The occurrence of climate change at an unprecedented scale has resulted in alterations of ecosystems around the world. Numerous studies have reported on the potential to slow down climate change through the sequestration of carbon in soil and trees. Freshwater wetlands hold significant potential for climate change mitigation owing to their large capacity to sequester atmospheric carbon dioxide (CO2). Wetlands among all terrestrial ecosystems have the highest carbon density and are found to store up to three to five times more carbon than terrestrial forests. The current study was undertaken to quantify carbon stocks of two carbon pools: aboveground biomass (AGB) and belowground biomass (BGB). Chosen study sites; Kolonnawa wetland and Thalawathugoda wetland park are distributed within the Colombo wetland complex. Colombo was recognized as one of the 18 global Ramsar wetland cities in 2018. A combination of field measurements and allometric tree biomass regression models was used in the study. Stratification of the project area was performed using the normalized difference vegetation index (NDVI). The AGB carbon stock, across strata, is estimated to be in the range of 13.79 ± 3.65–66.49 ± 6.70 tC/ha and 8.13 ± 2.42–52.63 ± 10.00 tC/ha at Kolonnawa wetland and Thalawathugoda wetland park, respectively. The BGB carbon stock is estimated to be in the range of 2.47 ± 0.61–10.12 ± 0.89 tC/ha and 1.56 ± 0.41–8.17 ± 1.39 tC/ha at Kolonnawa wetland and Thalawathugoda wetland park, respectively. The total AGB carbon stock of Kolonnawa wetland was estimated at 19,803 ± 1566 tCO2eq and that of Thalawathugoda wetland park was estimated at 4180 ± 729 tCO2eq. In conclusion, the study reveals that tropical freshwater wetlands contain considerable potential as carbon reservoirs. The study suggests the use of tropical freshwater wetlands in carbon sequestration enhancement plans in the tropics. The study also shows that Annona glabra, an invasive alien species (IAS), has the potential to enhance the net sink of AGB carbon in these non-mangrove wetlands. However, further studies are essential to confirm if enhanced carbon sequestration by Annona glabra is among the unexplored and unreported benefits of the species.

中文翻译：

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斯里兰卡城市淡水湿地中地上和地下碳储量的估算。

气候变化以前所未有的规模发生，导致世界各地的生态系统发生了变化。许多研究报告了通过固存土壤和树木中的碳来减缓气候变化的潜力。淡水湿地拥有大量隔离大气中二氧化碳的能力，因此具有缓解气候变化的巨大潜力。在所有陆地生态系统中，湿地的碳密度最高，被发现的碳储存量比陆地森林高三到五倍。当前的研究是量化两个碳库的碳储量：地上生物量（AGB）和地下生物量（BGB）。选择学习地点；科伦坡湿地园区内分布着科隆纳瓦湿地和Thalawathugoda湿地公园。科伦坡被公认为2018年全球18个拉姆萨尔湿地城市之一。该研究结合了野外测量和异速树木生物量回归模型。使用标准化差异植被指数（NDVI）对项目区域进行分层。整个地层的AGB碳库估计分别在Kolonnawa湿地和Thalawathugoda湿地公园的13.79±3.65–66.49±6.70 tC / ha和8.13±2.42–52.63±10.00 tC / ha的范围内。据估计，科隆纳瓦湿地和Thalawathugoda湿地公园的BGB碳库分别为2.47±0.61–10.12±0.89 tC / ha和1.56±0.41–8.17±1.39 tC / ha。Kolonnawa湿地的总AGB碳储量估计为19,803±1566 tCO2eq，Thalawathugoda湿地公园的总AGB碳储量估计为4180±729 tCO2eq。总之，研究表明，热带淡水湿地具有巨大的碳储藏潜力。该研究建议在热带地区使用热带淡水湿地进行碳固存增强计划。该研究还表明，入侵性外来物种Annona glabra有可能增强这些非红树林湿地中AGB碳的净汇。但是，进一步的研究对于确认Annona glabra增强的碳固存是否属于该物种的未开发和未报道的益处是至关重要的。入侵性外来物种（IAS）具有增强这些非红树林湿地AGB碳净汇的潜力。但是，进一步的研究对于确认Annona glabra增强的碳固存是否属于该物种的未开发和未报道的益处是至关重要的。入侵性外来物种（IAS）具有增强这些非红树林湿地AGB碳净汇的潜力。但是，进一步的研究对于确认Annona glabra增强的碳固存是否属于该物种的未开发和未报道的益处是至关重要的。