| In this paper the growth and development, morphology, photosynthesis, secondary metabolism and biomass allocation of Acanthopanax senticosus (Rupr. & Maxim.)Harms in heterogenous habitats were studied. Based on the relationship between the characteristics of environment and energy allocation patterns of A. senticosus, the plant life cycle forms were put forward. The traits of life cycle forms of A. senticosus were concluded; the forming mechanism and significance of plant life forms were discussed. The main results as fellow:1. In the distributing area of A. senticosus, there were many factors, such as light level, humidity of soil and temperature et al, influenced the growth and development of A. senticosus. But the light was the leading factor which influenced the growth and development of A. senticosus greatly. Based on the light level, three typical habitats for A. senticosus were set, i.e. under forest habitat, forest gap habitat and forest edge habitat. The results indicated that the growth and development, morphology, photosynthesis, secondary metabolism and biomass allocation of A. senticosus in different habitats varied greatly and finally leading to the different life cycle patterns.2. Under forest habitat, the light intensity was low. The mean daily photosynthetic photon flux density (PPFD) of each month was about 25.0umol m'V1, which was the stressful for the growth and development of A. senticosus. In this habitat, A. senticosus with a few branches, larger leaf, bigger leaf area ration(LAR), and low net photosynthetic rates grows slowly. The sexual reproduction was not active. In all of the individuals of A. senticosus reaching reproductive age, only a few individuals could flower and fruit. Comparatively, the clonal reproductive organs i.e. the rhizomes could be conserved completely and was the main reproductive means in shade habitat. The biomass was mainly allocated to the underground parts.3. In forest gap habitat, the light intensity was medium. The mean daily PPFD of each month was about 228.3umol m"V, which almost equivalent to the light saturation point. So it was the optimal condition for the growth and development of A. senticosus. In this habitat, the species with many branches, larger and thick leaf, bigger LAR, and high net photosynthetic rates grows rapidly. The sexual reproduction was relatively active. In all of the individuals of A. senticosus reaching reproductive age, most individuals could flower and fruit. Because overground parts were active, so the clonal reproduction was relatively weak and the number of rhizomes was small. The biomass was mainly allocated to the overground parts for vegetative growth.4. In the edge of forest, the light intensity was the highest. The mean daily PPFD of each month was about 456.7umol m-2s-1, which exceeded the light saturation point greatly. The relatively higher light intensity restrained the development and establishment of A. senticosus obviously. Although the species with higher netphotosynthetic rates, many branches, but only with smaller leaf and LAR, so it grows not so much rapidly. The sexual reproduction was stronger. In all of the individuals of A senticosus reaching reproductive age, almost all individuals could flower and fruit. The reproductive age was small; the mean flowering ration and mean fruit set rate was higher per inflorescence. So the species was inclined to allocate the biomass to the sexual reproduction.5. The main secondary metabolites of A senticosus, including the compounds of Eleutheroside B (syringin), total flavonoids and hyperin, were determined. The content of syringin in shoots showed obviously seasonal dynamics, i.e. higher in the early spring and late autumn but lower in mid-summer. But the content of syringin of rhizomes and roots did not show obviously seasonal dynamics. But between different habitats there was significantly difference, from higher to the lower as: under forest >forest gap> forest edge. The content of flavonoids and hyperin mainly in the leaf showed positive...
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