Community Characteristics, Interspecific Relationship And Influencing Factors Of The Ecological Public Welfare Forest In Jiangshan City

The ecological public welfare forest construction is a major component of ecological constructionin Zhejiang Province. Based on5.256×104hm2ecological public welfare forest in Jiangshan,80permanent sample plots were taken as the research object monitoring. The characteristics of communitystructure were researched according to the research object monitoring. The stability of ecological publicwelfare forest and each community in Jiangshan were evaluated by the improved M-Godron methodand principal component analysis. The species distribution, interspecific relationship and relationshipbetween species distribution and environmental factors for the dominant species in study area wereanalyzed by niche theory, interspecific association and canonical correspondence analysis (CCA). Theresults were as follows:1) There are six kinds of forest types of ecological public welfare forest, Pine (Pinus massoniana)forest, China fir (Cunninghamia lanceolata) forest, broadleaved forest, Coniferous and broadleavedmixed forest, Phyllostachys heterocycla forest and Shrub forests. Among all kinds of ecological publicwelfare forests, broadleaved forest had the highest proportion of the total area while the shrub forest hadthe lowest proportion. The ecological public welfare forests had many characteristics, such as it has alarger proportion of coniferous forest and its revegetation was early. Overall, the community advantagespecies were relatively single, especially the tree layer. The ecological public welfare forests ofJiangshan are in a stable state, and there was a positive correlation between the community stability andbiological diversity.2) The existing total biomass of the ecological public welfare forest was571.76×104t, the unitbiomass of the ecological public welfare forest was104.8t·hm-2. And vegetation carbon density for anaverage of52.363t C·hm-2, the total carbon storage was285.685×104t C.Based on geographic information systems, biomass model inversion of ecological public welfareforest was established. The models were established on60plots, while had an accuracy validation by20plots. It showed that the Geographic Information System technique is suitable to estimate biomass inJiangshan.3) Based on the data, the80permanent sample plots were classified into15associations byTWINSPAN. A canonical correspondence analysis (CCA) between dominant species andenvironmental data was established by CANOCO5.0. The first two axes were able to reflect therelationships between the species and the environment. It showed that elevation and aspect were thedominant environmental factors on affecting plant species distribution in the study area, and the slopedirection (intensity) and the thickness of humus also influenced plant species distribution. By comparing the distribution of species in the study area between different altitudes, the peak occurs at an altitude of700m, the number of species plots showed a decreasing trend after the first increase.4）Analysis showed one of the factors which affecting the niche breadth and the overlap value ofspecies is the distribution frequency. The larger the distribution frequency was, the larger probability ofspecies niche overlap with other plants was. Most of the interspecific relationship in study area betweenthe dominant populations showed positive correlation, only9.09%of the total species number weresignificant or highly significant.Having the larger niche width, one species had a larger niche overlap with other species, andlocated in the species concentration area of CCA sequence diagram, while the species having a smallerniche width located beyond the species concentration area of CCA sequence diagram. The distancebetween one species and other species on the CCA sequence diagram were closely related with nicheoverlap value and interspecific association. Within a significant connection, positive correlation madethe distance closer, while negative correlation widened the distance. Without a significant connection,the higher niche overlap value, a closer distance in the CCA diagram was.This study was a research on community characteristics, interspecific relationship andenvironmental factors of the ecological public welfare forest in Jiangshan City. It was not onlybeneficial to understand the status of the ecological public welfare forest in Jiangshan City, but also togive an example to analysis the community characteristics of others. By combining niche theory,interspecific association and CCA ordination diagram to analyze the relationship between species andtheir impact factors provide new thinking direction to explain the relationship between the interspecificrelationship and plant-environment relationships of forest.