荒漠-绿洲过渡带典型固沙植物根区土壤大孔隙特征及影响因素  

Characteristics and influencing factors of soil macropores in the root zone of sand-fixing plants in the desert-oasis transition zone

作　　者：李嘉楠 周成乾 胡广录[2,3] 杨鹏华 李昊辰 LI Jianan;ZHOU Chengqian;HU Guanglu;YANG Penghua;LI Haochen(Gansu Provincial Institute of Soil and Water Conservation Science,Lanzhou 730020,Gansu,China;School of Environment and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,Gansu,China;Key Laboratory of Yellow River Water Environment in Gansu Province,Lanzhou 730070,Gansu,China)

机构地区：[1]甘肃省水土保持科学研究所,甘肃兰州730020 [2]兰州交通大学环境与市政工程学院,甘肃兰州730070 [3]甘肃省黄河水环境重点实验室,甘肃兰州730070

出　　处：《干旱区研究》2024年第12期2015-2026,共12页Arid Zone Research

基　　金：国家自然科学基金项目(41561102,41867074);甘肃省水利厅水利科学试验研究技术推广项目(甘水建管发[2021]71号)。

摘　　要：土壤大孔隙是土壤水分入渗的主要通道,探究荒漠-绿洲过渡带典型固沙植物根区土壤大孔隙特征及其影响要素,对于区域生态植被恢复和固沙植物的选择具有重要借鉴意义。通过水分穿透实验,研究了黑河中游荒漠-绿洲过渡带典型固沙植物根区土壤大孔隙特征,分析了土壤大孔隙的影响因素以及大孔隙对土壤饱和导水率的影响。结果表明:(1)土壤大孔隙半径范围在0.5~1.6 mm,大于最小通气孔隙半径0.3 mm,土壤水分运动主要以重力水为驱动力,过渡带固沙植物根区土壤大孔隙呈现出随土层深度增加而减小的趋势,整体表现为小半径孔隙多,大半径孔隙少的特点。(2)土壤容重与除大孔隙总数量外的其他土壤大孔隙特征指标均呈极显著负相关关系;饱和含水率与除土壤大孔隙总数量外的其他大孔隙特征指标均呈显著正相关关系;有机质含量与各土壤大孔隙特征指标均呈极显著正相关关系。(3)土壤饱和导水率在2.32~3.79 mm·min^(-1),且土壤大孔隙体积比、大孔隙面积比、大孔隙平均半径的4次方和大孔隙总数量分别决定了饱和导水率82%、68%、79%和43%的变异。(4)在研究区相同生境条件下,与裸地相比,固沙植物的栽植能够显著提升土壤水分的渗透能力,固沙植物根区土壤水分渗透能力从强到弱为梭梭、沙拐枣、泡泡刺。Soil macropores are the main channels for soil moisture infiltration.Investigating their characteristics and influencing factors in the root zone of typical sand-fixing plants in the desert-oasis transition zone is crucial for regional ecological vegetation restoration and plant selection.In this study,we investigated the characteristics of soil macropores in the root zone of these plants in the middle reaches of the Heihe River desert-oasis transi-tion zone through water penetration experiments.We analyzed the influencing factors of soil macropores and their impact on soil-saturated hydraulic conductivity.The results show the following:(1)The radius of soil mac-ropores ranges from 0.5 to 1.6 mm,exceeding the minimum aeration pore radius of 0.3 mm.Soil moisture move-ment is mainly driven by gravitational water.The density of soil macropores in the root zone of sand-fixing plants in the transition zone decreases with increasing soil depth,characterized by a higher number of smaller pores and fewer larger pores.(2)Soil bulk density and other soil macropore indicators,except for the total num-ber of macropores,showed a highly significant negative correlation.Conversely,saturated water content and oth-er macroporosity indicators,except for the total number of macropores,exhibited a significant positive correla-tion.Additionally,organic matter content and various soil macropore indicators showed a highly significant posi-tive correlation.(3)The saturated hydraulic conductivity of the soil ranged from 2.32 to 3.79 mm·min^(-1).The vari-ation in saturated hydraulic conductivity was determined by the soil macroporous volume ratio(82%),macropo-rous area ratio(68%),the fourth power of the average radius of macroporous space(79%),and the total number of macropores(43%).(4)Under the same habitat conditions in the study area,planting sand-fixing plants signifi-cantly improved the water infiltration ability of the soil compared to bare land.Among the three sand-fixing plants studied,their water infiltration abilities ranked as

关 键 词：荒漠-绿洲过渡带 固沙植物 水分穿透曲线 土壤大孔隙 

分 类 号：S152.7[农业科学—土壤学]