摘要
降水是干旱半旱地区土壤水分的主要来源,对该区植被恢复具有重要意义。本文采用EC-5土壤水分传感器对2014—2015年0~120 cm土壤水分进行连续监测,研究了退耕后不同恢复年限草地土壤水分动态变化及其0~40 cm土壤10 min时间尺度土壤水分对降水的响应。结果表明:土壤水分从恢复5 a草地向恢复15 a草地逐渐降低,这种降低趋势在恢复30 a草地减弱。恢复5 a草地土壤水分增幅最小,响应次数最少。单次降雨事件中,土壤水分增长过程和衰减过程均符合Logistic模型。恢复5 a草地相对稳定期(平台期)历时最长;恢复15 a草地土壤水分在表层(0~5,5~10 cm)增速最快,而在下层(20~40 cm)增速减慢且响应时间滞后;恢复30 a草地在下层(20~40 cm)增速最快。建议对恢复草地应适当采取措施,促进降雨向深层土壤水分转化,并减少恢复初期平台期历时。
Temporal variation in soil moisture and its response to precipitation are critically important for the growth of vegetation and ecological restoration in arid and semi-arid areas.Hence,we analyzed soil moisture dynamics and their response to rainfall on a 10 min timescale with EC-5 real-time soil moisture monitoring sensors in naturally restored grasslands of different restoration ages(5,15,and 30 years;RG5,RG15,and RG30,respectively).The results showed that soil moisture was high in RG5,decreased in RG15,and finally stopped decreasing in RG30.RG5 was characterized by lower response frequency and smaller response amplitude over two years with similar amounts of rainfall.The process of variation in soil moisture during a single heavy rainfall event can be divided into three periods:the rising period,the steady period,and the decreasing period,which is consistent with the logistic growth and decline model.The duration of the steady period in RG5 was greatest in each layer of the upper soil(0-40 cm).The response of RG15 was the most significant in the surface soil layer(0-5,5-10 cm),but there was an obviously lagged response in the 20-40 cm layer.Meanwhile,the response of RG30 was the most significant in the 20-40 cm soil layer.Our results indicate that the utilization of limited rainfall could be improved by promoting the conversion of rainfall to soil moisture in deep soil layers and by reducing the duration of the steady period or plateau period in the earlier restoration stage.
作者
邹慧
高光耀
朱斌
刘丹一
杨文斌
ZOU Hui;GAO Guang-yao;ZHU Bin;LIU Dan-yi;YANG Wen-bin(Chinese Academy of Forestry,Beijing 100091,China;China National Sand Control and Desert Industry Society,Beijing 100714,China;State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China)
出处
《干旱区研究》
CSCD
北大核心
2020年第4期890-898,共9页
Arid Zone Research
基金
中国林业科学研究院基本科研业务经费项目(CAFYBB2018MB011)
国家重点研发计划(2018YFC0507103)
国家自然科学基金项目(41390462)。
