Invasions (and extinctions) in ecological communities : the role of invasion fitness and feedbacks
Invasions (and extinctions) in ecological communities: the role of invasion fitness and feedbacks
Theory in ecology and evolution often relies on the analysis of invasion processes, and general approaches exist to understand the early stages of an invasion. However, predicting the long-term transformations of communities following an invasion remains challenging. I will describe some theoretical work that uses the density dependence of an invading population's growth rate to predict if the invasion will cause large long-term impacts on the invaded community, such as irreversible compositional shifts. We will see that the density dependence of the invasion growth rate is as much a property of the invading population as it is one of the invaded community, which will allow us to clarify the conditions for abrupt community shifts along smooth environmental gradients, triggered by invasions or extinctions. All in all, this theoretical work directs us towards new questions that may enrich the toolset of invasion analysis (for both ecology and evolution), and suggests that indirect interactions and dynamical stability are key determinants of invasion outcomes.