【作者】 刘刚；

【导师】 张克斌；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2007， 硕士

【摘要】 本文以宁夏盐池县不同封育年限的草场为研究对象，通过2002—2006连续5年的调查，发现盐池县自2002全县实行封育措施后，植被得到迅速恢复，生物量、覆盖度以及多样性指数都得到很大的提高，群落逐渐形成了以苦豆子和茵陈蒿为主的群落，群落稳定性逐渐增强，且自2002年封育草场的生长状况好于封育多年(二十世纪九十年代，全国风沙治沙工程试验示范区重点县进行的封育)的草场。同时，基于NDVI和植被覆盖度遥感定量模型，提取了植被覆盖等级图，在此基础上对盐池县1989、1999、2003年的植被覆盖度等级图进行对比分析，结果表明两个时间段的植被盖度都呈增加趋势，后期(1999～2003)年均变化明显高于前期(1989～1999)年均变化，这都归功于2002年全县实施封育措施。说明封育措施能促使植被快速恢复。进一步研究表明，随着封育年限的增加，早期封育(自2002年封育)的草场，在封育到4—5年后，植被生长状况有所衰退，出现退化的现象，尤其是封育多年的草场长势也在逐年下降，说明封育年限的长短对植被生长影响很大。与此同时，本文分析了盐池县草场植被变化原因，其中包括气候因素(包括降雨量、风速等)、人为因素、生物结皮、外界干扰影响植被的生长。由于生物结皮对植被的生长先促进后抑制，同时运用冗余对群落的稳定性的影响，干扰对植被的影响，提出草场应该进行多元化管理，不应是单一的封育，在植被恢复到一定阶段，应该适度利用，达到经济效益和生态效益双赢的局面。更多还原

【Abstract】 Taking the different enclosed period pasture of Yanchi County as the research object, The research time lasted from 2002 to 2006, the vegetation recovered quickly since the enclosed measures done in 2002, the biomass, coverage, biodiversity index value is getting higher, forming the Sophora alopecuroides and Artemisia capillaries Thunb community, the stabilization of the community is increasing. The pasture enclosed since 2002 is better than long-time enclosed (the combating desertification demonstration project carried out in the typical county on the end of last century). At the same time, Based on NDVI and quantificational remote sensing model on vegetation fraction, extract the grade map of vegetation fraction. Based on the analysing of the grade map of vegetation fraction in 1989 1999 2003,the results show that the vegetation fraction is increasing in this two period. The annual average change in later period (1999-2003) is more than that in early period (1989-1999), it attributes to the enclosed measured. It declarates that the enclosed measure could make the vegetation recover quickly.As the enclosed time increasing, the pasture enclosed since 2002, the growth is getting decline after enclosed 4-5 years, specially the long-time enclosed pasture, the growth is also getting decline, this all note that the enclosed time effect the growth of the vegetation huge.The paper analyzing the reasons of the vegetation variation, the climate (including rainfall and wind), artificial factors, microbiotic soil crust, external disturbance effect the growth of the vegetation. The microbiotic soil crust has a course inhibited to the growth of the vegetation after promoting it, applying the redundancy impact on vegetation stabilization, disturbance impact on the vegetation, it is considered that the management of the pasture should be adjusted, not just enclosed, but using properly, then the ecological and economic benefit could all win.更多还原