Influence of Altitude and Climate on the Distribution of Vegetation, Ecosystem Services and Human Population in Garhwal Himalayan Region

Altitude plays a crucial role in determining habitat distribution, species diversity, and ecological resources, which support livelihoods and employment in the Himalayan region. Covering 18% of India's territory, the Himalayas house over 50% of the country's forest cover and 40% of the Indian subcontinent's endemic species, providing ecosystem services to 115 million people. However, the relationships between elevation, ecological services, and population resource dependency are poorly understood. This study examines the spatial linkages between elevation, climate, and ecosystem distribution, as well as the relationship between ecosystem services and population density using livelihood indicators. Spatial analysis reveals an inverse relationship between population density and relative relief (-0.69; P<0.05). Population density is concentrated (14.44%) along the fertile Alaknanda and Bhagirathi River valleys (900–2200m), which cover 14.95% of the area. Conversely, 5.33% of the population is scattered across 41% of the region, with higher elevations (>2000m) relying on non-timber forest products (NTFPs) for over 30% of income. These findings highlight critical patterns in population distribution, resource dependency, and ecosystem services, offering valuable insights for policymakers to promote biodiversity conservation, equitable resource sharing, and sustainable development in the Himalayan region.