Experts and governmental officials in South China's Guangdong
Province have called for greater awareness of invasive species of
foreign origin.
The call came after the State Environmental Protection
Administration listed the first batch of 16 alien species earlier
this year.
Of
the 16 alien species, water hyacinth, mile-a-minute weed, American
bullfrog, alligator weed, amazonian snail and bitter bush have
rooted in Guangzhou and caused serious ecological problems.
Other than the alien species named in the list, a total of some 40
animals and 11 fungi, insects and animal diseases have damaged the
province's farming and forestry industries.
"It is important that the government establish a complete mechanism
to evaluate possible damage before introducing foreign species, to
monitor alien species' activities and to carry out timely and
proper measures to prevent any possible ecological disaster caused
by alien species," said Yun Yongli, an official at the provincial
pollution control department.
Yun said China was still in the first stages of tackling the
problem of invasive alien species and the government is drafting
laws and regulations to ensure a safe and healthy ecosystem.
Currently, environmental protection authorities have joined forces
with other governmental departments such as customs, forestry and
agriculture in a bid to prevent the spread of alien species.
There should also be greater public awareness of invasive species
as exchanges with foreign countries increase.
Given their ability to reproduce, adapt quickly to their new
environment and establish a sustainable population, alien species
are able to dominate the ecosystem, said Xing Fuwu, a professor at
the South China Institute of Botany.
Curbing the spread of invasive species is a major task. China
spends around 600 million yuan (US$72 million) annually to tackle
the spread of alligator weed.
In
order to curb the growth of water hyacinth, the province's Zhuhai
spends 100 million yuan (US$12 million) annually on destroying the
plant.
Xing warned that, so far, there is no effective and efficient
method to eliminate invasive species.
Spraying weed-killer is an option. However, using chemicals becomes
far less effective when the invasive plants has grown into a large
population.
According to Xing, some scientists are working on introducing
insects that can eat certain alien plants. Some scientists are also
researching to bringing in dodder, a kind of parasitic climbing
vine, into the place where mile-a-minute weed grows out of
control.
However, from Xing's observations in the wild, dodder cannot
completely stop growth of mile-a-minute weed on its own. Using
dodder could also have other ecological consequences.
But Xing says there is no need to panic about alien species.
"Not all foreign origin species are invasive. More than 1,000
species now existing in China are of foreign origin. Only several
dozen has caused damage to the ecosystem," Xing added.
(China Daily April 11, 2003)