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

Tessema Toru,Kibebew Kibret

doi:10.1186/s13021-019-0122-z

Abstract

BackgroundDeveloping 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.ResultsThe 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.ConclusionThis 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.

Highlights

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
Across the three soil depths, significantly lower bulk density values were recorded in soils under the natural forest, whilst higher values were observed in soils under the crop land (Table 3)
The current results indicate that the subsistence farming practices that have been followed by the smallholder farmers in the study area are exploitative in nature, and have taken much of the soil organic carbon as compared to the natural forest

Summary

Introduction

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. 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. The two most common factors distorting the carbon cycle are land use change and combustion of fossil fuel [4]. In Ethiopia, the emission from fossil fuel generated 2.3 million tons of CO2 in 1990, and the figure increased to 8.5 million tons of CO2 in 2013 [3]

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Discussion

Conclusion