Joint variation in intrinsic growth and density dependence provides insight into context-dependent competition in a rocky intertidal two-species system

This repository contains data and R code for examining spatial variation in density dependence between the barnacle Chthamalus dalli and the red alga Gloiopeltis furcata in rocky intertidal communities of eastern Hokkaido, Japan. The study uses an 18-year record (2002–2019) from 33 quadrats. Included are species abundance data, JAGS input data, posterior median estimates of demographic parameters, and a dataset combining these estimates with environmental predictors. The R scripts implement a two-species Gompertz state-space model, piecewise structural equation modelling, and dominance analysis to assess associations among environmental conditions, intrinsic growth rates, and strengths of intra- and interspecific density dependence.