Webs of Interaction Networks: feedbacks between the spatial connectivity and the functioning of food webs – WINE

Land-use changes, habitat destruction and habitat fragmentation are among the most important drivers of the current biodiversity crisis. While species-centred approaches have helped develop potential remediation strategies against the decline of endangered species, they are clearly insufficient given the complexity of ecological interactions and the potential for these interactions to amplify or attenuate anthropogenic ecological damage.
The general goal of the WINE project is to understand how spatial connectivity affects ecological interactions in meta-ecosystems by altering the movement of organisms and their resources, and, conversely, how ecological interactions affect effective spatial connectivity within landscapes by altering the space use of organisms and their associated impact on their resources. These feedbacks between spatial connectivity and ecological interactions are likely to take place at different spatial and temporal scales, and determine the properties of ecosystems.
To achieve a better understanding of these processes, we propose to conduct both theoretical and empirical research by developing predictive models, using microcosm experiments, and analysing large existing datasets on spatial food webs. This integrated approach should enhance our understanding of the mechanisms at work in the functioning of spatial food webs. The WINE project brings together six laboratories with complementary expertise, enabling the research proposed for these three lines of inquiry to be carried out.
We will start the modelling activities by developing a meta-food web model to understand how the structure of the underlying spatial web affects the properties of local food webs. We will then extend this model by considering the evolutionary dynamics of food webs in response to the spatial network and environmental heterogeneity, notably via the size and dispersal abilities of species. Finally, we will distinguish between foraging and dispersal movements to better understand the consequences of different types of movement for the connectivity of meta-ecosystems and their dynamics.
Experiments on protists in microcosms will allow us to test some of the model predictions. First, we will measure effective connectivity as a function of the complexity of the food webs used. Then, we will explore the link between spatial network complexity and local food web properties. We will combine this with a gradient of environmental heterogeneity. Finally, we will study the evolution of the manipulated species to understand how the spatial network affects their dispersal abilities.
The study of existing datasets on food webs in rivers, lakes, coral reefs, and agricultural landscapes will allow us to explore some of the predictions of the developed models. A first step will be to complete the datasets, mainly through the acquisition of the spatial networks involved. These data sets will first be explored to analyse how spatial structure and environmental heterogeneity affect local food webs. In a second step, we will focus on the link between spatial network and meta-network properties and explicitly compare the effects observed between dendritic (river-like) and planar (grassland-like) networks.
Armed with such fundamental knowledge, we believe that the management and restoration of ecosystems in response to human impacts will better handle the complexity of species interactions.