科尔沁沙地樟子松人工林土壤水分动态及其对降雨的响应  

Dynamic changes in soil moisture and its response to rainfall in Pinus sylvestris var.mongolica plantation in Horqin Sandy Land

作　　者：吉吉佳门 程一本 谌玲珑 万鹏翔 张祎晖 杨文斌[2] 白旭赢 王涛 JIJI Jiamen;CHENG Yiben;CHEN Linglong;WAN Pengxiang;ZHANG Yihui;YANG Wenbin;BAI Xuying;WANG Tao(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Institute of Desertification Studies,Chinese Academy of Forestry,Beijing 100091,China;Inner Mongolia Low Coverage Sand Control Technology Development Co.,Ltd.,Hohhot 010010,Inner Mongolia,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]中国林业科学研究院荒漠化研究所,北京100091 [3]内蒙古低覆盖治沙科技开发有限公司,内蒙古呼和浩特010010

出　　处：《干旱区研究》2023年第5期756-766,共11页Arid Zone Research

基　　金：中国和美国政府间合作项目(2019YFE0116500);内蒙古自治区科技重大专项(2019ZD003);中国林科院荒漠化所结余经费新立项目(IDS2022JY-8,IDS2022JY-9);林业科学技术推广项目([2019]33号);北京林业大学大学生创新训练项目(X202110022026,X202110022042,S202110022028)。

摘　　要：在科尔沁沙地采用“两行一带”种植模式低密度栽培樟子松进行生态修复后,林地土壤水分动态及其对降雨的响应影响了同类型地区是否可以持续使用樟子松进行生态修复。为了研究科尔沁沙地南缘植被修复后土壤水分动态特征,本研究综合运用原位观测、数值模拟的方法,基于土壤水分实测数据校正Hydrus-1D模型,探究降雨-土壤水分响应关系。结果表明:(1)樟子松人工林显著改变了地区水分分布,裸沙地2.0 m处深层渗漏量占降雨量的44.16%,而樟子松林地深层渗漏量仅占降雨量的0.7%。(2)监测期内,0.4 m深度以下土壤水分对小雨无响应,土壤水分对中雨的响应深度可达1.0 m,对大雨和暴雨的响应深度涉及整个观测剖面。随着土壤深度的增加,水分波动幅度呈现减小的趋势。(3)降雨量和深度较浅的土壤体积含水量之间存在较强的相关关系,周期为周、半月的累计降雨量与各层土壤体积含水量显著相关;降雨量大于50 mm时,能保证对2.0 m处土壤水分的补给。(4)模型的决定系数范围在0.61~0.85,均方根误差范围在0.0061~0.0096 cm^(3)·cm^(-3),能较好地模拟研究区土壤水分的动态变化特征,且深层模拟精度高于浅层。研究结果对科尔沁沙地雨养型植被造林、生态恢复和水资源管理具有重要的意义。After ecological restoration in Horqin Sandy Land,the soil moisture dynamics of the forest and its response to rainfall affect whether Pinus sylvestris var.mongolica(PSM)can be continuously used for the ecological restoration in the same type of area.To study the characteristics of soil moisture dynamics after vegetation restoration on the southern edge of Horqin Sandy Land,this study used the methods of in situ observation and numerical simulation and corrected the HYDRUS-1D model based on the measured data of soil moisture to explore its relationship with rainfall.We obtained the following results:(1)The regional moisture distribution was changed by the PSM plantation,deep soil recharge at 2.0 m in bare sand accounted for 44.16%of the annual rainfall,whereas deep soil recharge at 2.0 m in PSM land accounted for only 0.7%of the annual rainfall.(2)Soil moisture below a depth of 0.4 m had no response to light rain,but the response depth of soil moisture to moderate rain could reach 1.0 m.The response depth to heavy rain and rainstorm involved the entire observation profile.With increasing soil depth,a decreasing trend was observed in the variation in moisture fluctuation.(3)There was a strong correlation between rainfall and volumetric soil water content at shallow depth,and the cumulative rainfall at weekly and semi-monthly intervals was significantly correlated with the volumetric soil water content of each layer(P<0.05).Rainfall>50 mm can ensure the supply of soil moisture within 2.0 m.(4)The determination coefficient of the model was between 0.61 and 0.85,and the root mean square error ranged from 0.0061 to 0.0096 cm^(-3)·cm^(-3).The accuracy of the deep layer simulation was higher than that of the shallow layer.These results have important implications for rain-fed vegetation afforestation in the Horqin Sandy Land.

关 键 词：降雨入渗 土壤水分 深层渗漏 樟子松 科尔沁沙地 

分 类 号：S714.2[农业科学—林学]