New Delhi: Tropical forests across Southeast Asia could face unprecedented heat stress within the next three decades as climate change and forest degradation weaken the natural cooling effect of forest canopies, according to a new study published in Geophysical Research Letters.
The research warns that rising temperatures beneath forest canopies could expose countless plants, animals and fungi to conditions beyond their thermal tolerance, threatening biodiversity across one of the world’s richest ecological regions.
Researchers combined temperature measurements from 46 forest sites across Southeast Asia with satellite observations and climate model projections. They found that peak daytime temperatures inside forests could rise by 1.4°C to 2.1°C by 2050, with some lowland regions experiencing increases of up to 4°C under high greenhouse gas emission scenarios.
Lead researcher Erone Ghizoni Santos formerly of the University of Helsinki, said climate change is not only warming the atmosphere but also altering the local microclimates that forest species depend on. Many tropical species already live close to their heat tolerance limits, meaning even modest increases in understory temperatures could affect survival, reproduction and ecological interactions.
The study identifies lowland forests in northern Cambodia, southeastern Indonesia and Borneo as among the most vulnerable to future warming. In contrast higher elevation forests in Myanmar and Laos may remain relatively cooler, potentially serving as climate refuges for biodiversity.
Researchers say forest degradation, including logging, further weakens forests’ ability to buffer heat by opening the canopy allowing more sunlight to reach the forest floor and reducing moisture retention.
The study recommends prioritising the protection of intact forests, conserving cooler upland “micro-refugia”, restoring degraded landscapes and improving habitat connectivity to help species adapt to rising temperatures.
Independent experts noted that while the findings significantly improve understanding of future forest warming, further research incorporating factors such as humidity, wind and ecosystem feedbacks is needed to better predict how climate change will affect forest ecosystems and the services they provide.