Coupling Soil nutrient fluxes with photosynthetic functioning in Mangrove ecosystem

Mangrove ecosystems are influenced by a complex interaction of edaphic factors, among which soil nutrient availability plays a pivotal role in regulating photosynthetic productivity. The present study focuses on the productivity patterns of selected mangrove species of Kannur district, Kerala. For this study, three mangrove rich sites of various degrees of nutrient availability and ecological conditions were selected. Analysis of Chlorophyll a, Chlorophyll b, and total chlorophyll content revealed clear habitat-dependent variations, influenced by environmental factors and the concentrations of key nutrients such as nitrogen, phosphorus, potassium, magnesium, iron, and manganese. The results indicate a clear gradient in productivity, with Site 1 showing the highest and Site 2 the lowest, despite its relatively nutrient-rich profile. This paradox suggests that pollution-induced stress limit the physiological utilization of nutrients, thereby suppressing overall photosynthetic efficiency. Among the nutrients analyzed, potassium, magnesium, and iron emerged as key contributors to enhanced productivity, supporting their fundamental roles in chlorophyll synthesis, stomatal regulation, and enzymatic activity. The result reveals, the highest productivity, and ecological adaptability of Kandelia candel due to the efficient nutrient uptake mechanisms. The study focuses on the significance of balancing nutrient utilisation and ecological stress related to the functioning of mangrove ecosystem. The study of edaphic factors and its relation to physiological functioning of mangroves helps to formulate conservation and restoration practices in the most fragile ecosystem.