华东师范大学学报(自然科学版) ›› 2021, Vol. 2021 ›› Issue (4): 109-120.doi: 10.3969/j.issn.1000-5641.2021.04.013

• 地理学 • 上一篇    下一篇

不同土地利用类型土壤温室气体排放对温湿度的响应

桑文秀1, 杨华蕾1, 唐剑武1,2,*()   

  1. 1. 华东师范大学 河口海岸学国家重点实验室, 上海 200241
    2. 崇明生态研究院, 上海 202162
  • 收稿日期:2020-07-30 出版日期:2021-07-25 发布日期:2021-07-23
  • 通讯作者: 唐剑武 E-mail:jwtang@sklec.ecnu.edu.cn
  • 基金资助:
    国家自然科学基金(41571130053)

Response of soil greenhouse gas emissions to temperature and moisture across different land-use types

Wenxiu SANG1, Hualei YANG1, Jianwu TANG1,2,*()   

  1. 1. State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
    2. Institute of Eco-Chongming, Shanghai 202162, China
  • Received:2020-07-30 Online:2021-07-25 Published:2021-07-23
  • Contact: Jianwu TANG E-mail:jwtang@sklec.ecnu.edu.cn

摘要:

针对我国南方红壤(江西鹰潭孙家坝小流域)4种不同土地利用类型, 在2019年6—10月开展了室内土壤温湿度控制实验, 采用温室气体分析仪(Picarro-G2508)结合静态箱法对土壤温室气体(CO2、CH4、N2O)排放通量进行同步实时监测, 以研究全球气候变化背景下不同土地利用类型土壤温室气体排放差异及其对温湿度的响应. 结果显示, 4种土地利用类型土壤的全球增温潜势(global warming potential, GWP)从高到低依次为稻田、橘园、林地、旱地, 表明稻田土壤温室气体排放对全球变暖贡献最大. 温控实验中, 土壤呼吸(CO2排放)与土壤温度呈显著正指数相关关系(p < 0.01), 且4种土地利用类型土壤呼吸的温度敏感系数 Q10值分别为林地2.61、旱地2.51、橘园3.12、稻田3.17. 其中, 稻田土壤呼吸的温度敏感度最高, 表明稻田土壤具有较高的CO2排放潜力, 而CH4、N2O排放与土壤温度的相关性不显著. 湿度控制实验中, 土壤CO2排放随土壤湿度增加而先升高后降低, 并在土壤湿度20% GWC (gravity water content)时达到最大; 稻田土壤CH4排放与土壤湿度正相关(R2 = 0.8875), 但其他3种土地利用类型土壤CH4排放与土壤湿度不相关; 4种土地利用类型土壤N2O排放通量均随土壤湿度的增加呈先增后减趋势, 并在土壤湿度为25% GWC时达到峰值.

关键词: 土地利用类型, 温室气体, 红壤, 温度, 湿度

Abstract:

In this paper, soil samples were collected from the red soil region of southern China (namely, the Sunjiaba small watershed in Yingtan, Jiangxi) across four different land-use types. Laboratory incubation experiments were subsequently carried out from June 2019 to October 2019. We used a closed chamber to measure soil greenhouse gases (CO2, CH4, N2O) simultaneously with the help of an advanced greenhouse gas analyzer (Picarro-G2508). The aim was to explore the response of soil greenhouse gas emissions across different land-use types to changes in temperature and soil moisture levels under the premise of global climate change. The results showed that the global warming potential (GWP) of the four land-use types increases with paddy, orangery, forest, and upland, respectively. This suggests that greenhouse gas emissions from paddy soils have the greatest relative impact on global warming. In a temperature-controlled experiment, soil CO2 emissions were shown to have a significant positive correlation with soil temperature. The Q10 values of soil respiration coefficients for the four land-use types were: 2.61 (forest), 2.51 (upland), 3.12 (orangery), and 3.17 (paddy). Thus, paddy soil respiration has the highest temperature sensitivity, indicating that paddy soil has a higher CO2 emission potential. Correlations were not significant between CH4 and N2O emissions to soil temperature. In the moisture-controlled experiment, the results indicated that soil CO2 emissions increased at the beginning and then decreased with increasing soil moisture, with the maximum emission rate at 20% GWC (gravity water content). CH4 emissions from paddy soils increased with soil moisture (R2 = 0.8875); CH4 fluxes from the other three land-use types, however, were not significantly related to soil moisture. The soil N2O emissions increased at the beginning and then decreased across the soil moisture range measured; all land-use types had the highest N2O fluxes at 25% GWC.

Key words: land-use types, greenhouse gas, red soil, temperature, moisture

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