天津七里海湿地生长季土壤CO_(2)通量及水热因子变化特征  

Characteristics of soil CO_(2) flux and hydrothermal factors during the growing season in Qilihai wetland, Tianjin

作　　者：李世勇 丁虎 陈静 韩晓昆 薛浩 华海锋 郎赟超 LI Shiyong;DING Hu;CHEN Jing;HAN Xiaokun;XUE Hao;HUA Haifeng;LANG Yun-chao(Institute of Surface-Earth System Science,School of Earth System Science,Tianjin University,Tianjin 300072,China;Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim,Tianjin 300072,China;Tianjin Bohai Rim Coastal Earth Critical Zone National Observation and Research Station,Tianjin 300072,China;Haihe Laboratory of Sustainable Chemical Transformations,Tianjin 300192,China;Qilihai Wetland Conservation Center,Ninghe District,Tianjin 301509,China)

机构地区：[1]天津大学地球系统科学学院,表层地球系统科学研究院,天津300072 [2]天津市环渤海地球关键带科学与可持续发展重点实验室,天津300072 [3]天津环渤海滨海地球关键带国家野外科学观测研究站,天津300072 [4]物质绿色创造与制造海河实验室,天津300192 [5]天津市宁河区七里海湿地保护中心,天津301509

出　　处：《生态学杂志》2025年第1期85-93,共9页Chinese Journal of Ecology

基　　金：国家科技基础资源调查专项项目(2021FY101001);天津市科技局项目(21ZYJDJC00090);国家自然科学基金项目(41971123);天津市研究生科研创新项目(2021YJSS034)资助。

摘　　要：土壤呼吸是陆地CO_(2)排放的重要来源,明确CO_(2)动态及其控制因素对于全球变化研究具有重要意义。然而,目前关于湿地土壤呼吸的原位连续观测相对较少。本研究以环渤海地区的天津七里海湿地土壤为对象,采用CO_(2)通量传感器和土壤温、湿度传感器进行原位连续观测,探究生长季期间(2022年5月1日至9月30日)湿地土壤的CO_(2)通量昼夜和季节变化及水热因子特征,以及CO_(2)通量对土壤水热因子的响应。结果显示,生长季期间土壤CO_(2)通量先增加后降低,其平均值为6.68±2.55μmol·m^(-2)·s^(-1)。土壤CO_(2)通量与温度呈显著正相关,指数回归关系可以阐明研究期土壤呼吸75.7%的变化,生长季湿地土壤呼吸温度敏感性较强(Q_(10)=3.21)。昼夜尺度上,CO_(2)通量呈单峰型变化,与土壤温度之间具有滞后效应,主要呈现逆时针的变化特征。此外,土壤呼吸与土壤含水率呈弱负相关。在土壤先前水分条件的限制下,降雨初期会出现瞬时的CO_(2)通量峰值,随后在降雨时CO_(2)排放明显受到抑制,在短期降雨结束后土壤CO_(2)通量快速升高。本研究表明,温度是研究区生长季土壤呼吸的首要控制因子,同时土壤呼吸在降雨事件期间也明显受到土壤含水率影响。因此,在未来气候背景下的升温和降雨频率变化可能导致该湿地生态系统土壤碳通量变化更加强烈。Soil respiration plays a critical role in the CO_(2) emissions of terrestrial ecosystems. It is of great significance to identify the dynamics of CO_(2) and its controlling factors for global change research. Nevertheless, continuous in-situ observations of soil respiration in wetlands are relatively rare. In this study, we utilized CO_(2) flux sensor and soil temperature and moisture sensors to continuously monitor soil respiration in the Qilihai wetland, located in Tianjin, the Bohai Rim. Our objective was to investigate the diurnal and seasonal variations of CO_(2) flux, hydrothermal factors in wetland soil, and the response of CO_(2) flux to soil hydrothermal factors during the growing season(May 1 to September 30, 2022). The results showed that soil CO_(2) flux exhibited a first increasing and then decreasing trend during the growing season, with a mean value of 6.68±2.55 μmol·m^(-2)·s^(-1). Temperature was positively correlated with soil CO_(2) flux, which explained 75.7% of the variation in soil respiration during the study period. Moreover, wetland soil demonstrated a strong temperature sensitivity of soil respiration, with a Q_(10) value of 3.21. On a diurnal scale, CO_(2) flux displayed a unimodal variation, with a lag effect to soil temperature and a counterclockwise characteristic overall. Additionally, soil respiration exhibited a weak negative correlation with soil water content. With the limitations of initial soil moisture, CO_(2) flux reached a transient peak at the beginning of rainfall event, followed by a significant reduction in CO_(2) emissions during the rainfall, and then a rapid increase in CO_(2) flux at the end of the short-term rainfall. Overall, our results illustrated that soil temperature was the primary controlling factor for soil respiration during the growing season, and soil respiration was also influenced by soil water content during rainfall events. Thus, future warming and rainfall frequency associated with climate change could lead to significant changes in soil carbon f

关 键 词：湿地 土壤呼吸 土壤温度 Q_(10) 滞后现象 降雨事件 

分 类 号：X144[环境科学与工程—环境科学]