<scp>adapt3</scp> : Adaptive dynamics and community projection in the <i>R</i> programming language

Abstract Ecologists typically use matrix projection to understand population dynamics. Recently, they have applied matrix projection to analyse communities and evolutionary dynamics. Particularly, matrix community models (MCMs) provide a reductionist, demographic approach to the study of ecological interactions, while adaptive dynamics assess the mechanistic links between demography and evolution via invasibility analyses. Package adapt3 is an R package that applies a simple, standardized approach to community projection and adaptive dynamics. The package consists of core kernels meant to handle large and complex matrix population models (MPMs), linked via aggregate density dependence in vital rates and projected together forward in time. In adaptive dynamics, adapt3 can also be used to explore and estimate evolutionary stable strategies (ESS). We provide examples using adapt3 to replicate a previously published pairwise invasibility analysis and a matrix community model. The former assesses whether vegetative dormancy is an ESS in a North American herbaceous plant. The latter explores the possible impacts of hypothesized changes in climate on a riparian plant community. Package adapt3 is available on CRAN and can be used to study the nature and stability of ecological interactions, the mechanics of natural selection and even speciation. Further extensions will include individual‐based modelling to incorporate sexual reproduction into both approaches.