Assessing the impacts of forest cover change on carbon stock and soil moisture dynamics using geospatial techniques: a case study of Nensebo forest, Southern Ethiopia

Assessing the impacts of forest cover change on carbon stock and soil moisture dynamics is critical for understanding environmental degradation and guiding sustainable land management. This study evaluates the effects of forest cover change on carbon stock and soil moisture dynamics in Nensebo Forest from 1993 to 2023 using geospatial techniques. Landsat imagery including TM (1993), ETM + (2009), and OLI/TIRS (2023) were used. Land use land cover (LULC) classification was performed using supervised classification approach with maximum likelihood algorithm. The study reveals that agricultural land expanded significantly from 143.2 km² (21.8%) to 230.0 km² (35.1%), along with increases in bare land and grassland. Moreover, result reveals a substantial decline in vegetation health (forest), with the Normalized Difference Vegetation Index (NDVI) decreasing from 0.78 in 1993 to 0.55 in 2023, indicating an increase of deforestation and land degradation. The soil moisture index (SMI) shows a reduction in soil moisture retention from 0.51 to 0.39, reflecting the adverse impact of forest loss on soil moisture dynamics. Carbon stock analysis reveals a dramatic decrease in forest area from 489.5 to 220.5 km², leading to increased carbon dioxide emissions from forest loss, which rose from 293.03 tons to 1550.34 tons. The study underscores the urgent need for integrated land management strategies that balance agricultural development with ecological conservation. Therefore, to mitigate climate change and maintain ecological stability, the study recommends implementing sustainable land use practices, promoting reforestation, and developing environmental related policies to preserve the remaining forest cover while supporting agricultural productivity.