change and grassland mowing. The stageand cohort-based model was run for the spatially differentiated environmental conditions temperature and soil moisture across the whole study region. We implemented three climate change scenarios and analyzed the population dynamics for four consecutive 20-year periods. Climate change alone would lead to an expansion of the regions suitable for the LMG, as warming accelerates development and due to reduced drought stress. However, in combination with land use, the timing of mowing was crucial, as this disturbance causes a high mortality rate in the aboveground life stages. Assuming the same date of mowing throughout the region, the impact on viability varied greatly between regions due to the different climate conditions. The regional negative effects of the mowing date can be divided into five phases: (1) In early spring, the populations were largely unaffected in all the regions; (2) between late spring and early summer, they were severely affected only in warm regions; (3) in summer, all the populations were severely affected so that they could hardly survive; (4) between late summer and early autumn, they were severely affected in cold regions; and (5) in autumn, the populations were equally affected across all regions. The duration and start of each phase differed slightly depending on the climate change scenario and simulation period, but overall, they showed the same pattern. Our model can be used to identify regions of concern and devise management recommendations. The model can be adapted to the life cycle of different target species, climate projections and disturbance regimes. We show with our adaption of the HiLEG model that high-resolution PVAs and applications on large environmental gradients can be reconciled to develop conservation strategies capable of dealing with multiple stressors. KW - Climate change KW - Land use KW - Population viability analysis KW - Stage-based model KW - High resolution KW - Environmental gradients Y1 - 2020 U6 - https://doi.org/10.1016/j.ecolmodel.2020.109355 SN - 0304-3800 SN - 1872-7026 VL - 440 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Horn, Juliane A1 - Becher, Matthias A. A1 - Johst, Karin A1 - Kennedy, Peter J. A1 - Osborne, Juliet L. A1 - Radchuk, Viktoriia A1 - Grimm, Volker T1 - Honey bee colony performance affected by crop diversity and farmland structure BT - a modeling framework JF - Ecological applications N2 - Forage availability has been suggested as one driver of the observed decline in honey bees. However, little is known about the effects of its spatiotemporal variation on colony success. We present a modeling framework for assessing honey bee colony viability in cropping systems. Based on two real farmland structures, we developed a landscape generator to design cropping systems varying in crop species identity, diversity, and relative abundance. The landscape scenarios generated were evaluated using the existing honey bee colony model BEEHAVE, which links foraging to in-hive dynamics. We thereby explored how different cropping systems determine spatiotemporal forage availability and, in turn, honey bee colony viability (e.g., time to extinction, TTE) and resilience (indicated by, e.g., brood mortality). To assess overall colony viability, we developed metrics,P(H)andP(P,)which quantified how much nectar and pollen provided by a cropping system per year was converted into a colony's adult worker population. Both crop species identity and diversity determined the temporal continuity in nectar and pollen supply and thus colony viability. Overall farmland structure and relative crop abundance were less important, but details mattered. For monocultures and for four-crop species systems composed of cereals, oilseed rape, maize, and sunflower,P(H)andP(P)were below the viability threshold. Such cropping systems showed frequent, badly timed, and prolonged forage gaps leading to detrimental cascading effects on life stages and in-hive work force, which critically reduced colony resilience. Four-crop systems composed of rye-grass-dandelion pasture, trefoil-grass pasture, sunflower, and phacelia ensured continuous nectar and pollen supply resulting in TTE > 5 yr, andP(H)(269.5 kg) andP(P)(108 kg) being above viability thresholds for 5 yr. Overall, trefoil-grass pasture, oilseed rape, buckwheat, and phacelia improved the temporal continuity in forage supply and colony's viability. Our results are hypothetical as they are obtained from simplified landscape settings, but they nevertheless match empirical observations, in particular the viability threshold. Our framework can be used to assess the effects of cropping systems on honey bee viability and to develop land-use strategies that help maintain pollination services by avoiding prolonged and badly timed forage gaps. KW - apis mellifera KW - BEEHAVE KW - colony viability KW - crop diversity KW - cropping system KW - decline KW - forage availability KW - forage gaps KW - honey bees KW - landscape generator KW - modeling Y1 - 2020 U6 - https://doi.org/10.1002/eap.2216 SN - 1939-5582 SN - 1051-0761 VL - 31 IS - 1 SP - 1 EP - 22 PB - Wiley Periodicals LLC CY - Washington DC ER - TY - JOUR A1 - Leins, Johannes A. A1 - Grimm, Volker A1 - Drechsler, Martin T1 - Large-scale PVA modeling of insects in cultivated grasslands BT - the role of dispersal in mitigating the effects of management schedules under climate change JF - Ecology and evolution N2 - In many species, dispersal is decisive for survival in a changing climate. Simulation models for population dynamics under climate change thus need to account for this factor. Moreover, large numbers of species inhabiting agricultural landscapes are subject to disturbances induced by human land use. We included dispersal in the HiLEG model that we previously developed to study the interaction between climate change and agricultural land use in single populations. Here, the model was parameterized for the large marsh grasshopper (LMG) in cultivated grasslands of North Germany to analyze (1) the species development and dispersal success depending on the severity of climate change in subregions, (2) the additional effect of grassland cover on dispersal success, and (3) the role of dispersal in compensating for detrimental grassland mowing. Our model simulated population dynamics in 60-year periods (2020-2079) on a fine temporal (daily) and high spatial (250 x 250 m(2)) scale in 107 subregions, altogether encompassing a range of different grassland cover, climate change projections, and mowing schedules. We show that climate change alone would allow the LMG to thrive and expand, while grassland cover played a minor role. Some mowing schedules that were harmful to the LMG nevertheless allowed the species to moderately expand its range. Especially under minor climate change, in many subregions dispersal allowed for mowing early in the year, which is economically beneficial for farmers. More severe climate change could facilitate LMG expansion to uninhabited regions but would require suitable mowing schedules along the path. These insights can be transferred to other species, given that the LMG is considered a representative of grassland communities. For more specific predictions on the dynamics of other species affected by climate change and land use, the publicly available HiLEG model can be easily adapted to the characteristics of their life cycle. KW - bilinear interpolation KW - climate change KW - dispersal success KW - land use KW - large marsh grasshopper KW - spatially explicit model Y1 - 2022 U6 - https://doi.org/10.1002/ece3.9063 SN - 2045-7758 VL - 12 IS - 7 PB - Wiley 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 - JOUR A1 - Weise, Hanna A1 - Auge, Harald A1 - Baessler, Cornelia A1 - Bärlund, Ilona A1 - Bennett, Elena M. A1 - Berger, Uta A1 - Bohn, Friedrich A1 - Bonn, Aletta A1 - Borchardt, Dietrich A1 - Brand, Fridolin A1 - Jeltsch, Florian A1 - Joshi, Jasmin Radha A1 - Grimm, Volker T1 - Resilience trinity BT - safeguarding ecosystem functioning and services across three different time horizons and decision contexts JF - Oikos N2 - Ensuring ecosystem resilience is an intuitive approach to safeguard the functioning of ecosystems and hence the future provisioning of ecosystem services (ES). However, resilience is a multi-faceted concept that is difficult to operationalize. Focusing on resilience mechanisms, such as diversity, network architectures or adaptive capacity, has recently been suggested as means to operationalize resilience. Still, the focus on mechanisms is not specific enough. We suggest a conceptual framework, resilience trinity, to facilitate management based on resilience mechanisms in three distinctive decision contexts and time-horizons: 1) reactive, when there is an imminent threat to ES resilience and a high pressure to act, 2) adjustive, when the threat is known in general but there is still time to adapt management and 3) provident, when time horizons are very long and the nature of the threats is uncertain, leading to a low willingness to act. Resilience has different interpretations and implications at these different time horizons, which also prevail in different disciplines. Social ecology, ecology and engineering are often implicitly focussing on provident, adjustive or reactive resilience, respectively, but these different notions of resilience and their corresponding social, ecological and economic tradeoffs need to be reconciled. Otherwise, we keep risking unintended consequences of reactive actions, or shying away from provident action because of uncertainties that cannot be reduced. The suggested trinity of time horizons and their decision contexts could help ensuring that longer-term management actions are not missed while urgent threats to ES are given priority. KW - concepts KW - ecosystems KW - ecosystem services provisioning KW - management KW - resilience Y1 - 2020 U6 - https://doi.org/10.1111/oik.07213 SN - 0030-1299 SN - 1600-0706 VL - 129 IS - 4 SP - 445 EP - 456 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Li, Shuang A1 - Abdulkadir, Nafi'u A1 - Schattenberg, Florian A1 - da Rocha, Ulisses Nunes A1 - Grimm, Volker A1 - Müller, Susann A1 - Liu, Zishu T1 - Stabilizing microbial communities by looped mass transfer JF - Proceedings of the National Academy of Sciences of the United States of America : PNAS N2 - Building and changing a microbiome at will and maintaining it over hundreds of generations has so far proven challenging. Despite best efforts, complex microbiomes appear to be susceptible to large stochastic fluctuations. Current capabilities to assemble and control stable complex microbiomes are limited. Here, we propose a looped mass transfer design that stabilizes microbiomes over long periods of time. Five local microbiomes were continuously grown in parallel for over 114 generations and connected by a loop to a regional pool. Mass transfer rates were altered and microbiome dynamics were monitored using quantitative high-throughput flow cytometry and taxonomic sequencing of whole communities and sorted subcommunities. Increased mass transfer rates reduced local and temporal variation in microbiome assembly, did not affect functions, and overcame stochasticity, with all microbiomes exhibiting high constancy and increasing resistance. Mass transfer synchronized the structures of the five local microbiomes and nestedness of certain cell types was eminent. Mass transfer increased cell number and thus decreased net growth rates mu'. Subsets of cells that did not show net growth mu'SCx were rescued by the regional pool R and thus remained part of the microbiome. The loop in mass transfer ensured the survival of cells that would otherwise go extinct, even if they did not grow in all local microbiomes or grew more slowly than the actual dilution rate D would allow. The rescue effect, known from metacommunity theory, was the main stabilizing mechanism leading to synchrony and survival of subcommunities, despite differences in cell physiological properties, including growth rates. KW - microbial ecology KW - metacommunity assembly KW - stability KW - microbial KW - community cytometry KW - single-cell analytics Y1 - 2022 U6 - https://doi.org/10.1073/pnas.2117814119 SN - 0027-8424 SN - 1091-6490 VL - 119 IS - 17 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Drechsler, Martin A1 - Wätzold, Frank A1 - Grimm, Volker T1 - The hitchhiker's guide to generic ecological-economic modelling of land-use-based biodiversity conservation policies JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Biodiversity loss is a result of interacting ecological and economic factors, and it must be addressed through an analysis of biodiversity conservation policies. Ecological-economic modelling is a helpful approach to this analysis, but it is also challenging since modellers often have a specific disciplinary background and tend to misrepresent either the ecological or economic aspects. Here, we introduce some of the most important concepts from both disciplines, and since the two modelling cultures also differ between the two disciplines, we present an integrated, consistent guide through all the steps of generic ecological-economic modelling, such as formulation of the research question, development of the conceptual model, model parametrisation and analysis, and interpretation of model results. Although we focus on generic models aimed at a general understanding of causes and remedies for biodiversity loss, the concepts and guidance provided here may also help in the modelling of more specific conservation problems. This guide is aimed at the intersection of three disciplines: ecology, economics and mathematical modelling, and addresses readers who have some knowledge in at least one of these disciplines and want to learn about the others to build and analyse generic ecological-economic models. Compared to textbooks, the guide focuses on the practice of modelling rather than lengthy explanations of theoretical concepts. We attempt to demonstrate that generic ecological-economic modelling does not require magical powers and instead is a manageable exercise. KW - Biodiversity KW - Conservation policy KW - Ecological-economic modelling KW - Generic modelling KW - Land use Y1 - 2022 U6 - https://doi.org/10.1016/j.ecolmodel.2021.109861 SN - 0304-3800 SN - 1872-7026 VL - 465 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Milles, Alexander A1 - Dammhahn, Melanie A1 - Grimm, Volker T1 - Intraspecific trait variation in personality-related movement behavior promotes coexistence JF - Oikos N2 - Movement behavior is an essential element of fundamental ecological processes such as competition and predation. Although intraspecific trait variation (ITV) in movement behaviors is pervasive, its consequences for ecological community dynamics are still not fully understood. Using a newly developed individual-based model, we analyzed how given and constant ITVs in foraging movement affect differences in foraging efficiencies between species competing for common resources under various resource distributions. Further, we analyzed how the effect of ITV on emerging differences in competitive abilities ultimately affects species coexistence. The model is generic but mimics observed patterns of among-individual covariation between personality, movement and space use in ground-dwelling rodents. Interacting species differed in their mean behavioral types along a slow-fast continuum, integrating consistent individual variation in average behavioral expression and responsiveness (i.e. behavioral reaction norms). We found that ITV reduced interspecific differences in competitive abilities by 5-35% and thereby promoted coexistence via an equalizing mechanism. The emergent relationships between behavioral types and foraging efficiency are characteristic for specific environmental contexts of resource distribution and population density. As these relationships are asymmetric, species that were either 'too fast' or 'too slow' benefited differently from ITV. Thus, ITV in movement behavior has consequences for species coexistence but to predict its effect in a given system requires intimate knowledge on how variation in movement traits relates to fitness components along an environmental gradient. KW - animal behavior KW - animal movement KW - coexistence KW - competitive ability KW - foraging KW - individual-based model Y1 - 2020 U6 - https://doi.org/10.1111/oik.07431 SN - 0030-1299 SN - 1600-0706 VL - 129 IS - 10 SP - 1441 EP - 1454 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Langhammer, Maria A1 - Grimm, Volker T1 - Mitigating bioenergy-driven biodiversity decline BT - a modelling approach with the European brown hare JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - The cultivation of energy crops leads to direct and indirect land use changes that impair the biodiversity of the agricultural landscape. In our study, we analyse the effects of mitigation measures on the European brown hare (Lepus europaeus), which is directly affected by ongoing land use change and has experienced widespread decline throughout Europe since the 1960s. Therefore, we developed a spatially explicit and individual-based ecological model to study the effects of different landscape configurations and compositions on hare population development. As an input, we used two 4 x 4 km large model landscapes, which were generated by a landscape generator based on real field sizes and crop proportions and differed in average field size and crop composition. The crops grown annually are evaluated in terms of forage suitability, breeding suitability and crop richness for the hare. In six mitigation scenarios, we investigated the effects of a 10 % increase in the following measures: (1) mixed silphie, (2) miscanthus, (3) grass-clover ley, (4) alfalfa, (5) set-aside, and (6) general crop richness. All mitigation measures had significant effects on hare population development. Compared to the base scenario, the relative change in hare abundance ranged from a factor of 0.56 in the grass-clover ley scenario to-0.16 in the miscanthus scenario. The mitigation measures of mixed silphie, grass-clover ley and increased crop richness led to distinct increases in hare abundance in both landscapes ( > 0.3). The results show that both landscape configuration and composition have a significant effect on hare population development, which responds particularly strongly to compositional changes. The increase in crop diversity, e.g., through the cultivation of alternative energy crops such as mixed silphie and grass-clover ley, proves to be beneficial for the brown hare. KW - agent-based modelling KW - mitigation measures KW - agriculture KW - European brown KW - hare KW - land-use change KW - Lepus europaeus Y1 - 2020 U6 - https://doi.org/10.1016/j.ecolmodel.2019.108914 SN - 0304-3800 SN - 1872-7026 VL - 416 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Wang, Ming A1 - White, Neil A1 - Grimm, Volker A1 - Hofman, Helen A1 - Doley, David A1 - Thorp, Grant A1 - Cribb, Bronwen A1 - Wherritt, Ella A1 - Han, Liqi A1 - Wilkie, John A1 - Hanan, Jim T1 - Pattern-oriented modelling as a novel way to verify and validate functional-structural plant models BT - a demonstration with the annual growth module of avocado JF - Annals of botany N2 - Background and Aims Functional-structural plant (FSP) models have been widely used to understand the complex interactions between plant architecture and underlying developmental mechanisms. However, to obtain evidence that a model captures these mechanisms correctly, a clear distinction must be made between model outputs used for calibration and thus verification, and outputs used for validation. In pattern-oriented modelling (POM), multiple verification patterns are used as filters for rejecting unrealistic model structures and parameter combinations, while a second, independent set of patterns is used for validation. Key Results After calibration, our model simultaneously reproduced multiple observed architectural patterns. The model then successfully predicted, without further calibration, the validation patterns. The model supports the hypothesis that carbon allocation can be modelled as being dependent on current organ biomass and sink strength of each organ type, and also predicted the observed developmental timing of the leaf sink-source transition stage. KW - Pattern-oriented modelling KW - agent-based model KW - individual-based model KW - functional-structural plant model KW - model analysis KW - model verification KW - model validation KW - ODD (Overview, Design concepts, Details) protocol KW - Persea americana KW - plant architecture KW - carbon allocation KW - L-systems Y1 - 2018 U6 - https://doi.org/10.1093/aob/mcx187 SN - 0305-7364 SN - 1095-8290 VL - 121 IS - 5 SP - 941 EP - 959 PB - Oxford Univ. Press CY - Oxford ER -