Floristic Characteristics of the Rare and Endangered Plant Species in North Guangdong and Their Conservation Strategies

North Guangdong hilly and mountainous area is a place in South China’s Guangdong Province where rare and endangered plant species most abundantly distribute.31 species of rare and endangered plants of national level and 4 such species of provincial level are found to distribute naturally in this area,accounting for 52.3 percent of the total number of rare and endangered species distributing across the province.These rare and endangered plant species fall into 3 categories.The first is of second-ranking protection which includes Tsuga longibracteata,Fokienia hodginsii, Cephalotaxus oliveri,Pseudotaxus chienii,Tsoogiodendron ordorum,Camellia sinensis var.assamica,Disanthus cercidifolius var.longipes,Archiboehmeria atrata,Euryocorymbus cavaleriei,Bretshneidera sinensis and Diplopanax stachyanthus.The second is of third ranking protection which includes Pinus kwangtungensis,Tsuga chinensis var.tchekiangensis,Amentotaxus argotaenia,Magnolia officialis subsp.biloba,Parakmeria lotungensis,Cinnamomum micranthum,Phoebe bournei,Coptis chinensis var.brevisepala,Dysosma versipellis,Semiliquidambar cathayensis,Zenia insignis, Euchresta japonica,Glycine soja,Castanopsis kawakamii,Pteroceltis tatarinowii,Artocarpus hypargyreus,Toona cilita,Tapiscia sinensis,Halesia macgregorii and Morinda officinalis.The last is of provincial level protection which includes Cephalotaxus fortunei,Taxus mairei,Castanopsis jucunda and Scleropyrum wallichianum.The rare and endangered plants are characterized by the generic areal type of endemic to China,of Indo Chinese peninsula to south China and of discontinuous dispersion.This,coupled with the lack of cosmopolitan areal type,indicates the confinement of dispersal in geography of rare and endangered plant species.Of the 35 rare and endangered plant species,some are relic taxa or occupy critical position in the phylogenetic chain,which have significant scientific implications,such as C.fortunei,F.hodginsii and B.sinensis; some are of economic importance,such as T.mairei, which bears in the bark an anticancer wonder drug,taxol;some are provenance species of important crops in China,which have significant importance for germplasm improvement,such as C.sinensis var.assamica and G.soja.In view of the above,the rare and endangered plant species should be rigorously protected and a series of strategies are thus proposed,i.e.enlargement of nature reserves as well as establishing new ones should be carried out,in order to conserve more local populations; some critical species should be listed for conservation of highest priority,for which ex-situ conservation and germplasm preservation and storage methods should be studied,as well as in situ conservation methods.To this end,coordination of nature conservation and local sustainable development should also be considered.