黄土高原极端降水对人工林地深层土壤水分的补给效应  

Recharge effect of extreme precipitation on deep soil water in artificial forest on the Loess Plateau

作　　者：吴亚彪 高晓东[2,3] 何娜娜 葛东 于流洋 张利 WU Yabiao;GAO Xiaodong;HE Nana;GE Dong;YU Liuyang;ZHANG Li(College of Water Resources and Architectural Engineering,Northwest Agriculture and Forestry University,Yangling 712100,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,China;College of Soil and Water Conservation Science and Engineering,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,杨凌712100 [2]中国科学院水利部水土保持研究所,杨凌712100 [3]西北农林科技大学水土保持科学与工程学院,杨凌712100

出　　处：《生态学报》2024年第23期10757-10769,共13页Acta Ecologica Sinica

基　　金：国家重点研发计划(2021YFD1900700);陕西省自然科学基础研究计划(2021JC-19);唐仲英基金。

摘　　要：深层土壤干燥化严重制约了黄土高原深根系植被的持续发展。然而,频发的极端降水事件能否缓解深层土壤水分亏缺仍尚不明晰。采用文献调研和实地重采样相结合的方法探究2021年黄土高原极端降水事件对典型人工林地(苹果和刺槐)深层土壤水分亏缺的影响。结果表明:(1)2021年长武(累积极端降水量524.5 mm)和洛川(累积极端降水量467.4 mm)地区极端降水能完全恢复2.2—6.8 m的土壤干层,最低干燥化指数从29.1%恢复到147%。(2)长武14龄、19龄和24龄苹果园的补给深度均达到10 m,降水补给量分别为777.7 mm、1513.1 mm和1301.4 mm;洛川19龄和29龄苹果园的补给深度为6 m和10 m,降水补给量为388.4 mm和459.9 mm。由于极端降水贡献率高,平水年的庆阳地区16龄苹果园补给深度也达到10 m,补给量为619.7 mm。(3)米脂和子长地区人工林地面临严重的土壤干燥化问题,1—10 m垂直剖面分布深厚的土壤干层,其平均土壤含水量已低于6.5%。综上,极端降水有补给深层土壤水分的潜力,而缓解土壤干燥化的能力与极端降水量有关。研究结果为极端天气频发背景下黄土高原不同地区人工林的发展趋势提供理论依据。Severe deep soil desiccation seriously constrains the sustainable development of deep root vegetation on the Loess Plateau.However,it remains unclear whether frequently extreme precipitation events can alleviate the deficit of deep soil moisture.This study employed a combination of literature review and field resampling to investigate the impact of extreme precipitation events in 2021 on deep soil moisture deficits in typical artificial forest areas(apple and locust)on the Loess Plateau.The results indicated that:(1)In 2021,the extreme precipitation in Changwu(cumulative extreme precipitation of 524.5 mm)and Luochuan(cumulative extreme precipitation of 467.4 mm)could completely restore the soil dry layer of 2.2—6.8 m,with the lowest desiccation index recovering from 29.1%to 147%.(2)In the 14-year-old,19-year-old,and 24-year-old apple orchards in Changwu,the recharge depth reached 10 m,with precipitation recharge amounts of 777.7 mm,1513.1 mm,and 1301.4 mm,respectively.In the 19-year-old and 29-year-old apple orchards in Luochuan,the recharge depths were 6 meters and 10 meters,with precipitation recharge amounts of 388.4 mm and 459.9 mm,respectively.Due to the high contribution rate of extreme precipitation,even in normal water years,the 16-year-old apple orchard in Qingyang had a recharge depth of 10 meters,with a precipitation recharge amount of 619.7 mm.(3)Artificial forest land in Mizhi and Zichang areas was facing serious soil desiccation problems,resulting in a deep soil desiccation layer in the 1—10 meter vertical profile,with an average soil moisture content of less than 6.5%.In conclusion,extreme precipitation has the potential to recharge deep soil water,and the ability to alleviate soil desiccation is related to extreme precipitation.The research results provide a theoretical basis for the development trend of plantation in different areas of the Loess Plateau under the background of frequent extreme weather.

关 键 词：黄土高原 人工林 极端降水 土壤干燥化 深层土壤水补 

分 类 号：S714.2[农业科学—林学]