TY - GEN A1 - Winkler, Eckart A1 - Heinken, Thilo T1 - Spread of an ant-dispersed annual herb : an individual-based simulation study on population development of Melampyrum pratense L. N2 - The paper presents a simulation and parameter-estimation approach for evaluating stochastic patterns of population growth and spread of an annual forest herb, Melampyrum pratense (Orobanchaceae). The survival of a species during large-scale changes in land use and climate will depend, to a considerable extent, on its dispersal and colonisation abilities. Predictions on species migration need a combination of field studies and modelling efforts. Our study on the ability of M. pratense to disperse into so far unoccupied areas was based on experiments in secondary woodland in NE Germany. Experiments started in 1997 at three sites where the species was not yet present, with 300 seeds sown within one square meter. Population development was then recorded until 2001 by mapping of individuals with a resolution of 5 cm. Additional observations considered density dependence of seed production. We designed a spatially explicit individual-based computer simulation model to explain the spatial patterns of population development and to predict future population spread. Besides primary drop of seeds (barochory) it assumed secondary seed transport by ants (myrmecochory) with an exponentially decreasing dispersal tail. An important feature of populationpattern explanation was the simultaneous estimation of both population-growth and dispersal parameters from consistent spatio-temporal data sets. As the simulation model produced stochastic time series and random spatially discrete distributions of individuals we estimated parameters by minimising the expectation of weighted sums of squares. These sums-ofsquares criteria considered population sizes, radial population distributions around the area of origin and distributions of individuals within squares of 25*25 cm, the range of density action. Optimal parameter values, together with the precision of the estimates, were obtained from calculating sums of squares in regular grids of parameter values. Our modelling results showed that transport of fractions of seeds by ants over distances of 1…2 m was indispensable for explaining the observed population spread that led to distances of at most 8 m from population origin within 3 years. Projections of population development over 4 additional years gave a diffusion-like increase of population area without any “outposts”. This prediction generated by the simulation model gave a hypothesis which should be revised by additional field observations. Some structural deviations between observations and model output already indicated that for full understanding of population spread the set of dispersal mechanisms assumed in the model may have to be extended by additional features of plant-animal mutualism. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 152 KW - Pattern-oriented parameter estimation KW - spatially explicit modelling KW - individual-based model KW - Melampyrum pratense KW - seed dispersal Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46491 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 - TY - THES A1 - Romero Mujalli, Daniel T1 - Ecological modeling of adaptive evolutionary responses to rapid climate change T1 - Ökologische Modellierung anpassungsfähiger evolutionärer Reaktionen auf schnellen Klimawandel N2 - A contemporary challenge in Ecology and Evolutionary Biology is to anticipate the fate of populations of organisms in the context of a changing world. Climate change and landscape changes due to anthropic activities have been of major concern in the contemporary history. Organisms facing these threats are expected to respond by local adaptation (i.e., genetic changes or phenotypic plasticity) or by shifting their distributional range (migration). However, there are limits to their responses. For example, isolated populations will have more difficulties in developing adaptive innovations by means of genetic changes than interconnected metapopulations. Similarly, the topography of the environment can limit dispersal opportunities for crawling organisms as compared to those that rely on wind. Thus, populations of species with different life history strategy may differ in their ability to cope with changing environmental conditions. However, depending on the taxon, empirical studies investigating organisms’ responses to environmental change may become too complex, long and expensive; plus, complications arising from dealing with endangered species. In consequence, eco-evolutionary modeling offers an opportunity to overcome these limitations and complement empirical studies, understand the action and limitations of underlying mechanisms, and project into possible future scenarios. In this work I take a modeling approach and investigate the effect and relative importance of evolutionary mechanisms (including phenotypic plasticity) on the ability for local adaptation of populations with different life strategy experiencing climate change scenarios. For this, I performed a review on the state of the art of eco-evolutionary Individual-Based Models (IBMs) and identify gaps for future research. Then, I used the results from the review to develop an eco-evolutionary individual-based modeling tool to study the role of genetic and plastic mechanisms in promoting local adaption of populations of organisms with different life strategies experiencing scenarios of climate change and environmental stochasticity. The environment was simulated through a climate variable (e.g., temperature) defining a phenotypic optimum moving at a given rate of change. The rate of change was changed to simulate different scenarios of climate change (no change, slow, medium, rapid climate change). Several scenarios of stochastic noise color resembling different climatic conditions were explored. Results show that populations of sexual species will rely mainly on standing genetic variation and phenotypic plasticity for local adaptation. Population of species with relatively slow growth rate (e.g., large mammals) – especially those of small size – are the most vulnerable, particularly if their plasticity is limited (i.e., specialist species). In addition, whenever organisms from these populations are capable of adaptive plasticity, they can buffer fitness losses in reddish climatic conditions. Likewise, whenever they can adjust their plastic response (e.g., bed-hedging strategy) they will cope with bluish environmental conditions as well. In contrast, life strategies of high fecundity can rely on non-adaptive plasticity for their local adaptation to novel environmental conditions, unless the rate of change is too rapid. A recommended management measure is to guarantee interconnection of isolated populations into metapopulations, such that the supply of useful genetic variation can be increased, and, at the same time, provide them with movement opportunities to follow their preferred niche, when local adaptation becomes problematic. This is particularly important for bluish and reddish climatic conditions, when the rate of change is slow, or for any climatic condition when the level of stress (rate of change) is relatively high. N2 - Eine aktuelle Herausforderung in der Ökologie und Evolutionsbiologie besteht darin, das Schicksal von Populationen verschiedener Lebewesen im Kontext einer sich verändernden Welt zu antizipieren. Der Klimawandel und die durch anthropologische Aktivitäten verursachten Landschaftsveränderungen sind im Laufe der Geschichte von großer Bedeutung geworden. Von den Organismen, die sich diesen Veränderungen stellen, wird erwartet, dass sie durch lokale Anpassung (d.h. genetische Veränderungen oder phänotypische Plastizität) oder durch Verschiebung ihres Verbreitungsgebietes (Migration) darauf reagieren. Allerdings sind diese Reaktionen begrenzt. So werden beispielsweise isolierte Populationen mehr Schwierigkeiten bei der Entwicklung adaptiver Neuheiten mittels genetischer Variation haben als vernetzte Metapopulationen. Ebenso kann die Topographie der Umgebung die Ausbreitungsmöglichkeiten für zum Beispiel kriechende Organismen im Vergleich zu denen, die auf Wind angewiesen sind, einschränken. So können Populationen von Arten mit unterschiedlichen Lebensstrategien verschiedene Fähigkeiten haben, mit den sich ändernden Umweltbedingungen umzugehen. Empirische Studien, die die Reaktionen von Organismen auf Umweltveränderungen untersuchen, können jedoch, je nach Taxon, zu komplex, langwierig und teuer werden. Ebenso sollten Komplikationen im Umgang mit gefährdeten Arten nicht außer Acht gelassen werden. Die ökoevolutionäre Modellierung bietet jedoch die Möglichkeit, diese Einschränkungen zu überwinden und empirische Studien zu ergänzen, die Wirkung und Grenzen der zugrunde liegenden Mechanismen zu verstehen und mögliche Zukunftsszenarien zu erstellen. In dieser Arbeit untersuche ich mittels einer Modellierungsmethode die Wirkung und relative Bedeutung evolutionärer Mechanismen (einschließlich phänotypischer Plastizität) auf die Fähigkeit zur lokalen Anpassung von Populationen mit unterschiedlichen Lebensstrategien, die Szenarien des Klimawandels durchleben. Dazu habe ich in einem Review den Stand der Technik ökoevolutionärer individuenbasierender Modelle (Individual-Based Models; IBMs) zusammengefasst und Ansätze für eine zukünftige Forschung identifiziert. Die Erkenntnisse des Reviews nutzte ich, um ein ökoevolutionäres, individuelles Modellierungsprogramm zu entwickeln. Dieses analysiert die Rolle genetischer und plastischer Mechanismen zur Förderung der lokalen Anpassung organismischer Populationen mit unterschiedlichen Lebensstrategien, welche Szenarien des Klimawandels und der ökologischen Stochastik erfahren. Die Umweltbedingungen wurden durch eine klimatische Variable (z.B. Temperatur) simuliert, die ein phänotypisches Optimum definiert, das sich mit einer bestimmten Änderungsrate bewegt. Verschiedene Änderungsraten wurden angewandt, um unterschiedliche Szenarien des Klimawandels darzustellen (keine Veränderung, langsamer, mittlerer, schneller Klimawandel). Es wurden mehrere Szenarien stochastischen Farbrauschens untersucht, die verschiedene klimatische Bedingungen widerspiegeln. Die Ergebnisse zeigen, dass Populationen sexueller Arten hauptsächlich auf genetische Variation und phänotypische Plastizität hinsichtlich lokalen Anpassung angewiesen sind. Populationen von Arten mit relativ langsamer Wachstumsrate (z.B. große Säugetiere), und insbesondere die mit kleiner Populationsgröße, sind am anfälligsten, vor allem wenn ihre Plastizität begrenzt ist (d.h. spezialisierte Arten). Wenn Individuen dieser Populationen zu adaptiver Plastizität fähig sind, können sie Fitnessverluste unter „rötlichen“ Klimabedingungen ausgleichen. Zugleich können diese Populationen durch Anpassung der Plastizität auch unter bläulichen Umweltbedingungen zurecht kommen (z.B. Bed-Hedging-Strategie). Im Gegensatz dazu können sich Lebensstrategen mit hoher Reproduktionszahl auf nicht-adaptive Plastizität zur lokalen Anpassung an neue Umweltbedingungen verlassen, es sei denn, die Änderungsrate ist zu schnell. Eine empfohlene Handlungsmaßnahme ist es, die Eingliederung von isolierten Populationen in Metapopulationen zu gewährleisten, so dass die genetische Variation erhöht werden kann. Wenn eine lokale Anpassung problematisch wird, sollte ihnen gleichzeitig Migrationsfreiraum gegeben werden, um ihrer bevorzugten Nische zu folgen. Dies ist besonders wichtig für „bläuliche“ und „rötliche“ Klimabedingungen, bei denen die Änderungsrate langsam ist, oder für jede klimatische Bedingung, wenn die Belastung (Änderungsrate) relativ hoch ist. KW - climate change KW - local adaptation KW - plasticity KW - evolution KW - individual-based model KW - Klimawandel KW - lokale Anpassung KW - Plastizität KW - Evolution KW - Individuen-basierende Modelle Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-430627 ER - TY - JOUR A1 - Radchuk, Viktoriia A1 - De Laender, Frederik A1 - Cabral, Juliano Sarmento A1 - Boulangeat, Isabelle A1 - Crawford, Michael Scott A1 - Bohn, Friedrich A1 - De Raedt, Jonathan A1 - Scherer, Cedric A1 - Svenning, Jens-Christian A1 - Thonicke, Kirsten A1 - Schurr, Frank M. A1 - Grimm, Volker A1 - Kramer-Schadt, Stephanie T1 - The dimensionality of stability depends on disturbance type JF - Ecology letters N2 - Ecosystems respond in various ways to disturbances. Quantifying ecological stability therefore requires inspecting multiple stability properties, such as resistance, recovery, persistence and invariability. Correlations among these properties can reduce the dimensionality of stability, simplifying the study of environmental effects on ecosystems. A key question is how the kind of disturbance affects these correlations. We here investigated the effect of three disturbance types (random, species-specific, local) applied at four intensity levels, on the dimensionality of stability at the population and community level. We used previously parameterized models that represent five natural communities, varying in species richness and the number of trophic levels. We found that disturbance type but not intensity affected the dimensionality of stability and only at the population level. The dimensionality of stability also varied greatly among species and communities. Therefore, studying stability cannot be simplified to using a single metric and multi-dimensional assessments are still to be recommended. KW - Community model KW - disturbance intensity KW - disturbance type KW - extinction KW - individual-based model KW - invariability KW - persistence KW - recovery KW - resistance Y1 - 2019 U6 - https://doi.org/10.1111/ele.13226 SN - 1461-023X SN - 1461-0248 VL - 22 IS - 4 SP - 674 EP - 684 PB - Wiley CY - Hoboken 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 - Martin, Benjamin T. A1 - Jager, Tjalling A1 - Nisbet, Roger M. A1 - Preuss, Thomas G. A1 - Grimm, Volker T1 - Predicting population dynamics from the properties of individuals - a cross-level test of dynamic energy budget theory JF - The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences N2 - Individual-based models (IBMs) are increasingly used to link the dynamics of individuals to higher levels of biological organization. Still, many IBMs are data hungry, species specific, and time-consuming to develop and analyze. Many of these issues would be resolved by using general theories of individual dynamics as the basis for IBMs. While such theories have frequently been examined at the individual level, few cross-level tests exist that also try to predict population dynamics. Here we performed a cross-level test of dynamic energy budget (DEB) theory by parameterizing an individual-based model using individual-level data of the water flea, Daphnia magna, and comparing the emerging population dynamics to independent data from population experiments. We found that DEB theory successfully predicted population growth rates and peak densities but failed to capture the decline phase. Further assumptions on food-dependent mortality of juveniles were needed to capture the population dynamics after the initial population peak. The resulting model then predicted, without further calibration, characteristic switches between small-and large-amplitude cycles, which have been observed for Daphnia. We conclude that cross-level tests help detect gaps in current individual-level theories and ultimately will lead to theory development and the establishment of a generic basis for individual-based models and ecology. KW - population dynamics KW - dynamic energy budget theory KW - bioenergetics KW - individual-based model Y1 - 2013 U6 - https://doi.org/10.1086/669904 SN - 0003-0147 VL - 181 IS - 4 SP - 506 EP - 519 PB - Univ. of Chicago Press CY - Chicago ER - TY - JOUR A1 - Grimm, Volker A1 - Berger, Uta A1 - Bastiansen, Finn A1 - Eliassen, Sigrunn A1 - Ginot, Vincent A1 - Giske, Jarl A1 - Goss-Custard, John A1 - Grand, Tamara A1 - Heinz, Simone K. A1 - Huse, Geir A1 - Huth, Andreas A1 - Jepsen, Jane U. A1 - Jorgensen, Christian A1 - Mooij, Wolf M. A1 - Mueller, Birgit A1 - Piou, Cyril A1 - Railsback, Steven Floyd A1 - Robbins, Andrew M. A1 - Robbins, Martha M. A1 - Rossmanith, Eva A1 - Rueger, Nadja A1 - Strand, Espen A1 - Souissi, Sami A1 - Stillman, Richard A. A1 - Vabo, Rune A1 - Visser, Ute A1 - DeAngelis, Donald L. T1 - A standard protocol for describing individual-based and agent-based models JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Simulation models that describe autonomous individual organisms (individual based models, IBM) or agents (agent-based models, ABM) have become a widely used tool, not only in ecology, but also in many other disciplines dealing with complex systems made up of autonomous entities. However, there is no standard protocol for describing such simulation models, which can make them difficult to understand and to duplicate. This paper presents a proposed standard protocol, ODD, for describing IBMs and ABMs, developed and tested by 28 modellers who cover a wide range of fields within ecology. This protocol consists of three blocks (Overview, Design concepts, and Details), which are subdivided into seven elements: Purpose, State variables and scales, Process overview and scheduling, Design concepts, Initialization, Input, and Submodels. We explain which aspects of a model should be described in each element, and we present an example to illustrate the protocol in use. In addition, 19 examples are available in an Online Appendix. We consider ODD as a first step for establishing a more detailed common format of the description of IBMs and ABMs. Once initiated, the protocol will hopefully evolve as it becomes used by a sufficiently large proportion of modellers. (c) 2006 Elsevier B.V. All rights reserved. KW - individual-based model KW - agent-based model KW - model description KW - scientific communication KW - standardization Y1 - 2006 U6 - https://doi.org/10.1016/j.ecolmodel.2006.04.023 SN - 0304-3800 VL - 198 SP - 115 EP - 126 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Dalleau, Mayeul A1 - Kramer-Schadt, Stephanie A1 - Gangat, Yassine A1 - Bourjea, Jerome A1 - Lajoie, Gilles A1 - Grimm, Volker T1 - Modeling the emergence of migratory corridors and foraging hot spots of the green sea turtle JF - Ecology and evolution N2 - Environmental factors shape the spatial distribution and dynamics of populations. Understanding how these factors interact with movement behavior is critical for efficient conservation, in particular for migratory species. Adult female green sea turtles, Chelonia mydas, migrate between foraging and nesting sites that are generally separated by thousands of kilometers. As an emblematic endangered species, green turtles have been intensively studied, with a focus on nesting, migration, and foraging. Nevertheless, few attempts integrated these behaviors and their trade‐offs by considering the spatial configurations of foraging and nesting grounds as well as environmental heterogeneity like oceanic currents and food distribution. We developed an individual‐based model to investigate the impact of local environmental conditions on emerging migratory corridors and reproductive output and to thereby identify conservation priority sites. The model integrates movement, nesting, and foraging behavior. Despite being largely conceptual, the model captured realistic movement patterns which confirm field studies. The spatial distribution of migratory corridors and foraging hot spots was mostly constrained by features of the regional landscape, such as nesting site locations, distribution of feeding patches, and oceanic currents. These constraints also explained the mixing patterns in regional forager communities. By implementing alternative decision strategies of the turtles, we found that foraging site fidelity and nesting investment, two characteristics of green turtles' biology, are favorable strategies under unpredictable environmental conditions affecting their habitats. Based on our results, we propose specific guidelines for the regional conservation of green turtles as well as future research suggestions advancing spatial ecology of sea turtles. Being implemented in an easy to learn open‐source software, our model can coevolve with the collection and analysis of new data on energy budget and movement into a generic tool for sea turtle research and conservation. Our modeling approach could also be useful for supporting the conservation of other migratory marine animals. KW - connectivity KW - corridors KW - individual-based model KW - migration KW - movement KW - sea turtle Y1 - 2019 U6 - https://doi.org/10.1002/ece3.5552 SN - 2045-7758 VL - 9 IS - 18 SP - 10317 EP - 10342 PB - Wiley CY - Hoboken 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 - THES A1 - Buchmann, Carsten M. T1 - Modelling the structuring of animal communities in heterogeneous landscapes : the role of individual home range formation, foraging movement, competition and habitat configuration T1 - Modellierung zur Strukturierung von Tiergemeinschaften in heterogenen Landschaften : die Bedeutung von individuellen Aktionsräumen, Bewegung, Konkurrenz und Habitatkonfiguration N2 - This thesis aims at a better mechanistic understanding of animal communities. Therefore, an allometry- and individual-based model has been developed which was used to simulate mammal and bird communities in heterogeneous landscapes, and to to better understand their response to landscape changes (habitat loss and fragmentation). N2 - Diese Doktorarbeit strebt ein besseres mechanistisches Verständnis von Tiergemeinschaften an. Dafür wurde ein allometrie- und individuen-basiertes Modell entwickelt und dazu benutzt, Säugetier- und Vogelgemeinschaften in heterogenen Landschaften zu simulieren, und ihre Reaktion auf Landschaftsveränderungen (Habitatverlust und -fragmentierung) besser zu verstehen. KW - Allometrie KW - Aktionsraum KW - Artengemeinschaft KW - Bewegung KW - Modell KW - home range KW - allometry KW - individual-based model KW - allometry KW - community Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-59031 ER -