长江中游（以湖北湖南为主）的植物生物多样性及其保护对策

在对植物调查研究的基础上，对长江中游(湖北、湖南为主)的植物区系、植被、生物多样性保护及保护对策进行了系统的论述。根据两省土著种子植物名录统计，本区共有202科1476属7037种(包括种下等级)，其中裸子植物7科30属64种；被子植物196科1445属6973种。以鄂湘为代表的华中区分布类型复杂、物种丰富、起源古老，而且特有的科、属、种多，特有度高。北温带木本植物属高度集中，体现了长江中游具有古第三纪．泛北极植物区系的代表性。拥有众多的东亚特有属、东亚．北美间断分布属和中国特有属，它们既是本地植物区系的特色，也代表了中国植物区系的核心。本地中山以亮叶水青冈(Fagus lucida)为主的阔叶林系第三纪．泛北中生落叶阔叶林的后裔。在植被区划上，本区属于常绿阔叶林区域，包括北亚热带常绿阔叶．落叶阔叶混交林地带及中亚热带常绿阔叶林两个植被地带。后者分为北部典型常绿阔叶林亚地带，南部含华南植物区系成分的常绿阔叶林亚地带。本区主要的自然植被类型(以原生类型为主)有171个类型(相当于群系formations)。从生物多样性保护的三个层次上(物种、群落、景观)对保护现状、特点、保护方针和策略等进行了探讨并提出了建议。

Plant Biodiversity in the Middle Reaches of the Yangtze River and Conservation Strategies

The flora and vegetation of the middle reaches of the Yangtze River (mainly Hunan and Hubei Provinces) were surveyed. On the basis of statistics of the lists of indigenous seed plants for Hubei and Hunan, there are 7 037 species of 1 476 genera in 202 famillies in this area, among which gymnosperm comprises 64 species, 30 genera and 7 families, and angiosperm 6 973 species, 1 445 genera and 196 families. Statistical analysis of the plant areal-types indicates that the flora of Central China including Hubei and Hunan Provinces,is rich in plant species with complicated types, and of ancient origin. This area possesses considerable amount of endemic species, genera and families. North temperate woody plants are highly concentrated in this area, which implies the characteristics of Early Tertiary and Boreal flora in middle reaches of the Yangtze River. There are numerous genera here which are endemic to East Asia and to China, and many genera with East Asian - North America disjunct distribution. The above mentioned components not only are the essence in the flora of Central China, but also of the whole China. In the mountain regions, the mixed forest dominated by Fagus lucida is virtually originated from Boreal-Tertiary mesophilous deciduous broadleaved forests. This area belongs to the evergreen broadleaved forest region, which includes two vegetation zones, i.e. north-subtropical evergreen broadleaved and deciduous broadleaved mixed forest zone, and mid-subtropical evergreen broadleaved forest zone. The latter can be further divided into mid-subtropical northern typical-evergreen broadleaved forest subzone and southern part of mid- subtropical southern evergreen broadleaved forest subzone with the floral components of South China. The natural vegetation includes 171 types (equivatent to formations), mainly original vegetation types. Conservation strategies and suggestions are made from the aspects of the protection of species biodiversity, plant communities, and landscape.