Long-term warming results in species-specific shifts in seed mass in alpine communities

PeerJ

article

Chunhui Zhang¹  Zhen Ma²  Huakun Zhou²  Xinquan Zhao² 

[1] State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University;Key Laboratory of Restoration Ecology for Cold Regions in Qinghai Province, Northwest Institute of Plateau Biology, Chinese Academy of Sciences;Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences

关键词: Climate change;    Functional traits;    Grazing;    Qinghai-tibet plateau;    Trait variation;   

DOI  :  10.7717/peerj.7416

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundGlobal warming can cause variation in plant functional traits due to phenotypic plasticity or rapid microevolutionary change. Seed mass represents a fundamental axis of trait variation in plants, from an individual to a community scale. Here, we hypothesize that long-term warming can shift the mean seed mass of species.MethodsWe tested our hypothesis in plots that had been warmed over 18 years in alpine meadow communities with a history of light grazing (LG) and heavy grazing (HG) on the Qinghai-Tibet plateau. In this study, seeds were collected during the growing season of 2015.ResultsWe found that warming increased the mean seed mass of 4 (n = 19) species in the LG meadow and 6 (n = 20) species in the HG meadow, while decreasing the mean seed mass of 6 species in the LG and HG meadows, respectively. For 7 species, grazing history modified the effect of warming on seed mass. Therefore, we concluded that long-term warming can shift the mean seed mass at the species level. However, the direction of this variation is species-specific. Our study suggests that mean seed mass of alpine plant species appears to decrease in warmer (less stressful) habitats based on life-history theory, but it also suggests there may be an underlying trade-off in which mean seed mass may increase due to greater thermal energy inputs into seed development. Furthermore, the physical and biotic environment modulating this trade-off result in complex patterns of variation in mean seed mass of alpine plant species facing global warming.

【 授权许可】

CC BY