Assessment Of Useful Homegarden Plant Species Diversity Along Altitudinal Gradient In Ilu Gelan And Cheliya Districts Of West Shewa Zone, Oromia, Ethiopia

Abstract

Homegardens with diverse plant species play a significant role in sustainability of livelihood and socio-economic value. These useful plants and their management and conservation practices are not well documented in the study area. Hence, this study was conducted to investigate the diversity of useful homegarden plants along altitudinal gradient in two districts of West Shewa zone, Oromia, Ethiopia. The research was conducted from May 2021 to August 2021. A total of 150 households were systematically selected based on altitude variation from 1660 to 3010 m.a.s.l. Ethinobotanical data were collected through semi-structured interviews, direct field observation, free listing and key informants’ interviews. Data were analysed by using descriptive statistical methods. The survey revealed that people of the study area used homegardens that ranges from 0.04 to 2 hectare to manage different plants with different use value. Over all, 134 plant species belonging to 133 genera and 62 families were documented. Out of 134 plant species the origin of plant species identified as indigenous plant species to Ethiopia with the number of 62 (46.3%) species and exotic plant species to Ethiopia with 72 (53.7%) species. The highest number 83 (61.9%) of species cultivated and 23 (20.9%) of species semi-wild and 28 (17.2%) of species wild. Moreover, the most frequently distributed plant species were Ocimum lamiifolium (100%) followed by Vernonia amygdalina (96%) and Eucalyptus camaldulensis (91.33%). Among ten study sites or altitudes, site 4 (2065-2200) m.a.s.l was the top with the 119 (88.8%) species by mean number of species of 35.93 and with the coefficient of variation value 20.8. The diversity index and evenness was calculated with the highest diversity index value of 0.93 at the altitudes of 2470 to 2605m.a.s.l; while the highest evenness value of 0.47 was observed at the altitudes of 2740-2875 m.a.s.l. The highest Similarity value was found between site 3 (1930-2065) m.a.s.l. and site 5 (2200-2335) m.a.s.l.with lowest dissimilarity value of 0.554 (55.4%) and Relatively less similarity coefficient value 0.1 (10%) was determined between site 1(1795 to 1930) m.a.s.l. and site 10 (2875 to 3010) m.a.s.l.with the highest dissimilarity value of 0.9 (90%). Interms of the area covrages, Zea mays was the upmost with 21.08 hectare proceded by Plectranthus edulis with 10.01 hectare out of the total area of 127.7 hectare. Out of 134 plant species, edible plant categories ranked first with number of plant species 54 (40.3%) followed by medicinal use was the second with number of plant species 51 (38.1%), and Fuel wood was the third with number of plant species 38 (28.4%). The maintaince of diverse plants with well management practices involves family management to protecting crops from barriers, and xv increasing soil fertility by adding organic and inorganic fertilizer were more emphasized. But threats like disease and pests, farm size, climate conditions (rainfall and Tempreture) and others were documented that affect the diversity and composition of plants in study area. This result showed that the existing status of diversity and composition of useful plants varied along altitude variation, and contribution of traditional knowledge on management plants. In conclusion homegardens and its surroundings harbor diverse plants with their careful management practice to protect environmental threats and forwarding important recommendation on conservation and sustainable use of homegarden components and traditional knowledge in the study area of stakeholders.