Impact of alpine land cover change on semi-nomadic pastoralists in the Eastern Himalayan region of Bhutan

Woodland encroachment into Bhutan’s alpine meadows has adversely affected 1156 alpine pastoralist households by reducing pastureland and lowering the yield of medicinal herbs. However, the extent of alpine meadow loss to woodland has not been adequately studied. The study evaluated alpine land-cover dynamics and drivers over the past 30 years (1994–2024) using Landsat satellite data and an alpine residents’ perception survey on climate change and its impacts, conducted among 355 households. We further analysed alpine meadow dynamics and change in transhumance practices along an elevation gradient from 3500 to 7500 masl. Change in land cover types revealed that the alpine meadows' net area decreased by 114 km², with 91 km² lost to woodland and 31 km² to bare area offset by a gain of 8 km² from retreating snow, glaciers and water bodies. This alpine meadow changes of 114 km² also varied along an elevation gradient with 88 km² lost below 4100 masl and 34 km² lost above 4500 masl, offset by a corresponding gain in 8 km² within the elevation range of 4200–4400 masl. Climate change and varying transhumance practices may have contributed to the decline of alpine meadows through warming temperatures, reduced snow cover, and changes in pastoral practices. We discuss adaptive alpine meadow management practices based on ecological succession and the elevation range of alpine meadows for the sustainability of pastoral-based alpine communities in Bhutan. In particular, the adaptive alpine meadow management practices have the potential to enhance the protection, conservation and sustainable use of the mountain ecosystem which underpins United Nations’ Sustainable Development Goal 15.