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中国沙漠 ›› 2009, Vol. 29 ›› Issue (3): 499-507.

• 生物土壤与生态 • 上一篇    下一篇

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

吴 涛1,2, 王雪芹1, 盖世广1,2, 郭洪旭1,2, 陈 明3, 王 琪3, 全永威3, 金兴强3   

  1. 1.国家荒漠-绿洲生态建设工程技术研究中心, 中国科学院 新疆生态与地理研究所, 新疆 乌鲁木齐 830011; 2.中国科学院研究生院, 北京 100039; 3.新疆额尔齐斯河流域开发工程建设管理局, 新疆 乌鲁木齐 830000
  • 收稿日期:2008-01-20 修回日期:2008-05-09 出版日期:2009-05-20 发布日期:2009-05-20

Effect of Grazing in Spring-Summer on Soil Seed Bank and Vegetation in Southern Part of Gurbantunggut Desert

WU Tao1,2, WANG Xue-qin1, GAI Shi-guang1,2, GUO Hong-xu1,2, CHEN Ming3, WANG Qi3, QUAN Yong-wei3, JIN Xing-qiang3   

  1. 1.National Engineering Technology Research Center for Desert-Oasis Ecological Construction, Xinjiang Institute of Ecology and geography, CAS, Urumqi 830011, China; 2.Graduate School of Chinese Academy of Sciences, Beijing 100049, China; 3.Engineering Construction Management for Ertix River Basin Development in Xinjiang, Urumqi 830011, China
  • Received:2008-01-20 Revised:2008-05-09 Online:2009-05-20 Published:2009-05-20

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,但近年来的放牧活动在春夏季也开始进入沙漠腹地,使地表性质与植被覆盖发生了明显改变。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: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,后者明显减少了植物种数。冬季放牧沙垄种子库密度为(353.2±87)粒·m-2,而春夏季放牧沙垄为(189.1±23)粒·m-2,比前者减少了88%。两类沙垄土壤种子库的生活型组成都以一年生植物为主,相似性系数为0.711。相同沙垄不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他部位。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种和26种,各生活型所有物种均为后者低于前者,其中短命、类短命物种数量减少幅度最大。春夏季放牧沙垄地上植被的物种多样性和均匀度降低,而优势度升高。回归分析显示,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。

关键词: 古尔班通古特沙漠, 半固定沙垄, 放牧影响, 土壤种子库, 地上植被

Abstract: Gurbantunggut desert is the largest fixed and semi-fixed desert in China, and its vegetation species is relatively multiple. The semi-fixed longitudinal dune area in the desert was winter pasture in history, but recently grazing entered the desert even in spring and summer. Therefore, it changes the density and composition of soil seed bank and vegetation. The comparing results show that there are 24 seed banks under winter grazing and 20 seed banks under spring-summer grazing, and their corresponding seed bank density is (355.1±88) viable seeds·m-2 and (189.1±23) viable seeds·m-2, respectively. The annual herbages dominate in both grazing sites, with the similarity coefficient of soil seed bank being 0.711. The similarity coefficients of soil seed bank vary in a range of 0.429~0.600 at different parts of a same sand dune. The plant species in winter grazing dune and spring-summer grazing dune are 36 and 26 species respectively. The species number of every life form in spring-summer grazing dune is less than that in winter grazing dune. There are lower biodiversity index and evenness index in spring-summer grazing dune, but with a higher dominance index. Regression analysis shows that difference in seed bank density accounts for 21% of the variance of standing vegetation density in winter grazing dune and for 51% of that in spring-summer grazing dune. It indicates that the density of seed bank and standing vegetation in winter grazing dune has weak correlation, and grazing during spring and summer would enhance the relationship between them remarkably.

Key words: Gurbantunggut Desert, semi-fixed longitudinal dune, effect of grazing, soil seed bank, vegetation

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