Future forest composition under a changing climate and adaptive forest management in southeastern Vermont, USA

Abstract

Global change represents the greatest challenge facing forest managers today. The uncertainty and variability of potential future impacts of shifting climatic and disturbance regimes has led resource managers to seek out alternative approaches to sustain the long-term delivery of forest ecosystem services. We use a spatially explicit forest landscape simulation model, LANDIS-II, to examine and evaluate a range of long-term effects of current and adaptive forest management under three projected climate scenarios within a forested landscape in southeastern Vermont, USA. We found that land-use legacies and the inertia associated with long-term forest successional trajectories are likely to be the dominant driver of future forest composition and biomass conditions for the next 100 years. Nevertheless, climate is projected to have a greater influence on species composition and aboveground biomass over the next 200 years. Eastern hemlock (Tsuga canadensis) and red spruce (Picea rubens) are likely to experience reductions in aboveground biomass and a compression of relative dominance on the landscape. American beech (Fagus grandifolia) and sugar maple (Acer saccharum) are projected to persist within the landscape and are likely to continue to occupy a prominent compositional position in the forests of this region. Extreme climate warming under RCP 8.5 projections resulted in compositional shifts and reductions in landscape-scale aboveground biomass (120.09 ± 4.51 Mg·ha-1) at the end of the 200 year simulation when compared to RCP 4.5 (150.55 ± 1.04 Mg·ha-1) and current climate projections (147.90 ± 0.79 Mg·ha-1). These findings highlight the expected lag effects of a changing climate, which present significant challenges and opportunities as managers seek to sustain critical ecosystem services in the region.