A new way may have been found to prevent a parasite from killing hundreds of thousands of pine trees across the country.
Nematoda, a parasite that spreads on certain types of beetles, has been found on hundreds of trees at the Jiulisong scenic spot in Hangzhou, capital of east China's Zhejiang Province
"Once pine trees are infected with nematodiasis, the beautiful scene in this area will no longer exist," said Yan Jingsong, an official with the Linyin Temple Administration in Hangzhou.
Some pine trees in the Jiulisong area have turned yellow, a warning of the arrival of the nematodiasis, a "forest cancer" known to affect pine trees, Yan said.
Located north of the West Lake in Hangzhou, the Jiulisong area is famous for its vast stretches of pine trees.
Pines there are being injected with preventative drugs to help them fight off the parasites, Yan said. The injections are effective on trees with diameters of 20-30 centimeters and can keep them free of the disease for three years.
Every pine gets three injections, with each injection costing 60 yuan (US$7.2).
Although the injections are expensive, they have proven effective to prevent the disease.
"We are trying to protect pine trees at any cost as pines in the Jiulisong area are valuable scenic resources which can not be replaced," Yan said.
The government spent 140,000 yuan (US$16,800) on protecting pine trees last year, with 200 yuan (US$24) spent on each pine tree, according to Yan.
"It is very difficult to cope with the nematodiasis as it spreads very quickly," said Jiang Ping, director of the Tree Disease Prevention and Control Quarantine Station in Zhejiang Province.
Until now, there was no effective way to prevent the disease, Jiang added.
The Jiulisong area is not the only place hit by an outbreak of the parasite.
About 92,800 hectares of pine forest areas in the Qiandaohu Lake in Zhejiang Province are in danger. Nematodiasis has been found in neighboring areas such as east China's Anhui Province, according to local officials.
Statistics show that nematodiasis was detected in more than 10 counties or cities in the whole Zhejiang Province since the disease was first found in 1991.
"Zhejiang is one of the most severely affected provinces in the country," said Jiang.
The disease has already killed more than 30 million pine trees on 26,700 hectares in the entire province and caused economic losses of no less than 10 million yuan (US$1.2 million), according to official statistics.
Besides using the drug to prevent the disease, the local government plans to plant different species in pine forests in a bid to fight pine trees' infectious character, according to officials from the Zhejiang Provincial Forestry Bureau.
Nematodiasis comes from imported lumber and spreads via artificial factors, according to Chai Ximin, an expert from the Academy of Forestry Science in Zhejiang Province.
(China Daily November 26, 2004)
