植物功能性状对气候变暖的响应及其与生产力的关联：以冻土生态系统为例

植物功能性状是关联环境变化与生态系统功能的桥梁。探究气候变暖情景下冻土区植物功能性状的变化及其与生态系统生产力的关联有助于增加学术界对气候变暖影响冻土生态系统碳循环机理的认识。然而，以往的研究主要关注植物地上性状，对冻土区根系性状变化的关注相对不够。并且，以往的研究主要集中在植物性状值变化对生态系统生产力的影响，忽视了性状间权衡关系以及性状种内、种间变异的作用。为此，本项目拟以青藏高原冻土区沼泽化草甸为研究对象，依托增温控制实验平台，测定生态系统总初级生产力以及群落主要物种个体水平物候、结构、叶片及根系性状(初花期、株高、叶片和根系养分含量及根系分泌物等)。进一步地，基于个体水平性状值计算群落水平植物性状加权平均值，性状间权衡关系和性状种内、种间功能多样性，并量化这些性状参数调控生态系统总初级生产力对增温响应的相对重要性。本项目的实施有望为理解冻土区碳循环的生物学调控机制提供新视角。

Plant functional traits could elucidate linkages between ecosystem function and environmental change. Exploring the responses of plant functional traits to global warming and their effects on ecosystem productivity in permafrost regions could improve our understanding of the mechanism underlying the impact of warming on permafrost carbon cycle. However, previous studies mainly focused on aboveground plant functional traits, with less attention being paid to root traits in permafrost ecosystem. Moreover, previous studies emphasized the effects of plant trait values on ecosystem productivity, ignoring the role of trait tradeoff and trait intra- and interspecific variation. In this project, based on an established swamp meadow warming experiment in Tibetan permafrost regions, we intend to determine ecosystem total primary productivity and individual-level phenology, structure, leaf and root traits (flowering onset time, plant height, leaf and root nutrient concentration as well as root exudate etc.) of the dominant and subordinate species. We will then calculate trait community weighted mean, trait tradeoff and trait intra- and interspecific functional diversity according to plant individual-level traits. Furthermore, we will quantify the relative importance of these trait parameters in regulating the response of ecosystem total primary productivity to experimental warming. The implementation of this project could be expected to provide a new perspective for understanding the biological regulatory mechanisms for permafrost carbon cycle.