Forty years of vegetation dynamics in the subarctic‐alpine landscape of the Cairngorm Mountains of Scotland using Landsat image analysis

The Cairngorms is a mountain range in northeastern Scotland, with a subarctic‐alpine environment and tundra‐like vegetation communities of low‐biomass heath, acid grassland and boulder fields. It is the most extensive subarctic mountain range in the British Isles; but little is known about whether its vegetation communities have experienced the greening trends that have been observed in other Arctic regions. We analysed the past 40 years of Landsat imagery over the Cairngorms and calculated trends in the Normalised Difference Vegetation Index (NDVI) as a proxy for vegetation productivity/biomass using time‐series analysis. Our time series showed significant NDVI increases in 75% of the pixels sampled, with the remainder showing no significant trend. Average decadal increase in NDVI was 0.033. The rate of greening varied significantly with topography and vegetation class. Areas of high plateau acid grassland had the greatest increase, with an increase in NDVI of 0.16 over the forty‐year study period. Practical implications . Our analysis suggests that regional warming trends represent the best explanation for these observed vegetation changes and highlight the threats of climate change to this mountain environment. These changes threaten the ecological integrity and unique biodiversity of this subarctic‐alpine ecosystem. Conservation management must prioritise climate resilience strategies, including habitat connectivity and monitoring sensitive vegetation communities, to mitigate these impacts.