Chesson's coexistence theory: reply.

Abstract

Chesson's (2019) comment on our review of modern coexistence theory (Barabás et al. 2018) focuses on perceived mistakes and provides a re-derivation of key results from his own perspective. The criticisms concern three main issues: the definition of standardized environmental and interaction parameters; the definition of comparison quotients and the meaning of their non-uniqueness; and the status of the theory when there are at least as many limiting factors as species in the system. He makes many important observations, and the provision of his own derivation of the theory gives a unique perspective on what elements of the theory are deemed important and why. Additionally, Chesson (2019) mentions in passing several elements of our review which he believes are not handled well. However, we argue that the differences between Chesson's (2019) account of the theory and ours are overstated, turning out to be differences of emphasis and interpretation, rather than fundamental mistakes. We therefore take this opportunity to clarify our point of view, and to synthesize Chesson's perspective with ours for an improved outlook on the theory.