Extinction Risk from Climate Change in Tropical Forests

Abstract

Tropical forests are biologically the richest biomes on Earth, home to half of global biodiversity and most of the insects described in the previous chapter. The prospects for the earth’s treasure of living organisms over this century are thus inevitability tied to the prospects of its greatest treasure houses, the tropical rain forest regions, whether influenced by deforestation or climate change. The extinction risk in tropical forests will have a large effect on total global extinction risk, but like that of insects is currently difficult to quantify because of several key unknowns. This chapter explores the nature of contemporary and likely future climate change in the tropics, and possible implications for the biodiversity and functioning of tropical ecosystems. It begins by reviewing the likely nature of tropical climate change, then explores the likely response of tropical organisms to such change. It highlights key uncertainties in estimation of extinction risk from climate change, including the likely pattern of precipitation change, the influence of carbon dioxide on forest persistence, the upper thermal tolerance and adaptation/acclimation ability of tropical organisms, and the relationship between habitat restriction and extinction risk.