【作者】 郭建英；

【导师】 蓝登明；

【作者基本信息】 内蒙古农业大学 ， 植物学， 2007， 硕士

【摘要】 多伦县是锡林郭勒草原的重要组成部分，也是我国北方草原带沙地的一个重要组成部分。90年代末以来，生态环境发生了急剧变化，优良牧草品种逐渐减少甚至消失，沙漠化速度加快，使该地成为我国北方频繁发生沙尘暴的主要源地之一。本文通过对多伦县全县的植被状况进行调查并对人工修复区选取样地进行实地调查研究，分析了该地的种子植物区系、退化草场植物群落与环境的关系、沙地的人工修复效果、草场的封育效果及其评价、不同人工林对林下植被多样性的影响，旨在为多伦县的植物多样性保护、植被的人工恢复重建提供科学依据。研究取得的初步结论如下：(1)多伦县共有野生种子植物75科，249属和465种，分别占内蒙古全区野生种子植物的64.1％，37.5％和21.1％；种子植物区系以温带分布区类型占绝对优势，地理成分混杂且具有过渡性，具有一定数量的古老成分，特有性程度较低。(2)通过排序轴分类得到8种群落类型，并结合植物多样性的回归分析表明，物种多样性与环境因子之间具有密切的联系。(3)在调查过程中样方面积以10m~2左右调查较好，项目的实施不仅控制了土壤风蚀，而且还增加了示范区内的物种丰富度。(4)在该地区，退化草场一经封育其植被盖度、草层高度、牧草产量明显增加，植被恢复较快。恢复后的植被如继续封育，其封育效果已不明显，封育期以5年左右为宜。(5)营造人工林也不一定会造成物种多样性和草本植被生物量的显著减少，草原区营造人工林对物种多样性的影响与所造的林种有关。更多还原

【Abstract】 Duolun County situated in the south-east of Xilin Gol league, it is also an important part of north stepped in China. After the 1990s, with the increasing of population and livestock, it has suffered desertification. Now it is one of sources of sandstorm.This thesis research on the characteristics of compact of floristic elements and the relation ship of plant community in the degenerated grassland and environment, the effect of manpower restoration to sand and pasture that is closed and the effect to plant diversity under the different plantation in Duolun county. The intention is to provide scienced proof for the protection of plant diversity and vegetation restoration in Duolun County. Some conclusions are made in the thesis displayed below:(1) The flora of Duolun County consists of 465 species belonging to 75 families and 249 genera, respectivty proportion is 21.1% and 64.1 and 37.5 of the all wild seed plants in Inner Mongolia. Focusing the research on plant distribution, we will know that the temperate zone is dominant in Duolun flora. The composition diversity is complex and passageway at the same time there are mang age-old composition but lacking of endemic element.(2) Eight types of community can be identified with the DCCA method and showed by plant diversity Return to the analysis.it prove that there are closed connection between species diversity and its environment factors.(3) In this field the sample area is about 10 m~2 is better. Human-induced Vegetation Restoration is concluded that not only controlled soil Erosion but also increased species richness in the representative area.(4) The experiment for closing the degenerated rangeland in Duolun county Results showed that, once degenerated rangeland was closed, the coverage and the hight and the forage production and the root biomass of the rangeland increased evidently, and the vegetation recovered rapidly. If recovered vegetation continued to be closed, the results were not evident.So reasonable close period for degenerated rangeland is about 5 years in Hunshandake Sandyland.(5) The grassland areas construction plantations would not result in the biodiversity and herbages biomass remarkable decrease; it have something to do with plantations species; the central plantations herbaceous species variety compares edge ’s variety greatly.更多还原