| Abstract Osmanthus fragrans, one of the sweet-scented plants cultivated traditionally in China, ranks among national traditional the ten most famous flowers, is classified as the important economic varieties of trees in our country by National Light Industrial Products Department of China, etc. The scent of its flower is fragrant, deep, elegant and sweet, and can move remote. The medicinal extract and net oil of Osmanthus fragrans are the exclusive products of China on the international spices market, which can be used for compounding such industry as the advanced essence, face cream, etc. to adjust fragrantly. Meanwhile, it possesses horticultural ornamental and medicinal value and many other uses. So it is very significant to carry on ecological study on Osmanthus fragrans and study the forming mechanism of secondary forest of Osmanthus fragrans to protect the wild population and biodiversityvalidly and utilize the resource of Osmanthus fragrans etc.Population and its module of Osmanthus fragrans in Sifengzai scenic spot in Changtin, Fujian Province were analyzed and discussed by quantitative statistic method in the work, including interspecific association of dominant species, size structure, spatial distribution pattern and its fractal trait and life process of the population, as well as branching patterns as affected by growth and developmental phases and the architectural variation in different habitats and the architectural variation of seedlings in different light conditions. The results indicated as follows:(DA series of techniques including the analysis of variance, x~2-test, association coefficient ,Ochiai's coefficient were calculated based upon a 2×2 contingency table to determine statistical significance of the overall association and the coefficient of the each species-pair association of the 21 dominant species in the woody plants of Osmanthus fragrans forest. The results indicated that the overall association of 21 dominant species was not correlated. The interspecific association between the main species pairs was not formed and relatively weak because most plants came into the community shortly and still stayed in the growth spurt of puberty. So only 10 species-pairs have significant positive association at p=0.05, 10 species-pairs have significant negative association at p=0.05. Some species-pairs showed high coefficient indicated either they appear along with high probability or they really have positive or negative association. So we must combine the characteristics of community appearance to analyze the association of species-pairs, which may change with time.(2)By applying the method of "spatial sequence instead of temporal change" and contiguous grid quadrat, the quantity characteristics, death dynamics, the cause and size structures of Osmanthus fragrans populations were analyzed. Using six aggregateindices(C\ K I?, M\ PAK Ca) to present the spatial distribution pattern and dynamics of Osmanthus fragrans populations, the results indicated that Osmanthus fragrans populations in the different sites showed a revered "J" type approximately(possess many seedlings, saplings and little mature trees) and being a growing pattern. From saplings to mature trees, the curve of mortality had a peak. Spatial distribution patterns of Osmanthus fragrans populations in the different sites were different with the types of clump or random, which may have relationships to environment and Osmanthus fragrans biological characteristics. Degree of aggregation of the population patterns varied with the different items. From seedlings to mature trees, the degree of intensity is decreasing from high to low. The distribution patterns of seedling and samplings are of clump while mature trees are of random.(3)The standard life table of Osmanthus fragrans populations are founded by mathematical technique according to premising with "space deducing time", and the curve of survival rate, mortality rate and killing power were drew. The results showed the survival curve of population appeared to be a type of Deevey-111 with the high mortality in the earliness. In the development of the population, there was a peak that only few seedlings can get through to the forth age class of which occurrence was perhaps one of the important reason of few mature trees.Survivability of the population dropped down monotonously, and accumulative mortality rose up correspondently with increment of the age class (Caliper class) and varying extent was large in the earliness and small in the late stage, as reflected survival and dead states of the population on the given age classes. Death density function curve displayed the character of stabilization in the earliness, fluctuation in the middle period and stabilization in the late stage with the convex point in the third age class. And the curve forms of danger scale function and mortality function were different.The results of spectral analysis showed that the characteristic of quantitative fluctuation of Osmanthus fragrans populations was multi-harmonic superposition with minor cycle in the major cycle. Influences of these cycles varied and depressed with diminishment of cycle, effect of superior wave was the most prominent with obvious major cycle, and there existed more prominent wave of minor cycle at the same time. The wave of minor cycle was maybe correlative with the effect of destroy by human.(4)The branching patterns of Osmanthus fragrans originated naturally in different growth and developmental phases are examined. The results showed that overall bifurcation ratio and stepwise bifurcation (SBRi:2) didn't vary significantly among different phases, but the stepwise bifurcation(SBR2:3) in the seedling and sapling phases are significantly lower than that in the mature phase(P<0.05). The first-order branch length, branch angle to horizon and leaf angle to horizon in sapling phase are significantly different with seedling and mature phases. In different development stages, thearchitectural comparison showed that: in mature tree stage, tree's growth slowed down and crown's expansion enlarged; in seedling stage, tree's height grew rapidly; in sapling stage, the trend of growth transform the growth of height into crown's expansion. The leaves are distributed at the first-order branch to the third-order branch, but most of them are distributed at the first-order and second-order branch in the three different phases. The leaf size increases with growth and development. The differences in branching patterns suggest that Osmanthus fragrans have different adaptive strategy during different growth and developmental phases.(5)Comparative analyses were made on the architecture of Osmanthus fragrans originated naturally and plantation. The results indicated that there was a great architectural variation between the individuals of the two habitats. It was shown concretely as follows: overall bifurcation ratio, stepwise bifurcation (SBRi:2), stepwise bifurcation(SBR.2;3), the first-order branch length, ratio of branch diameter(RBDi2), branch angle to horizon, leaf length and width, leaf area, etc. of Osmanthus fragrans vary significantly between originated naturally and plantantion which showed not only in individual but also in four aspects. It suggests that it is synergitic for individual and part to modify plastically in response to different environments.(6)The shape of crown, the distribution of branch and leaf of Osmanthus fragrans seedlings were studied. It showed that the structure of the seedlings was modified plastically in response to different light conditions. Because the seedlings who live in gaps get light intermittent, overall bifurcation ratio are significantly lower than that under canopy and full sun. Under full sun, most of leaves are distributed at the second-order branch, the length and area of them is small comparatively, and can use light fully. In gaps, most of leaves are distributed at the first-order branch to avoid being shaded by canopy; the length and area of them are big comparatively. Under canopy, the leaves are distributed at the first-order branch to the third-order branch but little, and the height growth of branch is significantly higher than that under full sun. Branching patterns of Osmanthus fragrans seedlings have unique traits: under strong radiation, Osmanthus fragrans seedlings can give rise to short branch and high bifurcation ratio; under adequate shade condition they can give rise to long branch and low bifurcation ratio; under intense shade condition they can give rise to comparatively long branch and comparatively high bifurcation ratio for height and horizon growth.(7)We will still study the biomass of underground root of Osmanthus fragrans, distribution character of root, litter fall decomposing dynamic, nutrients releasing rule and ' which kind of climax the community will succeed. Protective measures suggested in the work should be to carry on strengthening the construction of scenic spot, carefully the survey of Osmanthus fragrans resources, executing strictly the protection of Osmanthus fragrans and vegetation in its habitat, restoring the damaged vegetation, reinforcing the... |
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