三峡库区经果林地生物结皮发育对土壤饱和导水率的影响  

Effects of Biological Crust Development on Soil Saturated Hydraulic Conductivity in the Three Gorges Reservoir Area

作　　者：杨澜 陈晓燕[1,2] 朱平宗 冯滔 王定斌 YANG Lan;CHEN Xiaoyan;ZHU Pingzong;FENG Tao;WANG Dingbin(Key Laboratory of Soil and Water Conservation and Ecological Restoration of Chongqing,Southwest University,Chongqing 400716,China;College of Resources and Environment,Southwest University,Chongqing 400716,China)

机构地区：[1]西南大学水土保持生态修复重庆市重点实验室,重庆400716 [2]西南大学资源环境学院,重庆400716

出　　处：《水土保持学报》2024年第5期244-251,共8页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(42307422);中央高校基本科研业务费项目(SWU-KQ22039)。

摘　　要：[目的]为了探究三峡库区生物结皮发育对土壤饱和导水率的影响及其驱动机制。[方法]在经果林下选取5个盖度梯度(0~20%,20%~40%,40%~60%,60%~80%,80%~100%)的苔藓结皮样地,以林下无生物结皮覆盖样地为对照,通过野外采样和室内分析测定不同盖度梯度生物结皮的土壤饱和导水率和基本土壤理化性质,利用非线性回归、偏最小二乘回归和结构方程模型等方法明确经果林地土壤饱和导水率随生物结皮盖度的变化规律及其主控因素。[结果](1)经果林下生物结皮的发育显著增加土壤饱和导水率,与对照相比,0~20%,20%~40%,40%~60%,60%~80%,80%~100%生物结皮盖度梯度的土壤饱和导水率分别增加36.98%,338.09%,407.17%,900.66%,713.11%。(2)随着生物结皮盖度增加,土壤饱和导水率呈近似对数函数趋势增加,当生物结皮盖度>60%时,土壤饱和导水率趋于稳定。(3)土壤饱和导水率与生物结皮特性及其驱动的土壤理化性质变化显著相关,生物结皮厚度、土壤容重、总孔隙度、饱和含水率和水稳性团聚体含量是导致不同生物结皮盖度土壤饱和导水率存在差异的主控因素。(4)结构方程模型结果表明,生物结皮的发育主要通过间接改良土壤结构(间接通径系数1.655>直接路径系数0.887)来增加土壤饱和导水率。[结论]研究结果为三峡库区经果林地生物结皮发育对水文和侵蚀过程的认识提供理论基础,也为经果林地水土流失的防控提供实践指导。[Objective]Soil saturated hydraulic conductivity(K s)reflects soil infiltration capacity and erosion resistance potential,which significantly affects hydrology and erosion processes.Economic fruit forest is an important land use type in the Three Gorges Reservoir area,biological crust wide-developed under the forest,which will inevitably drive the change in soil physical and chemical properties,thereby affecting K s,but the effect of biological crust development on soil saturated hydraulic conductivity and its driving mechanism in reservoir area is still unclear.[Methods]Therefore,in order to investigate the effect of biological crust development on K s in the Three Gorges Reservoir area.One site without biological crust(as control)and five moss crust sites with different coverage(0~20%,20%~40%,40%~60%,60%~80%,80%~100%)were selected under the economic fruit forest.The soil saturated hydraulic conductivity and basic soil physical and chemical properties of biological crust with different coverage gradients were determined by field sampling and laboratory analysis,combined with nonlinear regression,partial least squares regression and structural equation model methods.The changes in K s with biological crust coverage and main factors attributed to these changes were clarified.[Results](1)The development of biological crust significantly increased K s,and compared to control,K s of economic fruit forest covered by 0~20%,20%~40%,40%~60%,60%~80%,80%~100%biological crust increased by 36.98%,338.09%,407.17%,900.66%,713.11%,respectively.(2)K s increased in an approximate logarithmic trend with the increase of biological crust coverage.When biological crust coverage was greater than 60%,K s tended to be stable.(3)K s was significantly correlated with the biological crust characteristics and the differences in soil physical and chemical properties driven by biological crust.The thickness of biological crust,soil bulk density,total porosity,saturated water content and water-stable aggregate content were the main influencing

关 键 词：生物结皮 饱和导水率 三峡库区 经果林 

分 类 号：S157.1[农业科学—土壤学]