Communities, ecosystem engineers, and functional domains

Communities are shaped by the activity of ecosystem engineers, which modify their environment to their benefit and that of subordinate species within their functional domain. Communities are defined as embedded assemblages of interactions, from cells to landscapes. They are threatened by present-day global changes which trigger the invasive nature of ecological engineers, with cascading effects. This perspective paper starts with a definition of ecosystem engineers and functional domains in the frame of developments in community ecology. Then I show that the concepts of ecosystem engineer and functional domain explain (i) most of the observed cases of community boundaries, and (ii) the passage from small-scale interactions among individuals to community-wide processes of dynamics and stability. I will further show that ecological engineering exists at various scales, from viruses to landscapes, functional domains being embedded in a flexible manner. At last, I will show that threats posed by global changes to communities are mainly mediated by their negative or positive effects on ecosystem engineers.