Assessment of carbon stock and selected soil fertility indicators in a bush encroached savanna at Erichsfelde farm, Namibia
type: CreativeWork
description: Bush encroachment is a form of land degradation common predominantly in semi-arid areas of the world. The resulting habitat degradation and loss of resource productivity make bush encroachment a serious environmental and economic problem in Namibia. Despite these negative effects, bush encroachment offers potential woody carbon stock storage, which can render Namibia a net carbon sink. This study was, therefore, aimed at quantifying potential woody carbon stock storage from different pools and assessing selected soil fertility indicators in low, medium and high bush-encroached sites at Erichsfelde farm in Otjozondjupa region. This was a quantitative study employing a stratified random sampling with systematic sampling along transects. For vegetation surveys in each site, five 20m x 10m plots were set up along two line transects, while established allometric equations were applied to related measured vegetation variables to estimate carbon stock. Additionally, five 1m x 1m soil pits were nested within the vegetation plots and soil samples collected at different soil depths for analysis. Across the three sites, the Kruskal-Wallis test showed no significant difference in the total (P=0.294>0.05) and above-ground (P=0.718>0.05) carbon stock. However, the below-ground carbon stock was significantly higher in the medium encroached site (P<0.001). This can be attributed to the fact that savanna vegetation accumulates most of its biomass underground as a protection against fire and herbivory. Additionally, the dense shrubs in the high encroached site do not invest in the below-ground biomass and carbon stock because of low herbivory as livestock will find it difficult to roam in there as oppose to the medium encroached site that feature higher below-ground carbon storage to protect the vegetation from herbivory and fire. The fact that themedium encroached site sequestered more below-ground carbon than the high encroached sites, suggest that bush encroachment does not positi…
abstract: Bush encroachment is a form of land degradation common predominantly in semi-arid areas of the world. The resulting habitat degradation and loss of resource productivity make bush encroachment a serious environmental and economic problem in Namibia. Despite these negative effects, bush encroachment offers potential woody carbon stock storage, which can render Namibia a net carbon sink. This study was, therefore, aimed at quantifying potential woody carbon stock storage from different pools and assessing selected soil fertility indicators in low, medium and high bush-encroached sites at Erichsfelde farm in Otjozondjupa region. This was a quantitative study employing a stratified random sampling with systematic sampling along transects. For vegetation surveys in each site, five 20m x 10m plots were set up along two line transects, while established allometric equations were applied to related measured vegetation variables to estimate carbon stock. Additionally, five 1m x 1m soil pits were nested within the vegetation plots and soil samples collected at different soil depths for analysis. Across the three sites, the Kruskal-Wallis test showed no significant difference in the total (P=0.294>0.05) and above-ground (P=0.718>0.05) carbon stock. However, the below-ground carbon stock was significantly higher in the medium encroached site (P<0.001). This can be attributed to the fact that savanna vegetation accumulates most of its biomass underground as a protection against fire and herbivory. Additionally, the dense shrubs in the high encroached site do not invest in the below-ground biomass and carbon stock because of low herbivory as livestock will find it difficult to roam in there as oppose to the medium encroached site that feature higher below-ground carbon storage to protect the vegetation from herbivory and fire. The fact that themedium encroached site sequestered more below-ground carbon than the high encroached sites, suggest that bush encroachment does not positi…
author: Shifa, Rufina I.
language: en
keywords: Carbon stock, Soil fertility, Bush encroachment
date published: 2017
date modified: 2026-07-27T20:22:14Z
provider: University of Namibia
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Namibia

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11070/1940