The Synecological Studies On Castanopsis Forest In Fujian Province

Castanopsis were the constructive or dominant species of evergreen broad-leaved forest.Research on Castanopsis forest could provide many important data for vegetation classification research.Based on the data of sample field investigation of Castanopsis communities in nature reserves in Fujian province,which were good protected,and existing data about Castanopsis communities.This paper investigated Castanopsis forests' ecological characteristics,such as community structure,floristic characteristics,species diversity and interspecific association between dominant species in Castanopsis communities.Analyzed difference betwee the characteristics for different Castanopsis formations and the overall characteristics of Castanopsis formation group in Fujian province.And discussed the position and function of Castanopsis populations in communities.The conclusions were as follows:1.The arbor layer of evergreen broad-leaved forest dominated by Castanopsis,were often composed of several species.And the upper and lower layers of the shrub layer were slightly different from each other.Because of the high canopy density of the arbor and herb layer,in most cases,the gap surface was covered by seedlings,with few species of undergrowth plant.The stability of tree layer was higher than that of shrub layer.2.In the floristic composition,the families/genera of tropical distribution were more than others,which was most fully illustrated pan-tropical of Castanopsis formation group.Beacuse of the little significance of cosmopolitan distribution type for the discussioning the origin and evolution of flora in the world.After the exclusion of the cosmopolitan distribution,founded that the distribution of tropical families in evergreen broad-leaved forest accounted for 74±15%,and tropical genera accounting for 72.5±16%.And the tropical genera had a very significant negative correlation between altitude,and the tropical families had a significant negative correlation between and altitude.And there was no significant correlation between the tropical families/genera and altitude/latitude.3.Combined with importance value and presence of families in different communities,we can draw some generalizations:Common dominant trees were attributed to Fagaceae,Lauraceae,Elaeocarpaceae,Araliaceae,Daphniphyllaceae,Hamamelidaceae.Common dominant shrubs were attributed to Theaceae,Myrsinaceae,Rubiaceae,Aquifoliaceae,Ericaceae.Rosaceae was common woody plants,but rarely become the dominant species,mostly as associated species.The families of advantage vines were Smilacaceae,Papilionaceae,Papilionaceae,Rubiaceae,Lardizabalaceae,Apocynaceae.The families of dominant herbs were Blechnaceae,Gramineae,Gleicheniaceae,Zingiberaceae.4.Looking at the species composition,the number of species in the 400m2 sampling area was 53.5±18.5,the number of genera was 40.5±17.5,and the number of families was 29.5±11.5.Compared species diversity index like R,H',D,Jsw of different Castanopsis formations,we can found the species diversity between different formations were small.The species diversity index like R,H',and Jsw,of the tree layer had significant or extremely significant negative correlation with latitude.And there was a significant positive correlation between D and latitude.There was asignificant negative correlation between D of shrub layer and latitude.5.According to analyzed the community similarity between different associations of different formations,the number of similarity values ranging from 3%-63%,the majority concentrated in 20%-40%.The community similarity index between associations in Castanopsis eyrei formation,C.carlesii formation,C.fabri formation were higher than others,because the composition of species,in there commint ies,was relatively stable.Aassociations in C.eyrei formation had the highest mean similarity with the others,probably due to its adapted to a wider range of types of evergreen broad-leaved forest.It maybe also was the reason for the formation of C.eyrei widely distributed in Fujian province.6.Observed the existence of Castamopsis in the same sample plots and Interspecific Association between different dominated species,there were 13 species attributed to Castanopsis in Fujian.C.eyrei had the highest existence in other Castanopsis formation communities,followed by C.fargesii,C.carlesii and C.fabri.The chance of coexistence of C.eyrie and C.fargesii was in the highest rate,followed by C.fabri and C.eyrei,C.carlesii and C.fargesii,C.lamontii and C.eyrei.