INFLUENCE OF TRADITIONAL GRAZING MANAGEMENT PRACTICES ON VEGETATION STRUCTURE AND RANGELAND CARBON STOCK POTENTIALS IN GUJI ZONE, SOUTHEAST ETHIOPIA

Abstract:

This study was conducted in the Liben woreda of Oromia regional state, southeastern Ethiopia in May at the end of main rainy season (March-May, 2020). The objective of this study was to determine vegetation structure and carbon stock potential of Guji zone rangelands under the three traditional rangeland management practices i.e., near the village, main grazing land and communal enclosure. A combination of stratification and systematic random sampling was applied to collect the relevant information. Nested plots for collecting tree, shrub, herbaceous, litter and soil data were placed systematically on two parallel lines within each grazing management practice. The tree and/or shrub biomass was estimated using generalized allometric equations and carbon content was measured as 50% of dry biomass, and then converted to tons per hectare. Herbaceous plants were clipped to the ground, collected, oven dried, and their carbon stock was estimated as 50% of oven dried biomass. Litter was manually collected, oven dried and their carbon stock was estimated. A two way ANOVA was used for the data generated from vegetation and 3x3 factorial experiments with Randomized Complete Block Design (RCBD) was used for soil and herbaceous root data using R software. A total of 111 vascular plant species belonging to 40 families were identified. Of which, 61 were herbaceous plant whereas 50 were different tree and/or shrub species. Poaceae and Fabaceae families dominated the study areas. Of 61 herbaceous species identified, 31 (50.8%) were grass while 30 (49.2%) were non-grass species. The highest percentage of less desirable grasses and undesirable non-grass species were recorded in both near village and main grazing land whereas the highest desirable grasses recorded in the communal enclosure. There was significantly (P