The role of sustainable land management practices on enhancing ecosystem services in the highlands of Ethiopia

Le résumé fourni par la source

Soil erosion significantly impacts agricultural productivity and sustainable economic development in Ethiopia. Soil erosion alone causes significant economic loss annually and thus, sustainable land management (SLM) practices are essential for mitigating land degradation. The main aim of this study was to assess the impacts of SLM interventions for soil loss reduction and biomass improvement through comparative analysis of intervened and non-intervened watersheds from 2007 to 2022 in Ethiopia. The study used 14 SLM intervened watersheds and 14 non-intervened watersheds. The land-use and land cover (LULC) data of the sample watersheds were prepared using Landsat 5-TM, 7-TM, and Sentinel 2 sensors and processed using Google Earth Engine. The soil loss estimation was estimated using the Revised Universal Soil loss Equations (RUSLE) in the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model. The above ground biomass (AGB) was estimated using tree height, Diameter at Breast Height (DBH) and wood density. The AGB was estimated using allometric equation developed for tropical countries. The findings showed that soil loss increased and latter decreased in the intervention sites, which were 28.9, 43, 27.6, and 28 tons ha −1 in 2007, 2012, 2017, and 2022, respectively. However, the average soil loss from the non-intervention watersheds continuously increased from 43.1 tons ha −1 in 2007 to 47.3 tons ha −1 in 2012, 52 tons ha −1 in 2017, and 55.3 tons ha −1 in 2022. The paired sample t -test confirmed that there was a statistically different mean soil loss between the two groups [t (3) = −3.35; p = 0.044]. In the intervened watersheds, the total mean AGB increased from 64.71 to 96.82 tons ha −1 from 2007 to 2022. The average carbon stock increased from 56.12 to 66.66 tons ha −1 during the same period. On contrary, in the non-intervened watersheds, the AGB and TC were increased from 42.49 to 49.98 tons ha −1 and 25.1 to 27.48 tons ha −1 from 2007 to 2022, respectively. The statistical results of the analysis of variance (ANOVA) on AGB and TC indicated statistically a significant difference (p-value < 0.001). Overall, the study proved that the SLM practices in the study area enhance land productivity and mitigate land degradation.

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