晋西黄土丘陵区与土石山区交错地带植物区系特征分析

The Characteristics of Flora of Seed Plants in the Ecotone Between the Bedrock Area and Loess Area of Western Shanxi Province

本文以晋西黄土丘陵区与土石山区的典型交错地带中阳县为研究对象,分别对黄土丘陵区和土石山区的植物区系科、属、种的组成、属的分布类型等进行了系统研究;同时,对这两个区域的植物区系组成的差异性进行了对比分析。中阳县土石山地区,共计有种子植物64科,204属,354种。植物区系属的分布类型中,北温带分布类型最多,有87属,占总属数43%。黄土丘陵边缘区仅有种子植物134种,分属93属,42科;分别占中阳县土石山区的37.85%,45.59%,65.63%。从维持植物物种多样性的角度来讲,晋西土石山次生林区应该是重点保护的区域。同时,发现黄土丘陵区泛热带成分分布的多种灌木均自然分布在极端干旱的阳坡地段,这种区系的分布类型与生态适应性之间的关系值得进一步研究。黄土丘陵区与土石山区交错地带天然次生植物区系特征的分析,对于深入研究该区域天然植被分布的空间异质性及其成因具有重要的理论意义。

China is one of the countries which is marked by the most abundant plant species and the richest plant resources in East Asia and even in the world, and has always been attended by botanists worldwide,especially by Chinese botanists. As a result of the successful work by the Chinese botanists of several generations,the Flora of China, including more than 30000 plants,has almost been finished. The flora of loess plateau belongs to a Subregion in the North China Region in the Japan-China Forest Plant Subkingdom in the Holarctic Kingdom in Chinese Flora,which is the crisscrossing and assembling place of xerophyte,mesophyte and hygrophyte from south to north and from east to west. It is comparatively rich in species,ancient in origin,complex,varied in geographical elements,and dominant in the temperate. In this text, Zhongyang county of west Shanxi Province was chosen as the research area which was the ecotone between the loess hilly area and bedrock area. The characteristics of flora of seed plants were studied detailedly in the region. The characteristics of flora of vegetation in the bedrock area and loess area were investigated respectively. The characteristics of flora was contrasted in the two districts. It is now known that there are 354 species of seed plants, which belong to 204 generas and 64 families. The analysis and statistics on the flora element show that the distribution of north temperate zone distribution is the main distribution pattern of genus. In the edge of the loess hill area, there are 134 species of seed plants, which belong to 93 genera and 42 families. Their the proportions in ecotone are 37.85% ,45. 59%, 65.63 % respectively. The area of bedrock natural forest region is the important region in the loess plateau. The analysis of characteristics of flora in the ecotone is very important, and the conclusion can be used to direct the restoration of loess plateau of west Shanxi provice.