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The function-dominance correlation drives the direction and strength of biodiversity-ecosystem functioning relationships

2021, Crawford, Michael S., Barry, Kathryn E., Clark, Adam T., Farrior, Caroline E., Hines, Jes, Ladouceur, Emma, Lichstein, Jeremy W., Maréchaux, Isabelle, May, Felix, Mori, Akira S., Reineking, Björn, Turnbull, Lindsay A., Wirth, Christian, Rüger, Nadja

Community composition is a primary determinant of how biodiversity change influences ecosystem functioning and, therefore, the relationship between biodiversity and ecosystem functioning (BEF). We examine the consequences of community composition across six structurally realistic plant community models. We find that a positive correlation between species' functioning in monoculture versus their dominance in mixture with regard to a specific function (the "function-dominance correlation") generates a positive relationship between realised diversity and ecosystem functioning across species richness treatments. However, because realised diversity declines when few species dominate, a positive function-dominance correlation generates a negative relationship between realised diversity and ecosystem functioning within species richness treatments. Removing seed inflow strengthens the link between the function-dominance correlation and BEF relationships across species richness treatments but weakens it within them. These results suggest that changes in species' identities in a local species pool may more strongly affect ecosystem functioning than changes in species richness.

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Adaptive behaviour in a predator-prey model leads to multiple equilibrium states

2014, Pimenov, Alexander, Korobeinikov, Andrei, Rachinskii, Dmitrii

There is evidence that multiple stable equilibrium states are possible in real-life ecological systems. In order to verify a hypothesis that such a multitude of equilibrium states can be caused by adapting of animal behaviour to changes of environmental conditions, we consider a simple predator-prey model where prey changes a mode of behaviour in response to the pressure of predation. This model exhibits two stable coexisting equilibrium states with basins of attraction separated by a separatrix of a saddle point.

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Survival and complete convergence for a spatial branching system with local regulation

2006, Birkner, Matthias, Depperschmidt, Andrej

We study a discrete time spatial branching system on Zd with logistic-type local regulation at each deme depending on a weighted average of the population in neighbouring demes. We show that the system survives for all time with positive probability if the competition term is small enough. For a restricted set of parameter values, we also obtain uniqueness of the non-trivial equilibrium and complete convergence, as well as long-term coexistence in a related two-type model.