Dynamics of Sundarbans mangroves under climate extremes and changing soil nutrient composition

Mangroves are vital for resilience of coastal communities against climate extremes. They have high carbon densities and sequestration rates which makes them a promising tool for carbon removal from atmosphere using terrestrial vegetation. However, human activities like deforestation and rapid urbanisation pose a major threat to mangroves globally. Sundarbans in South Asia are the largest continuous mangrove forest in the world and due to rampant degradation by human activities, they have been classified as ‘endangered’ under the Red List of Ecosystems. In addition to physical damage to mangroves caused by climate extremes, human activities change the chemical composition of soil leading to changing nutrient availability for mangroves. The ratio of carbon to nitrogen to phosphorous (also called the Redfield ratio) is critical for coastal vegetation productivity and has an optimum value of 106:16:1. While nutrient availability around most mangroves across the globe has changed because of anthropogenic activities, it is projected to further deteriorate in the future augmenting anthropogenic stress on mangroves. The physiological mechanism of mangrove’s resistance to extreme events and changing nutrient supply is poorly understood. The present study fills this gap by advancing our understanding of the dynamics of Sundarbans mangroves in South Asia under climate extremes and changing soil nutrient composition.