摘要
[目的]本研究以青海共和盆地中间锦鸡儿人工林为研究对象,分析其土壤呼吸与环境因子的关系及自然降雨对土壤呼吸和环境因子的影响机制,以期为高寒沙区人工林土壤碳通量估算和碳循环研究提供依据和理论参考。[方法]于2018年7月,在观测样内地开展30 d的连续定位观测试验,对其土壤呼吸速率和环境因子变化及自然降雨过程进行定量分析研究。[结果](1)土壤呼吸受太阳总辐射、空气温度、土壤温度和土壤含水量等环境因子影响,其中,太阳总辐射影响较直接;(2)无降雨日土壤呼吸主要受表层(10 cm)土壤温湿度影响,降雨过程中主要受深层(150 cm)土壤温湿度影响。累计降雨量大于0.8 mm的自然降雨对土壤呼吸日均值有抑制作用,且激发效应通常出现在降雨结束次日,约持续3 d;(3)大于0.07 mm的自然降雨发生即抑制土壤呼吸速率,其在累计降雨量达10.44 mm、降雨时长达3~4 h时抑制率最高;(4)自然降雨可使Q10值短期升高。[结论]研究区土壤呼吸主要源于植物根系自养呼吸,自然降雨过程对其具有显著抑制作用,并在降雨结束次日出现激发效应;同时,自然降雨可使Q10值升高。
[Objective] Caragana intermedia plantation in Gonghe Basin of Qinghai province was used to analyze the relationship between soil respiration and environmental factors, and the effects of natural rainfall on soil respiration and environmental factors, so as to provide reference for estimation of soil carbon flux and the study of carbon cycle in the alpine sandy plantations. [Method] A 30-days’ continuous positioning observation was conducted in July, 2 018. The changes of soil respiration rate, environmental factors and natural rainfall process were analyzed quantitatively. [Result](1) The soil respiration was affected by environmental factors such as solar radiation, air temperature, soil temperature and soil moisture, among which the total solar radiation showed a more direct effect.(2) Soil respiration in non rainy day was mainly affected by soil temperature and moisture of the surface soil layer, while during rainfall, it was mainly affected by deep soil temperature and moisture. The natural rainfall with cumulative rainfall more than 0.8 mm showed an inhibitory effect on the daily average of soil respiration, and the excitation effect usually occurred on the next day after the end of rainfall, and lasted about 3 days.(3) Soil respiration rate was inhibited when the rainfall was more than 0.07 mm, and the inhibition rate was the highest when the cumulative rainfall reached 10.44 mm and rainfall time reached 3-4 hours.(4) Natural rainfall caused a short-term increase of the sensitivity of soil respiration to temperature. [Conclusion] Soil respiration in the study area is mainly due to plant root autotrophic respiration, the natural rainfall process has a significant inhibitory effect on it, and the excitation effect occurs in the next day after the rain ends. Natural rainfall can increase the sensitivity of soil respiration to temperature.
作者
戴捷
贾志清
李清雪
何凌仙子
杨凯悦
高娅
DAI Jie;JIA Zhi-qing;LI Qing-xue;HE Ling-xian-zi;YANG Kai-yue;GAO Ya(Institute of Desertification Studies,Chinese Academy of Forestry,Boijing 10091,China;Rescarch Institute of Forestry,Chinese Academy of Forestry,Bejing 10091,China;Qinghai Gonghe Desert Eoosystem Research Station,Gonghe 813005,Qinghai,China)
出处
《林业科学研究》
CSCD
北大核心
2020年第4期151-159,共9页
Forest Research
基金
国家自然科学基金(31670706、31600585)
林业公益性行业科研专项经费项目(201504420)。
关键词
高寒沙地
人工林
土壤呼吸
自然降雨
温度系数
alpine sandland
plantation
soil respiration
natural rainfall
temperature quotient
