南方红豆杉无性系种群研究

Taxus chinensis var. mairei is the material for medicine of Taxol which is an effective, low poison and large range cancer-resistant. Study on Taxus chinensis var. mairei population ecology will construct scientific basis for protecting, regenerating and expanding its population. Yuanbaoshan seats in Rongshui county, northern Gunagxi of China (109°07￠~190°13￠E, 25°22￠~25°32￠N). Taxus chinensis var. mairei distribute area in Yuanbaoshan is above 1550m altitude with a center distribution on over 1900m altitude around Lanpin peak, where Taxus chinensis var. mairei found almost at two sides of ravine.Base on the resource investigation of Taxus chinensis var. mairei, four quadrates of 600m2 were selected for plot square and each of them was divided into 5m′5m unit for study. The census datum include: the arbors, height over 3m were recorded the height, crown, height below shoot, diameter breast high and growth position; the seedling and sapling (H<3m) were recorded the height. Datum of shrub and herb were obtained by recorded the cover rate and height. In the mean time, the environment condition was also recorded.According to the Taxus chinensis var. mairei life history and basing on the former study, the modular population can be divided into 6 classes: S1, seedling(H≤30cm);S2, sapling(DBH≤300cm);S3, 3cm≤D.B.H≤20cm; S4,21cm<D.B.H≤45cm; S5, 45cm<D.B.H.≤70cm and S6, D.B.H.>70cm. .Before germination, the seed of Taxus need to be dormant for more than one year, and the bird and the beast like to eat its seed so that it is hard to find seedling and sapling from seed in natural condition. Therefore Taxus chinesis var. mairei has been considered as a decline or none descendant population. In this study, it is found that Taxul chinesis var. mairei have a powerful asexual multiplication in Yuanbaoshan, especially ramet sprouting on stem. Taxul chinesis var. mairei depends on this way to develop and expand its population. The results show that the development of Taxus chinensis var. mairei populations greatly depend on its ramets which sprout on its stem, and the population size structure are stable type. As integrating the datum of all plots, the vertical scale of size structure is approximated pyramidal and the survival curve is slightly protruding but a linear. In another word, the structure is "revere-J", and the survival curve is likely a linear with a little protruding so that it belongs to stable type. To expanding and continuing the population, there are high ramet sprouting rate, but the resource limit induce a higher seedling and sapling mortality rate. When sapling grows up bigger as young tree, it takes adventitious root to stretch into soil and assimilate the nutriment and water, then it becomes independent individual. In this period, the individual mortality rate inclines. However, when the individual is high enough to gain spatial resource its height growth decrease then it turns to diameter growth. Mature trees of 7.1~9m class possess a great percentage in populaiton.The result of intraspecific and interspecific competition form the difference individual height of Taxus chinensis var. mairei population. .The morphological traits of ramets in different plots were variable, the average ramet height and base-diameter of 4 plots were 2.45m, 6.2cm. The index v of different plots ranged 0.60 to 0.87, it showed that the architectures of Taxus chinensis var. mairei were differed in different environment, and this may means that Taxus chinensis var. mairei clonal population was likely to have comparatively larger morphological plasticity. The index v had good effect on describing architecture of Taxus chinensis var. mairei. The population recruitment of Taxus chinensis var. mairei included seeds recruitment and ramets recruitment. In natural conditions, ramets recruitment was the primary way of population recruitment. The ramets recruitment was dominant in guerrilla Taxus chinensis var. mairei, and the seedlings from seeds were seldom found, whereas seeds recruitment increased in phalanx Taxus chinen

研究南方红豆杉无性系种群结构动态、克隆生长格局、克隆构型、形态可塑性，分析异质性生境对植物克隆生长的影响，探索无性系种群生长繁殖的觅食性反应和搜寻行为，揭示克隆生长对种群更新的影响及其种群延续的策略，为保护珍贵物种资源提供科学依据，并将丰富植物种群生态学的植物克隆生长理论的内容，在国际学科前沿探索方面具有重要意义。