The theory of island biogeography (TIB) is arguably the closest we have to an ecological law. Its simplicity is part of its elegancy, but it comes at a cost to accuracy. The TIB is essentially a neutral model where the chance of any species to reach a patch is a probabilistic function of patch size and isolation distance. As such, the TIB ignores any constraints that species interactions might impose on colonization such as the fact that a predator cannot establish to a patch without its prey present. Because of its purely stochastic nature, the TIB is also inadequate to predict turnover in species composition on fragmented patches because all species are considered equivalent. In the lab we try to understand how trophic interactions constraint spatial dynamics of certain trophic groups, in turn, influencing the structure and functioning of local communities.
The meta-ecosystem concept postulates that flows of energy (biotic and abiotic) among ecosystems have important reciprocal effects on the community structure and ecosystem processes of all connected ecosystems. A meta-ecosystem perspective provides a clear mechanistic link among spatial dynamics, biodiversity and ecosystem function that is fundamental to our understanding of how perturbations might affect ecosystem processes over an entire landscape. The concept, however, has remained until recently only theoretical. Our work aims at developing experimental tests of the theory, especially some of the key concepts such as spatial cascade, bi-directional flows and spatial feedbacks between connected communities.
Landscape perspective on ecosystem functioning
Meta-ecosystem dynamics can couple the functioning of ecosystems over large spatial extent. Thus, although cross-ecosystem subsidies are generally very local in their direct effects, indirect effects can potentially lead to cascading effects in space. The magnitude of spatial cascades should be controlled by the movement of subsidized organisms acting as consumers (trophic meta-community dynamics), through the passive movement of altered nutrient or detritus from a subsidized location (classic meta-ecosystem theory) and finally via direct landscape constraints on cross-ecosystem subsidy and their zone of influence. A better understanding of the cause and consequences of spatial cascade is essential to scaling up local-scale ecosystem functioning to a regional level. In the lab, we develop experimental and observational approaches to understand how perturbations can spread through the landscape. This includes research on i) how varying biotic interactions in the recipient or donor ecosystem might constraint the quality/quantity of resource flows and the response of recipient communities to those resource flows (spatial cascades modulated by biotic interactions), ii) landscape configuration and how it constraints spatial cascades, iii) quantifying natural variations in cross-ecosystem subsidy across time and space - done at our beautiful university research station, iv) quantifying and predicting the distribution of stoichiometric elements in the landscape to, in turn, predict trophic structure and ecosystem functioning across the landscape (in collaboration with Shawn Leroux).
Bridging fundamental to applied science
Ecology has changed considerably over the past decades with the emergence of new methodological tools and significant conceptual advancements, but efforts to link those new developments to conservation sciences is often lacking thus breaking an important feedback loop between fundamental and applied sciences. Although research in the lab is mostly fundamental in nature, I believe it is important to make explicit the significance of new findings for conservation sciences. Those contributions often take the form of a conceptual, commentary or review paper written as a group effort, but also sometime working groups, which allow for a more direct discussion.
