干旱区研究

干旱区研究 ›› 2024, Vol. 41 ›› Issue (11): 1969-1980.doi: 10.13866/j.azr.2024.11.16 cstr: 32277.14.AZR.20241116

• 农业生态 • 上一篇    

模拟干湿条件下土壤酶活性对坝地土壤有机碳矿化的影响

邢欣然1(), 张祎1(), 李鹏2, 刘晓君3, 陶清瑞4, 任正龑4, 胥世斌5   

  1. 1.宁夏大学生态环境学院，宁夏 银川 750021
    2.西安理工大学，西北旱区生态水利工程国家重点实验室培育基地，陕西 西安 710048
    3.宁夏大学农学院，宁夏 银川 750021
    4.宁夏回族自治区水土保持监测总站，宁夏 银川 750002
    5.西吉县滥泥河流域水土保持试验工作站，宁夏 西吉 756200
  • 收稿日期:2024-04-21 修回日期:2024-06-12 出版日期:2024-11-15 发布日期:2024-11-29
  • 通讯作者: 张祎. E-mail: yzhang026@nxu.edu.cn
  • 作者简介:邢欣然（2000-），男，硕士研究生，主要从事土壤侵蚀及碳循环研究. E-mail: 13099525526@163.com
  • 基金资助:
    宁夏自然科学基金项目(2023AAC03054);国家自然科学基金项目(42473069)

Simulated effects of soil enzyme activity on soil organic carbon mineralization in dam land under dry and wet conditions

XING Xinran1(), ZHANG Yi1(), LI Peng2, LIU Xiaojun3, TAO Qingrui4, REN Zhengyan4, XU Shibin5   

  1. 1. College of Ecology and Environment, Ningxia University, Yinchuan 750021, Ningxia, China
    2. National Key Laboratory Cultivation Base of Ecological Water Conservancy Project in Northwest Arid Region, Xi’an University of Technology, Xi’an 710048, Shaanxi, China
    3. College of Agriculture, Ningxia University, Yinchuan 750021, Ningxia, China
    4. Soil and Water Conservation Monitoring Station of Ningxia Hui Autonomous Region, Yinchuan 750002, Ningxia, China
    5. Xiji Indiscriminate Mud River Basin Soil and Water Conservation Test Workstation, Xiji 756200, Ningxia, China
  • Received:2024-04-21 Revised:2024-06-12 Published:2024-11-15 Online:2024-11-29

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摘要：

气候变化导致长期干旱和强降雨事件的发生频率增加，从而对生态系统碳循环产生影响。因此，了解不同干湿条件土壤酶活性如何影响有机碳矿化，能够帮助深入理解碳循环机制并推进全球碳中和目标达成。据此，本研究选择黄土高原特有的控制侵蚀所修建的淤地坝为研究对象，并设计淹水胁迫、干旱胁迫和干湿循环3种处理监测土壤酶活性及有机碳矿化过程。结果表明：干湿循环对有机碳矿化存在瞬时激发效应，且有机碳累积矿化量介于干旱胁迫和淹水胁迫之间。同时干湿循环均会增加碳循环和氮循环相关酶活性，但随着循环次数的增加酶活性逐渐降低并趋于稳定。三种水分处理条件下酶活性均受到碳和磷的限制，而干湿循环次数越多碳限制越强烈，第四次干湿交替后干湿交替条件下磷限制作用超过淹水胁迫和干旱胁迫。当土壤处于干旱、淹水胁迫以及干湿循环时，限制有机碳矿化的酶活性因子也各不相同。干旱胁迫下磷酸酶因子的直接作用为99%，淹水胁迫下EAAC/N（碳循环相关酶/氮循环相关酶）和木糖苷酶因子的直接作用为87%，干旱胁迫和淹水胁迫下因子间交互作用仅为1%和13%。干湿循环条件下，磷酸酶和β-N-乙酰氨基葡萄糖苷酶因子的直接作用为75%，因子间交互作用为25%，干湿循环可以显著增加因子之间的相互联系。本研究可为明晰黄土高原淤地坝建设在国家碳中和目标中发挥的作用提供理论支撑。

关键词: 干湿交替, 土壤酶, 土壤有机碳矿化, 黄土高原

Abstract:

Climate change has increased the frequency of long-term droughts and heavy rainfall events, impacting ecosystems’ carbon cycle. Therefore, understanding how soil enzyme activity in different dry/wet conditions affects organic carbon mineralization can help deepen our understanding of the carbon cycle mechanism and advance the goal of global carbon neutrality. This study was based on the unique terraces built to control erosion in the Loess Plateau, and three treatments of flooding stress, drought stress, and wet/dry cycles were designed to monitor soil enzyme activity and organic carbon mineralization. The results indicate that the wet/dry cycle has a transient stimulating effect on organic carbon mineralization, and the cumulative mineralized organic carbon occurs between the drought and flooding stress. At the same time, the wet/dry cycle will increase the activity of carbon and nitrogen cycle-related enzymes; however, the enzyme activity will gradually decrease and stabilize as the number of cycles increases. The enzyme activity in all three water treatment conditions was limited by carbon and phosphorus, and the carbon limitation was more substantial with increasing wet/dry cycles. After the fourth alternating wet/dry cycle, the phosphorus limitation exceeded the flooding and drought stress treatments. When the soil was under drought stress, flooding stress, or wet/dry cycles, the enzyme activity factors that limit organic carbon mineralization were different. The direct effect of the phosphatase factor under drought stress was 99%, the direct impact of EAAC/N (carbon cycle- /nitrogen cycle-related enzyme) and xyloglucosidase factor under flooding stress was 87%, and the direct effect of the interaction between factors under drought and flooding stress was only 1% and 13%. Under wet/dry cycle conditions, the direct impact of phosphatase and N-acetyl-beta-glucosaminidase factor was 75%, the direct effect of interaction between factors was 25%, and the wet/dry cycle significantly increased the interaction between factors. This study provides theoretical support for clarifying the role of Loess Terrace.

Key words: dry and wet alternate, soil enzymes, soil organic carbon mineralization, Loess Plateau