Coastal wetland ecosystems make an important contribution to the global carbon pool, yet their extent is declining due to aquaculture-related land use changes. We conducted an extensive investigation into the carbon stock and area coverage of macrophytes in a tropical coastal Ramsar wetland, Kolleru in Andhra Pradesh, India. A total of 72 quadrats of size 1 × 1 m were laid in the wetland, 19 species of macrophytes were collected and analyzed for carbon content using a CNHS analyzer. To assess changes in the wetland macrophytes, Normalized Difference Vegetation Index (NDVI) was estimated using Landsat time series data from 1975 to 2023. The importance value index (IVI) of macrophytes scored highest for the (41.4) and the lowest for (1.9). Non-metric multidimensional scaling (NMDS) significantly ( = 0.1905, = 0.0361) revealed a clear separation of macrophytes in ordination space. ANOVA indicated highly significant ( < 0.0001) variations in the carbon content of aboveground and belowground components of macrophytes. Among the different macrophytes, the highest carbon content was found in (0.6 g. g) and the lowest was recorded in (0.2 g. g). On an average, emergents in the Kolleru wetland sequester 1525 ± 181 g C m yr, rooted floating species sequester 858 ± 101 g C m yr, submerged macrophytes sequester 480 ± 60 g C m yr, and free-floating macrophytes sequester 221 ± 90 g C m yr. Land cover mapping revealed a decrease in spread of aquatic vegetation from 225.2 km in 1975 to 100.6 km in 2023. Although macrophytes are vital carbon sinks, the wetland conversion into fishponds has resulted in a loss of 55.3 % of carbon storage. Therefore, immediate restoration of macrophyte cover is vital for the proper functioning of carbon sequestration and mitigation of climate change impacts.

中文翻译：

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将拉姆萨尔沿海湿地的碳储存与土地利用动态联系起来


沿海湿地生态系统对全球碳库做出了重要贡献，但由于与水产养殖相关的土地利用变化，其范围正在缩小。我们对印度安得拉邦科莱鲁热带沿海拉姆萨尔湿地的碳储量和大型植物的面积覆盖度进行了广泛的调查。湿地内共铺设72个1×1m的样方，采集19种大型植物，并使用CNHS分析仪分析碳含量。为了评估湿地大型植物的变化，利用1975年至2023年的Landsat时间序列数据估算了归一化植被指数（NDVI）。大型植物的重要性值指数（IVI）得分最高为（41.4），最低为（1.9） 。非度量多维标度（NMDS）显着（= 0.1905，= 0.0361）揭示了排序空间中大型植物的清晰分离。方差分析表明大型植物地上和地下成分的碳含量存在高度显着（< 0.0001）的变化。在不同的大型植物中，碳含量最高的是（0.6 g. g），最低的是（0.2 g. g）。平均而言，Kolleru 湿地的挺水植物隔离量为 1525 ± 181 g C m 年，有根漂浮物种隔离量为 858 ± 101 g C m 年，沉水植物隔离量为 480 ± 60 g C m 年，自由漂浮的大型植物隔离量为 221 ± 90 g C m 年。土地覆盖测绘显示，水生植被的分布面积从 1975 年的 225.2 公里减少到 2023 年的 100.6 公里。虽然大型植物是重要的碳汇，但湿地转变为鱼塘导致碳储存损失了 55.3%。 因此，立即恢复大型植物覆盖对于碳封存的正常发挥和缓解气候变化影响至关重要。