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应用生态学报 ›› 2020, Vol. 31 ›› Issue (6): 1989-1998.doi: 10.13287/j.1001-9332.202006.015

• 研究报告 • 上一篇    下一篇

科尔沁沙地流动沙丘不同时空尺度水热变化及CO2交换特征

杨晓君1, 刘廷玺1,2*, 王冠丽1,2, 段利民1,2, 李东方1,2, 黄天宇1   

  1. 1内蒙古农业大学水利与土木建筑工程学院, 呼和浩特 010018;
    2内蒙古自治区水资源保护与利用重点实验室, 呼和浩特 010018
  • 收稿日期:2020-01-16 出版日期:2020-06-15 发布日期:2020-06-15
  • 通讯作者: * E-mail: txliu1966@163.com
  • 作者简介:杨晓君, 女, 1995年生, 硕士研究生。主要从事干旱区水热碳通量研究。E-mail: 1628197917@qq.com
  • 基金资助:
    国家自然科学基金重点国际(地区)合作研究项目(51620105003)、国家自然科学基金项目(51479086,51669017,51769020)、内蒙古自然科学基金重点项目(2018ZD05)、教育部创新团队发展计划项目(IRT_17R60)、科技部重点领域科技创新团队项目(2015RA4013)、内蒙古自治区草原英才产业创新创业人才团队项目、内蒙古农业大学寒旱区水资源利用创新团队项目(NDTD2010-6)和内蒙古自然科学基金项目(2016BS0514)资助

Characteristics of humidity and temperature variations and CO2 exchange of mobile dunes at different space-time scales in Horqin sandy land, China

YANG Xiao-jun1, LIU Ting-xi1,2*, WANG Guan-li1,2, DUAN Li-min1,2, LI Dong-fang1,2, HUANG Tian-yu1   

  1. 1College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China;
    2Inner Mongolia Key Laboratory of Water Resource Protection and Utilization, Hohhot 010018, China
  • Received:2020-01-16 Online:2020-06-15 Published:2020-06-15
  • Contact: * E-mail: txliu1966@163.com
  • Supported by:
    This work was supported by the National Natural Science Foundation for the Key Program of International Cooperation Project (51620105003), the National Natural Science Foundation of China (51479086, 51669017, 51769020), the Region Key Program of the Inner Mongolia (2018ZD05), the Ministry of Education Innovation Research Team (IRT_17R60), the Innovation Team in Priority Areas Accredited by the Ministry of Science and Technology (2015RA4013), the Inner Mongolia Industrial Innovative Research Team, the Inner Mongolia Agricultural University Innovative Research Team of Water Resource in Cold and Dry Area (NDTD2010-6) and the Natural Science Program of the Inner Mongolia (2016BS0514).

摘要: 陆面碳循环在气候变化和生态系统碳收支平衡中起到关键作用。水热变化与CO2交换分析对于深刻揭示荒漠生态系统的区域碳循环规律及机制具有重要意义。本研究选取科尔沁沙地典型流动沙丘为对象,利用涡度相关技术和波文比气象观测系统所测的数据分析近地层水热变化及CO2交换特征,探讨了日和季节尺度,以及0~10 m垂直空间尺度下流动沙丘近地层温湿度与CO2交换过程的相互关系。结果表明: 研究区近地表气温垂直变幅在0.4~2 ℃,4—9月,气温随着高度的升高呈减的趋势,其余月份则相反,空气相对湿度季节变幅超过40%;在2018年生长季,沙丘净生态系统碳交换量(NEE)的日均值为-0.02 mg·m-2·s-1,全年水平的NEE日均值为0.003 mg·m-2·s-1,全年整体上表现为碳源;垂直空间尺度上,垂直温、湿度差与NEE拟合均较好,水热影响拐点分别为10%和0.5 ℃,而全年尺度上温度拟合结果相对较好,水热影响拐点分别为17 ℃和65%。在生长季,研究区近地层垂直温差为负,会抑制流动沙丘对大气CO2的吸收,而大气高湿环境则会促进流动沙丘对大气CO2的吸收。不同时间和不同垂直高度上,水热变化与CO2交换关系较密切,对沙丘碳汇和碳源的产生具有一定的影响,且碳收支对温度的敏感性强于相对湿度。

Abstract: Terrestrial carbon cycle plays a key role in driving climate change and ecosystem carbon balance. Understanding the variations of humidity and temperature and CO2 exchanges are meaningful to reveal the law and mechanism of regional carbon cycles in deserts. We examined the near surface humidity, temperature variations, and CO2 exchanges by eddy covariance and Bowen ratio systems in a typical mobile dune of Horqin sandy land. We analyzed the relationships between water-heat and CO2 exchanges of 0 to 10 m vertical height at daily and seasonal scales were analyzed. The results showed that the vertical variations of near surface temperature ranged from 0.4 ℃ to 2 ℃ and decreased with the increases of height from April to September, but with an opposite pattern in other months. The seasonal variation of air relative humidity was greater than 40%. During the growing season of 2018, the averaged daily net ecosystem carbon exchange (NEE) was -0.02 mg·m-2·s-1. The annual averaged daily NEE was 0.003 mg·m-2·s-1, indicating that the mobile dunes were carbon sources at the whole year scale. The vertical differences of temperature and humidity well fitted the NEE. The inflexion points of the fitting curve were at 10% humidity and 0.5 ℃ temperature, respectively. At the scalem of the year, the NEE fitting result of temperature was better than that of humidity, with the inflexion points at 17 ℃ and 65% humidity, respectively. In the growing season, the near surface vertical temperature difference was negative, which would inhibit CO2 absorption of mobile dunes. The circumstances of high humidity would promote the absorption of atmospheric CO2. Across different time and vertical height, the variations of humidity and temperature were closely related to CO2 exchanges, which affected carbon sink and source of mobile dunes. Carbon budget was more sensitive to temperature than humidity.