CLIMATE-CHANGE ON MEXICAN FORESTS AND NATURAL PROTECTED AREAS

In order to determine the vulnerability of Mexican forest ecosystems,n atural protected and forestry areas to climate change, an assessment w as performed under two climate change scenarios generated by the Canad ian Climate Center (CCC) and the Geophysical Fluid Dynamics Laboratory (GFDL) models. Based on Holdridge's life zones and local classificati ons, the results suggest that the most vulnerable life zones would be temperate cold and warm forests, mainly due to the increase in tempera ture. Tropical dry, very dry and thorn forests would enlarge their cur rent area coverage under the climate change CCC scenario, while under the GFDL scenario increases in the distribution of tropical humid and wet forests would occur. For some ecosystems, such as tropical forest, climate change is a minor threat compared to the degradation currentl y induced by human activities, A current land-use assessment indicates that, in the recent years, the ecosystems most affected by human acti vities are the tropical forests due to the expansion of grasslands for tropical cattle ranching, Man-induced forest fires, to increase pastu re production, are the main cause of degradation in temperate forests. The natural protected areas most affected by climate change would be the northern and western regions of the country, as well as the southe rn tropical mountains where an important number of endemic plants exis t. On the other hand, forestry areas that would be most affected are l ocated in the Sierra Madre Occidental, where timber exploitation in co niferous forests is high. (C) 1998 Elsevier Science Ltd. All rights re served.