植物生态学报 ›› 2017, Vol. 41 ›› Issue (3): 290-300.DOI: 10.17521/cjpe.2016.0258

• 研究论文 • 上一篇    下一篇

新疆古尔班通古特沙漠土壤N2O、CH4和CO2通量及其对氮沉降增加的响应

周晓兵1, 张元明1,*(), 陶冶1,2, 吴林1,3   

  1. 1中国科学院新疆生态与地理研究所, 干旱区生物地理与生物资源重点实验室, 乌鲁木齐 830011
    2安庆师范大学, 安徽安庆 246000
    3湖北民族学院, 湖北恩施 445000
  • 出版日期:2017-03-10 发布日期:2017-04-12
  • 通讯作者: 张元明
  • 作者简介:* 通信作者Author for correspondence (E-mail:sunzhiqiang1956@sina.com)
  • 基金资助:
    新疆维吾尔自治区自然科学基金面上项目(2015211A052)

Effluxes of nitrous oxide, methane and carbon dioxide and their responses to increasing nitrogen deposition in the Gurbantünggüt Desert of Xinjiang, China

Xiao-Bing ZHOU1, Yuan-Ming ZHANG1,*(), Ye TAO1,2, Lin WU1,3   

  1. 1Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Ürümqi 830011, China

    2Anqing Normal University, Anqing, Anhui 246000, China
    and
    3Hubei University for Nationalities, Enshi, Hubei 445000, China
  • Online:2017-03-10 Published:2017-04-12
  • Contact: Yuan-Ming ZHANG
  • About author:KANG Jing-yao(1991-), E-mail: kangjingyao_nj@163.com

摘要:

沙漠土壤在全球土壤主要温室气体通量中扮演着重要角色, 但是在环境变化条件下的通量估算结果存在很大的不确定性。在新疆古尔班通古特沙漠设定N0、N0.5、N1、N3、N6和N24 6个样方, 以0、0.5、1.0、3.0、6.0和24.0 g·m-2·a-1 6个不同模拟氮(N)沉降浓度进行N处理, 两年后开始对施N样方进行为期两个生长季的N2O、CH4和CO2通量测定。研究表明生长季对照样方(N0)的N2O、CH4和CO2的平均通量分别为4.8 μg·m-2·h-1、-30.5 μg·m-2·h-1和46.7 mg·m-2·h-1, 季节变化显著影响3种气体的通量。N0、N0.5和N1在春季和夏季具有相似的N2O排放速率, 排放速率高于秋季, 而N6和N24的N2O排放主要受N输入时间影响; CH4的吸收在春季和夏季相对较高, 秋季较低; CO2的排放量在第一年春季和夏季之间变化较小, 但高于秋季排放量, 第二年CO2动态与N浓度相关。N增加通常能显著促进N2O的排放, 但受测定季节和年度的影响, 且各处理的N2O排放因子大小无明显规律; CH4的吸收受N增加影响不显著; CO2的排放在第一年不受N增加的影响, 第二年高浓度N增加对春季和夏季CO2排放具有限制作用, 对秋季影响不显著。结构方程模型的研究表明, 对N2O、CH4和CO2的动态变化影响较大的因子分别是施N浓度、土壤温度或土壤含水量和植株密度。整个生长季由N带来的净通量和增温潜力非常小。

关键词: 氮沉降, N2O, CH4, CO2, 生物量, 结构方程模型

Abstract:

Aims Desert soils play an important role in the exchange of major greenhouse gas (GHG) between atmosphere and soil. However, many uncertainties existed in understanding of desert soil role, especially in efflux evaluation under a changing environment. Methods We conducted plot-based field study in center of the Gurbantünggüt Desert, Xinjiang, and applied six rates of simulated nitrogen (N) deposition on the plots, i.e. 0 (N0), 0.5 (N0.5), 1.0 (N1), 3.0 (N3), 6.0 (N6) and 24.0 (N24) g·m-2·a-1. The exchange rates of N2O, CH4 and CO2 during two growing seasons were measured for two years after N applications. Important findings The average efflux of two growing seasons from control plots (N0) were 4.8 μg·m-2·h-1, -30.5 μg·m-2·h-1 and 46.7 mg·m-2·h-1 for N2O, CH4 and CO2, respectively. The effluxes varied significantly among seasons. N0, N0.5 and N1 showed similar exchange of N2O in spring and summer, which was relatively higher than in autumn, while the rates of N2O in N6 and N24 were controled by time points of N applications. The uptake of CH4 was relatively higher in both spring and summer, and lower in autumn. Emission of CO2 changed minor from spring to summer, and greatly decreased in autumn in the first measured year. In the second year, the emission patterns were changed by rates of N added. N additions generally stimulated the emission of N2O, while the effects varied in different seasons and years. In addition, no obvious trends were found in the emission factor of N2O. The uptake of CH4 was not significantly affected by N additions. N additions did not change CO2 emissions in the first year, while high N significantly reduced the CO2 emissions in spring and summer of the second year, without affected in autumn. Structure equation model analysis on the factors suggested that N2O, CH4 and CO2 were dominantly affected by the N application rates, soil temperature or moisture and plant density, respectively. Over the growing seasons, both the net efflux and the global warming potential caused by N additions were small.

Key words: nitrogen deposition, N2O, CH4, CO2, biomass, structural equation model