基于新一代中国植被图(1∶50万)方法的漓江流域植被类型与分布OA

The Lijiang River basin,located in a typical karst region of southern China,has an ancient stratigraphic origin and a long history of karst development.It harbors diverse and spatially complex vegetation alliance types.However,high-resolution distribution data at the alliance level have been lacking.Based on the new generation 1∶500 000 China vegetation map compilation method,which integrates crowdsourced vegetation data,multi-source remote sensing fusion,and multi-scale image segmentation,this study identified the major vegetation alliance types(or alliance groups)in the Lijiang River basin and analyzed their area composition and spatial distribution patterns.The results were as follows:(1)The vegetation types exhibited high diversity and complexity.A total of 4 vegetation formation groups,10 vegetation formations,and 23 alliances(groups)were identified.(2)Anthropogenically influenced vegetation types accounted for more than 87％of the basin's area.Specifically,Pinus massoniana forest,P.massoniana mixed needleleaf and broadleaf forest,Cunninghamia lanceolata forest,and Phyllostachys edulis forest together occupied over 61％of the basin,while agricultural vegetation(food crops and orchards)covered approximately 26％.In contrast,primary zonal evergreen broadleaf forests(e.g.,Castanopsis eyrei forest and C.carlesii forest)together comprised less than 5％of the total basin area.(3)Clear spatial differentiation patterns were observed among alliances.Zonal alliances were strictly confined to non-karst mountains(e.g.,Yuechengling,Haiyangshan,Jiaqiaoling),whereas non-zonal alliances(e.g.,Cyclobalanopsis glauca mixed evergreen and deciduous broadleaf forest,Vitex negundo+Loropetalum chinense shrubland)dominated the karst areas.Vertically,a distinct altitudinal zonation was evident,transitioning from typical evergreen broadleaf forest belt to mixed evergreen and deciduous broadleaf forest belt.Horizontally,forest alliances mainly occupied the surrounding mountainous regions,whereas shrubland and agricultural alliances prevailed in the central gentle terrain.This study reveals the classification,area composition,and spatial distribution patterns of vegetation alliances in the Lijiang River basin,providing a scientific basis and supporting evidence for the conservation and restoration of the basin's vegetation ecosystems,as well as for sustainable development of the basin and the assessment of its ecological value.