2.1. Description of the Study Area
The study will be conducted in the Ameya District, which is one of the 12 districts of South West Shewa Zone of Oromia Regional State, Ethiopia (Fig. 1). The capital of the District is Gindo, which is 30 km away from the Zonal Capital, Waliso, and 144 km South West of Addis Ababa. The District is divided into 40 kebeles, where 36 of them are rural and four of them are urban Kebeles. The total land area size of the District is about 93,279 ha (unpublished document of Ameya District Agricultural Office, 2017). The District is located between 8\(^\circ\) 29’59, 99’’N and 37\(^\circ\) 44’59, 99” E latitude and longitude, respectively. The altitude of the study area ranges between 1500–3240 m above sea level.
The District is classified into three agro-climatic zones: 1) highlands, ranging from 2,700 m to 3,240 m; 2) midlands, ranging from 2,100 m to 2,600 m, and 3) lowlands, ranging from 1,500 m to-2000m above sea levels. The climate data were obtained from the Metrological station of the study District. Accordingly, the rainfall pattern of the study area is unimodal, where the heavy rainy season ranges from April to September, whereas the dry season extends from October 15 to March 15, but still there is intermittent rainfall in October, March and April. The maximum and minimum mean annual rainfalls of the area were 1127 mm and 8.38 mm, respectively. The highest and lowest mean temperatures were also 28.40C and 12.30C, recorded in February and December, respectively. The mean annual temperature and rainfall of the study area is 19.60C and 1127 mm, respectively.
Regarding the populations and health services of human and livestock in the study area also described briefly here. Accordingly, the total populations of the Amaya districts in 2018 were 122,056 (61.578 males and 60.478 females), out of the total population 5.13% is urban dweller (CSA, 2007). In this district, there was one hospital, 8 clinics and 34 health posts under governmental ownership (ADHO, 2018). Amaya District has also a livestock population of 345,600; out of this, 160,600 were cattle,35,400 were goats, 32,600 were sheep,15,200 were donkey, 3,300 were mules, 8,500 were horse and 99,000 were poultry (ADANRO, 2017). The major livestock feeds on the natural grazing, hay, crop residues and local beverage by-products. Concerning to the availability veterinary services, up to the end of 2017, there was eight clinic and 15 health post in the District (ADANRO, 2017). There were various diseases (such as fever, malaria, tonsilin, cancer, anthrax and so on) affecting the health of both humans and/or livestock in the District.
2.3. Study site selection and their sampling techniques
Before starting the actual field study, a one-week reconnaissance survey was conducted to select sample Kebeles, and to obtain preliminary information about agro-climatic zones, availability of both medicinal plants and the local traditional healers in which Kebeles of the District. Thus, the whole kebeles (40) of Amaya District are already stratified to three agro-climatic zones (highland, midland and lowland); of which, five Kebeles, representing the three agro-climatic zones, were selected purposively depending upon their proximity to forest areas, different altitudinal ranges and availability of both MPs and traditional healers. Therefore, one Kebele named by Marii Saqalaa Karrayyuu, from lowland; two Kebeles named by Arba Sadden Kuraa and Gindoo town from midland, and two Kebele named by Guultii Bolaa and Kuraa Bolaa from highland agroclimatic zones were selected using both stratified and purposive sampling techniques.
2.4. Informant Selection and their sampling techniques
For ethnobotanical data collection, totally, 70 participants were selected from the representative sample Kebeles. Out of the total, 60 informants were household respondents, who are ordinary residents, and were selected randomly. Based on the recommendation of each selected Kebele administrative bodies, development agents, local authorities and religious leaders (Martins, 1995), the remaining 10 key informants, who are knowledgeable elders and traditional healers, were selected purposively for interview.
2.5. Ethnobotanical data collection methods
2.5.1. Structured and semi-structured interviews and focus group discussion
Ethnobotanical data were collected from February 15, 2019 to March 30, 2019 during two field trips to the study area. The first field trip was conducted to collect primary data from respondents regarding ethnobotanical data. The second field trip was conducted in order to confirm ethnobotanical information and to request people participated in study in order to show the wild medicinal plants they used to treat human and livestock aliments (Martin, 1995; Cotton, 1996). Accordingly, structured and semi-structured interviews, focus group discussions, and guided field walks with informants were employed to obtain IK of the local people on health, plant parts used, mode of preparation, applications, and route of administration.
Structured and semi-structured interviews were conducted with both household respondents and key informants, respectively, based on the items prepared beforehand in English, and translated to local language, ‘Afaan Oromoo’, later on. Then, the interviews were held in ‘Afaan Oromoo’ directly. Information regarding local names of MPs, plants part used, methods and condition of preparation, disease treated, route of administration, and uses other than medicinal values, threats and conservation practices to MPs was recorded. Field observation was also made on the morphological features and habitats of MPs species in the guided field walk.
2.5.2. Market survey
Market survey was also made to record the name and availability of MPs, mixture used in preparation of drugs sold in the local markets of the study area. The market survey was conducted two times for each open market found in Gindoo and Qotaa towns via observation and using semi-structured questionnaire interviews with drug producers and sellers.
2.6. Data Analysis
2.6.1. Descriptive statistics
Descriptive statistics such as percentage and frequency were employed to summarize the data on the MPs uses. The information gathered from local people such as medicinal values, application, methods of preparation, routes of administrations, disease treated, parts used and growth form of MPs and other associated IK were summarized using descriptive statistics. To make summary calculation, to draw bar graphs, scatter graph and pie-charts, MS Excel spreadsheet 2010 was used. Statistical package for social science (SPSS) version 20 was also applied to summarize Pearson correlation between age of respondents and level of education in relation with number of species cited.
2.6.2. Informant Consensus
Informant consensus factor (ICF) was calculated for each category to identify the agreements of the informants on the reported cures for the group of ailments. The ICF was calculated as the follows: number of use citation in each category (nur) minus the total number of species used (ns), divided by the number of use citation in each category minus one (Heinrich et al, 1998).
ICF = Nur-Ns/Nur-1, where, IFC = Informant consensus, Nur = number of use citation and Ns = number of species used. The ICF values range from 0.00 to 1.00. High ICF values are obtained when only one or a few plant species are reported to be used by a high proportion of informant to treat a particular ailment. The low ICF values indicate that informants disagree on the plant species to be used to treat a category of ailments.
2.6.3. Preference Ranking
Preference ranking was conducted to rank some selected MPs based on degree of their effectiveness in treating a particular disease. Following the methods of Martin (1995), key informants was asked to think order and rank the MPs based on their personal preference, community importance, or any other criteria set by him /her, and this help to indicate the most effective MPs used by the community to treat disease.
2.6.4. Paired comparison
Paired comparison was conducted for evaluating the degree of preference or levels of importance of selected plants. This method used to find out the efficacy and popularity of MPs species used to treat disease following the procedure described by Martin (1995). Key informants were showed their responses independently for paired of MPs that was noted for treating diseases. A list of the paired of selected MPs with all possible combinations was made and sequence of the pairs and order within each pairs was randomized before every pair is presented to select key informants. Then, their response was recorded. The total value summed and the ranks were made on the total score of the key informants. Accordingly, the plant that gets the highest score was the most popular for treating the ailments.
2.3.5. Direct matrix ranking
Direct matrix ranking was conducted in order to compare multipurpose MPs commonly reported by informants following Cotton (1996). Based on the relative benefits obtained from each MPs, multipurpose MPs species were selected out of the total MPs, and use diversities of these plants were also listed. Key informants were chosen to assign use values to each attribute (5 = best, 4 = very good, 3 = good, 2 = less used, 1 = least used and 0 = not used). Based on information gathered from key informants, average value of each use-diversity for a species was taken and the values of each species was summed up and ranked.