Carbon stock under major land use/land cover types of Hades sub-watershed, eastern Ethiopia

Abstract

Background: Developing land management scenarios that have the potential to sequester carbon and reduce greenhouse gasses (GHG) emission on a sustainable basis entails quantifying the current carbon stock under different land uses. In light of this, a study was conducted in Hades sub-watershed, eastern Ethiopia, to explore the carbon stock under four major land uses: natural forest, coffee agroforestry, grazing land and cropland, involving samples from four carbon pools: aboveground, belowground, litter, and soil. To this end, vegetation and soil samples were collected from the respective land uses following recommended procedures. Results:The results indicate that organic carbon concentration decreased with soil depth though substantial amount of carbon was found in the lower soil depths under land use with woody perennials. The mean total organic carbon stock ranged from 138.95 t ha −1 in the cropland to 496.26 t ha −1 in the natural forest. The soil organic carbon stock was found to be relatively higher than that of the vegetation carbon stock in the natural forest and coffee agroforestry land uses. Conclusion:This study highlights the importance of assessing watershed level carbon stock for better and carbon friendly land use decision making. Land uses with woody perennials have high carbon stock than those without. Hence, conservation-based production systems with inclusion of woody perennials are options suggested to enhance carbon sequestration in the sub watershed.

Carbon stock, sequestration and soil properties among fields in smallholder farms in southern Ethiopia

“…Soil deterioration index (DI) (%) was calculated by adopting the approach indicated in Tessema and Kibebew (2019). It is assumed that the farm before conversion into coffee, enset, root and tuber, main field and fallow fields was similar in terms of SOC and other properties.…”

“…Thus, carbon sequestration in soil could be a 'win-win' situation, helping to reduce greenhouse gas levels in the atmosphere and improving soil quality for agricultural and forestry industries (Walcott et al 2009). Meanwhile, agricultural practices can influence the C balance through emission as well as sequestration (Tessema and Kibebew 2019).…”

“…Disturbance of soil ecosystems results in rapid depletion of SOC. This in turn results land degradation through deterioration of soil physicochemical properties (Tessema and Kibebew 2019) and finally results declining of crop production, and food security problems. These activities could have brought an increased interest in soil C sequestration and maintenance of soil ecosystem (Vagen and Winowiecki 2013).…”

“…Management practices applied to each field within a farm are variable. Difference in soil management practices influences soil C stock and soil quality (Tessema and Kibebew 2019). This subsequently depresses the efficiency of each field to functioning best and produce more yields.…”

“…Research findings in Ethiopia and elsewhere highlighted that the magnitude of soil C storage, carbon emission and soil quality responds strongly to aboveground landscape dynamics, including land-use change, soil management practices and land degradation processes (Tessema and Kibebew 2019;Bhunia et al 2018;Manna et al 2015;Melenya et al 2015;Vagen and Winowiecki 2013). For instance, in Eastern Ethiopia at 20 cm depth 88.23 t ha −1 organic carbon could have been lost if forest land is converted into crop land (Tessema and Kibebew 2019). The same study further indicated higher C stock in coffee agroforestry (277.38 ± 28.58 t ha −1 ) than in cropland uses (138.95 ± 25.0.1 t ha −1 ).…”