植物生态学报 ›› 2013, Vol. 37 ›› Issue (6): 503-516.DOI: 10.3724/SP.J.1258.2013.00052

所属专题: 碳水能量通量

• 研究论文 • 上一篇    下一篇

开垦对黄河三角洲湿地净生态系统CO2交换的影响

杨利琼1,2,韩广轩1,*(),于君宝1,吴立新3,朱敏4,邢庆会1,2,王光美1,毛培利1   

  1. 1中国科学院海岸带环境过程与生态修复重点实验室, 中国科学院烟台海岸带研究所, 山东烟台 264003
    2中国科学院大学, 北京 100049
    3黄河三角洲国家级自然保护区管理局, 山东东营 257091
    4鲁东大学地理与规划学院, 山东烟台 264025
  • 收稿日期:2013-03-06 接受日期:2013-04-24 出版日期:2013-03-06 发布日期:2013-06-05
  • 通讯作者: 韩广轩
  • 基金资助:
    国家科技支撑计划项目(2011BAC02-B01);中国科学院知识创新工程重要方向项目(KZCX2-YW-223);国家林业科技支撑计划项目(2009BADB2B0502-01)

Effects of reclamation on net ecosystem CO2 exchange in wetland in the Yellow River Delta, China

YANG Li-Qiong1,2,HAN Guang-Xuan1,*(),YU Jun-Bao1,WU Li-Xin3,ZHU Min4,XING Qing-Hui1,2,WANG Guang-Mei1,MAO Pei-Li1   

  1. 1Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Chinese Academy of Sciences, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
    3Administration Bureau of the Yellow River Delta National Nature Reserve, Dongying, Shandong 257091, China
    4College of Geography and Planning, Ludong University, Yantai, Shandong 264025, China
  • Received:2013-03-06 Accepted:2013-04-24 Online:2013-03-06 Published:2013-06-05
  • Contact: HAN Guang-Xuan

摘要:

近年来, 由于对湿地的不合理利用, 自然湿地被大面积地垦殖为农田, 导致湿地生态系统碳循环的模式发生改变, 从而影响了湿地生态系统碳汇功能。该研究通过涡度相关法, 对山东省东营市黄河三角洲芦苇(Phragmites australis)湿地和开垦多年的棉花(Gossypium spp.)农田的净生态系统CO2交换(NEE)进行了对比观测, 以探讨该地区典型生态系统NEE的变化规律及其影响因子, 揭示开垦对芦苇湿地NEE和碳汇功能的影响。结果表明: 在生长季, 湿地和农田生态系统NEE的日平均值各月均呈明显的“U”型变化曲线, 非生长季NEE的变幅很小。生长季湿地生态系统日最大净吸收值和释放值分别为16.04 g CO2·m-2·d-1(8月17日)和14.95 g CO2·m-2·d-1(8月9日); 农田生态系统日最大净吸收值和释放值分别为18.99 g CO2·m-2·d-1 (8月22日)和12.23 g CO2·m-2·d-1 (7月29日)。生长季白天两个生态系统NEE与光合有效辐射(PAR)之间呈直角双曲线关系; 非生长季NEE主要受土壤温度(Ts)的影响; 生态系统生长季夜间NEETs和土壤含水量(SWC)的共同影响; 湿地和农田的生态系统呼吸熵(Q10)分别为2.30和3.78。2011年生长季, 黄河三角洲湿地和农田生态系统均表现为CO2的汇, 总净固碳量分别为780.95和647.35 g CO2·m-2, 开垦降低了湿地的碳吸收能力; 而在2011年非生长季, 黄河三角洲湿地和农田生态系统均表现为CO2的源, CO2总释放量分别为181.90和111.55 g CO2·m-2。全年湿地和农田生态系统总净固碳量分别为599.05和535.80 g CO2·m-2

关键词: 涡度相关, 净生态系统CO2交换, 开垦, 芦苇湿地, 黄河三角洲

Abstract:

Aims Wetland ecosystems are an obvious carbon sink, but with constant land reclamation, many wetlands disappeared and degenerated, and reclamation also influences the carbon-cycle between wetland ecosystems and the atmosphere. Cropland is a dominant use of reed (Phragmites australis) wetland in the Yellow River Delta, but the CO2 flux of wetland ecosystems under escalating human influences remains unclear. Our objective was to investigate the impact of wetland reclamation on net ecosystem CO2 exchange (NEE) dynamics and quantify CO2 exchange of the two ecosystems’ response to environmental and biological factors.
Methods Based on eddy covariance technique, we measured CO2 fluxes over the reed wetland and cropland ecosystems and monitored environmental and biological factors in 2011.
Important findings The averaged diurnal variation of NEE showed the U-type curve in different months of the growing season over wetland and cropland ecosystems. In the non-growing season, NEE lacked a diurnal pattern and the range of NEE was very small as the result of soil microbial activity. Analyses of NEE showed that the wetland was a net sink for each month from April to September 2011 and a source of CO2 to the atmosphere for the fall and winter months of November to March. In contrast, the cropland was calculated to be a significant net sink for CO2 in the growing season (May to October), while significant net losses of CO2 occurred in the non-growing season (November to April). During the growing season, the maximum daily CO2 uptake and release rates were 16.04 (August 17) and 14.95 (August 9) g CO2·m-2·d-1 and 18.99 (August 22) and 12.23 (July 29) g CO2·m-2·d-1over wetland and cropland, respectively. Daytime NEE values were strongly correlated with photosynthetic active radiation (PAR) in the growing season. The CO2 flux was mainly affected by temperature of soil (Ts) in the non-growing season. Soil water content (SWC) and Ts were the main factors that influenced nighttime NEE in the growing season. The two ecosystem respiration quotient (Q10) were 2.30 (wetland) and 3.78 (cropland) during the growing season. The wetland and cropland ecosystems were both carbon sinks during the growing season as they absorbed 780.95 and 647.35 g CO2·m-2, respectively, which means wetland reclamation can reduce its carbon sequestration ability. During the non-growing season, the two ecosystems were carbon sources, releasing 181.90 (wetland ecosystem) and 111.55 (cropland ecosystem) g CO2·m-2. Over all of 2011, the wetland and cropland ecosystems both were obvious carbon sinks with absorption of 599.05 and 535.80 g CO2·m-2, respectively.

Key words: eddy covariance, net ecosystem CO2 exchange, reclamation, reed wetland, Yellow River Delta