Patterns Of Flowering Phenology On Alpine Meadow In Qinghai-Tibetan Plateau And Their Response To Different Disturbances

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.