Mangroves on southwestern coast of India exhibit remarkable heat tolerance crucial for climate resilience, says study

A recent study conducted jointly by the Indian Institute of Science Education and Research (IISER), Pune, and the Kerala Forest Research Institute (KFRI) has revealed that mangroves on the southwestern coast of India exhibit exceptionally high heat tolerance, potentially making them more resilient to future climate change.

A team of researchers led by Dr. Deepak Barua, Associate Professor and Deputy Chair, Biology, IISER, and Sreejith Kalpuzha Ashtamoorthy, Principal Scientist and head, Forest Ecology department, KFRI, analysed as many as 13 mangrove species, including Aegiceras corniculatum, Avicennia marina, and Bruguiera gymnorhiza and found that they maintained wide thermal safety margins, allowing them to thrive under higher temperature conditions than earlier assumed.

The study emerges at a crucial time as coastal ecosystems, particularly mangroves, confront escalating threats due to climate change, characterised by rising temperatures and an uptick in heat waves. As vital components of these ecosystems, mangroves offer protection against coastal erosion, sequester carbon, and support diverse wildlife.

“The findings of this study are globally significant and underscore the significance of mangrove ecosystem in climate change scenario,” Dr. Sreejith and Dr. Barua said.

The research determined the temperature at which heat starts to significantly affect the health of mangrove plants, specifically by reducing the efficiency of a key part of their photosynthesis process (called photosystem II function) by 50%. On average, the temperature limit for the thirteen mangrove species studied was 53.3°C, higher than that of trees in other ecosystems worldwide.

This means these mangroves were especially good at surviving in higher temperatures, which was crucial as global warming continues. The findings were published in the journal Science of the Total Environment, they said.

“The study also established a correlation between leaf size and heat tolerance. Species with larger leaves, such as Bruguiera gymnorhiza and Sonneratia alba, exhibited enhanced heat tolerance, likely necessary because bigger leaves experience higher leaf temperatures,” Abdulla Naseef, PhD Scholar, KFRI, said. Research scholars Akhil Javad and Kausal are the other members of the team.

The study illuminates the resilience of mangrove ecosystems along the southwestern coast of the country, emphasising their role as a natural bulwark against climate change, says Kannan C.S. Warrier, Director, KFRI. The findings reinforce the call for enhanced conservation and afforestation efforts to safeguard these essential ecosystems from future adversities, Dr. Warrier said.

Published - September 30, 2024 08:05 pm IST