Flower Color Diversity And Influencing Factors In Alpine Meadow Community Of Qinghai-Tibet Plateau

Floral color is related to the pollinator’s perception and preference,its the most easily recognizable signal in the "pollination syndrome".Biological and abiotic factors can directly affect the floral color diversity within communities.Floral color is one of the important functional traits that mediate the interaction between plants and pollinators.However,quantitative research on floral color is still rare,how floral color affects the interaction between species and its role in community assembly is not clear.In order to explore the potential factors how to affect the floral color diversity within communities,and understand the role of floral color in community assembly and species coexistence,we studied in the eastern part of the Qinghai-Tibet Plateau alpine meadow and swamp meadow,used the pollinator visual model to studied the effects of grazing system,phylogenetic structure,and seasons on the floral color diversity within communities.We answer the following questions :(1)Whether the floral color distribution in alpine plant community is related to the phylogenetic history of flowering plants?(2)How does the floral color diversity within communities changed with different grazing systems and different months?(3)Can pollinators distinguish the floral color within communities ? How pollinators affect the diversity and distribution pattern of floral color(clustered,overdispersion or random distribution).Our main conclusions are as follows: 1)The flower colors of coexist species were more dissimilar,the floral color diversity within communities was not restricted by phylogenetic relationship between plants.This is because anthocyanidin are easily affected by environmental,and the floral colors does not directly affect the pollen displacement.2)Grazing and seasonal factors doesn’t change the floral color diversity within communities,this mainly because the color diversity within communitieschanged.In alpine meadow and swamp meadow habitat,grazing and ungrazing communitie’s floral color showed no difference in the cues to attract hymenoptera pollinators.July and August communitie’s floral color also showed no difference in the cues to attract hymenoptera pollinators.3)Bee pollinators can distinguish the floral colors within all communities,while fly pollinators can distinguish part of the colors within the community.Because the color classification visual model of fly pollinators,it can only distinguish the floral colors within part of communities.Flowering density will affect the green reflectance of flowers in the community and thus affect the visitation rate of pollinators.The lower of flowering density,the lower of green reflectance in the community,the higher total visitation rate of pollinators and the higher visitation rate of diptera pollinators.Fly pollinators prefer yellow/white flowers,the selection exerted by flies and the interaction between plants mediated by pollinators under low flowering density resulted in the clustered structure of flower color within communities,this indicate that pollinators’ selection of floral colors played a role in the plant community assemblely.