The Research Of Plant Diversity In Wulingyuan World Natural Heritage Site

Wulingyuan World Natural Heritage site is located in the northwest of Hunan Province, known to the world as the unique quartz sandstone peak-forest, and rich in plant species diversity. After the wild plant diversity survey, specimen collection, data consultation and specimen determination, the vascular plant diversity status of Wulingyuan World Natural Heritage site has been understood. The flora of study area has been analyzed, and the diversity of plant survival mechanism on quartz sandstone peak-forest landform has been discussed. Results are as follows:1 The plant species diversity of Wulingyuan World Natural Heritage Site is rich. According to the survey, there are 1611 species (including varieties and forms) wild vascular plants belonging to 689 genera and 192 families in Wulingyuan World Natural Heritage site. Among them,38 families,77 genera,215 species are ferns; 5 families,7 genera,12species are gymnosperms, and 149 families,605 genera,1384 species are angiosperm.2 The composition of the flora is complex and various, which is near the northern margin of the subtropical flora. At the genus level,77 genus of ferns can be divided into 10 areal types and 2 subtypes, and the tropical character is more obvious than the temperate nature. At the species level,215 species of ferns can be divided into 11 distribution types, and the flora of ferns is mainly of temperate and subtropical components.159 families of wild seed plants can be divided into 12 distribution types. The tropical elements and temperate elements ratio is about 1.69:1, and the tropical floristic is stronger. According to the distribution types analysis of genera,613 genera are divided into 13 distribution types and 19 subtypes, and the tropical elements and temperate elements ratio is about 1:1.33, the temperate component slightly dominant.3 The flora composition is relict, original and the origin is ancient. Differentiation of pteridophyte families and genera are not high, and the structure is relatively simple in families and genera, so the flora of fens is ancient and relict. For spermatophyte, there are original ancient families and genera, polycarpous plants of euanthium theory, and amentiferae plant of pseudanthium theory.4 The endemism is obvious and there are numerous rare and protected plants. There are 3 chinese unique families,29 chinese endemic genus,82 unique seed plants of central China,8unique seed plants of Wulingshan mountainous and there are rare and protected plants 53 species, which are included in< China Key Protected Wild Plants List(1999)> 22 species, included in< China Rare and Endangered Plants List (2010)> 19 species, included in< Convention on International Trade in Endangered Species of Wild Fauna and Flora(CITES)> Appendix Ⅱ 28 species.5 The feature plants of the quartz sandstone landform is obvious.The xerophytes of the quartz sandstone landform is abundant, which survival strategy mainly with leathery leaves, fleshy leaves, recovery, pseudobulb(or rhizome), drought-tolerant plant dwarfing or formation of drought-tolerant mix is various.6 In the process of plant diversity survey, we found four new record plants plants in hunan province and a new species of Chrysosplenium. There are Aconitum carmichaelii var. Tripartitum, Scutellaria lotienensis, Youngia pratti, Isodon excisoides and Chrysosplenium rosulatum.