Vegetation in six Himalayan regions shifted upwards due to warming, reduced snow depth

The vegetation in the higher alpine reaches across six regions of the Himalayas, mostly small plants and woody shrubs, shifted upwards by varied distances between 1999 and 2022 due to warming and reduced snow depth, according to a research paper published in the journal Ecography on April 13, 2026. 

Alpine vegetation is generally found at a height of 4,100-5,000 metres above mean sea level. Above that from 5,000-5,500 metres above mean sea level lies the sub-nival belt which is more barren. Exceeding 5,500 metres, the terrain is mostly snowfields, glaciers, rocks and ice. 

The study led by the University of Exeter assessed and quantified the upward trend in the growth of vegetation over 24 years in elevations higher than 4,000 metres. Previous studies by the same team already showed the expansion of plants in the Himalayan region. In the current paper, the researchers studied the regions of Ladakh, Reckong and Ngari in the western Himalayas, Manthang and Khumbu in central Himalayas and Bhutan in the eastern Himalayas. 

“This study is the first to demonstrate vegetation line shifting patterns across the Himalayas at a 30 m spatial resolution, providing robust evidence of upward vegetation line movement under climate change and exploring underlying climatic trends,” according to the study.

The vegetation shifted upwards by as much as 6.95 metres per year in Manthang in Nepal and the least average distance of 1.42 metres per year in Khumbu, a region home to the Mt Everest.

The study team used a combination of satellite imagery and long-term climatic data from these regions to analyse greening and browning trends. Greening depicts more vegetation or more leafy vegetation and browning denotes less vegetation or more woody vegetation. 

The authors of the report found more greening than browning trend in their analysis across all the regions but more browning was observed in the eastern regions of Khumbu and Bhutan. 

“The Himalaya are warming faster than the global average. A lot of research has focused on the melting of snow and ice, and the implications of this for water supplies on which billions of humans depend,” said lead author Ruolin Leng from the University of Exeter’s Department of Earth and Environmental Sciences in a press release.

“Less research has focused on plants, particularly the impact of these small alpine plants living at high altitude. But plant communities can also affect the water cycle — so our findings raise important questions that must be investigated,” she added.    

“The alpine zone is a harsh environment dominated by smaller plants and woody shrubs,” said Leng. “But as the climate changes, conditions in the Himalaya are changing in various ways — from temperature shifts and changes in snow cover to the availability of water and nutrients.”

“We tend to overlook these little plants but this is a perfect example of how small-scale processes might have impacts on important catchments, feeding rivers that supply millions of people with drinking water,” said Karen Anderson, co author of the study and professor at the Environment and Sustainability Institute, University of Exeter, Penryn campus. 

“When you consider that we’re talking about a very extensive alpine ecosystem covering a massive area in the Himalaya, it has the potential to generate significant effects. For example, alpine plants may shade the soil, trap snow, change stores and flows of water, and therefore profoundly affect the water cycle,” Anderson added. 

Along with the warming of the Himalayas, the scientists identified the reduction of snow depth over many of the regions as the reason behind the growth of vegetation in higher altitudes than before. The changes in precipitation was the major reason for the observed browning trends.