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Assessing Land Use/Land Cover Change and its Effects on Soil Physicochemical Properties and Soil Macro-Fauna Diversity in Shenkolla Watershed South Central Ethiopia

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dc.contributor.advisor Elias, Eyasu (Professor)
dc.contributor.advisor Getu, Emana (Professor)
dc.contributor.author Bufebo, Belayneh
dc.date.accessioned 2021-11-26T11:11:33Z
dc.date.available 2021-11-26T11:11:33Z
dc.date.issued 2021-03-02
dc.identifier.uri http://etd.aau.edu.et/handle/123456789/28997
dc.description.abstract Land Use/Land Cover (LU/LC) change is one of the major global challenges induced by anthropogenic and natural factors. Understanding the scope of LU/LC changes, the driving forces and consequences are crucially important for maintaining sustainable use of natural resource and promoting sustainable agriculture. This study examined the land use/land cover changes that have occurred, during the 1973-2017 period and its driving forces. In addition, the study explored the effects of the LU/LC changes and landscape positions on soil physicochemical properties, and diversity of soil invertebrate macro-fauna. Unsupervised and supervised classification techniques were employed to get thematic information from satellite imagery (1973, 1995 and 2017). Household survey, focus group discussion and key informant interview were also used to determine the drivers and consequences of this land use/land cover dynamics. Analysis of top soil samples collected from four adjacent land use/land cover types (forest land, grazing land, crop cultivated outfields and homestead garden fields) all under lower landscape position was conducted to determine the effects of LU/LC changes on soil physicochemical properties. Besides, analysis of top soil samples collected from three landscape positions (upper, middle and lower) each landscape category having three land use types: forest, grazing land and cultivated land was conducted to determine the effects of landscape positions on soil physicochemical properties. The soil data was analyzed using ANOVA to determine variations in soil parameters among landscape positions and land use types and treatment means comparison was determined using the least significant difference (LSD) at 0.05 level of significances. In order to evaluate the diversity of soil invertebrate macro fauna (SIMF) community eight parameters were measured: Shannon-Wiener index, Simpson diversity index, Pielou’s measure of evenness, Margalef’s diversity index, the Number of Occurrence Index, Relative abundance, Density (individuals per square meter) of each taxon and density of all SIMF and Bray-Curtis similarity index. SIMF data was further analysed using ANOVA and a general linear model to determine variations and the influence of land use types on abundance and diversity of SIMF, respectively. The results showed that agricultural land significantly increased while area covered by forest, was diminished drastically over the past four decades (1973-2017). Forest land was reduced from 29.51% in 1973 to 20.52% in 2017, while agricultural land use increased from 70.49% in 1973 to 79.48% in 2017. Agricultural expansion, regime change and social unrest, population pressure, shortage of farm land and biophysical factors were major driving forces of the LU/LC changes. Environmental implications such as climate change, biodiversity loss, scarcity of basic forest products; habitat alteration, decline in quality and availability of water and crop yield reduction were consequences of the LU/LC change. The results of soil analysis indicated that there were significant (p<0.05) differences in soil physicochemical properties among the four LU/LC types. For most parameters evaluated, the most favourable soil properties were observed in forest land followed by homestead garden fields, while the least favourable soil properties were found in intensively cultivated outfields. With regard to landscape positions, the soils with best qualities were found in the lower landscape position. Concerning the soil invertebrate macro-fauna, 332 individuals, 10 orders, 12 families and 15 species were identified, from the collected samples that showed significant variation (p<0.05) among land use types except wireworm, spiders and millipedes. The forest land use had relatively higher value of species diversity (Simpson diversity index D = 0.83, Pielou’s evenness index J′ = 0.428, Margalef diversity index d= 2.56, and Species richness r = 15) followed by homestead garden fields, while the lowest was recorded in the cultivated outfields that had significantly lower species diversity (Simpson diversity index D = 0.22, Pielou’s evenness index J′ = 0.075, Margalef diversity index d= 1.06, and Species richness r = 5). Overall abundance and diversity were lowest in the cultivated outfields and grazing land and highest in homestead garden fields and forest land. The results suggest the need for proper land use planning that ensures conservation of existing forest cover and additional plantation of both indigenous and exotic trees in order to maintain the ecological balance. Moreover, proper use of physical and biological soil conservation measures on cultivated land play a decisive role in minimizing the removal of soils and loss of soil macro fauna diversity. en_US
dc.language.iso en en_US
dc.publisher Addis Ababa University en_US
dc.subject Land Use/Land Cover Change en_US
dc.subject Physicochemical Properties en_US
dc.subject Remote Sensing en_US
dc.subject Satellite Images en_US
dc.subject Soil Invertebrate Macro Fauna en_US
dc.title Assessing Land Use/Land Cover Change and its Effects on Soil Physicochemical Properties and Soil Macro-Fauna Diversity in Shenkolla Watershed South Central Ethiopia en_US
dc.type Thesis en_US

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