干旱区研究

干旱区研究 ›› 2012, Vol. 29 ›› Issue (6): 1032-1038.

• 植物与植物生理 • 上一篇    下一篇

古尔班通古特沙漠地衣结皮对放牧踩踏干扰的小尺度响应

吴楠，张元明，潘惠霞   

  1. 中国科学院干旱区生物地理与生物资源重点实验室，中国科学院新疆生态与地理研究所，新疆 乌鲁木齐 830011
  • 收稿日期:2012-06-18 修回日期:2012-08-02 出版日期:2012-11-15 发布日期:2012-11-19
  • 通讯作者: 张元明. E-mail: zhangym@ms.xjb.ac.cn
  • 作者简介:吴楠（1980-），女，副研，博士，主要从事干旱区植物生态学研究. E-mail: wunan@ms.xjb.ac.cn
  • 基金资助:

    新疆维吾尔自治区青年科学基金项目（2009211B31）；国家自然科学基金项目 (40901123)；国家重点基础研究发展计划（2009CB825104）；中国科学院西部之光项目（XBBS200906）

Response of Fungialgae Symbiotic Lichen Crusts to Grazed  Livestock Disturbance in the Gurbantunggut Desert

WU Nan, ZHANG Yuan-ming, PAN Hui-xia   

  1. Key laboratory of Biogeography and Bioresources in Arid land, Xinjiang Institute of Ecology and Geography,  Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China
  • Received:2012-06-18 Revised:2012-08-02 Online:2012-11-15 Published:2012-11-19

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被引次数

28

摘要： 古尔班通古特沙漠地衣结皮对放牧踩踏干扰及其所引起的生境异质性具有重要的指示作用。研究表明：① 放牧踩踏干扰主要集中于结皮层（0~5 cm），随机调查的样方中，90%的样方干扰率均低于30%,生物土壤结皮(BSCs)破损尚处于较安全的范围；② 放牧踩踏干扰降低了BSCs总盖度，不同类型的结皮对践踏干扰的反应具差异性，其中，真菌-藻类共生形成的地衣结皮与干扰率呈极显著负相关（P<0.01），干扰率>30%的样方中,抗风蚀能力较强的苔藓结皮、地衣结皮盖度均显著低于未受干扰样方，地衣共生体的破坏导致真菌数量显著增加（P<0.05）；③ 有机质、土壤容重等土壤理化指标均与干扰率呈负相关，干扰率>30%的样方中各指标均低于未受干扰样方。其中，土壤容重是对放牧干扰比较敏感的指标，与地衣结皮盖度亦呈极显著正相关（P<0.01），与流沙盖度呈显著负相关（P<0.05）。

关键词: 生物土壤结皮, 放牧, 干扰强度, 盖度, 微生物活性, 古尔班通古特沙漠

Abstract: Biological soil crusts (BSCs) occur extensively in the southern part of the Gurbantunggut Desert, and serve as one of the important biological factors relating to sand surface fixation. As a winter rangeland, the desert is trampled by grazed livestock widely. Lichen crusts are the main type of BSCs in the southern part of the Gurbantonggut Desert and serve as one kind of the important nitrogen resources. They are also one of the sensitive biomonitors of desert ecosystem health, habitat heterogeneity and humaninduced disturbances. This study investigated the effect of trampling on cover of BSCs. The results were as follows: (1) The local disturbance rate mainly ranged from 10% to 20%, which was a relatively safe range against wind erosion; (2) The total coverage of BSCs was decreased due to the grazed livestock disturbance. The response of BSCs to grazing disturbance was different. Holistically, trample of grazed livestock reduced the coverage of dominant crusts, especially the lichen crusts. When disturbance rate was exceeded 30%, the average coverage of lichen crusts was lower than 30%. Because of the destroyed structure of fungalalgae symbiont, the quantity of fungi was increased (P<0.05). Contrast to the reduction of lichen crusts, more bare sand appeared with the increasing disturbance rate; (3) Grazing disturbance reduced soil organic matter content, soil bulk density and ion contents. There was an extremely significant positive correlation between soil bulk density and lichen crust coverage (P<0.01).

Key words: biological soil crust, grazing, disturbance intensity, coverage, microbial activity, Gurbantunggut Desert