The Phylogenetic Structure And Quantitative Analysis And Ordination Of Taxus Chinensis Var.Mairei Community,in Shanxi Province

In this paper,the sample of Taxus chinensis var.mairei community at 850-1200 m above altitude was investigated,and the ecological method was used to study the flora,the numerical classification and ordination of community and community phylogenetic structure of Taxus chinensis var.mairei community in Lingchuan,Shanxi Province.(1)there were 102 species of seed plants belonging to 42 families and 82 genus in Taxus chinensis var.mairei community in Lingchuan Shanxi Province: 12 species of monocotyledonous plants belonging to 6 families,10 genus,86 species of dicotyledonous plants belonging to 32 families,68 genus;2 families,2 genus and 2species of gymnosperms.There are 2 families,2 genus and 2 species of pteridophytes.The families with more species in Lingchuan area of Shanxi Province are Rosaceae,with 10 genera and 14 species,followed by Liliaceae and 5 genera and 8 species.(2)Forty-two families of the Taxus chinensis var.mairei community in Lingchuan,Shanxi is divided into 6 distribution areas,among which 16 families(38.10 %),13 families(30.95 %)of the pan-tropical distribution,1 families(2.38 %)of the pan-tropical distribution dominated by the southern hemisphere,and 1 family(2.38 %)in the tropical Asia and the tropical America.There are 9 families(21.43 %)in the north temperate zone and 2 families(4.76 %)in the north temperate zone and the south temperate zone.There are 13 distribution types in 82 genus,12 genera(14.63 %),23 genera(28.05 %),38 genera(46.34 %),7 genera(8.54 %)in East Asia and 1 genera(1.22 %)in China.(3)In this paper,TWINSPAN,DCA and CCA were used to classify and rank Taxus chinensis var.mairei communities in Lingchuan,Shanxi Province to explore the effects of environmental factors on the distribution of different community types.The results showed that 30 sampling sites and 94 plant species in the study area can be classified into seven subtypes: Carpinus turczaninowii-Deutzia scabra-Carex spp.,Taxus chinensis var.mairei-Lonicera japonica-Arthraxon hispidus,Taxus chinensis var.mairei+Carpinus turczaninowii-Viburnum schensianum-Polygonatum sibiricum,Carpinus turczaninowii-Cotoneaster acutifolius-Carex spp.,Taxus chinensis var.mairei-Spiraea salicifolia-Carex spp.,Taxus chinensis var.mairei-Forsythia suspensa-Smilacina japonica,Carpinus turczaninowii-Forsythia suspensa-Carex spp.,Taxus chinensis var.mairei-Vitex negundo-Carex spp.and Taxus chinensis var.mairei-Forsythia suspensa-Epimedium sagittatum.Detrended correspondence analysis(DCA)indicated that changes in light intensity and soil water content could affect the distribution of community types.In addition,canonical correspondence analysis(CCA)revealed that in the upper and middle reaches of the Taxus chinensis var.mairei community in Lingchuan,Shanxi,changes in temperature and precipitation caused by longitude are the main factors controlling the formation and transition of vegetation community types.(4)The net relatedness index(NRI)and nearest taxon index(NTI)of Taxus chinensisi var.mairei community from different spatial scale and different elevation were studied by the method of sampling analysis.The phylogenetic structure characteristics of Taxus chinensis var.mairei community formed along the spatial scale gradient were discussed and the historical process of the construction of Taxus chinensis var.mairei community was analyzed.The results showed that,the phylogenetic tree of Taxus chinensis var.mairei community in these reserve arbor layer(26 species),shrub layer(32 species),and herbaceous layer(39 species)include16 families,19 genus,16 family,25 genus and 19 family,33 genus,respectively.Arbor layer(86.67% of the plot,the below is same)and shrub layer(73.33%)species community phylogenetic structure were phylogenetically overdispersed(NRI<0,NTI<0),but the herbaceous layer(86.67%)species community phylogenetic structure were phylogenetically clustered(NRI>0,NTI>0).The species richness index(S)of arbor layer(r=0.969),shrub layer(r=0.943)and herbaceous layer(r=0.875)was positively correlated with PD(P<0.01),indicating that the richness of species has a significant effect on PD.Izn the arbor layer of Taxus chinensis var.mairei community,from the first stage to the second stage,the NRI index decreased with the increasing of the diameter at byeast height(DBH),but the NTI index increased.From the second stage to the fifth stage,with the increasing of DBH,the NRI index and the NTI index showed a decreasing trend;at different DBH level,NRI and NTI index was significant difference(P<0.05).The results showed that the community phylogenetic structure changed from phylogenetic clustering to phylogenetic overdisperseding.Shrub layer NRI index(r=0.424,P=0.019)and NTI index(r=0.407,P=0.025)were significantly correlated with altitude(P>0.01),while there was no significant correlation of arbor layer NRI index(r=0.283,P=0.130),NTI index(r=0.171,P=0.366)and herbaceous layer NRI index(r=0.201,P=0.285),NTI index(r=0.308,P=0.098)to elevation(P>0.05).The arbor layer on sunny slope and herbaceous layer on both shady and sunny slope community were unable to determine whether the phylogenetic structure of the community was clustered or overdispersed.