Research On Structure And Competition Of Dominant Species Population In Castanea Henryi、Liquidambar Formosana Communities

This paper object of study is the mixed forests of Castanea henryi and Liquidambarformosana of the nature reserve in Zha Bay, Qimen County, Anhui Province. The investigatedforest stands formed by natural secondary forest succession, stand growth in good conditionwith no visible pests. The mixed forests of Castanea henryi and Liquidambar formosana of thenature reserve have a large area, less widely distribute and are researched less, the paper isusing the quantitative analysis and Soft ware of EXCEL, SPSS, MATLAB and MAPINFOdeals with several theoretical aspects of this species such as community features and structure,species diversity, relationship between species and area, population fluctuation patterns, staticlife table, dynamics characteristics of population, distribution patterns, inter-specific ofdominate species and competition in both Castanopsis eyrei population and other species. Theresults are as follows:1. Plot of5400m2has53tree layer species,76shrub layer species and20herb layerspecies. This community levels is more complicated. The main species of T tree layer speciesare Castanea henryi, Liquidambar formosana, Loropetalum chinense, Quercus glandulifer,Machilus thunbergii, Eurya muricata Dunn and Platycarya strobilacea Sieb. Their importantvalues are20.84,15.98,8.62,4.48,4.2,4.01and3.3. The main species of shrub layer speciesare Eurya muricata Dunn, Castanea henryi, Lindera glauca, Machilus thunbergii, Ardisiacrenata Sim, Loropetalum chinense.Their important values are14.4,12.17,10.2,8.6,6.9and5.18. The main specie of herb layer species is Wood wardia japonica, which occupies adominant position at the herb layer species. Important value is41.92. The different levels ofchange rule of community species diversity are as follows:shrub layer> tree layer> herbaceouslayer. Tree layer of uniformity and richness were positively correlated, and diversity wasnegatively correlated.2. The study of species-area relationships shows that as the sample size increases, theamount and type of species increases. The regression model is closer to the prediction function,a function and power function model can very well reflect within the community of thespecies-area relationship of Zha Bay nature reserve. Power model is most suitable andfunction.Logarithmic function is relatively the most inappropriate. The power function equationfitting is y=0.2489x^0.7459,R²=0.96.3. Castanea henryi and Liquidambar formosana indices Vpi of the population dynamicsare respectively45.56%and16.59%. Taking into account the external interference, V′pi arerespectively1.72%and0.92%for a stable population. Individual population of Liquidambarformosana seedling have less young individuals, more saplings and trees in the individual andless stable individual old trees. Compared with Deevey survivorship curves, Liquidambarformosana survival curve tends to Deevey-I. Early mortality is low and later mortality is higher. Mortality peak occurs in the IX age class. Survival curves showed that gum stocks showed aweak early, medium-term stability and late downturn. Survivor ship curves of Castanea henryitens to Deevey-III. I age-class has very low seedling survival. This is due to larger amount oflibrary seedling Bank, seedling mortality of85%. Environmental screening selected highstrength. Only very few Beliel （15%） stage of seedlings can get through this screen. Themortality rate of adult Castanea henryi is low and stable.4. Castanea henryi is in advantage of competition with Liquidambar formosana,Quercus glandulifer, Machilus thunbergii, Eurya muricata Dunn competition, and in a state ofbalance and stability of competition with Loropetalum chinense, and investigation of castaneahenryi under forest, loropetalum small tree are more Liquidambar trees but less correlated.Updating of notes in the normal case, Castanea henryi, liquidambar formosana mixed forestswill change into Castanea henryi, Loropetalum chinense mixed forests. Quercus glandulifer,Machilus thunbergii, Eurya muricata Dunn will be weeded out by Liquidambar formosana andLoropetalum chinense. Liquidambar formosana will be weeded out by Loropetalum chinenseout. Machilus thunbergii will be crowded out byEurya muricata Dunn. Quercus glandulifer,Machilus thunbergii and Eurya muricata Dunn is balanced and stable.5. Castanea henryi species competition is stronger than competition with other speciesin mingled forest.The competition of Liquidambar formosana and Castanea henryi is moreintense. The relationship of the competition intensity between the competitive tree and theobjective tree conforms to exponential function rule and the effect is very good.The model isCI=AeSB.