Study On Community Characteristics Of Secondary Castanopsis Eyrei- Schima Superba And Cyclobalanopsis Forest In Zhejiang Province

This article compares the community structure of the secondary Cyclobalanopsis eyrei-Schima superb forests in different ages of enclosure in Ankou Village,Suichang County,Lishui City,Zhejiang Province,including species composition,diameter structure and tree height structure,species diversity and uniformity,and population.The spatial pattern distribution and the growth law of dominant tree species,the main conclusions are as follows:(1)Among the three stages of different closed-ages in the study,the important value of Castanopsis eyrei,Schima superb and Quercus glauca are dominant,tree species for advantage,as the growth of the age gradually reduce the number of tree layer buck,secondary broad-leaved forest tree species number is relatively stable,but the layers of tree species composition changes significantly,in one of the top wood Castanopsis eyrei,Schima superb and Quercus glauca three dominant species increased obviously,showed that in different ages gradually showing a stable state.The Shannon-Weiner index all went up in order.The Pielou index decreased successively,indicating that the older the age,the more uniform the species distribution.In the process of stand growth,the size distribution of dominant tree species showed a tendency of large diameter deviation.The dominant tree species,castanopsis eyrei,schima superba and cyclobalanopsis in the sample area,and the high-pectoral area and important value are relatively high,which occupy an important position in the stand and affect the future development direction of the stand.(2)In the study of the spatial distribution pattern of different enclosure ages,the forest populations in Stage 1 are aggregated over a large scale,while in Stage 2 and Stage 3,the spatial distribution of the forest stands as a whole.The pattern also appears to be randomly or evenly distributed as the scale increases.During the development of this population from the small diameter to the large diameter,the distribution pattern generally shows a change in the trend from aggregation to random distribution.(3)For the main dominant tree species in the study site,castanopsis eyrei is a fast-growing timber tree species,with rapid growth of tree height and chest diameter,belonging to the growth peak of castanopsis eyrei.As intraspecific and interspecific resources began to compete with each other,and with the continuous growth of trees,self-thinning and its thinning produced effects until the later growth stage was slightly slowed down.After the growth rate slows down,the occupied space is also in a stable state,and the intraspecific and interspecific competition is reduced.The growth of castanopsis eyrei has the characteristics of early growth,intermediate reduction and late recession.