摘要
为了了解呼伦贝尔沙地植被的沙漠化演变规律及其机制,于2009年在呼伦贝尔沙地陈巴尔虎旗设置样地,调查不同类型沙地植被差异和变化特征,分析植被变化与土壤理化特性的关系,得到如下结果:①随着沙漠化的发展,草地的植被盖度、高度、地上地下生物量和凋落物量急剧下降,物种丰富度、多样性指数、均匀度指数和植物密度呈波动式下降;②沙漠化过程中,受损最严重的是植被盖度、高度和生物产量,物种丰富度、生物多样性对于沙漠化的响应较为迟缓或具有滞后效应;③沙漠化过程中,多年生优良牧草在群落中的作用下降,一年生杂类草在群落中的作用增强,草地由多年生禾本科植物占优势的群落向一年生禾本科、藜科杂类草为优势种的群落演替;④沙漠化过程中,土壤粗化、松散度的增加、有机质和养分含量的降低是导致植被退化的主要因素,土壤温度和水分含量的变化对植被退化也有一定影响,但土壤容重和土壤pH的变化对植被退化的影响较小。
A field investigation on vegetation difference and change properties among different kinds of sand lands was conducted in the Qingbarhu Banner,Hulunbeir Sandy Land of Inner Mongolia in 2009 to understand desertification process and its mechanism of steppe vegetation.The results are as follows：（1） With development of desertification,the vegetation coverage,height,aboveground and underground biomass and litter yield of the steppe were sharply decreased,and the species richness,Shannon-Wiener index,Pielou evenness index and plant density were decreased in a fluctuation way;（2） Vegetation coverage,height and biomass were the most sensitive to desertification,and the response of species richness,biodiversity index and plant density to desertification was slow and lagged;（3） In desertification process,the effect of perennial high-quality forage was decreased but that of annual forbs was increased gradually in the community,the succession was gradually shifted from the community dominated by perennial gramineous plant Agropyron cristatum to the community dominated by annual gramineous and Chenopodiaceae plants,Setaria viridis ＋ Corispermum macrocarpum;（4） In desertification process,soil coarseness,loose degree increase and decrease of soil organic matter and nutrient contents were the primary factors to cause vegetation degeneration,soil temperature and moisture content also affected the vegetation degeneration of the steppe to a certain extent,but the impact of soil bulk density and pH value on vegetation degeneration was quite low.
出处
《干旱区研究》
CSCD
北大核心
2011年第4期565-571,共7页
Arid Zone Research
基金
国家"973"课题(2009CB421303)
国家自然科学基金课题(30972422)
关键词
草地植被
沙漠化过程
群落演替
土壤理化特性
呼伦贝尔沙地
内蒙古
steppe vegetation
desertification process
community succession
soil physical and chemical properties
Hulunbeir Sandy Land
Inner Mongolia
