【作者】 杨晓；

【导师】 杜国祯；

【作者基本信息】 兰州大学 ， 生态学， 2010， 硕士

【摘要】 植物的生殖物候尤其是开花物候,从个体水平到种群水平,再到群落水平,都能体现出植物对生物和非生物等各种因素的适应及响应。作为对各种策略的权衡,植物的开花物候只能选择在最合适但并不是最佳的时间内进行,同样因为群落对环境的长期的适应性进化,物种间形成了相对比较稳定的开花次序。由于放牧等对青藏高原东部高寒草甸植物群落的影响,近年来高寒草甸出现严重的退化现象,本研究通过分析放牧和施肥两种不同的干扰类型对高寒草甸的群落中植物的开花物候格局的影响,进入揭示不同植物在同一群落中的开花物候特征和同一物种在不同结构的群落中开花物候的差异。结果表明：在封育的对照群落中,48种常见植物的开花物候在从5月初到9月中旬的5个多月的生长季内物种间采取“集中开花”的模式,同时因为受到系统发育的限制,不同科间的植物的开花物候表现出一定的随机性,而不同物种的个体水平的开花同步性处于中等偏高的花期重叠指数,但48个物种的花期同步性在种间的差异性并不显著。生长季初期和末期开花的物种的花期同步性要高于中期开花的物种。放牧和施肥以不同的方式改变着群落的结构,群落中物种的开花物候同时也发生了变化。放牧群落中,能够观察到开花的40种植物的花期较封育群落平均提前了1.41天,但不显著；而且不同种的植物对放牧的响应不同,部分植物的开花物候期提前,也有个别物种有所推迟。和封育地相比,出现两级趋异分化的现象。除过毛莨科,其他科的植物在同一个科内的开花物候的变化表现一致；而施肥群落中,能够观察到的20种开花植物的花期较对照群落平均推迟了3.57天,同样不显著。开花物候同样在种间有所差异,但是不论是从种还是到科的水平,变化规律和放牧地中植物开花物候的变化规律相似。在两种干扰方式下,群落中植物的开花次序出现了变动,表现出高寒草甸植物在适应不同干扰时具有一定的可塑性。更多还原

【Abstract】 Plant reproductive phenology, particularly flowering phenology, from the individual to the population level, even to the community level, all can reflect the adaptation and response between plants to biotic and abiotic factors. As a trade-off to various strategies, the flowering phenology of plants can only choose the most suitable but not the best times over the grow season. At the same time, as a result of community’s long-term adaptive evolution to environment, all plants have formed stable flowering orders between species in the community.Factors such as grazing on the east alpine meadow plant communities of the Tibetan Plateau have led to serious degradation in alpine meadow on in recent years, With two different disturbances of grazing and fertilization on alpine meadow, in this study we analyzed plant communities flowering phenology pattern of change, and further revealing the different plant species’characteristics in the community and the flowering phenology differences of the same species in different communities.The results showed that:in the contrasted communities under enclosured, the flowering phenology of 48 kinds of common species take the model of concentrated flowering from early May to mid-September that more than 5 months of the growing season, both subjected by phylogenetic effects, the flowering phenology of plants show some random, and different species of flowering synchronization of the individual level show the middle set of high flowering overlapping mode,and flowering synchronization between species was no significant difference. Because of the trade-off to the environment and other factors, in the early and late period of growing season, species flowering synchronization are higher than the mid-flowering species.Grazing and fertilization changed the community structure in different ways. And the flowering phenology of species also changed. In the grazed communities, flowering phenology of 40 kinds species that can be observed advanced 1.41 days than the contrasted communities, yet not significant. Different species had different responses to grazing, some plants advanced the date of flowering phenology, there are also some species delayed it. And comparing with contrasted community, it occurs the phenomenon of divergent differentiation to bipolar. In addition to Ranunculaceae, the flowering phenological variation of other plants within the same family showed consistent. The flowering phenology of 20 species in the fertilized community delayed 3.57 days compared with the contrasted community, and is not significant, Different species of plants flowering phenology is different, but whether it is from the species or to the family level, it showed the same rules of variation like the grazed land.Meanwhile, under the two kinds of disturbances, the species appeared to adjust the orders of flowering phenology. Which showed different alpine plants to adapt to a certain degree of plasticity in response to different interference.更多还原