| Emmenopterys henryi,an endemic species in China,is one of the Chinese national second protective wild plants.It is a particular rare,highly severe endangered and protective plant.The biodiversity conservation of E.henryi is timely needed.The communities' character, the caloric value,ash content and their dynamics in various layer mature leaves of the dominant plant species,the population structure,the distribution pattern,the intra-specific and inter-specific competition,and the element distribution and its relationship with soil nutrients were studied.The main results are as follows:The companion species of E.henryi were evergreen and from Lauraceae and Camelliaceae.The richness index,species diversity index and evenness index in the E.henryi community were low,but ecological dominance index was high.In the community,dominant life form,dominant leaf size,dominant leaf form,dominant leaf texture was phanerophytes, mesophyll,single leaves,herbaceous leaves,respectively and whose percentage was 75.9%, 53.97%,74.70%,63.86%respectively.The second leaf size was microphyll,whose percentage was 36.51%.The tree layer could be easily divided into 3 sublayers in terms of height.The population structure of E.henryi was a spindle type.The age structure of the population of E.henryi was declining due to lack of seedlings.There are two regeneration modes of E.henryi in forest:sexual and asexual reproduction,but the latter was the main mode. As to the distribution pattern of E.henryi,generally speaking,the E.henryi population was clump,but there are differences among various developmental stages:clump for saplings, random for adult trees and big trees.It was related to their biological and ecological characteristics.To increase accuracy,both methods of Greig-Smith and Kershaw were used to analyse the pattern scale of the population of E.henryi.It was showed in the results that the pattern scale was between 8 m~2 and 32 m~2.The ash content(AC)of the species ranged from 3.60%to 17.55%,and varied with plant species and sampling seasons.The AC of autumn and summer were higher than that of spring. The rank order of the average AC in the leaves was the following:herbaceous layer(10.42% ±3.24%)＞liana layer(8.56%±2.22%)＞tree layer(8.80%±2.69%)＞shrub layer(6.16%±1.78%),and the differences among herbaceous layer and shrub layer was found to be significant(P＜0.05).Gross caloric value(GCV)and ash-free caloric values(AFCV)of the species were highest in the autumn.The rank order of average GCV and GCV were the following:shrub layer(32.15±1.61 kJ/g)＞tree layer(30.92±1.15 kJ/g)＞liana layer (30.24±2.33 kJ/g)＞herbaceous layer(30.59±1.63 kJ/g),and the differences among those layers were found not to be significant(P＞0.05).To reflect the effect of fragmentation on the caloric value,the caloric values of six species in different habitats were compared.Gross and ash-free caloric values of six species in fragmentation habitat were all higher,indicating that fragmentation had remarkable influence on the caloric values.The niche breadth of E.henryi was the broadest in the community.The niche overlaps among the species with the same or similar environment requirements were great,such as Lindera glauca,Camellia cuspidate and Litsea rubuonervia Gamble.The niche overlaps were in the order of C.Ianceolata＞L.rubronervia＞L.glauca＞H.miconioides＞C.cuspidate. The results of study of Hegyi's competition index model for individual tree indicated that the competition intensity increased with the growth of the DBH(diameter at breast height)at early time till DBH was more than 15 centimeter,which accorded with the fact of the population of E.henryi.The competition intensities were in the order of E.henryi＞C.Ianceolata＞H. miconioides＞L.rubronervia＞L.glauca＞C.cuspidate.Relationship between the competition index and the base diameter of objective tree conformed closely to power function, and competition intensity reduced with the growth in base diameter of objective tree.The results by using the two different methods were accordant,for example the competition in intra-species was more intense than that in inter-species and the competition between E.henryi and C.Ianceolata was the most intense in inter-species,while E.henryi and C.cuspidate was least.Synthesizing our results,the authors consider that combined the two methods to study the competition will be better.There were not significant differences of element content among different plots except K,Fe,Ni,Sb,Cr.The content of k,Ca and Mg were higher in macroelement.The content of Fe was highest in microelement,while Cu was lowest.The content of Sb was highest in noessential element,while Tl was lowest.The relativities among the matel elements were all quite low in different organs.The coeffient of enrichment was Th＞k＞Ca＞Mg＞Tl>Cu＞Ba＞Cr＞Sb＞Zn＞Ni＞Fe＞Mn.
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