Mangrove ecosystems play a crucial role in the global carbon cycle. However, the carbon fluxes in the mangrove ecosystems found in the Indian subcontinent are not well understood. Here, for the first time, we estimate the net ecosystem exchange (NEE) in a mangrove ecosystem at Pichavaram, southeast India, using the eddy covariance method for the period October 2017–September 2018. The half-hourly daytime NEE varied from −11.05 μmol m⁻² s⁻¹ in the winter months (January–March 2018) to −6.06 μmol m⁻² s⁻¹ during the summer (April 2018). The estimated annual evapotranspiration during the study period was 610 mm, whereas the precipitation was 653 mm (much dryer than the long-term average). The half-hourly NEE data were gap filled and partitioned to estimate the gross primary productivity (GPP) and ecosystem respiration (R_eco). The estimated annual GPP was 1466 gC m⁻² and R_eco was 1283 gC m⁻². The mangrove forest appeared to be a modest sink of atmospheric CO₂, with an annual average net ecosystem productivity of 183 gC m⁻². However, in the summer months, it acted as a source. We observed that the mangrove CO₂ fluxes strongly responded to environmental factors such as temperature, rainfall, and salinity. However, it is noteworthy that the carbon sink capability may decline in the future due to rising temperatures, decreasing rainfall patterns, variation in salinity, and changes in tidal inundation patterns.

红树林生态系统在全球碳循环中起着至关重要的作用。但是，人们对印度次大陆的红树林生态系统中的碳通量知之甚少。在这里，我们首次使用涡度协方差方法估算了印度东南部Pichavaram的红树林生态系统的净生态系统交换（NEE），其时间范围为2017年10月至2018年9月。白天的半小时NEE值范围为−11.05微摩尔米^-2小号^-1在冬季（1月至2018年3月），以-6.06微摩尔米^-2小号^-1在夏季（2018年4月）。在研究期间，估计年蒸散量为610毫米，而降水量为653毫米（比长期平均值要干燥得多）。将半小时的NEE数据填补空白并进行分区，以估算总初级生产力（GPP）和生态系统呼吸（R _eco）。估计的年度GPP为1466 gC m ^-2，R _eco为1283 gC m ^-2。红树林似乎是大气中CO ₂的适度吸收者，年平均净生态系统生产力为183 gC m ^-2。但是，在夏季，它充当了来源。我们观察到红树林的CO ₂通量强烈响应环境因素，例如温度，降雨和盐度。但是，值得注意的是，未来由于温度升高，降雨模式减少，盐度变化以及潮汐淹没模式的变化，碳汇能力可能会下降。