An early warning and inspection system to protect against the invasion of exotic species will soon be established in the capital of Guangdong Province, sources with the Guangzhou Municipal Forestry Bureau said.

The new system will tackle the increasing number of biological invasions, Zhong Tiankui, director of the bureau, told China Daily.

The invasion of exotic plants and animals, introduced either intentionally or unintentionally, into the province is threatening local ecosystems, according to Zhong.

Under the early warning and inspection system, alien species will hopefully be discovered as early as possible in farms or forests to avoid problems developing, said Zhong.

Sources with the bureau said that it will also establish a research institute with an investment of 150,000 yuan (US$18,000) this year to cope with the most aggressive plant species that have invaded the province.

The species called Jinzhongteng, or merremia boisiana, was identified recently as seriously threatening trees in Longyandong farm in a suburb of Guangzhou.

The plant, with bell-like yellow flowers, has climbed up trees and rapidly spread over the farm's hills.

"Its fast growth gives rise to a green and dense canopy which blankets native shrubs, even high trees, until the latter are suffocated," said Zhong.

The farm's hills were covered by the plant, with more than 66 hectares of forest falling victim to its spread.

The invasive plant species probably came from tropical regions of Hainan Province and the Guangxi Zhuang Autonomous Region, both neighboring Guangdong, according to scientists.

"The plant first settled on the farm in the 1980s. It is one of the most aggressive alien plant species that have invaded Guangdong," Cao Hongling, a researcher with the South China Botanical Garden, told China Daily.

"However, we have found no effective measures to cope with it so far," said Cao.

In the past 10 years, workers on the farm have used herbicides to try to get rid of the plant, but in vain, Cao said.

In addition, manual felling does not work as the vine is difficult to uproot, Cao added.

"But as there are no more effective methods available, we simply have to cut off its stems and dig up its roots," he said.

Cao also recommended the introduction of the species' natural enemies to prevent it from spreading.

(China Daily June 6, 2005)