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中国沙漠 ›› 2015, Vol. 35 ›› Issue (2): 393-399.DOI: 10.7522/j.issn.1000-694X.2014.00009

• 生物与土壤 • 上一篇    下一篇

固沙植被区两类结皮斑块土壤呼吸对降雨脉冲的响应

赵蓉1,2, 李小军1, 赵洋1, 杨昊天1, 李刚1   

  1. 1. 中国科学院寒区旱区环境与工程研究所 沙坡头沙漠研究试验站, 甘肃 兰州 730000;
    2. 中国科学院大学, 北京 100049
  • 收稿日期:2013-12-20 修回日期:2014-02-16 出版日期:2015-03-20 发布日期:2015-03-20
  • 通讯作者: 李小军 (Email: xiaojunli@lzb.ac.cn)
  • 作者简介:赵蓉 (1988-), 女, 甘肃武威人, 硕士研究生, 主要从事干旱区土壤生态学研究。Email: zhaorong0814@126.com
  • 基金资助:

    中国科学院知识创新工程重要方向项目(KZCX2-EW-301-2)

CO2 Efflux from Two Typies Biologically Crusted Soil in Response to Simulated Precipitation Pulses in the Tengger Desert

Zhao Rong1,2, Li Xiaojun1, Zhao Yang1, Yang Haotian1, Li Gang1   

  1. 1. Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2013-12-20 Revised:2014-02-16 Online:2015-03-20 Published:2015-03-20

摘要:

与降水事件密切相关的土壤水分有效性是荒漠生态系统土壤呼吸的重要驱动因子。研究了固沙植被区以藓类和藻类为主的生物土壤结皮斑块土壤呼吸对模拟降雨(5、10、20 mm)的响应。结果表明:3种降雨量对不同结皮斑块土壤呼吸均有显著的激发作用, 但2种土壤的响应特征不同。藓类结皮斑块土壤呼吸速率在降雨后0.5 h达到最大值, 而藻类结皮斑块土壤在降雨后2 h达到最大值, 其呼吸速率分别是降雨前土壤呼吸速率的43~58、21~25倍,随后, 两类结皮斑块土壤呼吸速率逐渐下降并恢复到降雨前水平。随着降雨量的增加, 藓类结皮斑块土壤最大呼吸速率和平均呼吸速率显著增大, 而藻类结皮斑块土壤则无明显变化; 2种土壤碳释放量均随着降雨量的增大而增加。在相同降雨条件下, 藓类结皮斑块土壤呼吸速率峰值和平均值及碳释放量均显著大于藻类结皮斑块土壤。表明生物土壤结皮和降雨量均对荒漠生态系统土壤呼吸起着重要的调控作用。

关键词: 土壤呼吸, 降雨, 生物土壤结皮, 固沙植被区, 腾格里沙漠

Abstract:

In arid and semiarid region, soil water availability, which is closely related to precipitation, is the major driver of soil respiration. In this study, different simulated precipitations (5, 10, 20 mm) were applied to two biologically crusted soils to investigate soil CO2 efflux in response to precipitation pulse in these regions. The results showed that three levels of rainfall significantly stimulated CO2 efflux from both biologically crusted soils. However, the response patterns varied between crust types. After rainfall, the respiration rates of moss and algal overlying soils reached their maximum within 0.5 h and 2 h, respectively. The peak values were 43-58 and 21-25 times greater than the background levels. After it reached the peak, soil CO2 efflux gradually decreased and returned to background level. The peak and average respiration rates of moss crusted soils significantly increased with the amount of water added, while these parameters did not vary with experimental pulse in algae crusted soil. Total carbon release of both biologically crusted soils increased with precipitation size. Following the same amount of water addition, peak and average respiration rates as well as total carbon emissions of moss overlying soils were significantly greater than the algae ones. Our results suggest that biological soil crusts and precipitation can co-regulate soil CO2 efflux.

Key words: soil respiration, precipitation, biological soil crust, fixed sand dunes, Tengger Desert

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