• Understanding how plant communities respond to temporal patterns of precipitation in water‐limited ecosystems is necessary to predict interannual variation and trends in ecosystem properties, including forage production, biogeochemical cycling, and biodiversity.
• In North American shortgrass prairie, we measured plant abundance, functional traits related to growth rate and drought tolerance, and aboveground net primary productivity to identify: species‐level responsiveness to precipitation (precipitation sensitivity S_spp) across functional groups; S_spp relationships to continuous plant traits; and whether continuous trait–S_spp relationships scaled to the community level.
• Across 32 plant species, we found strong bivariate relationships of both leaf dry matter content (LDMC) and leaf osmotic potential Ψ_osm with S_spp. Yet, LDMC and specific leaf area were retained in the lowest Akaike information criterion multiple regression model, explaining 59% of S_spp. Most relationships between continuous traits and S_spp scaled to the community level but were often contingent on the presence/absence of particular species and/or land management at a site.
• Thus, plant communities in shortgrass prairie may shift towards slower growing, more stress‐resistant species in drought years and/or chronically drier climate. These findings highlight the importance of both leaf economic and drought tolerance traits in determining species and community responses to altered precipitation.

中文翻译：

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半干旱矮草草原与物种和群落对降雨敏感性的植物性状

• 必须了解植物群落如何响应缺水生态系统中降水的时间模式，才能预测生态系统特性的年际变化和趋势，包括牧草生产，生物地球化学循环和生物多样性。
• 在北美短草草原，我们测量了植物的丰度，与生长速度和耐旱性相关的功能性状以及地上净初级生产力，以识别：各功能组对降水的物种水平响应（降水敏感性S _spp）；S _spp与连续植物性状的关系；以及连续性状– S _spp关系是否扩展到社区级别。
• 在32种植物中，我们发现叶片干物质含量（LDMC）和叶片渗透势_Ψosm与S _spp都具有很强的二元关系。然而，LDMC和特定叶面积保留在最低的Akaike信息标准多元回归模型中，解释了59％的S _spp。连续性状和S _spp之间的大多数关系都按比例扩展到社区水平，但通常取决于特定物种是否存在和/或某个地点的土地管理。
• 因此，在干旱年代和/或长期干旱的气候下，短草草原的植物群落可能会向生长缓慢，抗逆性强的物种转变。这些发现突出了叶片经济和耐旱性状在确定物种和群落对降水变化的反应中的重要性。