| Since 1970, the studies of plant reproductive ecology have caught extensive attention, especially in the last two decades, plant reproductive ecology has made rapid development, but the study was almost just started in China. Genetic diversity is another hot field in modern ecology, with rapid development of molecular marker technique recently, the research of genetic diversity of dominant tree species in tropical forest, subtropical forest and temperate forest have been carried out steadily. With special geographic location and climatic conditions, the subtropical areas in China has developed the most largest and typical evergreen broadleaved forest in the world, of which, evergreen shrub is one of important components. In order to explore the ecological mechanism of evergreen shrub population in subtropical areas from reproductive adaptation, have knowledge of genetic diversity and genetic variation with regard to natural evergreen shrub population, and the role soil plays in vegetational succession. Camellia rosthornina ~ one of the widely distributed species in shrub layer of evergreen broadleaved forest in subtropical regions in our country, was taken as the object of our study. From 2000~2002, through field investigation> field determination in Jinyun Shan Nature Reserve (29?50' N and 106 26' E) and experiments in the laboratory, the principles and methods of many disciplines, such as population ecology > reproductive ecology N statistics ecology v molecular biology > conservation biology and soil science, were applied to study the spatial pattern of C. rosthornina populations in different communities(giant bamboo forest > mixed conifer-broad forest and evergreen broadleaved forest ) and at different development stages; fecundity and reproductive value table of C. rosthornina populations in different communities were drawn up on the basis of static life table; three hypothesis were evaluated in terms of reproductive allocation of C. rosthornina populations and trade off relationship between reproduction and growth of C. rosthornina populations was discussed; by path analysis, the effects of pluristic environmental factors on the reproductive allocation of C. rosthornina populations were analysized; a preliminary study of size inequality for seed weight of C. rosthornina populations was made by using Gini coefficint; RAPD (random amplified polymorphic DNA) was used to detect the genetic diversity and genetic variation of C. rosthornina populations in different communities; changing trend of soil characteristics in different communities. The results are as follows:(1) C. rosthornina is a perennial iteroparous shrub and begin to reproduce when its basal diameter reach about 1.0 cm, the largest of which could be as high as five meters . C.rosthornina distributes widely in giant bamboo forest, mixed conifer-broad forest and evergreen broadleaved forest but does not occur in Pinus massomiana forest, so is a relatively shade-tolerant plant.(2) Individuals of C. rosthornina populations in different communities all show clumped spatial distribution pattern, but the degree of which varies in different communities, with giant bamboo being the highest, mixed conifer-broad forest being in the middle, evergreen broadleaved forest being the lowest and almost close to be random. Individuals of C. rosthornina populations at development stages in different communities show the same changing trends, that is, from seedlings to young and adult plants, the degree of clumping will decrease gradually.(3) The size of C. rosthornina populations varies in different communities, which indicates each population at successional stages, the average basal diameter of individuals or reproductive individuals of C. rosthornina population in giant bamboo forest is the smallest, that of of individuals or reproductive individuals of C. rosthornina population in evergreen broadleaved forest is largest, the size order of individuals of C. rosthornina populations in different communities is in accordance with community...
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