Archive | 2021
A new framework to understand context dependence of two-species population dynamics: A case study of rocky intertidal sessile assembly
Abstract
How population dynamics depend on changes in the environment is a\nclassic but important question in ecology. We propose a new framework to\nunderstand the context dependence of the mechanism driving two-species\npopulation dynamics, in which we use intrinsic growth rates as a proxy\nfor environmental suitability, then assess how the strengths of intra-\nand interspecific density dependence in a two-species system change\ndepending on environmental suitability. By using census data for\npairwise sessile species on a rocky intertidal shore, collected over 18\nyears, we showed that the strength of both intra- and interspecific\ndensity dependence decreased as the environmental suitability of the\nfocal species increased, but was scarcely affected by the environmental\nsuitability of the other species. Combining this framework with modern\ncoexistence theory could provide a deeper understanding of coexistence\nmechanisms and context-dependence in two-species systems.