Anthropogenic disturbances greatly alter community composition and
diversity. However, it remains largely unknown which underlying
processes - colonizations, local extinctions or abundance changes -
drive compositional changes in response to disturbance, and whether
these processes are constrained by environmental gradients. Here, we
investigated the processes underlying temporal turnover of vascular
plant communities in boreal forests in response to silvicultural
practices along a soil fertility gradient. Our analyses were based on
long-term data from 1985 to 2006 covering up to 1700 sites across
Finland. While average richness remained static, we found that
silvicultural practices induced greatest turnover in the most fertile
habitats. In recently disturbed sites, colonizations and species losses
altered dominance structure of the communities, while the undisturbed
old forests were characterized by stable dominant species even when the
majority of species shifted their identity. We conclude that disturbance
history and fertility constrain temporal turnover in boreal forest
communities.