Climate change destabilising Western Ghats’ forest ecosystems in Nilgiri Biosphere Reserve, warn researchers

Researchers warn that climate change is destabilizing forest ecosystems in the Western Ghats, specifically within the Nilgiri Biosphere Reserve (NBR). A study published in 2024 in the open access peer-reviewed scientific journal 'Remote Sensing' examined the impact of climate change on four forest types within the NBR over a 20-year period.

The researchers found that average temperatures have increased by 0.01°C per year since 1950, while rainfall has decreased by 3.97 millimeters annually during the same period. These changes have had varying effects on the four forest types analyzed: the Start of Season (SOS) for moist deciduous, dry deciduous, and wet evergreen forests was delayed, while it advanced for semi-evergreen forests.

The length of the growing season also varied, with longer seasons in moist deciduous, semi-evergreen, and wet evergreen forests and shorter seasons in dry deciduous forests. This pattern shifted during Phase II of the study, between 2011 and 2020, when the SOS advanced across all four forest types, leading to longer growing seasons overall.

Climate change is not simply making forests greener or less green, but altering the timing of their biological activity. Researchers emphasize that factors such as temperature, rainfall, soil moisture, drought, and photoperiod all interact to influence the start, end, and duration of seasons within the NBR's forests. Monitoring these changes can help forest managers identify vulnerable ecosystems and plan conservation and restoration strategies.

Experts also note that climate change is having a noticeable impact on cloud forests, where the amount of epiphytes, mosses, ferns, and orchids is visibly decreasing season after season. The microclimate inside these forest fragments is also changing, with warmer temperatures and altered moisture levels.