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  - GEN
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
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1351 
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  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-556943
SN  - 1866-8372
IS  - 1
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  - GEN
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
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1444 
KW  - concepts
KW  - ecosystems
KW  - ecosystem services provisioning
KW  - management
KW  - resilience
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515284
SN  - 1866-8372
IS  - 4
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  - 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  -