Department of Earth Science and Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
Environment Department, University of York, Heslington, York YO10 5DD, UK.
Nat Commun. 2017 Jun 15;8:15698. doi: 10.1038/ncomms15698.
Modern mangroves are among the most carbon-rich biomes on Earth, but their long-term (≥10 years) impact on the global carbon cycle is unknown. The extent, productivity and preservation of mangroves are controlled by the interplay of tectonics, global sea level and sedimentation, including tide, wave and fluvial processes. The impact of these processes on mangrove-bearing successions in the Oligo-Miocene of the South China Sea (SCS) is evaluated herein. Palaeogeographic reconstructions, palaeotidal modelling and facies analysis suggest that elevated tidal range and bed shear stress optimized mangrove development along tide-influenced tropical coastlines. Preservation of mangrove organic carbon (OC) was promoted by high tectonic subsidence and fluvial sediment supply. Lithospheric storage of OC in peripheral SCS basins potentially exceeded 4,000 Gt (equivalent to 2,000 p.p.m. of atmospheric CO). These results highlight the crucial impact of tectonic and oceanographic processes on mangrove OC sequestration within the global carbon cycle on geological timescales.
现代红树林是地球上碳储量最丰富的生态系统之一，但它们对全球碳循环的长期（≥10 年）影响尚不清楚。红树林的范围、生产力和保存受到构造、全球海平面和沉积物的相互作用的控制，包括潮汐、波浪和河流过程。本文评估了这些过程对南海（SCS）渐新世-中新世含红树林地层的影响。古地理重建、古潮模拟和相分析表明，潮汐范围的增加和床面剪切应力优化了沿受潮汐影响的热带海岸线的红树林发育。高构造沉降和河流沉积物供应促进了红树林有机碳（OC）的保存。南海周边盆地岩石圈储存的 OC 可能超过 4000 吉吨（相当于大气 CO2 的 2000ppm）。这些结果强调了构造和海洋过程对地质时间尺度内全球碳循环中红树林 OC 封存的关键影响。
