Vegetation Mapping And Quantitative Analysis Of Main Plant Communities On The Southern Slope Of Beishan Mountain In Jinhua,Zhejiang,China

Vegetation is an assemblage of all plant individuals or plant communities in an area.It is formed by long-term development and evolution under the influence of past and current climate conditions and human disturbances.As an important component of the Earth's ecosystems and an important indicator of the state of environmental conditions,all issues of the environment and resource that human is facing are closely related to vegetation.Especially at present,human is facing a series of global environmental problems such as climate change and environmental pollution.These problems are largely related to the degradation and areal reduction of vegetation.The study of vegetation therefore becomes more important and urgent.The vegetation in Beishan Mountain of Jinhua is a secondary forest restored driven by natural recovery and artificial afforestation after being damaged in the middle of the last century.It is currently undergoing rapid development and succession.This provides us a good platform for studying the dynamic succession mechanism of plant communities and the restoration of damaged ecosystems.So,what is the current vegetation composition and distribution pattern of Beishan Mountain in Jinhua? How will it develop in the future? And what reasonable vegetation management concepts and management measures should be adopt for relevant management departments? These scientific questions need to be answered urgently.In view of the problems mentioned above,this study produced a high-precision digital vegetation map in a 65.5 km2 area in the middle part of the southern slope of Beishan mountain in Jinhua,based on GF-2 remote sensing image data and field vegetation surveys,and using GIS technology and related software(ENVI,ArcGIS).Vegetation characteristics in the mapping area were further described and analyzed.At the same time,based on the survey data of 24 plant communities(21 forest communities and 3 shrub communities)of the plant community characteristics of the main vegetation types were statistically analyzed.Results showed that:The vegetation coverage of the mapping area is about 91%.The vegetation includes eight types: forest,bamboo forest,shrub,shrub and grass community,grass-forb community,mixed wood forest,greening vegetation,and cultivated vegetation.Except for cultivated vegetation and greening vegetation,other types are subtropical vegetations in geographical composition.The main vegetation types(formation)are Pinus massoniana forest,Pinus massoniana + Schima superba forest,Schima superba forest,Cunninghamia lanceolata forest,Pinus taiwanensis forest,Phyllostachys sulphurea var.viridis forest,Pinus massoniana + Schima superba + Liquidambar formosana forest,Pinus massoniana + Liquidambar formosana forest,Liquidambar formosana forest,and Schima superba + Liquidambar formosana forest.The area of Pinus massoniana forest is 10.5 km2,distributed below 900 m in altitude.Pinus massoniana + Schima superba forest in an area of 5.2 km2,distributed in 108-946 m in altitude.The area of Schima superba forest is 4.5 km2,distributed in 100-1037 m in altitude.Cunninghamia lanceolata forest in an area of 4.1 km2,distributed in 139-1223 m.The area of Pinus taiwanensis forest is 2.4 km2,distributed in 740-1277 m in altitude.The area of Phyllostachys sulphurea var.viridis forest is 2.0 km2,distributed in 100-1115 m in altitude.The area of Pinus massoniana + Schima superba + Liquidambar formosana forest forest is 1.2 km2,distributed in 120-902 m in altitude.The area of Pinus massoniana + Liquidambar formosana forest is 1.2 km2,distributed in 118-609 m in altitude.The area of Liquidambar formosana forest is 1.1 km2,distributed in 146-1016 m in altitude.The area of Schima superba + Liquidambar formosana forest is 1.0 km2,distributed in 181-859 m in altitude.Vegetation in this area is mainly evergreens,together with some components of mixed evergreen and deciduous vegetation.The flora composition of the genera is mainly the North temperate,Pantropic,East Asia and North America disjuncted,and East Asia Distributions.This is consistent with the climatic conditions in the northern part of the middle subtropical zone in which the region is located.In addition,the Tropical Asia(India-Malaysia),Tropical Asia and tropical America disjuncted species also account for a considerable proportion,indicating the tropical-subtropical-temperate transitional characteristics of the flora in this region.Analyses of main plant communities in Beishan mountain of Jinhua showed that species diversity and functional diversity of mixed needleleaf and broadleaf forest and mixed broadleaf evergreen and deciduous forest communities are better than those of pure forests.Species richness of the tree,shrub and herb layers of Cryptomeria fortunei forest and Cunninghamia lanceolata forest,and the tree layer of Pinus taiwanensis forest are small.Species richness of shrub and herb layers in Pinus taiwanensis forest is relatively larger.Timber volume in Cunninghamia lanceolata forest and Cryptomeria fortunei forest is the largest in the region.At present,the age structure of Pinus taiwanensis,Cryptomeria fortunei forest and Cunninghamia lanceolata populations are all stable,and will maintain their dominant position for a certain period of time.However,there are no seedlings or few seedlings under the forest,indicating the lack of natural regeneration.Age structure of the Pinus massoniana population is generally stable,but the Pinus massoniana population in some mixed forests has begun to decline.Schima superba is the main dominant species of broadleaf evergreen forest in the area.Its population is mainly composed of young and middle trees,showing an increasing age structure.Some deciduous broadleaf species(mainly Liquidambar formosana,Castanea henryi,and Quercus serrata var.brevipetiolata)which co-exist with Schima superba,mostly have declining age structure.Such evidence implies that Schima superba populations are currently recovering,and some communities with Schima superba populations will success towards the Schima superba community.In general,the current vegetation pattern on the southern slope of Beishan Mountain in Jinhua was formed by the artificial afforestation and natural restoration after severe damage in the last century.At present,its vegetation composition and distribution pattern are largely affected by those of plantations.Schima superba forest as the main dominant vegetation type of the broadleaf evergreen forest as zonal vegetation in this area,it is currently in the process of rapid development and succession.Without significant changes in climate in the region,along with the restoration of some broadleaf evergreen tree species such as Schima superba and the decline of other artificial needleleaf forests,the broadleaf evergreen forests represented by Schima superba forest will definitely affect or change the vegetation pattern in this area in the future.