Altitudinal Variations of the Reproductive Strategies of Primula florindae
ZHANG Jie;JIANG Xianfeng;CHEN Lingling;LI Qingjun;Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences;University of Chinese Academy of Sciences;Laboratory of Ecology and Evolutionary Biology,State Key Laboratory in Conservation and Utilization of Bioresources in Yunnan,Yunnan University;
Primula florindae is a typical distylous speices of Primulaand an endemic species in the Qinghai-Tibet Plateau.In this research,we set 5plots of natural population from 3 100 mto the treeline(4 350m)along the Sygera Mountains without anthropogenic interference and select flowering phenology,floral display traits,pollinators,sex allocation,and natural seed set as characters.By comparing these characters among five populations along altitudinal gradients,we make certainly the adaptive strategies of repro-ductive characters to altitudinal variation,and discuss the possible influences of future climate change on distribution pattern of P.florindae.We highlight three conclusions:(1)initial blooming time of P.florindae did not show a correlation with elevation:the middle elevation population bloomed the earliest and the highest population bloomed last.Nevertheless,with the increase of elevation,flower longevity and floral display area of both morphs of P.florindaeincreased significantly,but varieties of pollinators decreased,and both morphs tend to allocate more resources to assure female sexual function.The adaption of the traits studied to heterogeneity habitats among different elevations may lead to the variation of reproductive strategies.(2)With the increase of elevation,flower number of P.florindae significantly diminished,but both herbivory number and rate also reduced,so effective fruit number of all populations showed no distinct disparity,and there were also no significant differences in seed number,showing that by shaping corresponding reproductive strategies to different environment,P.florindae guaranteed breeding success,then stabilized population in all elevations.(3)Climate change will have profound and lasting impacts on the distribution of P.florindae,the lower altitudinal limit may shift up,but sandy soils at higher elevations are unfavorable to its growth,while the temporal-spatial distribution of pollinators under climate change are still unknown.We predict the lower altitudinal limit of P.florindae will move up to middle elevation and result in a decrease in its distribution over the next 100 years.
【Key Words】： Qinghai-Tibet Plateau Primula florindae altitudinal gradients reproductive strategies climate change
【CateGory Index】： Q948.1
【CateGory Index】： Q948.1