Comparatively Study On The Structure Characteristics Of Cryptomeria Fortunei Communities With Different Origins

The research was based on the methods of statistical methods,and made a comparison between the natural Cryptomeria fortunei community in Yong'an Tian baoyan national nature reserve and planted Cryptomeria fortunei community in Fuding Houping national forest farms,including the comparisons of the species composition and quantity characteristics,species diversity features,the high scales and diameter scales,various kinds of model fittings, and the spatial distribution patterns of the main species in tree layer etc. The main results were as following:Analyzed the different species compositions between the two kinds of communities,and the results showed that the natural Cryptomeria fortunei community had 112 kinds of species in all,belonging to 53 families and 82 genus, including 68 kinds of woody plants and 44 kinds of herbaceous plants. Planted Cryptomeria fortunei community had 55 kinds of species in all, belonging to 30 families and 49 genus,including 34 kinds of woody plants and 21 kinds of herbaceous plants. The species composition of the natural Cryptomeria fortunei community was richer than the planted Cryptomeria fortunei community and the vertical structures of the two different kinds of communities were very obvious,and both of them could be divided into tree layer,shrub layer and herb layer.There were 40 kinds of species in the tree layer of Tian baoyan natural Cryptomeria fortunei community,and the main components were Cryptomeria fortunei , Pinus massoniana Lamb ,Eurya japonica Thunb,Tsuga longibracteata W. C. Cheng,Quercus palustris ,Schima superba Gardn , Pinus taiwanensis Hayata , Castanopsis fargesii Franch ,etc.The main species of the tree layer of the planted Cryptomeria fortunei community was eight kinds,and they were Cryptomeria fortunei Hooibrenk, Cunninghamia lanceolata,Castanopsis fissa,Pinus massoniana Lamb.The analysis of the flora features of the two kinds of communities showed that the difference between the natural Cryptomeria fortunei community and the planted Cryptomeria fortunei community wasn't very much.The dispersion patterns of the natural Cryptomeria fortunei community was 11 kinds,but only 8 kinds in planted Cryptomeria fortunei community.The distribution types of the two communities which took up the most families were world distribution type and pan-tropical distribution type.Based on the distribution of the genera in the world,the eight distribution types of the genera were divided. According to the geographical distribution types of genus,the natural Cryptomeria fortunei community had 17 kinds,among which there were 13 genus in pan-tropical distribution and 11 genus in world distribution,and the latter one took up almost 13.41 percent.The genus distribution patterns of planted Cryptomeria fortunei community was less with a 15 kinds of distribution patterns.In a nutshell,the genus with a great proportion both tended to tropics and semi-tropics distribution,no matter what kind of community it was.Analyzed from the quantity characteristics of the main species in tree layer,the results showed that the main species with a relative bigger importance value were Cryptomeria fortunei , Pinus massoniana Lamb , Eurya japonica Thunb ,Tsuga longibracteata W. C. Cheng,Quercus palustris,Schima superba Gardn.,Pinus taiwanensis Hayata,Castanopsis fargesii Franch, Ternstroemia gymnanthera,etc.The species with a biggest importance value in natural community was Cryptomeria fortunei which reached 97.087 percent. The order of the species who had the biggest importance value in planted Cryptomeria fortunei community was Cryptomeria fortunei> Cunninghamia lanceolata >Castanopsis fissa>Pinus massoniana Lamb > Cinnamomum micranthum> Schima superba Gardn.The most dominant species was Cryptomeria fortunei which had the biggest importance value which reached 250.704 percent.There was a significant difference in quantity characteristics between them,and the evenness of the importance value in different layers was different.The species importance value in different layers of the natural Cryptomeria fortunei community was relatively even than that of planted Cryptomeria fortunei community,and the dominant species in the latter one was very obvious.The research of species diversity in different communities showed that the difference between the natural Cryptomeria fortunei community and planted Cryptomeria fortunei community was significant . Every index of species diversity of the natural Cryptomeria fortunei community was bigger than that in planted Cryptomeria fortunei community no matter it was in which layer.During the three layers of both communities,the order of the species diversity was following tree layer>herb layer>shrub layer.The comparison of the spatial distribution patterns of the main species between the natural Cryptomeria fortunei community and planted Cryptomeria fortunei community showed that,in general,Cryptomeria fortunei, Pinus massoniana,and Eurya japonica Thunb all followed aggregated distribution pattern in the former,while Cryptomeria fortunei in the latter one followed the even distribution and random distribution patterns.It would have some affection to the distribution patterns if you chose the different indexes and scales.The research of the high scales,diameter scales and various kinds of model fittings showed that in general,the average DBH in the tree layer of the natural Cryptomeria fortunei community was smaller than that in the planted Cryptomeria fortunei community.The DBH distribution curves of the natural Cryptomeria fortunei community showed that with the increase of the DBH scales,the individual quantity decreased quickly , while the DBH distribution curves of planted Cryptomeria fortunei community presents a down and up but at last drop rapidly trend. From the comparison of the two DBH distribution curves, the difference between them can seen,but they all showed pyramidal shapes which had a great potential in communities development . The average tree height of the natural community was bigger than that of plantation community.The curves of the tree layer distribution in the natural community were more complicated than that in the plantation community.The model fittings of DBH distributions, height distributions and the relationship of DBH and height had been made.The results showed that the perfect results could be got if the best models among many mathematic equations could be selected,and those models could be used to make some prediction.