Introduction
The societies of mainland Southeast Asia Vietnam , Laos , Cambodia ,Thailand , and Yunnan province of China share a unique upland ecoregion that is under intense pressure from demographic changes , lowland-driven development priorities , and regional infrastructure schemes. Policies to preserve the rich biodiversity of the uplands , protect remaining forests , and reforest denuded hills have largely failed ,depriving the entire region of water and carbon regulation and other services provided by intact ecosystems. Together , these factors have further impoverished upland populations.