LHASA - Southwest China's Tibetan wetland system, the country's largest, maintained sound development thanks to a series of protective measures put in place over the past five years, local authorities said.

Wetland preservation has become an important part of the autonomous region's envrionmental protection drive, with five state-level wetland parks established in the region, said Tibet's forestry bureau chief Lei Guilong.

Another two wetlands - the Maidika marshes and Lake Manasarovar - are listed on the Ramsar Convention, or the Convention on Wetlands of International Importance, he said. Tibet also has eight regional-level wetland reserves.

A new law on Tibetan wetland conservation became effective in March this year, banningthe?unauthorized exploitation of all wetland resources, discharges of waste and collection of birds' eggs.

The law also requires forestry authorities to keep wetlands from deteriorating by supplying sufficient water, prohibiting herding and closing some of the more fragile wetland areas.

Tibet has six million hectares of wetlands, about 10 percent of China's total, and they are home to rare species like the Tibetan antelope and ?black-necked cranes, according to the forestry bureau.

The plateau region's wetland system includes 2.5 million hectares of lakes, 3.2 million hectares of swamps and 264,000 hectares of rivers.