The feasibility principle in community ecology

Serguei Saavedra

The structure and function of ecological communities emerge from the interactions among populations within specific environmental contexts. Yet, it remains unclear whether general principles can explain the patterns and transitions of ecological communities across diverse settings. Identifying such principles is crucial for guiding conservation and restoration efforts aimed at mitigating the negative impacts of anthropogenic effects on biodiversity. To address this challenge, I propose the feasibility principle in community ecology. Grounded in a synthesis of theoretical work and empirical studies, this principle is articulated through three core hypotheses: (i) each ecological community possesses a feasibility domain—that is, a range of environmental conditions under which it can persist—determined by a time-specific, invariant internal structure; (ii) the likelihood of observing a particular community in nature is proportional to the size of its feasibility domain that aligns with local environmental conditions; and (iii) the probability of transitioning between two communities is inversely proportional to differences in their feasibility domains compatible with local environmental contexts. I summarize how the feasibility principle can be studied under a quantitative framework and contrasted with empirical data across a wide diversity of organisms and contexts. In the face of rapid climate change and habitat modification, I discuss how the feasibility principle can be used to assess the challenges and opportunities for community restoration.