A Study On The Classification Of Plant Communities In Land–water Ecotone Of Li River

Land–water ecotone is the important ecosystem transition zone of energy,material and information exchange between aquatic ecosystem and terrestrial ecosystem.Meanwhile,it plays an important role in climate regulation,soil and water conservation,riparian stability and water resource conservation and so on.Therefore,it is necessary to know more about the types of plant communities,distribution,structure and function of this area.In order to have a good knownlege of the species composition,community characteristics and distribution features of land–water ecotone,we did the field survey of the vegetation in this area Li River,which allows us to systematically master background data of plant communities of this special area and provides theoretical basis in the utilization,protection,manage and restoreration of vegetation rasources and landscape planning.1.The Quadrat method and the route survey method were used to study the land–water ecotone vegetation of Li River,in which a total of 103 sample plots were investigated.Based on the results of investigation data and related literatures,a list of plant species in the composition of land –water ecotone vegetation of Li River was proposed,and the flora of these plant species was analysed.According to the classified principle and taxonomic unit in“Guang Xi vegetation”,the classification system of Land – water ecotone vegetation in Li River was put forward.The features of main community types were described by combining with habitat characteristics.2.There are 246 major species in land–water ecotone vegetation of Li River,which belonging to 188 genera and 80 families.Moreover,it respectively includs 11 species of pteridophyte(account for 4.47%),which belong to 7 genera(account for 3.72%)and 7 families(account for 8.75%);4 species of gymnosperm(account for 1.63%),which belong to 3 genera(account for 1.60%)and 3 families(account for 3.75%);231 species of angiosperm(account for 93.90%),which belong to 178 genera(account for 94.68%)and 70 families(account for 87.50%).These indicated that land–water ecotone vegetation of Li River is mainly occupied by angiosperm.Our study suggested that herb is the main life form and mesophyte,and mesophyte is the main component when it comes to the ecotype.3.The distribution types were complex,and dominated by tropical elements.There are 5 distribution types and 3 subtypes of families,and 13 distribution types and 6 subtypes of genera.Meanwhile,the tropical distribution section has 32 families,accounting for 74.41% of the total.However,there were 95 genera in the tropics,accounting for 67.38% of the total.4.Land–water ecotone vegetation of Li River can be divided into two major categories,artificial vegetation and natural vegetation.The artificial vegetation can be divided into 15 formation,while the natural vegetation can be divided into 3 vegetation type groups,including warm deciduous broad-leaved forest,broad-leaved forest,warm shrubs and weeds grass vegetation type and 39 formations,such as Form.Liquidambar formosana,Form.Vitex negundo var.cannabifolia and Form.Leersia hexandra.5.Innovation of this paper: Based on the application of the theories and methods of synecology,the land –water ecotone vegetation of Li River was taken as the research object in this paper.A more comprehensive investigation of species composition and floristic characteristics of land–water ecotone vegetation of Li River were analysed.The classification system of the land– water ecotone vegetation were put forward for the first time,and the gradient change rule of the land–water ecotone vegetation of Li River were put forward by drawing ecological series.With comprehensive and systematic backgroud data of wetland vegetation,this article could provide a theoretical basis for the utilization,protection,management,restoration and Landscape Planning.