VULNERABILITY OF ISLAND TROPICAL MONTANE CLOUD FORESTS TO CLIMATE-CHANGE, WITH SPECIAL REFERENCE TO EAST MAUI, HAWAII

Island tropical montane cloud forests may be among the most sensitive of the world's ecosystems to global climate change. Measurements in an d above a montane cloud forest on East Maul, Hawaii, document steep mi croclimatic gradients. Relatively small climate-driven shifts in patte rns of atmospheric circulation are likely to trigger major local chang es in rainfall, cloud cover, and humidity. Increased interannual varia bility in precipitation and hurricane incidence would provide addition al stresses on island biota that are highly vulnerable to disturbance- related invasion of nonnative species. Because of the exceptional sens itivity of these microclimates and forests to change, they may provide valuable 'listening posts' for detecting the onset of human-induced g lobal climate change.