PNNL

Abstract

Forest dynamics arise from the interplay of disturbances with the demographic processes of recruitment, growth, and mortality, and drive the biomass and species composition of terrestrial ecosystems. However, forest disturbances and associated succession are shifting with global changes, altering vegetation dynamics. We reviewed the literature of forest demographic responses to drivers and disturbances to generate hypotheses on future trajectories of these factors and their subsequent impacts on vegetation dynamics. Ongoing changes in both environmental drivers and disturbance regimes are forcing forests towards shorter and younger stands, reducing carbon storage, and impacting biodiversity. Rising CO2, acclimation, adaptation, and migration may partially mitigate these impacts. Recent developments now allow Earth System Models to simulate vegetation dynamics, but many uncertainties and challenges must be overcome to ensure accurate prediction. Pervasive shifts in forest vegetation dynamics are already occurring and are likely to accelerate under future global changes, with large carbon cycle consequences.