Geomorphic and ecological constraints on the coastal carbon sink
Geomorphic and ecological constraints on the coastal carbon sink
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DOI：
10.1038/s43017-023-00429-6
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发表时间：
2023-05
影响因子：
42.1
通讯作者：
M. Kirwan;J. Megonigal;G. Noyce;Alexander J. Smith
中科院分区：
文献类型：
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作者：
M. Kirwan;J. Megonigal;G. Noyce;Alexander J. Smith
气候变化正在推动沿海地区的根本性重组，其中富含碳的生态系统正在同时迁移、增生和淹没。在这篇综述中，我们讨论了制约土壤碳积累的地貌过程和制约温室气体排放的生态过程，它们共同决定了沿海景观的净辐射强迫和沿海碳汇的大小。海平面上升创造了垂直和横向的容纳空间，可能会增加沼泽和红树林的土壤碳积累。然而，海平面上升和盐水入侵导致生态系统转型，导致现有碳库的损失，改变了碳固存和温室气体排放之间的平衡。我们建议，生态系统重组的结果在大，但大多抵消，辐射强迫的变化。在大陆一级，土壤固碳和木材生产的损失被淡水生态系统盐碱化引起的甲烷排放量减少所抵消。尽管如此，气候对沿海碳汇的影响仍主要在单个生态系统内进行研究。未来的工作需要确定生态系统之间碳的连通性，随着生态系统转型发生的碳积累和温室气体排放的变化，以及碳在沿海景观中移动时的命运。
Climate change is driving a fundamental reorganization of the coastal zone, in which carbon-rich ecosystems are simultaneously migrating, accreting and submerging. In this Review, we discuss the geomorphic processes constraining soil carbon accumulation and the ecological processes constraining greenhouse gas emissions that together determine the net radiative forcing of the coastal landscape and the size of the coastal carbon sink. Sea level rise creates vertical and lateral accommodation space that potentially enhances soil carbon accumulation in marshes and mangroves. However, sea level rise and saltwater intrusion lead to ecosystem transitions that result in loss of existing carbon pools, altering the balance between carbon sequestration and greenhouse gas emissions. We propose that ecosystem reorganization results in large, but mostly offsetting, changes in radiative forcing. At the continental scale, losses in soil carbon sequestration and wood production are offset by reduced methane emissions associated with salinization of freshwater ecosystems. Nevertheless, climate effects on the coastal carbon sink remain largely studied within individual ecosystems. Future work is needed to determine the connectivity of carbon between ecosystems, changes in carbon accumulation and greenhouse gas emissions as ecosystem transitions occur, and the fate of carbon as it moves through the coastal landscape.