Geospatial evaluation of ecosystem service values and carbon stock dynamics in the Yayu coffee forest biosphere reserve, Ilu Aba Bor Zone, Ethiopia

Abstract

Evaluating Ecosystem Service Values (ESVs) and carbon stocks is crucial for measuring ecosystem functions, promoting sustainable management, and improving efforts to mitigate climate change. The main aim of this study is to evaluate the spatiotemporal dynamics of Ecosystem Service Values (ESVs) and carbon stocks in the Yayu Coffee Forest Biosphere Reserve using Geospatial Techniques. For this study, Thematic Mapper (TM, 1995), Enhanced Thematic Mapper (ETM+, 2010), and Operational Land Imager and Thermal Infrared Sensor (OLI/TIRS, 2025) Landsat data were used. Land use and land cover (LULC) types were analyzed using a supervised classification approach with the Maximum Likelihood Algorithm. Ecosystem Service Values (ESVs) was evaluated and estimated for all potential Land use and land cover categories except bare land and settlement, whereas carbon stock assessment was focused on forest land cover. The results revealed substantial changes in land use and land cover (LULC) changes over the 30-year period. Forest land cover increased from 54.3% in 1995 to 62.6% in 2025, whereas cultivated land declined from 41.8% to 28.0%, indicating significant reforestation and land restoration efforts. Additionally, grassland increased from 3.1% to 7.6%, and wetlands remained relatively stable at around 0.6%. Moreover, the finding demonstrated that total Ecosystem service Values (ESVs) increased from USD 114.9 million in 1995 to USD 125.6 million in 2025, typically driven by sustainable forest development. Similarly, carbon stock increased from 15,949.3 to 18,369.7 tons ha⁻¹, improving CO₂ sequestration from 58,481.4 to 67,356.3 tons, mainly due to forest extension and improved land management. Therefore, the result demonstrates substantial ecological recovery, reflected in increased ecosystem service values and carbon sequestration potential, highlighting the critical role of forest restoration and the need to strengthen sustainable land management for regional ecological resilience and climate change mitigation.