PARKLAND AGROFORESTRY WOODY SPECIES DIVERSITY, STRUCTURE, BIOMASS CARBON AND MANAGEMENT PRACTICES IN GINDEBERET DISTRICT, WEST SHOA ZONE, OROMIA REGIONAL STATE, ETHIOPIA

Abstract

Parkland agroforestry woody species are prominent features in many landscapes worldwide, and their ecological, social and economic importance is widely acknowledged. It is strongly advisable to observe and try to understand how farmers manage their parkland before proposing any improvement or alternative techniques. This study was conducted to assess the woody species composition, structure, diversity, biomass carbon, and management practices in parkland agroforestry by local farmers. The study was conducted in Gindeberet District, West Shoa Zone, Oromia Regional State, Ethiopia. Woody species inventory was carried out on 103 plots (each, 50mx100m) in the crop field laid along 7 transects. A questionnaire was administered to gather information on farmers’ strategy of managing woody species and it was analyzed using SPSS version 20 at 5% significance level. For woody species ≥ 5cm DBH, measurements of DBH and tree height were taken. Woody density, basal area, diameter and height class distribution were computed to characterize structure of woody communities. Species diversity and biomass carbon were also determined. Biomass carbon was estimated using allometric equations. A total of 61 woody species belonging to 35 families were recorded. Of these, 53 woody species were recorded in lowland and 31 woody species were recorded in midland. The study indicated that the woody species Shannon and Simpson diversity indices were higher at lowland than midland agro-ecology. The total woody biomass and the biomass carbon of lowland parkland agroforestry was considerably higher (38.33Mg/ha) and (19.17MgC/ha) than at midland parkland agroforestry (20.28Mg/ha) and (10.14MgC/ha), respectively. Farmers retain and/or plant woody species in their parklands for the purpose of improving soil fertility, fodder, fuel-wood, timber, shade, construction and others. The management practices employed in the study area includes branch pruning, lopping, protection, coppicing, watering and fertilizers. Among socio-economic factors sex, educational background, number of livestock, land holding size and wealthy status, exert a significant positive influence on the management of woody species. These woody species need a series of management to save and sustain for the future to overcome the socio-economic and environmental problems.