典型草原围封后羊草地上功能性状对枯落物累积的响应

植物功能性状反映植物适应环境变化过程中在不同器官形态与功能间的资源权衡与分配策略。典型草原围封后枯落物累积导致群落光照、热量和水分的重新分配并改变微环境特征。在此过程中植物地上功能性状将通过怎样的变化来适应新的环境，目前尚不清楚。2015—2017年每年8月对内蒙古地区3种典型草原共有物种羊草（Leymus chinensis）的植株、叶片和茎干功能性状进行了测量与分析。结果表明：枯落物累积显著增加了羊草的植株高度、单株重量、茎叶比和总叶面积；枯落物累积显著增加了羊草的叶片长度、叶片重量、单叶面积、节间长度和茎干重量，这些性状属于敏感性状；枯落物累积对羊草的叶片数量和节间数量无显著影响，相对而言，这些性状属于惰性性状；羊草的单株重量与植株高度、叶片重量呈极显著的正相关关系（P<0.0001）；羊草的植株高度与节间数量、节间长度呈极显著的正相关关系（P<0.0001）。本研究结果从植物地上功能性状的角度阐明了典型草原植物对环境变化的适应方式，可为围封草原的合理管理提供基础数据与理论依据。

Response of aboveground plant functional traits of Leymus chinensis to litter accumulation in fenced grasslands

Plant functional traits indicate nutrient trade-offs among organs and functions of plants to adapt to community environmental changes. Litter accumulation modifies community microenvironment by reallocating light, heat, and water in fenced grasslands. However, plant adaptive strategy in this process is still not well understood. In every August of 2015-2017, aboveground plant functional traits (i.e., plant, stem, and leaf) of Leymus chinensis were comprehensively measured in three typical grasslands in Inner Mongolia, China. The results were follows. Litter accumulation significantly increased height, aboveground biomass, stem to leaf biomass ratio, and total leaf area of plant. The length, biomass and area of leaf, internode length, and stem biomass were significantly increased in the litter accumulation treatment of the three grasslands. These traits could be considered as sensitive traits to litter accumulation. The leaf number and internode number being considered as inert traits had no significant response to litter accumulation. Plant biomass showed positive correlations with plant height and leaf biomass (P < 0.0001). Similarly, plant height exhibited positive correlations with number and length of internode (P < 0.0001). Our findings elucidate the plant adaptive strategy to environmental changes in the context of aboveground plant functional groups in fenced grasslands and provide basic data and theoretical foundation for the management of fenced grasslands.