Chinese scientists are fighting an uphill battle to conserve biodiversity in the Three Gorges area, and reduce hazards to the ecosystem, scientists said at the Third World Botanic Gardens Congress in Wuhan, central China on Friday.

"Human activities and unchecked development degrade the environment and often destroy plant habitats, especially the habitats of rare and endangered species," said Professor Stephen Blackmore, director of the Royal Botanic Garden Edinburgh. "Large projects have a massive impact on local ecology."

There are more than 200 rare and endangered species in the Three Gorges area. Myricaria laxiflora, unique to the area, is a plant which helps conserve soil on river banks and dams. But it will be submerged when the water level in the Three Gorges reservoir reaches 175 meters.

Scientists at the Wuhan Botanic Garden (WBG) with the Chinese Academy of Sciences (CAS) have transplanted the species to the botanic garden and reproduced more than 30,000 individual plants.

Besides ex situ conservation, WBG scientists also set up seed banks, and froze the gene, farina and other parts of the species for long-term preservation.

"Our institute has conserved about 80 percent of the endangered plant species in the Three Gorges," said Dr Wu Jinqing with the WBG.

"Protecting plants in the Three Gorges is an arduous, long-term task, but China has set a good example," said Dr. Mikhail Romanov of the Department of Dendrology of the Main Botanic Garden, Russian Academy of Sciences.

Many areas where large projects have been built are key areas for conserving biodiversity, said Huang Hongwen, director of the Wuhan Botanic Garden.

Huang said that China issued the China Strategy for Plant Conservation this year to respond to the Global Strategy for Plant Conservation, and issued laws and regulations to prevent the destruction of biodiversity during the construction of large projects, including the Qinghai-Tibet railway and the south-north water diversion project.

The Chinese government invested more than 1.1 billion yuan (about 140 million US dollars) to protect vulnerable ecological zones along the Qinghai-Tibet railway, which runs across five nature reserves and a special ecological zone on Qinghai-Tibet Plateau.

"I appreciate the efforts of the Chinese government and the funds it has poured in to protect the environment," said Peter Raven, director of the Missouri Botanic Garden. "But large project construction almost inevitably causes ecological damage."

"Research on the railway's ecological impact is still at a preliminary stage," said Li Dezhu, director of the Kunming Botanic Institute of the CAS, "the seed bank for the species growing in the areas along the railway is yet to be established."

"But we should waste no time in reinforcing efforts to conserve plants in those areas," he said.

The same problems should be heeded for the Chinese south-north water diversion project, the biggest of its kind in the world, said WBG botanist Zhang Quanfa.

The eastern part of the project will see the water level in the lakes raised, which will change the ecosystem and have a direct impact on aquatic plants, said Su Ronghui, a biologist with CAS. He said that the western part of the project will threaten the aquatic environment in the Yangtze River and the Yellow River.

"Frankly, the research currently being carried out in China is not up to solving these problems," Su said.

He suggested that a comprehensive monitoring system be set up to check the project's impact on plant species in the areas concerned. "To protect the ecological system, we should limit large projects as much as possible," said Dr Raven.

"It is difficult for China to reconcile rapid economic growth with care for the environment. But we really must start thinking about the well-being of future generations," he said.

(Xinhua News Agency April 21, 2007)