Stochastic and deterministic effects on interactions between canopy and recruiting species in forest communities

1. Interactions between established (canopy) and recruiting individuals (recruits) are pervasive in plant communities. Studies on recruitment in forests have mainly focused on negative density-dependent conspecific interactions, while the outcomes of heterospecific canopy-recruit interactions have received much less attention and are generally assumed to be driven by stochastic processes. 2. Herein, we explore the relative influence of stochastic (abundance) and deterministic (species identity and phylogenetic distance) effects on the frequency of canopy-recruit interactions, and characterise the interactions in terms of their spatial consistency and effect on recruitment (depressing, neutral or enhancing). 3. In 12 plots (50  50 m) of mixed pine-oak forests in Southern Spain we identified all saplings recruiting beneath 56 shrub and tree species, and in open areas not covered by woody plants. We used generalised linear mixed models to investigate the influence of stochastic and determ...