Rat infestations that have been severely threatening the ecological environment in Qinghai will be tackled with a special 7.5 billion yuan (US$925 million) fund.

The money from the central government will also be used for a range of projects, including water conservation and the relocation of farmers as part of an ecological protection drive in the inland province in northwest China.

It will help protect the wetlands in the province, which are the highest and largest in the world, according to sources with Qinghai provincial government.

The local government and residents will make joint efforts to fight the rat infestations, which have been a major problem in the giant Sanjiangyuan Nature Reserve for several years.

The Sanjiangyuan area, located by the Qinghai-Tibet Plateau with a total area of 363,000 square-kilometer, is where China's three major rivers the Yangtze River, the Yellow River and the Lancang River are originated.

Since the early 1990s, rat colonies have destroyed large areas of grassland in the region, which exacerbated the deterioration of the ecological environment.

Official statistics show that 6.44 million hectares of grassland, 33 per cent of the total useable in the Sanjiangyuan region, have been damaged by rodents.

In some counties in the region, up to 70 per cent of grassland has been harmed by rats.

"The rat disaster in the Sanjiangyuan region is huge, with the population of rodents increasing sharply," said Sanzhi Caidan, an engineer with Qinghai Provincial Grassland Protection Station.

Sanzhi Caidan said that the rats not only eat grass leaves and roots, but also dig holes and turn up soil, which turns the grassland into wasteland.

Ban Duo, a herdsman living in the region's Guoluo Tibet Autonomous Prefecture, said that the dry weather, number of rats and desertification in recent years had decreased his husbandry production, causing his family great hardship.

According to local pest control experts and technicians, efforts made to kill the rats in the past few years were unsuccessful because the rodents have strong migrant and reproduction abilities.

Poison used to kill the rats have gradually made them resistant to the chemicals, but, more importantly, ended up killing the rats' natural predators.

Experts suggest more efforts should be made to develop better poisons or methods which can kill the rodents, but not harm other animals and the environment.

At the same time, ecological deterioration has also been caused in the region as a result of global warming and the impact of human activities in recent years.

"By the end of 2010, a number of protection projects will be completed, including reducing husbandry on grassland, rodent pest control, soil and water conservation, and the relocation of farmers and herdsmen for ecological protection," said Chen Shiqing, deputy director of Qinghai Agriculture and Husbandry Bureau.

(China Daily March 3, 2006)