Soil warming, carbon-nitrogen interactions, and forest carbon budgets
Soil warming, carbon-nitrogen interactions, and forest carbon budgets
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DOI：
10.1073/pnas.1018189108
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发表时间：
2011-06-07
影响因子：
11.1
通讯作者：
Tang, Jim
中科院分区：
文献类型：
--
作者：
Melillo, Jerry M.;Butler, Sarah;Tang, Jim
土壤变暖有可能改变影响森林生态系统中碳储存的土壤和植物过程。我们在新英格兰的一个落叶森林中进行了一项大型的、长期的（7年）土壤变暖研究，量化了这些影响。土壤变暖导致了土壤中的碳损失，并刺激了树木木质组织中的碳增加。气候变暖增强的土壤有机质衰变也向土壤溶液中释放了足够多的无机氮，以支持观测到的植物碳储量的增加。尽管在为期7年的研究中，土壤变暖导致了新英格兰森林相对于对照区碳的累计净损失，但随着时间的推移，随着植物碳储量的增加，年净损失通常会减少。在第七年，变暖引起的土壤碳损失几乎完全被响应变暖的植物碳增加所补偿。我们将植物的收益主要归因于变暖引起的氮有效性的增加。这项研究强调了在大气-海洋-陆地-地球系统模型中纳入碳氮相互作用以精确模拟陆地对气候系统的反馈的重要性。
Soil warming has the potential to alter both soil and plant processes that affect carbon storage in forest ecosystems. We have quantified these effects in a large, long-term (7-y) soil-warming study in a deciduous forest in New England. Soil warming has resulted in carbon losses from the soil and stimulated carbon gains in the woody tissue of trees. The warming-enhanced decay of soil organic matter also released enough additional inorganic nitrogen into the soil solution to support the observed increases in plant carbon storage. Although soil warming has resulted in a cumulative net loss of carbon from a New England forest relative to a control area over the 7-y study, the annual net losses generally decreased over time as plant carbon storage increased. In the seventh year, warming-induced soil carbon losses were almost totally compensated for by plant carbon gains in response to warming. We attribute the plant gains primarily to warming-induced increases in nitrogen availability. This study underscores the importance of incorporating carbon-nitrogen interactions in atmosphere-ocean-land earth system models to accurately simulate land feedbacks to the climate system.