黄土高原草地灌丛化对潜在植被截留和土壤蓄水能力的影响  

Effects of Shrub Encroachment on Potential Vegetation Interception and Soil Water-Holding Capacity of Grasslands on Loess Plateau

作　　者：乔文英 安琪琪 常小峰[1] 郑纪勇[1] 李维军 Qiao Wenying;An Qiqi;Chang Xiaofeng;Zheng Jiyong;Li Weijun(Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China;College of Forestry,Northwest A&F University,Yangling,Shaanxi 712100,China;Department of Yunwu Mountain Natural Reserve,Guyuan,Ningxia 756000,China)

机构地区：[1]西北农林科技大学水土保持研究所,陕西杨陵712100 [2]西北农林科技大学林学院,陕西杨陵712100 [3]宁夏云雾山国家级自然保护区管理局,宁夏固原756000

出　　处：《水土保持通报》2022年第1期69-76,共8页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目“黄土高原半干旱区草地灌丛化形成机制”(42177451)。

摘　　要：[目的]分析灌丛化后草地生态系统植被截留和土壤蓄水特征,为系统评价灌丛化后草地生态系统的水土保持能力提供参考。[方法]以黄土高原未灌丛化草地和灌丛化草地(包括禾草斑块、半灌木斑块、灌木斑块)为研究对象,系统研究了植被(包括冠层与枯落物)截留量与土壤饱和蓄水量的变化特征。[结果](1)灌丛化通过增加草地地上生物量使植被冠层截留量增加了0.3 mm,通过减少枯落物量使枯落物截留量减少了0.5 mm;(2)草地灌丛化过程中,只有灌木斑块显著增加了0—40 cm土壤饱和蓄水量。而且,灌木斑块与半灌木斑块土壤饱和蓄水能力显著不同,灌木斑块较半灌木斑块土壤饱和蓄水量增加12.8 mm,主要发生在0—20 cm土层。[结论]灌丛化没有降低草地生态系统土壤饱和蓄水能力,但若灌木继续扩张,可能会削弱草地生态系统植被截留能力。[Objective]Vegetation interception and soil water-holding capacity were analyzed in order to provied a scientific basis for systematically evaluating the soil and water conservation functions of semi-arid shrub-encroached grasslands.[Methods]Characteristics of vegetation interception(including canopy and litter layer),soil water-holding capacity of the primary grassland and shrub-encroached grassland(including grass patch,sub-shrub patch,and shrub patch)were measured on the Loess Plateau.[Results]①The capacity of canopy interception in shrub patches was increased by 0.3 mm with the increasing of aboveground biomass,while the capacity of litter interception was decreased by 0.5 mm through reduction in the litter biomass.②During shrub encroachment,only shrub patches significantly improved soil water-holding capacity.Moreover,there were significant differences in soil water-holding capacity between sub-shrub and shrub patches.Compared with sub-shrub patches,the capacity of shrub patches was enhanced by 12.8 mm,and the increase mainly occurred in the surface soil(0—20 cm).[Conclusion]Shrub encroachment did not reduce the potential soil water-holding capacity.However,if shrubs continue to expand in area coverage,the interception ability of grassland ecosystem by canopy and litter layer might be weaken.

关 键 词：灌丛化 冠层截留 枯落物层 土壤蓄水量 

分 类 号：S714.7[农业科学—林学]