Temperature optimum for marsh resilience and carbon accumulation revealed in a whole‐ecosystem warming experiment
Temperature optimum for marsh resilience and carbon accumulation revealed in a whole‐ecosystem warming experiment
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DOI：
10.1111/gcb.16149
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发表时间：
2022-03
影响因子：
11.6
通讯作者：
Alexander J. Smith;G. Noyce;J. Megonigal;G. Guntenspergen;M. Kirwan
中科院分区：
文献类型：
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作者：
Alexander J. Smith;G. Noyce;J. Megonigal;G. Guntenspergen;M. Kirwan
沿海沼泽是全球重要的碳密集生态系统，同时受到海平面上升的威胁。温度升高可能会增加湿地植物的生产力和有机质的积累，但生产力和分解之间的温度调节反馈使得很难评估湿地及其厚厚的有机物丰富的土壤将如何应对气候变暖。在这里，我们积极地增加了两个沼泽植物群落的地上植物表面和地下土壤温度，并发现适度的变暖（高于环境温度1.7°C）始终最大化根系生长，沼泽海拔增益和地下碳积累。在较高温度下观察到的沼泽海拔损失与碳矿化增加和微地形异质性增加有关，这是沼泽溺水的潜在预警信号。适度变暖情景下的最大海拔和地下碳积累独特地表明了个体代谢理论与景观尺度生态系统恢复力和功能之间的联系，但我们的工作表明，随着全球气温的持续上升，这些益处是非永久性的。
Coastal marshes are globally important, carbon dense ecosystems simultaneously maintained and threatened by sea‐level rise. Warming temperatures may increase wetland plant productivity and organic matter accumulation, but temperature‐modulated feedbacks between productivity and decomposition make it difficult to assess how wetlands and their thick, organic‐rich soils will respond to climate warming. Here, we actively increased aboveground plant‐surface and belowground soil temperatures in two marsh plant communities, and found that a moderate amount of warming (1.7°C above ambient temperatures) consistently maximized root growth, marsh elevation gain, and belowground carbon accumulation. Marsh elevation loss observed at higher temperatures was associated with increased carbon mineralization and increased microtopographic heterogeneity, a potential early warning signal of marsh drowning. Maximized elevation and belowground carbon accumulation for moderate warming scenarios uniquely suggest linkages between metabolic theory of individuals and landscape‐scale ecosystem resilience and function, but our work indicates nonpermanent benefits as global temperatures continue to rise.