Climate-induced changes in forest disturbance and vegetation

RECENT concern over the ecological effects of future trace-gas-induced climate change has accelerated efforts to understand and quantify climate-induced vegetation change^1-9. Here we discuss new and published climate-model results indicating that global warming favours increased rates of forest disturbance, as a result of weather more likely to cause forest fires (drought, wind and natural ignition sources), convective wind storms, coastal flooding and hurricanes. New sensitivity tests carried out with a vegetation model indicate that climate-induced increases in disturbance could, in turn, significantly alter the total biomass and compositional response of forests to future warming. An increase in disturbance frequency is also likely to increase the rate at which natural vegetation responds to future climate change. Our results reinforce the hypothesis⁶ that forests could be significantly altered by the first part of the next century. Our modelling also confirms the potential utility of selected time series of fossil pollen data for investigating the poorly understood natural patterns of century-scale climate variability.