Urban Forest Community Structure And Physiognomy In Different Regions Of Guangzhou,China

In the twenty-first Century,the process of urbanization inChinais accelerating,and the contradiction between urban development and ecology has become increasingly prominent.Urban forest community is the basis of urban forest ecosystem,so it is of great significance to study urban forest community for sustainable urban development and ecological city constructio n.This paper studied on the species composition,community structure,interspecific interactions,communityphysiognomy,species-environment relationshipin three forest communities in different regions of Guangzhou which are Huanghuagang Park(central area),Maofeng Mountain Forest Park(the suburb),and Shimen National Forest Park(the exurb),respectively.The main results are as follows:(1)The composition of urban forest community in different regions of Guangzhou was different.In terms of species richness of vascular plant,Shimen National Forest Park was the largest(158 species),which was higher than that of Maofeng Mountain Forest Park(111 species)and Huanghuagang Park plots(111 species).Thedominant familiesin different regions were not the same: Huanghuagang Park was dominated by Sankoh and Palm,whileMaofeng Mountain Forest Park and Shimen National Forest Park were dominated by Lauraceae and Rubiaceae.(2)The structure of urban forest communities in different regions of Guangzhou was different.There were no obvious laws with the increase of DBH level in the urban forestof Huanghuagang Park,while the number of trees showed a steady decline with the increase of diameters(J-shape distribution)inMaofeng Mountain Forest Park and Shimen National Forest Park.The average DBH of Shimen National Forest Park was thelargest,followed by Maofeng Mountain Forest Park,Huanghuagang Park.Nonparametric analysis of variance showed that there were significant differences in DBH(P< 0.05)and extremely significant differences(P<0.001)in tree height amongthe three urban forest communities.Moreover,compared to Huanghuagang Park and Maofeng Mountain Forest Park,the diversityof tree layer,shrub layer and herbaceous layerin Shimen National Forest Park werehigher.(3)The interspecific interactionsofmost dominant species in the tree layer,shrub layer and the herbaceous layerin the threeurban forestwere not significant.In Maofeng Mountain Forest Park,the number of negative correlation of dominant specieswas higher than that of the other two parks,while the number of unrelated specieswas higherin Shimen National Forest Park.(4)There weresome slight differences in the physiognomy of urban forest communities in different regions of Guangzhou.The proportion of leaf size in three forest was sorted as medium-sized leaf> small-sized leaf> large-sized leaf> micro-sized-leaf.The order of proportion of leaf texture,leaf margin,leaf type in three forest communities was the same:Leathery leaf>herbaceous leaf>Membranous leaf,Entire leaf> non-entire leaf,simple leaf >compound leaf > needle-point leaf.There werenot significant differences in tree abundance among three urban forest communities(P> 0.05).However,abundance of shrubs,ferns and vines in the three urban communities were significantly different(P<0.001),andvines in Huanghuagang Park were particularly absent.(5)The relationship between species and environmental factors wasdifferentin the three urban forest:In Huanghuagang Park,species had a great relationship with altitude,while species had a great relationship with slope in Maofeng Mountain Forest Park and Shimen National Forest Park.