Impacts of land use and land cover changes on carbon stocks (1992–2052) Using geospatial technologies in Gena district, Southwest Ethiopia

Land uses offer considerable capacity for both short-term and long-term carbon storage. However, human-induced land use/land cover (LULC) changes affect the carbon stock under different land uses. Hence, this study aimed to investigate the impacts of observed and predicted LULC changes on carbon stocks from 1992 to 2052 in the Gena district, Southwest Ethiopia. The supervised maximum likelihood classification technique was employed to classify LULC from Landsat imagery, while the CA-Markov and Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) models were utilized for LULC and carbon stock prediction, respectively.
Carbon stock was analyzed using samples from five carbon pools (aboveground, belowground, litter, deadwood, and soil) across five major land use types (forest, shrubland, grassland, farmland and settlement, and bareland).
Aboveground carbon stocks of trees and shrubs with a diameter at breast height (DBH) ≥ 2.5 cm were calculated using empirical equations based on DBH and height measurements. Between 1992 and 2022, the areas of grassland, forestland, and shrubland declined by 58.5%, 48.15%, and 33.48%, respectively.. In contrast, waterbodies increased by thirty–four times, while bareland and farmland and settlement increased by threefold. These trends are predicted to continue for the next thirty years, except for grassland, which has shown an upward trend. The estimated mean total carbon stocks in the forests, shrubs, grasslands, farmlands and settlements, and barelands were 374.35 ± 36.47Ctha−1, 261.77 ± 8.84C tha-1, 204.11 ± 3.17Ctha-1, 192.1 ± 2.76 C tha-1 and 178.86 ± 2.15 Ctha-1, respectively. The total carbon stocks are projected to decline by 23.4% from 275.94 Ctha-1 in 1992 to 211.54 Ctha-1 by 2052 due to LULC dynamics. These findings highlight the significant impact of LULC on carbon storage, emphasizing the urgent need for sustainable land management practices. The projected decline in carbon stocks underscores the importance of implementing targeted interventions such as afforestation, area enclosures, and integrated natural resource management to enhance carbon sequestration, support ecosystem resilience, and contribute to climate change mitigation at the landscape level.