Analysis Of Vegetation Community Characteristics And Water Conservation Capacity Of Tangpu Reservoir

This paper is based on the field investigation of Tangpu Reservoir in Shangyu City,Zhejiang Province.We calculated and analyzed the important value of species,diameter class structure,vertical structure,biological diversity,interspecific association of plant community.And we came to a scientific conclusion through experiment and analysis of litter and soil that there are differences between forest stands regarding to water conservation capacity.The results are as follows:1.Investigation statistics show that,the mountain vegetations consist of 7 vegetation types and 10 formations,and the wetland vegetations consist of 3 vegetation types and 10 formations.According to the important values and community structure characteristics of Tang Pu reservoir,the community can be roughly divided into 5 categories : Pine?Pinus massoniana?forest,Chinese fir?Cunninghamia lanceolata?forest,evergreen and deciduous Broad-leaved mixed forest,needle broad-leaved mixed forest and bamboo forest.Needle broad-leaved mixed and bamboo forest take up the largest portion,which are typified by Schima superba,Cunninghamia lanceolata and Moso bamboo forest.Pinus forest and Chinese fir forest come second.Evergreen and deciduous broad-leaved mixed forest come in the least which is typified by Schima superba,Liquidambar formosana forest.2.In species richness value's sequence,the sorts of communities can be arranged as evergreen and deciduous broad-leaved mixed forest,needle broad-leaved mixed forest,warm bamboo forest,Chinese fir forest,pinus forest.According to diversity index the sorts of communities can be sorted successively as evergreen and deciduous broad-leaved mixed forest,needle broad-leaved mixed forest,Chinese fir forest,pinus forest,warm bamboo forest.3.In the studied area,most of the dominant groups show positive correlation,with few species present significant or extremely significant correlation.In the tree layer some dominant species show significant positive correlation accounting for 10.7%,some show extremely significant positive correlation accounting for 3.6%,but none show significant negative correlation.Shrub layer's associations of groups was less obvious than tree layer's.In this layer some show extremely significant positive correlation,significantly positively correlation,significantly negative correlation and significant negative correlation accounting for 1.3%,3.9%,1.3%,0.7% respectively.In the herb layer,the number of negative associations is more than those of positive association;most of the species show relatively weak connection with significantly positive correlation,extremely significantly negative correlation,significant negative correlation accounting for 2.8%,2.8%,2.8% respectively.4.Through the study of different kinds of litter fall's water-holding capacity and soil water storage capacity,we found that the average value of different litter fall's water-holding capacity was 17.62t·hm^-2.Evergreen and deciduous broad-leaved mixed forest and mixed needle broad-leaved forest were above average.Chinese fir forest was similar to average,pinus forest and bamboo forest were below average.And the average value of effective water holding capacity of soil was 128.85t·hm^-2,evergreen and deciduous broad-leaved mixed forest had the highest value.Mixed needle broad-leaved forest was rank in the second place.Chinese fir forest and pinus forest's was behind mixed needle broad-leaved forest.Bmboo forest had minimum value.The result showed that the evergreen and deciduous broad-leaved mixed forest had the strongest ability of conservation water in unit area,the water conservation value was 177.76t·hm^-2.Mixed needle broad-leaved forest rank in the second place,the value was 172.84t·hm^-2.Chinese fir forest was slightly inferior to broad-leaved forest,the value was 163.69t·hm^-2.The row of pinus forest and bamboo forest was in the end,the value was 115.12t·hm^-2 and 102.91t·hm^-2.