From May to December,2006,the experiment on round pearl production with recipient oysters Pteria penguin which were 2 -4 years old and mantle tissue ( saibo ) donors which were 1 -3 years old was carried out at Fanghua pearl farm,Xuwen,Zhanjiang,Guangdong.

Analysis on Karst rocky desertification in upper reaches of Pearl River based on remote sensing;

In order to probe environmental effect and ecological security of upper reaches of Pearl River,the author chooses Guanling autonomous county of the Buyi and Miao as a base of research and comprehensively assets activities of this region since 1978 from the angle of historical and present situation by using mathematic model and AHP.

In order to probe into the accumulated environmental effect and ecological security of the upper reaches of the Pearl River,the authors choose Sandu Autonomous County of the Shuis as the base of the research and comprehensively asset the activities of this region since the founding of our(People's) Republic of China from the angle of historical and present situations.

The pilot area of soil and water conservation integrated management project of Nanpan and Beipan rivers limestone region on the upper reaches of the Pearl River is the most severe soil and water loss area of the Pearl River basin.

Taking the scientific concept of development as the guide,this article establishes an index system of early warning of ecological security in ethnic agricultural regions of the upper reaches of the Pearl River.

In vulnerable agricultural regions in China, such as the upper reaches of the Pearl River, the ecology worsens continuously with glaring ecological deficits.

On the basis of analysizing present condition of ecology in agriculture areas of upper reaches of Zhujiang River, this article expounds importance of ecological safety to sustainable development and necessity of establishing forecast system of ecological safety.