Ecosystem service assessment of carbon storage and sequestration across a heterogeneous Himalayan agroforestry landscape using the InVEST model: a case study from Una District, Himachal Pradesh, India

Climate change, driven largely by increasing greenhouse gas emissions, has intensified the need for reliable assessment of ecosystem carbon storage and sequestration across heterogeneous landscapes where forests and agricultural systems coexist. Himalayan foothill regions comprise diverse land-use systems that differ substantially in carbon storage capacity, yet integrated landscape-scale assessments remain limited. This study presents a spatially explicit ecosystem service assessment of carbon storage and sequestration across dense forest, moderately dense forest, agroforestry, cropland, built-up land, water bodies, and sandy areas in Una District, Himachal Pradesh, India, using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Carbon Storage and Sequestration model. Multi-temporal land use/land cover (LULC) maps for 2011 and 2019 were combined with literature-derived carbon pool coefficients to quantify carbon storage in aboveground biomass, belowground biomass, soil organic carbon, and dead organic matter. Dense forests maintained the highest carbon stocks, increasing from 4.479 Tg C in 2011 to 6.272 Tg C in 2019, corresponding with an increase in dense forest extent. In contrast, agroforestry systems and croplands exhibited reductions in both spatial extent and carbon stocks. Overall ecosystem carbon stock increased by 0.494 Tg C, reaching 17.495 Tg C in 2019, with an estimated ecosystem service value of approximately US$19.08 million. By integrating carbon dynamics across multiple interacting land-use systems within a heterogeneous Himalayan landscape, this study provides a framework for prioritizing forest conservation, agroforestry promotion, and ecosystem-service-based land-use planning to support climate mitigation in Himalayan socio-ecological systems.