自然资源学报 ›› 2014, Vol. 29 ›› Issue (10): 1686-1695.doi: 10.11849/zrzyxb.2014.10.005

• 资源生态 • 上一篇    下一篇

黄土高原半干旱区土壤呼吸对土地利用变化的响应

郭慧敏1, 张彦军2, 刘庆芳4, 姜继韶1, 李俊超4, 王蕊4, 李娜娜2, 李如剑2, 郭胜利1,2, 李春越3   

  1. 1. 中国科学院、水利部水土保持研究所, 陕西杨凌712100;
    2. 西北农林科技大学 水土保持研究所, 陕西杨凌712100;
    3. 陕西师范大学旅游与环境学院, 西安710119;
    4. 西北农林科技大学 资源环境学院, 陕西杨凌712100
  • 收稿日期:2013-10-10 修回日期:2014-02-27 出版日期:2014-10-20 发布日期:2014-10-20
  • 通讯作者: 郭胜利(1969-), 男, 河北栾城人, 研究员, 主要从事土壤侵蚀与生态研究。E-mail: slguo@ms.iswc.ac.cn E-mail:slguo@ms.iswc.ac.cn
  • 作者简介:郭慧敏(1987-), 女, 山东淄博人, 硕士研究生, 主要研究方向为土壤侵蚀与呼吸。E-mail:guodami@163.com
  • 基金资助:

    国家自然科学基金(41071338, 41371279);中国科学院战略性先导科技专项(XDA05050504)。

Responses of Soil Respiration to Land Use Changes in a Semiarid Region of Loess Plateau

GUO Hui-min1, ZHANG Yan-jun2, LIU Qing-fang4, JIANG Ji-shao1, LI Jun-chao4, WANG Rui4, LI Na-na2, LI Ru-jian2, GUO Sheng-li1,2, LI Chun-yue3   

  1. 1. Institute of Soil and Water Conservation, CAS and Ministry ofWater Resource, Yangling 712100, China;
    2. Institute of Soil and Water Conservation, Northwest A & F University, Yangling 712100, China;
    3. College of Tourism and Environmental Sciences, Shaanxi Normal University, Xi'an 710119, China;
    4. College of Resources and Environment, Northwest A & F University, Yangling 712100, China
  • Received:2013-10-10 Revised:2014-02-27 Online:2014-10-20 Published:2014-10-20

摘要:

明确土地利用方式变化条件下引起土壤呼吸差异性的因素,对预测黄土区退耕还草条件下土壤碳循环变化有重要意义。基于建立于1984 年的长期定位试验,于2011 年3 月至2012年12 月,利用Li-8100 系统(Li-COR,Lincoln,NE,USA)监测了退耕还草(苜蓿)处理和农田(冬小麦)土壤呼吸季节变化以及土壤表层(0~5 cm)温度和含水量,研究了土地利用变化下土壤呼吸变化特征及其与土壤温度、水分以及有机碳特性之间的关系。结果发现,退耕27 a 来(自1984年麦地转化为苜蓿地),土壤呼吸速率苜蓿地(3.55 μmol·m-2·s-1)达小麦地(1.36 μmol·m-2·s-1)的2.61 倍,累积呼吸量苜蓿地(981 g·m-2)达小麦(357 g·m-2)的2.75 倍。土壤呼吸温度敏感系数(Q10)苜蓿地较小麦地2011 年提高24.5%,2012 年提高2.4%。苜蓿地SOC含量(10.5 g·kg-1)较小麦地(6.5 g·kg-1)提高61.5%,微生物量碳(204 mg·kg-1)较小麦地(152 mg·kg-1)提高34%,0~5 cm土壤水分含量同期高于小麦地,但二者土壤温度差异不显著。土壤水分、SOC、微生物量碳等是造成二者呼吸差异的因素。

关键词: 土壤呼吸速率, 草地, 土壤有机质, 黄土高原, 农田, 土壤水分

Abstract:

Understanding the responses of soil respiration to land use changes becomes critical in predicting soil carbon cycling under conversion of arable land into grassland on the Loess Plateau. From March 2011 to December 2012, CO2 efflux from the soil surface was measured from 8:00 to 12:00 am in clear days by a Licor-8100 closed chamber system (Li-COR, Lincoln, NE, US). Also, soil temperature and soil moisture at the 5 cm depth was measured using a Li- Cor thermocouple and a hand- held frequency-domain reflectometer (ML2x, Delta-T Devices Ltd, UK) at each PVC collar, respectively. Since returning cultivated land for 27 years, the mean grassland soil respiration (3.55 μmol·m-2·s-1) was averaged 2.61 times higher than paired cropland soil respiration (1.36 μmol·m-2·s-1) and the cumulative CO2-C emission in grassland (981 g C·m-2) was 2.75 times higher than that in cropland (357 g C·m-2). In 2011, the temperature sensitivity of grassland (Q10) improved by 24.5% compared with cropland, and in 2012 it reduced to 2.4%. We found marked differences in soil characteristics related to different landuse types: the mean grassland SOC (10.5 g·kg-1) was averaged 61.5% higher than paired cropland SOC (6.5 g·kg-1) and the SMBC (204 mg·kg-1) was averaged 34% higher than cropland (152 mg·kg-1). Soil moisture from 0-5 cm depth was much drier in cropland and significantly different between cropland and grassland except for winter. However, there were no clear differences between soil temperatures. SOC and soil moisture differences between cropland and grassland can explain the soil respiration difference caused by land-use change, which was confirmed by the validation results.

Key words: grassland, soil moisture, soil respiration, cropland, soil organic carbon, Loess Plateau

中图分类号: 

  • S152