3.1. Taxonomic diversity of edible wild plants in study area
Overall, 46 WEPs belonging to 38 genera in 30 families were documented to be used by the people of study area (Table1). Family Moracea was best-represented, accounting for 4 species, followed by Cucurbitaceae and Myrtaceae (3 species in each), eight family’s (Amarathaceae, Annonaceae, Apocynaceae, Araceae, Discoreaceae, Rubiaceace, Sapindaceae and Sapotaceae) consisting of two species and 18 families represented by one species each. The highest number of plant species was recorded under family of Moraceae, Cucurbitaceae and Myrtaceae. This finding is in line with studies performed in Ethiopia researchers by [39, 37, 22, 2].This might be due to the better adaptation potential of WEPs in this family over the range of attitude deference, climatic change, soil type and other factors.
3.2 Life Forms and Parts of Wild Edible Plants
3.2.1 Life Forms of Edible Wild Plants
The largest numbers growth forms (habits) of edible wild plant in Metekel zone tree are (36.9%), followed by shrubs (26%), herb (21.2%), and climbers only (15.2%). This finding is in line with previous ethnobotanical studies conducted by[39, 21, 42, 38, 36]reported the abundance of wild edible trees in three Districts of Amhara Region, Debub Omo Zone, Konso Ethnic Community and Adola District in Northern and Southern Ethiopia. These similarities could be due to similarities in climatic conditions, WEPs species distribution and other environmental factors, harvesting from verity habitat ranging, or due to cultural variation among the community of the country the consumption of wild food.
3.2.2. Edible Parts of Edible Wild Plants
The edible plant parts in Metekel Zone used by shinasha ethnic group are fruit 26 (57.7%) followed by tuber 5(11.1%) and leaf 4(8.88%). As a result, the fruit was considered an important element of the wild food plant part by the people in the study area. This was consistent with the findings of research by [36, 22, 6, 10, 33, 38, 15, 31]. Due to the nature of the fruits that are not needed additional processing and it might be good to consume in raw forms and the other reason might be raw fruits are good source of nutrients that does not loss its nutrients but if it is boiled or cooked some essential nutrients might be lost. This is consistent with other findings including these of [25].
3.2.3. Plant Habitat wild edible plant
The people in Metekel Zone collect wild edible plants from various habitats, such as forest, riverine, wild and home garden. The largest number 30.4% species) was collected from forest habitats only, and followed by riverine banks (26.08%). The third and fourth largest natural habitats were wild and home garden habitat that each comprised 23.9% and 19.56% respectively (Fig 2). This finding is in line with studies performed in Ethiopia [25,29,2,31] showed that most WEPs were gathered from forest habitats. Due they are not deforest by anthropogenic factors
3.2.4. Preparation and consumption of WEPs
In study area about WEPs as regards the mode of consumption, 21 (45.65%) are consumed raw, 9(19.56%) cooked, (6.52%) both cooked and raw and (4.34%) in juice form, (Figure 4). The highest percentage distribution on mode of consumption of wild edible plants is shown below (figure :4). This result is similar with the study conducted by [32, 42, 1, 26, 38].The high consumption of wild edible plants in the form of fruit and vegetable might be explained by their nutritional value and their desirable taste[3,9,21. The high percentage of raw edibles may be due to the nature of the fruits that are not needed further processing and it might be good to consume in raw forms and the other reason might be raw fruits are good source of nutrients that does not loss its nutrients but if it is boiled or cooked some essential nutrients might be lost. This is consistent with other findings including these of [25].
3.2.5. Seasonal availability of wild edible plants
The plant parts used by Shinasha community were gathered in different seasons/times for food at four seasons of the year in Ethiopia. These seasons are spring (Sep, Oct and Nov) winter (Dec Jan, and Fab), autumn (Mar, Apr and May) summer (Jun, July and Aug) in which the season consists of three months of the year respectively. The highest number of edible plant parts15 (32.6%) were collected during the short rainy season of autumn 14(30.4) during winter rainy season, 10(21.7%) from winter season 7(15.2%), from all season and 1(2.17%) are also collected from spring season respectively. This due to the time of harvesting varies from plant to plant depending on its availability, and from place to place due to ecological and climatic conditions. The high uses of wild edible plants from March to May (autumn season) might be due to the high sprouting time for most WEPs. Besides, this season is the flowering time for most WEPs, and their fruiting is also harvested during this season. Likewise, studies performed elsewhere in Ethiopia by[31].During the dry season, rural people rely heavily on a stored diet .The relative seasonal availability of WEPs highly affects the nutritional and food insecurity of households [34]. According to the interview and group discussion of key informants harvesting Seasons of WEPs depending on phenology of the respective WEPs species, parts are collected for food in all season. The present study showed that, the identified wild edible plants of the study area were harvested and consumed in different seasons of the year. According to the group discussion and observation interview of the filed conducted also indicated that harvesting season and use of wild edible plant species vary from place to place, species to species and even from tree to tree. This might be due to climatic and intraspecific variations. Moreover, [25] on their study findings reported that time and frequency of harvesting of wild and semi wild edible plants depends on the plant parts and varies from place to place. The findings of this study revealed that, WEPs species of the study Districts were collected and consumed during dry season, wet season and year round.
Key informants explained that season and frequency of harvesting vary from plant to plant based on the availability of WEPs. As well, seasons of collection varied from place to place due to ecological and seasonal conditions. For instance, from WEPs of the study area, Vitex doniana, Phoex reclinata, Mimuosops kummel, Cordia africana, Ficus sur, Ficus Sycomorus, Ficus vasta and Disocorea prehensilis were harvested and consumed during winter season. Wild edible plant species such Asannona sengalensis, Amarathus cruentus, lepisanthes sengalensis, Soloanum nigrum and Amarathus cruentus were commonly gathered and consumed during summer season. However, Colocasia esculenta, Moringa stenopetala, Oxytenanthera abyssinica, and Grewia mollis were available throughout all seasons and consumed year round.
3.2.6. Market values of wild food plants
In the study of both districts also few wild edible plants were observed at two daily and weekly local and urban markets from four kebeles. During the study we observed eight wild edible plants such as Portulaca quadrifida, Vitex doniana, Saba comorensis, Dioscorea prehensilis, Diosocorreas alanata, Syzygium guineense, Foeniculum vulgare, Cucuribita peop, and Grewia mollis were reported to be sold by women and children can provide the opportunity to house holding additional income to the local communities of the study area. A few numbers of wild foods sold in the market were also reported by other studies made in Ethiopia[7,28].
Market assessment of wild edible plant species showed that most of the edible plants are not sold only for food purposes but also for other purposes such as for timber, agricultural tools, construction, and fuel wood purpose. The other economically important and marketable species is Cordia africana. It is the most preferred timber species with higher value and price at local markets. In general income derived from the sale of wild plant species is of particular importance to the poor household to supplement their food product items and needs. Most of the identified wild edible plants were marketed in the other part of Ethiopia [25, 40].
3.2.7. Multipurpose Use of Wild Edible Plants by Direct Matrix Ranking
In Metekel zone, ten commonly reported multipurpose species and ten use-categories were used for in direct matrix ranking exercise. In addition to food values, the local people used the plants for other different purposes such as fuel wood, life fence, construction materials, medicine, agricultural tools and charcoal. The result of direct matrix ranking revealed that Cordia africana, Ficus vasta, Syzygium guineense, Vitex doniana and Moringa stenopetala were ranked first to fifth, respectively. Similarly, the ten use-values categories reported on ten selected plant species were summed up and ranked and, the result showed that food value, construction materials, fuel wood collection, agricultural tools , medicine value, honey been hugging, erosion controlling ,life fence were ranked first, second, third, fourth, fifth, sixth and seventh, respectively. Cordia africana were also reported to be the most commonly used parts for baking bread and in rope preparation respectively.
3.3. Threats and Conservation of WEPs in the Study area
3.3.1. Threats to Wild Edible Plants
Informants ranked study area comparison of six threatening factors of wild edible plants was conducted using 12 key informants. The results (Table 5) indicated that expansion of agricultural land, fuel wood collection, timber production, cutting for construction, un-controlled fire setting and overgrazing management problems of plant resources respectively. Similarly, these threats to WEP resources have been reported in ethnobotanical studies conducted in Ethiopia by[25,37,15,6,22,31]. This is because rapid human population and high demand for forest and forest products uses in the study area from time to time. Due to these reasons, plant species such as Phoenix reclinata, Mimusops, kummel, Syzygium guineense, Carissa spinarum and Pappea capensis, Cordia africana and Diospyros mespiliformis are among the wild edible plants under series threatened and near threatened species respectively in the study area.
3.3.2. Conservation of Wild Edible Plants and Associated Knowledge
The local communities in the study area have a various indigenous knowledge on management and conservation of wild edible plants. For example, many wild edible plants are left to widely grow in farmlands, farm boundaries watershed areas, homesteads as live fence, shade, along road sides and degraded areas.
This practice was actually observed by the researchers in the study areas. For example, Cordia africana, Justicia schimperiana ,Cucuribitia peop and were widely grow in farmlands, farm boundaries and watershed areas and others frequently appear around homesteads as live fence (Moringa stenopetala, Oxytenathera abyssinica, Diosocorea alanata, Justicia schimperiana and Moras alba), shade (Phoenix reclinata, Ficus Vasta, and Moringa stenopetala) and along road sides and degraded areas. Similar trend has been reported in the indigenous communities in and the buffer area of Awash National Park[40] .
Besides, personal observation and communication revealed that children and livestock herders bring the seeds after consuming the fruits back to homes and cultivate them around homesteads and fence the seedlings saved from livestock foraging. This gives some hint for the possibility of conservation and domestication of wild edible plants. These are sustainable modes of resource use that need to be encouraged and applied by combination them with standard modern management practices.
Although the understanding of the local people about the importance of conserving the wild edible plants, only some in-situ and ex-situ conservation methods like planting in home garden the form of fences and protected pasture land in different worship areas (churches, mosques) and in their farm margins are being practiced in the study area. This indicates that the necessary conservation measures are not being taken in the area, and hence the wild edible plants are not free from threats. Awareness rising Community-based forest management, enclosure, reforestation, afforestation activities, and supplying of alternative energy sources to the community will have a huge chance conserving of the wild edible plants as well as the entire frost.