But the expansion of rubber production will continue to come at the expense of the area's ecosystem, which XTBG researchers say has quickly deteriorated during the last 10 years as demand for rubber has soared. The rubber trees suck up huge amounts of water, cause soil erosion and reduce the area's biodiversity. The pesticides used on the trees run off into local water supplies used by villages. Ecologists also believe that deforestation is partly responsible for an overall temperature increase in the area.

The most concern has come from the XTBG, which ironically got its start from the government's efforts to plant rubber trees here. In recent years, researchers have suggested that the government limit new rubber plantations to land currently used for other crops.

Local officials in Xishuangbanna Prefec-ture have taken notice. Last month, they were hammering out a regulatory plan to restore the area's ecosystem, increase controls over forestland in protected corridors, and restore others in buffer zones of national nature reserves that have been converted to rubber farms, according to Nature.

But such plans could have little impact, because the commodity's high demand and price will continue to be the main incentives for farmers and state-owned enterprises to grow rubber trees. Meanwhile, the Asian Development Bank has stepped in with a pilot project that seeks to increase villagers' ecological awareness and help them better manage their land. The project also provides microcredit funds to villagers in the Greater Mekong Subregion, including Xishuangbanna, if they set up new protected zones in their areas.

The writer is an American who lives and works in Beijing