草地覆盖度和鼠丘对高寒草地表层土壤颗粒特征的影响  

Influences of Vegetation Coverage and Rodent Mounds on Topsoil Particle Characteristics of Alpine Grassland

作　　者：翟辉 李国荣[1,2] 李进芳 童生春[1,2] 赵健赟 朱海丽[1,2] 刘亚斌 李希来[3] 胡夏嵩 ZHAI Hui;LI Guorong;LI Jinfang;TONG Shengchun;ZHAO Jianyun;ZHU Haili;LIU Yabin;LI Xilai;HU Xiasong(Department of Geological Engineering,Qinghai University,Xining 810016,China;Key Lab of Cenozoic Resource&Environment in North Margin of the Tibetan Plateau,Xining 810016,China;College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China)

机构地区：[1]青海大学地质工程系,西宁810016 [2]青藏高原北缘新生代资源环境重点实验室,西宁810016 [3]青海大学农牧学院,西宁810016

出　　处：《水土保持研究》2023年第5期122-129,共8页Research of Soil and Water Conservation

基　　金：青海省科技厅基础研究项目(2021-ZJ-701);国家自然科学基金项目(41662023,42161068)。

摘　　要：[目的]揭示黄河源区高寒草地表土颗粒粒径组成的变化特征,阐明影响草地土壤退化的因素,并进而为黄河源区退化草地的综合治理提供一定的指导作用。[方法]以青海省河南县禁牧区自然条件下不同覆盖度(0%,5%,25%,50%,75%和100%)和2类鼠丘的新旧表层土壤作为研究对象,通过野外调查和室内试验,分析黄河源区不同盖度草地及鼠丘分布对草地表土颗粒粒径组成的影响。[结果](1)高寒草地表面土壤平均粒径随草盖度的降低而增加,其中粒径小于2μm的土壤粒径含量变化幅度最小,20~50μm和50~250μm的粒径含量变化幅度最大,粒径为20~50μm的土粒是土壤侵蚀相对敏感的颗粒。(2)黄河源区未退化草地表层土壤粒径组成主要以粉粒为主,黏粒、粉粒含量和盖度间呈线性正相关,砂粒含量与盖度间呈线性负相关。裸地砂粒含量较原生草地增加了21.96%,高原鼢鼠和高原鼠兔鼠丘分别增加了27.86%和33.14%。(3)形成时间相同的2类鼠丘土壤粒径组成特征差异性不明显,高原鼠兔和高原鼢鼠旧鼠丘的黏粒含量较新生鼠丘分别减少了5.85%,6.32%,粉粒分别减少了28.99%,23.01%,砂粒分别增加了34.84%,29.33%,土壤平均粒径增加了近2倍,鼠丘表层土壤呈现出明显的土壤粗粒化和沙化现象。[结论]提高草地覆盖度到50%以上时和降低新生鼠丘密度能有效防治高寒草地土壤粗粒化。[Objective]The aim of this study is to explore the variation characteristics of topsoil particle size composition in the alpine grassland in the source region of the Yellow River,as well as main influencing factors on soil degradation in the grassland,and then to provide certain guidance.[Methods]The topsoil with different coverage(0%,5%,25%,50%,75%,and 100%)and two types of new and old rodent mounds in the forbidden grazing area of Henan County,Qinghai Province were used as research objects.The influences of different coverage of grassland and rodent mounds distribution on topsoil particle size composition in the source region of the Yellow River were analyzed.[Results](1)The average soil particle size on the surface of alpine grassland increased with the decrease of grass coverage,and the variation range of soil particle size less than 2μm was the smallest,and the variation range of soil particle size between 20μm and 50μm and 250μm was the largest.The soil particle size between 20μm and 50μm was relatively sensitive to soil erosion.(2)The surface soil particle size composition of undegraded grassland was mainly composed of silt,clay and silt contents and coverage showed a linear positive correlation,and sand content and coverage showed a linear negative correlation.Compared with the primary grassland,the content of sand in bare land increased by 21.96%,that of Eospalax baileyi mound increased by 27.86%and that of Ochotona curzoniae mound increased by 33.14%.(3)There was no obvious difference in soil particle size composition between the two types of mounds formed at the same time.Compared with the new mounds,the clay content of old mounds of Ochotona curzoniae and Eospalax baileyi decreased by 5.85%and 6.32%,the silt content decreased by 28.99%and 23.01%,and the sand content increased by 34.84%and 29.33%,respectively.The mean grain size of soil increased by nearly 2 times,and the soil erosion of rodent mounds showed the phenomenon of soil coarse-grained and desertification.[Conclusion]Increasing grasslan

关 键 词：高寒草地 自然退化区 鼠丘 粒径组成 土壤退化 

分 类 号：S152.3[农业科学—土壤学]