Ethno-ecological study of medicinal and wild edible plants in Sheka Zone, Southern Nations, Nationalities and Peoples Regional State, Ethiopia

An ethno-ecological study on medicinal and wild edible plants was conducted in Sheka Zone, Southwestern Ethiopia. The objective was to document and analyze the floristic composition and the associated ethnobotanical knowledge of medicinal and wild edible plants. The study applied a combination of standard plant taxonomic, plant ecological and ethnobotanical methods. Ninety five plots of 30 m by 30 m for trees, 10 m by 10 m for shrubs and 5 m by 5 m for herbs were used to collect vegetation data. Four hundred fourteen informants were involved in the ethnobotanical data collection using semi-structured interviews and discussion with informants. Data were analyzed using R Statistical Software version 3.2.3 and analytical methods of ethnobotany. A total of 555 plant species of which 266 (48%) those used as medicinal; 35 (6.31%) wild plants consumed by people were recorded. The plant species recorded indicated high taxonomic diversity as they belong to 341 genera and 115 families. Eight plant community types were identified. In addition to climatic variability, five environmental factors including altitude, slope, aspect grazing, and disturbance had significant contributions in determining plant community types where altitude is the most influential. Fourteen major plant use categories were identified including the medicinal and the wild edibles. The medicinal plants are distributed within the eight plant communities constituting 46% to 72% of their species composition. Of the 35 wild edible plants, 85.71% were also said to be medicinal. Increasing population, commercial agriculture and firewood collection were among the major threats to the vegetation. Plant communities: Ficus-sur-Croton macrostachyus, Schefflera abyssinica-Syzygium guineense, Ilex mitis-Macaranga capensis and Arundinaria alpina-Lepidotrichillia volkensii plant community types constituted more than 65% of their species composition as medicinal, hence, need priority attention for conservation.