中国地理科学 ›› 2019, Vol. 29 ›› Issue (6): 1001-1010.doi: 10.1007/s11769-019-1084-5

• 论文 • 上一篇    下一篇

Soil Microbial Metabolic Quotient in Inner Mongolian Grasslands: Patterns and Influence Factors

CAO Yingqiu1, XU Li2, ZHANG Zhen1, CHEN Zhi2, HE Nianpeng2,3,4   

  1. 1. Resources and Environment College, Anhui Agricultural University, Hefei 230036, China;
    2. Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
    3. College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China;
    4. Institute of Grassland Science, Northeast Normal University, and Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China
  • 收稿日期:2019-03-13 出版日期:2019-12-27 发布日期:2019-11-12
  • 通讯作者: XU Li, ZHANG Zhen E-mail:xuli@igsnrr.ac.cn;xjzhangzhen@163.com
  • 基金资助:

    Under the auspices of National Key R&D Program of China (No. 2016YFA0600104, 2016YFC0500102, 2017YFD0200604), National Natural Science Foundation of China (No. 31770655, 41671045, 31772235)

Soil Microbial Metabolic Quotient in Inner Mongolian Grasslands: Patterns and Influence Factors

CAO Yingqiu1, XU Li2, ZHANG Zhen1, CHEN Zhi2, HE Nianpeng2,3,4   

  1. 1. Resources and Environment College, Anhui Agricultural University, Hefei 230036, China;
    2. Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
    3. College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China;
    4. Institute of Grassland Science, Northeast Normal University, and Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China
  • Received:2019-03-13 Online:2019-12-27 Published:2019-11-12
  • Contact: XU Li, ZHANG Zhen E-mail:xuli@igsnrr.ac.cn;xjzhangzhen@163.com
  • Supported by:

    Under the auspices of National Key R&D Program of China (No. 2016YFA0600104, 2016YFC0500102, 2017YFD0200604), National Natural Science Foundation of China (No. 31770655, 41671045, 31772235)

摘要:

Microbial metabolic quotient (MMQ) is the rate of soil microbial respiration per unit of microbial biomass, and represents the capacity of soil microbes to utilize soil organic matter. Understanding the regional variation and determinants of MMQ can help predict the responses of soil respiration rate to global climate change. Accordingly, we measured and analyzed MMQ-related data (e.g., soil basic respiration rate at 20℃ and soil microbial biomass) from 17 grassland sites, which located in meadow steppe, typical steppe, and desert steppe along a 1000-km transect across the Inner Mongolian grasslands, China. Results showed that MMQ varied significantly among the different grassland types (P < 0.05; desert > typical > meadow) and decreased from southwest to northeast (r=-0.81) with increasing latitude (r=-0.50), and with increasing mean annual precipitation (r=-0.69). Precipitation accounted for 56% of the total variation in MMQ, whereas temperature accounted for 26%. MMQ was negatively correlated with precipitation across the Inner Mongolian grasslands. Therefore, climate change, especially in regard to precipitation, may influence soil microbial respiration and soil carbon dynamics through altering MMQ. These results highlighted the importance of spatial patterns in MMQ for accurately evaluating the responses of soil respiration to climate change at regional and global scales.

关键词: soil respiration, soil microbial biomass carbon, precipitation, temperature, Inner Mongolian grassland

Abstract:

Microbial metabolic quotient (MMQ) is the rate of soil microbial respiration per unit of microbial biomass, and represents the capacity of soil microbes to utilize soil organic matter. Understanding the regional variation and determinants of MMQ can help predict the responses of soil respiration rate to global climate change. Accordingly, we measured and analyzed MMQ-related data (e.g., soil basic respiration rate at 20℃ and soil microbial biomass) from 17 grassland sites, which located in meadow steppe, typical steppe, and desert steppe along a 1000-km transect across the Inner Mongolian grasslands, China. Results showed that MMQ varied significantly among the different grassland types (P < 0.05; desert > typical > meadow) and decreased from southwest to northeast (r=-0.81) with increasing latitude (r=-0.50), and with increasing mean annual precipitation (r=-0.69). Precipitation accounted for 56% of the total variation in MMQ, whereas temperature accounted for 26%. MMQ was negatively correlated with precipitation across the Inner Mongolian grasslands. Therefore, climate change, especially in regard to precipitation, may influence soil microbial respiration and soil carbon dynamics through altering MMQ. These results highlighted the importance of spatial patterns in MMQ for accurately evaluating the responses of soil respiration to climate change at regional and global scales.

Key words: soil respiration, soil microbial biomass carbon, precipitation, temperature, Inner Mongolian grassland