PNAS:沙漠红树林与下加利福尼亚州的碳汇
美国Scripps海洋学研究所一项研究发现，沿着下加利福尼亚州(Baja California)沿海沙漠生长的红树林比它们的热带表亲在地下固定了更多的碳。近来的研究已经证明了红树林的碳固定潜力，红树林是常见于沿海区域咸水中的一群灌木与树。红树林通过在表面加积厚的泥炭层从而增加在海平面上的生存，随着水上涨，这个过程不仅向上扩展了这种植物的根系，还掩埋了大量的有机碳。Paula Ezcurra及其同事研究了下加利福尼亚州沿海地区沙漠水湾的红树林沉积地形，这个地区相对低矮的红树林在将近2000年的时间里一直在积累根泥炭。这组作者估计，下加利福尼亚州不同的沙漠的地下保有该地区地下碳总量的大约28%，尽管它们仅占陆地面积的1%。此外，其储存率超过了来自两个大型繁茂热带红树林——Marismas Nacionales 和La Encrucijada——的样本。这组作者说，这些发现证明了红树林代表了墨西哥北部沙漠的一个重要的碳汇，并且凸显了保护这一重要生态系统的需求。
原文链接：
Coastal landforms and accumulation of mangrove peat increase carbon sequestration and storage
原文摘要：
Given their relatively small area, mangroves and their organic sediments are of disproportionate importance to global carbon sequestration and carbon storage. Peat deposition and preservation allows some mangroves to accrete vertically and keep pAce with sea-level rise by growing on their own root remains. In this study we show that mangroves in desert inlets in the coasts of the Baja California have been accumulating root peat for nearly 2,000 y and harbor a belowground carbon content of 900–34,00 Mg C/ha, with an average value of 1,130 (± 128) Mg C/ha, and a belowground carbon accumulation similar to that found under some of the tallest tropical mangroves in the Mexican Pacific coast. The depth–age curve for the mangrove sediments of Baja California indicates that sea level in the peninsula has been rising at a mean rate of 0.70 mm/y (± 0.07) during the last 17 centuries, a value similar to the rates of sea-level rise estimated for the Caribbean during a comparABLe period. By accreting on their own accumulated peat, these desert mangroves store large amounts of carbon in their sediments. We estimate that mangroves and halophyte scrubs in Mexico’s arid northwest, with less than 1% of the terrestrial area, store in their belowground sediments around 28% of the total belowground carbon pool of the whole region.
作者：Paula Ezcurra
