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题名	春夏季放牧对古尔班通古特沙漠南部土壤种子库和地上植被的影响
作者	吴涛
学位类别	硕士
答辩日期	2008
授予单位	中国科学院．新疆生态与地理研究所
导师	王雪芹，新疆生态与地理研究所
关键词	古尔班通古特沙漠
其他题名	Effect of grazing in spring-summer on soil seed bank and vegetation in the southern part of Gurbantunggut Desert
中文摘要	位于新疆北部准噶尔盆地腹地的古尔班通古特沙漠，是世界上温带荒漠生物多样性的精华和最为丰富的典型区域。历史上这里就是北疆羊和部分马匹重要的冬牧场，冬季放牧由于有稳定积雪和冻土存在，给予沙漠地表以极好的保护，并不会破坏沙漠地表状态，但近年来的放牧活动在春夏季也开始进入沙漠腹地，正与起沙风活动频繁的季节相吻合，使植被覆盖与地表性质发生了明显改变，进而影响到土壤种子库的组成和分布。应用野外随机取样与室内萌发实验相结合的方法，对比研究了古尔班通古特沙漠南部春夏季放牧沙垄和冬季放牧沙垄土壤种子库差异及其与地上植被的关系。结果表明：（1）冬季放牧沙垄种子库种数为24种，而春夏季放牧沙垄有20种，后者植物种数明显减少。春夏季放牧使得一年生长营养期植物比例下降，而短命、类短命植物比例上升。冬季放牧沙垄种子库密度为353.2±87粒/m2，而春夏季放牧沙垄为189.1±23粒/m2，比前者减少了88%。两类沙垄土壤种子库的物种相似性系数为0.727。相同部位的物种相似性系数在0.429～0.600之间，异质性较大，尤其表现在除垄顶之外的其它部位。春夏季放牧使得沙垄优势植物发生更迭。（2）冬季放牧沙垄和春夏季放牧沙垄地上植被中分别有植物36和26种，各生活型所有物种均为后者低于前者，其中短命、类短命物种数量变化幅度最大。两类沙垄地上植被物种组成上均以短命、类短命植物为主。非参数检验显示，不同季节放牧沙垄地上植被密度存在显著差异（n=80，sig=0）。春夏季放牧沙垄地上植被密度是冬季放牧沙垄的3.55倍，但是其物种多样性和均匀度指数较之冬季放牧沙垄有很大程度降低，而优势度大幅升高。（3）冬季放牧沙垄土壤种子库与地上植被物种相似性系数为0.63，春夏季放牧沙垄为0.56。两类沙垄地上植被物种的相似性系数为0.84。回归分析显示，土壤种子库密度与地上植物群落密度有显著的相关性，冬季放牧沙垄定植群落有21%的变异来源于土壤种子库，而春夏季放牧沙垄有51%的变异来源于土壤种子库，可见不同季节的放牧干扰显著影响土壤种子库及其与地上植被的相关关系。Gurbantunggut desert is the largest fixed and semi-fixed desert in China, and its vegetation is relatively luxuriant. There was winter pasture in history, but recently grazing entered the desert even in spring and summer. Therefore, it changed the density and composition of soil seed bank and vegetation in dunes. The results showed that: （1）There were 24 plant species in winter grazing dune and 20 plant species in spring-summer grazing dune in seed banks. In the winter grazing dune the seed bank density was 355.1±88 viable seeds/m2 and spring-summer grazing dune was 189.1±23 viable seeds/m2, with annual herbage dominated in both sites. The similarity coefficient of composition of the soil seed banks was 0.727 between two types dune, which varied in a range of 0.429~0.600 in the four different parts of sand dune. （2）There were 36 and 26 species plants in winter grazing dune and spring-summer grazing dune respectively. The species of every life form in spring-summer grazing dune were less than winter grazing dune. In spring-summer grazing dune, the species diversity index, SHANNON-WIENER index and species dominance index were distinctly lower than those in winter grazing dune, but equality index were higher. （3）there was a greater compositional similarity as measured by the Sorensen’s similarity coefficient between the seed bank species and the standing vegetation species in winter grazing dune than in spring-summer grazing dune, and the similarity coefficients of standing vegetation between two type dune was 0.84. Regression analysis showed that seed bank density strongly related to the standing vegetation density in both winter grazing dune and spring-summer grazing dune. Differences in seed bank density accounted for 21% of the variance of standing vegetation density in winter grazing dune and for 51% of that in spring-summer grazing dune. It indicated that the density of seed bank and standing vegetation in winter grazing dune had weak correlation, and grazing during spring and summer enhanced relationship between them remarkably.
语种	中文
学科主题	系统生态学,农学
公开日期	2010-11-12
页码	共60页
内容类型	学位论文
源URL	[http://ir.xjlas.org/handle/365004/8146]
专题	新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据)
推荐引用方式 GB/T 7714	吴涛. 春夏季放牧对古尔班通古特沙漠南部土壤种子库和地上植被的影响[D]. 中国科学院．新疆生态与地理研究所. 2008.

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