Deforestation and climate change killing vegetation in Himalayas of Uttarakhand

Satellites tracking the Himalayan landscape over the past two decades have revealed shifting vegetation patterns in Uttarakhand, highlighting both the resilience of mountain ecosystems and growing environmental pressures from climate change, deforestation, and pollution.

A team of researchers from the Aryabhatta Research Institute of Observational Sciences (ARIES) in Nainital, along with national and international collaborators, analysed satellite data from 2001 to 2022 to understand how vegetation in the state has responded to changing climate and human activity.

Their findings were published in the journal Environmental Monitoring and Assessment.

Mountain ecosystems are known to be highly sensitive to climate change, which can alter temperatures, rainfall patterns, and plant growth cycles. To study these changes, the researchers used Google Earth Engine, a platform that allows scientists to analyse large amounts of satellite data over long periods.

The team focused on a widely used satellite indicator called the Normalised Difference Vegetation Index (NDVI), which measures how green an area is.

Higher NDVI values indicate dense vegetation such as forests and croplands, while lower values represent barren land, snow, or exposed soil. The researchers also analysed the Enhanced Vegetation Index (EVI), which provides additional detail in areas with thick vegetation.

The study found clear seasonal patterns in vegetation growth. Both NDVI and EVI values were highest after the monsoon season, when plants receive sufficient water, and lowest before the monsoon, when conditions are drier. However, scientists say these natural cycles are beginning to shift, reflecting broader environmental changes.

More concerning were declining vegetation trends in some regions of Uttarakhand, which researchers linked to deforestation, agricultural expansion, illegal logging, and rising pollution from urban and industrial sources.

The analysis suggests that pollution does not affect vegetation evenly across the state, with certain locations experiencing stronger impacts that add to climate-related stress on ecosystems.

Scientists warn that these changes could have serious consequences for biodiversity, water resources, and ecological stability in the Himalayas, which support millions of people living downstream.

The study highlights how modern satellite monitoring can serve as an early-warning system, helping identify areas where vegetation is under stress and where conservation efforts are most urgently needed.

Researchers say understanding how climate, pollution, and human activity interact in fragile mountain environments is essential for protecting Himalayan ecosystems in the future.

Without timely intervention, the combined pressures of environmental change and human development could significantly alter vegetation patterns across the region in the coming decades.