Deforestation is one of the most serious threats to biodiversity in developing countries. It causes floods, soil erosion and disease (owing to the loss of organisms that help to control vector populations), degrades watersheds and destroys wildlife habitats. Deforestation may extirpate populations and reduce genetic diversity within populations (Kanowski 1999). In northern Thailand, large areas in national parks and wildlife sanctuaries have been deforested. Government and non-governmental organizations and local communities must all be involved in the reforestation and restoration of these forests.