BEIJING, May 29 -- GUANGZHOU: Thirteen varieties of orchid in South China's Guangdong Province are on the verge of extinction due to the worsening environment and the invasion of alien species, according to a recent report by Guangdong Environmental Protection Bureau.

    "We did extensive research throughout 2005, and discovered that Guangdong's biodiversity is falling much faster than at any time in the past. This is due to both natural laws and man-made problems," Peng Shaolin, leader of the investigation team, told China Daily. "Orchids are one group of plants that are being seriously affected."

    According to Peng's report, there are 230 varieties of orchid in Guangdong, and most of them are in trouble.

    The report investigated in total 360 endangered species in Guangdong Province and Hong Kong Special Administrative Region. Of the plants, 59 are under State protection.

    "Although orchids are expensive and difficult to plant, planting orchids at home has become a trend since the 1980s," Peng said. "Lots of flower traders exploit wild orchids illegally, causing a great loss of resources."

    The 13 most-endangered varieties include Aerides odorata lour, Calanthe nankunensis, and Coelogyne primulina barretto.

    Since the over-exploitation of orchids is a worldwide concern, all orchids were listed as key preserved plants by the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) in 2000, Peng said.

    The over-exploitation mostly happens in developing countries in tropical zones, which are the major habitats.

    Controlling exploitation is tougher in these areas, Peng said.

    Besides exploitation, the increasingly polluted environment and the industrialization of agriculture and forestry has also caused the extinction of orchids and the loss of biodiversity.

    Peng said the government should do more to publicize the concept of biodiversity protection. He said he hoped the International Day for Biological Diversity, which fell on May 22, could be enlarged.

    He also recommended that species similar to orchids that are also endangered should be moved to preservation zones.