Understanding the effect of environmental change on the functioning of interconnected ecological communities.

• Applicant: Dr. Angelos Amyntas
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems ; Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 580974935

Changes of the abiotic environment, such as temperature increase, can affect community-level functions, such as primary productivity. Two broad lines of research in ecology have focused, respectively, on the effects of local environmental change on species composition and diversity, and on the effect of species diversity or composition on ecosystem functioning. Combined, these two perspectives view changes in composition as the primary mediator of the effects of environmental change on ecosystem function. However, temperature change (directional or even seasonal), primarily alters species’ intrinsic rates (gross productivity and respiration), then restructures species interactions and ultimately reshapes community-level processes like productivity. Furthermore, local environments are neither homogeneous nor spatially isolated, so the influence of environmental change can spill over across space. I will develop a series of theoretical models emphasizing this perspective of environmental change effects on functioning. First, I will focus on the temperature dependence of competitive interactions and the implications of competitive asymmetry for community productivity under gradually increasing temperature. Competition among species relying on shared resources is inherently asymmetric, due to differences in acquisition rate. The latter is temperature dependent; therefore, asymmetric competition itself changes with changing temperature. Competitive asymmetry and its reliance on the biotic environment has been ignored in models that examine how changing environmental conditions affect multi-species communities. This work will serve as a foundation for the two subsequent projects, both examining spatial aspects of environmental change effects on community productivity. I will first expand the previous model into a metacommunity model and use it to examine the role of structure (i.e. restricted biomass flow among patches) and heterogeneity (i.e. patch-specific variation around an average temperature) of the environment on community productivity under seasonally fluctuating temperature. In the final project, communities will be positioned on a latitudinal gradient (from warmer to colder regions) and can be connected by dispersal. The location of a community along the gradient will also determine the rate of warming under climate change (faster near the pole). Dispersal may then determine whether declines in productivity due to lower performance of resident species can be compensated by species that successfully establish if the changing local conditions allow them to. Together, the aim of the three projects is to generate empirically testable hypotheses on environmental change effects on the productivity of interconnected communities.

• DFG Programme: Position