Rapid changes in functional trait expression and decomposition following high severity fire and experimental warming
Rapid changes in functional trait expression and decomposition following high severity fire and experimental warming
复制标题
高强度火灾和实验变暖后功能性状表达和分解的快速变化
DOI：
10.1016/j.foreco.2023.121019
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发表时间：
2023
影响因子：
3.7
通讯作者：
Mitchell, Rachel M.
中科院分区：
文献类型：
--
作者：
Taber, Ethan M.;Mitchell, Rachel M.
在全球许多地区，不同寻常的严重野火发生频率更高，空间范围更大，而且在新季节发生。与此同时，气候变化正在升高气温并改变降水模式。高强度火灾有可能导致群落生态系统类型和功能发生变化，而这些群落通过群落组成、功能性状值和养分循环过程的变化来适应低度火灾。然而，气候变暖和火灾严重程度之间的相互作用对群落组成、性状价值和生态系统功能的影响却很少被研究和了解。我们通过开放式顶部加温室对美国亚利桑那州北部黄松 (Pinus ponderosa) 森林林下植物群落的烧伤严重程度梯度进行了实验性增温的影响评估。具体来说，我们检查了火灾后第一个生长季节的群落组成、三种植物功能性状（比叶面积（SLA）、叶片干物质含量（LDMC）和株高）和一种生态系统功能（分解率）。高烧伤严重程度导致群落组成发生显着变化。实验变暖和高烧伤严重程度的结合显着降低了群落加权平均 LDMC 和株高，并增加了分解率。我们的研究表明，群落组成、性状表达和生态系统功能对烧伤严重程度、实验变暖及其相互作用有显着而快速的反应。这表明，在未来气候和野火条件下经历非典型严重火灾的生态系统可能会以与过去完全不同的方式恢复，有利于不同的物种和性状，生态系统功能也发生改变。
Uncharacteristically severe wildfires are occurring at higher frequency, across larger spatial extents, and in new seasons in many parts of the globe. At the same time, climate change is elevating temperatures and altering precipitation patterns. High severity fires have the potential to produce shifts in ecosystem type and function in communities that are adapted to low severity fire via changes in community composition, functional trait values, and nutrient cycling processes. However, interactive effects between climate warming and fire severity on community composition, trait values, and ecosystem functioning are rarely studied and poorly understood. We assessed the impact of experimental warming via open top warming chambers across a burn severity gradient on the understory plant community of a Ponderosa pine (Pinus ponderosa) forest in northern Arizona, USA. Specifically, we examined community composition, three plant functional traits (specific leaf area (SLA), leaf dry matter content (LDMC), and plant height) and one ecosystem function (decomposition rate) in the first post-fire growing season. High burn severity produced significant shifts in community composition. The combination of experimental warming and high burn severity significantly decreased community weighted mean LDMC and plant height, and increased decomposition rate. Our study demonstrates significant and rapid responses of community composition, trait expression, and ecosystem function in response to burn severity, experimental warming, and their interaction. This suggests that ecosystems experiencing atypically severe fire under future climate and wildfire conditions may recover in fundamentally different ways than in the past, favoring a different suite of species and traits, with altered ecosystem function.