赤水丹霞世界自然遗产地种子植物区系

Seed plant flora in Chishui Danxia natural world heritage site

调查统计显示，赤水世界自然遗产地拥有种子植物171科692属1715种，其中裸子植物7科12属13种，被子植物164科680属1702种。分析表明赤水遗产地种子植物区系具有以下特征：（1）区系物种组成丰富，优势科明显；单种科和非单种单属科较多，反映区系科分化明显；2～5种少型属和单种属分别占统计属数的40．03％and52．17％，从一定程度上反映出区系小生境的多样性；（2）区系起源古老。中生代孑遗植物桫椤（Cyathea spinulosa）广泛分布于深山峡谷区；该区域分布的小黄花茶（Camellia luteoflora）被认为是山茶属中在系统发育上较原始的种群。（3）区系成分复杂，除缺少中亚分布外，其它成分均有分布。热带、温带成分分别占区系统计成分的53．13％和43．60％，区系热带性质更明显。（4）与较低纬度的施秉世界自然遗产提名地相比，区系热带性质也更明显，且两区系科相似性较高，达81．52％，种相似性较低，仅为26．91％，反映小生境差异较大。

Research shows that there are seed plants of 171 families, 692 genuses and 1715 species in Chishui Danxia natural world heritage site, including gymnosperm of 7 families, 12 genues and 13 species and angiosperm of 164 families, 680 genuses and 1702 species. Analysis indicates that the flora has following characters. （ 1 ） With high species diversity, dominant family is notable. There are many families with one species or one genus, which reflects a dramatic differentiation of family. Genus with 2 -5 species and monotype genus respectively takes 40.03% and 52. 17% of total genus, which to some extents reflects habitat diversity. （2） The flora is ancient. There is a wide distribution of ancient species of Cyathea spinulos and Camellia luteoflora. （3） Beside Central Asia distribution, there are all other types. Tropic and temperature components respectively takes 53.13% and 43.60% of all statistic genuses, showing clear topical nature. （4） Comparing with Shibing nominated natural world heritage site, the former also shows clear tropical nature. They show high family comparability of 81.52% and lower genus comparability of 26. 91% , indicating a clear habitat difference.