植物生态学报 ›› 2016, Vol. 40 ›› Issue (9): 902-911.DOI: 10.17521/cjpe.2016.0029

• 研究论文 • 上一篇    下一篇

若尔盖高原湿地不同微地貌区甲烷排放通量特征

周文昌1,2, 崔丽娟1,*(), 王义飞1, 李伟1, 康晓明1   

  1. 1中国林业科学研究院湿地研究所湿地生态功能与恢复北京市重点实验室, 北京 100091
    2湖北省林业科学研究院, 武汉 430075
  • 收稿日期:2016-01-17 接受日期:2016-05-09 出版日期:2016-09-10 发布日期:2016-09-29
  • 通讯作者: 崔丽娟

Characteristics of methane emission fluxes in the Zoigê Plateau wetland on microtopography

Wen-Chang ZHOU1,2, Li-Juan CUI1,*(), Yi-Fei WANG1, Wei LI1, Xiao-Ming KANG1   

  1. 1Beijing Key Laboratory of Wetland Services and Restoration, Institute of Wetland Research, Chinese Academy of Forestry, Beijing 100091, China
    and
    2Hubei Academy of Forestry, Wuhan 430075, China
  • Received:2016-01-17 Accepted:2016-05-09 Online:2016-09-10 Published:2016-09-29
  • Contact: Li-Juan CUI

摘要:

若尔盖高原是我国泥炭沼泽湿地的主要分布区、青藏高原的主要甲烷(CH4)排放中心。为了研究湿地微地貌环境对高原湿地CH4排放通量的影响, 2014年5-10月, 采用静态箱和快速温室气体分析仪原位测量若尔盖高原湖滨湿地3种泥炭沼泽5种微地貌环境下的CH4排放通量特征。结果表明: (1)常年性淹水泥炭湿地洼地(P-hollow)和草丘(P-hummock)生长季平均CH4排放通量为68.48和40.32 mg·m-2·h-1, 季节性淹水的泥炭湿地洼地(S-hollow)和草丘(S-hummock)平均CH4排放通量为2.38和0.63 mg·m-2·h-1, 而无淹水平坦地(Lawn)平均CH4排放通量为3.68 mg·m-2·h-1; (2)湿地5种微地貌区CH4排放通量为(23.10 ± 30.28) mg·m-2·h-1 (平均值±标准偏差)), 变异系数为131%。分析显示这5种微地貌区CH4排放通量的平均值与其水位深度平均值存在显著的线性正相关关系(R2 = 0.919, p < 0.01), 表明水位深度是控制湿地微地貌区CH4排放通量空间变化的主要因子; (3) P-hummock、P-hollow和S-hummock的CH4排放通量存在显著的季节变化, Lawn和S-hollow无明显的季节性变化, 但5种微地貌区在夏季或秋季均观测到CH4排放通量峰值, 其影响因子可能与水位深度、土壤温度和凋落物输入密切相关; (4) P-hollow可能时常发生冒泡式CH4排放, 这可能导致过去低估了若尔盖高原湿地的CH4排放量。

关键词: 甲烷排放通量, 草丘, 洼地, 平坦地, 若尔盖高原湿地

Abstract:

AimsThe Zoigê Plateau, as a very important wetland distribution region of China, was the major methane (CH4) emission center of the Qinghai-Xizang Plateau. The objective of this study is to study the effects of microtopographic changes on CH4 emission fluxes from five plots across three marshes in the littoral zone of the Zoigê Plateau wetland.
Methods CH4 emission fluxes were measured in five plots across three marshes in Zoigê Plateau wetland using the closed chamber method and Fast Greenhouse Gas Analyzer from May to October in 2014.
Important findings During the growing season, mean CH4 emission fluxes from the permanently flooded hollow (P-hollow) and hummock (P-hummock) in the Zoigê Plateau wetland were 68.48 and 40.32 mg·m-2·h-1, while mean CH4 emission fluxes from the seasonally flooded hollow (S-hollow) and hummock (S-hummock) were 2.38 and 0.63 mg·m-2·h-1. CH4 emission fluxes from non-flooded lawn was 3.68 mg·m-2·h-1. Mean CH4 emission fluxes from five plots across three sites was 23.10 mg·m-2·h-1, with a standard deviation of 30.28 mg·m-2·h-1 and the coefficient of variation was 131%. We also found that there was a significant and positive correlation between mean CH4 emission fluxes and mean water table depth in the five plots across three sites (R2 = 0.919, p < 0.01), indicating that water table depth was controlling the spatial variability of CH4 emission fluxes from the Zoigê Plateau wetland on microtopography. CH4 emission fluxes in the P-hollow, P-hummock, and S-hummock showed an obvious seasonal pattern, which was not observed in the lawn and S-hollow. However, CH4 emission peaks were observed in all the plots during summer and/or autumn, which could be closely related to the water table depth, soil temperature, and the magnitude of litter mass. In addition, we found that the CH4 emission flux in the P-hollow was much higher than the other four plots in the Zoigê Plateau wetland, suggesting that CH4 in the P-hollow could be often transported to the surface by ebullition and CH4 emission from the Zoigê Plateau wetland may be under estimated in the past.

Key words: CH4 emission flux, hummock, hollow, lawn, Zoigê, Plateau wetland