In view of increasing anthropogenic influences and global changes, quantification of carbon assimilation through photosynthesis has gained tremendous significance. Precise estimation of Gross Primary Productivity (GPP) is essential for several ecosystem models and is typically done using coarser scale satellite data. The mangrove ecosystem, which offers significant protection to the coastal environment, is one of the critical habitats from a global change point of view. Light use efficiency (LUE) was measured using diurnal in situ photosynthetic rate observations for 13 dominant mangrove species for 3 seasons at each of the three mangrove dominant test-sites situated along the east and west coast of India. Variations in photosynthetic rates among these species were studied for 3 seasons that indicated varying responses of mangrove ecosystem at each site. Among all species, Rhizophora mucronata and Sonneratia apetala indicated higher values at two of the test-sites. IRS Resourcesat-2 LISS-IV datasets were used for the estimation of GPP. Mean GPP for all the sites varied from 1.2 to 7.7 g C m⁻² day⁻¹ with maximum value of 14.4 g C m⁻² day⁻¹. Mean values of GPP varied across the sites, based on its maximum LUE values and available photosynthetically active radiation (PAR). The results provide GPP values at much better spatial resolution for a threatened habitat like mangroves that typically survive in a narrow habitat along the coasts.

鉴于越来越多的人为影响和全球变化，通过光合作用对碳同化的量化具有重要意义。精确估算总初级生产力（GPP）对于几种生态系统模型至关重要，通常使用较粗规模的卫星数据来完成。从全球变化的角度来看，为沿海环境提供重要保护的红树林生态系统是重要的栖息地之一。在印度东海岸和西海岸的三个红树林优势试验场中的每一个，对三个红树林主导试验场所中的13个优势红树林物种进行了3天的昼夜光合速率光合速率观测，测量了光利用效率（LUE）。对这些物种的光合速率变化进行了3个季节的研究，表明每个站点的红树林生态系统的响应都不同。在所有物种中Rhizophora mucronata和Sonneratia apetala在两个测试点显示较高的值。IRS Resourcesat-2 LISS-IV数据集用于GPP估算。所有位点的平均GPP在1.2至7.7 g C m ^-2 天^{-1的范围内变化}，最大值为14.4 g C m ^-2 天^-1。GPP的平均值根据站点的最大LUE值和可用的光合有效辐射（PAR）而有所不同。该结果为通常在沿海狭窄生境中生存的濒危生境（如红树林）提供了更好的空间分辨率的GPP值。