Use and Conservation of Medicinal Plants by Indigenous People of Gozamin Wereda, East Gojjam Zone of Amhara Region, Ethiopia: An Ethnobotanical Approach

2.1. Description of the Study Area

2.2. Geomorphology and Vegetation Type

The topography of the Wereda is characterized by the three major agroclimatic zones within altitude range of 500–3500 meters above sea level: temperate (Dega) (35.55%), subtropical (Woina Dega) (41.41%), and tropical (Kolla) (15.72%). The Wereda relief in percentage is given as plateau 45%, mountain 48%, and valley 7%. With respect to soil type, the majority of the Wereda soil belongs to vertisol and lithosol [17].

The vegetation type of Gozamin could be Dry Evergreen Afromontane Forest. According to Friis et al. [18], Dry Evergreen Afromontane Forest (DAF) and grassland complex occurs in areas between 1800 and 3000 meters of altitude with rainfall < 1700 mm. Different authors also indicated the subtypes of DAF, namely, undifferentiated Afromontane Forest; dry single-dominant Afromontane Forest of the Ethiopian highlands; Afromontane woodland, wood grassland and grassland, and transition between Afromontane vegetation and Acacia-Commiphora Bushland on the Eastern Escarpments. The natural vegetation of the study area is dominated by remnant trees like Juniperus procera, Hagenia abyssinica, Podocarpus falcatus, Acacia abyssinica, Cordia africana, Ficus sycomorus, Erythrina brucei, Eucalyptus camaldulensis, Eucalyptus globulus, and others. Plantations of these trees are observed on farm lands and home-gardens in Wereda [17].

There is also an Afroalpine belt as long as the Wereda includes a particular subdistrict (Kebele) known as Gedellamma which is in the Choke mountain system. It is clearly indicated that mountains are virtually devoid of vegetation and the only few woody plant species observed are moorland types sparsely covered with Giant Lobelia (Lobelia rhynchopetalum), lady’s mantle (Alchemilla humania), Guassa grass (Festuca spp.), and other grasses. The woody plant cover includes Erica arborea and Giant St. John’s wort (Hypericum revolutum) [19].

The rainfall pattern is unimodal, stretching from May to September. The highest monthly rainfalls were record in July, 284.67 mm, and August, 298.03 mm, and the lowest ones were observed in January (14.52 mm) and February (10.6 mm). The mean annual rain fall distribution is 1342 mm. The mean annual maximum and minimum temperature records of the study site were 26°C and 8.6°C, respectively. Rainy months are blackened and dry months are dotted as indicated in Figure 2.

2.3. Health

The most important animal diseases in Gozamin Wereda include bacterial infections (black leg, pasteurellosis, anthrax, mastitis, fowl typhoid, and avian salmonellosis), endoparasites (fascioliasis, paramphistomiasis, and strongyloidiasis), ectoparasites (ticks, mites, lice, and insect flies), viral infections (rabies, African horse sickness, and foot and mouth diseases), and protozoal infections (trypanosomiasis, babesiasis, and coccidiosis) [17]. On the other hand, it was also reported that the most common human diseases include tuberculosis, malaria, diarrhea, trachoma, helminths, skin diseases, typhoid, eye diseases, and upper respiratory tract.

2.4. Reconnaissance Survey

Reconnaissance survey was conducted from September 23 to 30, 2013, in the study Wereda in order to obtain an impression about medicinal plants, topography, distribution of plants, and identification of sampling sites. During the survey 12 representative Kebeles (subdistricts) were selected. Local administrators were chosen as key resource persons in providing information in their respective Kebeles. During the survey, general information about the Wereda was also obtained.

2.5. Site Selection

Purposively twelve Kebeles were selected out of 26 Kebeles of the Wereda for ethnobotanical data collection based on the availability of traditional medicinal practitioners present, identified with the assistance of the Kebele administration leaders, elders, religious leaders, and others who have information about traditional healers. Those Kebeles which have almost the same agroclimatic conditions as other neighboring Kebeles were not included in the study and this is also additional factor for site selection. The study Kebeles were Libanos, Chimbord Yezangera, Cher Tekel, Denba, Asab Abo, Enerata, Lekilekita, Wenka, Chimit, Yegagina, Yebokila Zurya, and Yetijan-Shebelmma (Figure 1).

2.6. Selection of Informants

A total of 100 informants (88 males and 12 females) were selected from the representative Kebeles. Representative common informants and knowledgeable traditional medicine practitioners (key informants) of Gozamin Wereda were selected using random and purposive sampling approaches, respectively, following Martin [20].

Out of 100 informants, 80 general informants were sampled during random visits in the study Kebeles by asking every individual in the house or working fields or wherever they were. On the other hand, the remaining 20 key informants out of the total were selected purposively and systematically. In other words, this was based on comments and recommendations from the religious leaders, elders, Kebele administrators, students, and personal observation of the researchers from the community group. The selection of key informants was also based on the quality of explanations that particular informants gave during the interview. Local healers automatically qualified as key informants being traditional experts who are custodians of IK on the use of traditional MPs. Thus, key informants were identified, later interviewed, and followed for further details.

2.7. Data Sources

Ethnobotanical data were obtained from both primary and secondary sources. The primary sources were interview, focus group discussion, and observation in the field of the study area, where as the secondary data sources were various and relevant literature review related to the present study. A piece of other information was also collected from the Wereda of different offices.

2.8. Ethnobotanical Data Collection Techniques

The study has been carried out by interviewing the knowledgeable informants in different villages under various sites from January 5, 2014, to February 15, 2015, in Gozamin Wereda, East Gojjam Zone of Amhara Region Ethiopia. Ethnobotanical techniques were employed to collect data on knowledge and management of traditional MPs used by the local people in the study area. The methods used for ethnobotanical data collection were semistructured interviews following Martin [20] and Cotton [10], informant consensus, field observation, and group discussion as described below.

2.9. Voucher Specimen Collection

Plants used for herbal remedies were collected by a team comprising a botanist, biotechnologist, microbiologist, chemist, and parasitologist from Debre Markos University (DMU). The voucher specimens were collected at the spot during guided field walk, numbered, pressed, dried, and deep frozen for identification. Determination of specimens was carried out both in the field and in the herbarium. Then after that, nomenclature was determined using Flora of Ethiopia and Eritrea, other available taxonomic literatures, and visual comparison with authenticated herbarium specimens. Finally, the voucher specimens were kept at Debre Markos University Mini-Herbarium to aid confirmation of plant identity.

The information gathered included vernacular name of plant, species, ailments they cure, part used, route of administration, method of preparation, dose, and duration levels of herbal administration. Therefore, this is the starting point of documenting the flora of Gojjam in general and Gozamin Wereda of East Gojjam Zone in particular.

2.10. Ethnobotanical Data Analysis

3.1. Summary of Informants

A total of 100 herbalists from the study sites were interviewed and as a result ninety-three (93) plant species belonging to 51 plant families and 87 genera were identified for the management of both human and livestock ailments (Figure 3). The present study has shown that the people at various age groups in Gozamin Wereda have a very good knowledge base on herbal remedy for primary healthcare. Traditional healers (both males and females) still rely largely on naturally growing species in their locality.

3.2. Age and Sex of Informants

The informants were local residents aged between 18–73 years (Figure 3). Most of traditional healers range within the age group of 30–49 years, 46 (46%). They are within this range because it is at this stage whereby they have completed necessary rites of passage, notably initiation school. These are followed by those who are around 18–29 years of age, 30 (30%), who also constitute a reasonable number; thus in most cases these are newly inaugurated traditional healers. The remaining 24 (24%) of informants were between the ages of 50 and 73 (Figure 3). Although the age groups 50–73 constitute lower percentage (24), these groups are highly trusted by the community due to experience they have acquired and the number of traditional healers they have trained. Thus, at this age their decisions are credible based on their maturity level. Medicinal plant knowledge difference among age groups was also reported in Cotton [10].

Regarding sex, 88 (88%) of the total informants were males whereas the remaining 12 (12%) were reported as females (Table 1). In the case of knowledge difference between the two sexes, females tend to mention little number of MPs as compared to males. At this point, because of cultural influence, it is understandable that females were not allowed to go out of home; they look after babies and work at home. Similar results were reported in Megersa et al. [23], Kefalew et al. [24], and Chekole et al. [25] mentioning few numbers of plants by females in our study area.

3.3. Educational Level and Marital Status of the Informants

The educational status of the informants showed that most of them were literate, that is, having modern education (diploma holders, students, and those able to read and write) accounting for 64 (64%) followed by the uneducated ones but traditionally knowledgeable informants accounted for 19 (19%) and the least number of respondents was reported as church education attendants, 17 (17%) (Table 1). On the other hand, the marital status of the informants indicated that most of them were married people accounting for 66 (66%) followed by the unmarried ones, 30 (30%), and others were divorced, reported as 4 (4%) (Table 1). The interviewed informants were included from married, unmarried, and divorced people and people of different educational level. This enabled the researchers to come across the ethnobotanical information of the community from different groups. Similar results were also reported by Yineger et al. [26].

3.4. Traditional Knowledge Transfer

The most important way of transfer of IK on types of use of MPs, mode of preparations, way of administration, traditional idea of illnesses, and methods of diagnosis and treatment among indigenous herbal practitioners of Gozamin community was by word of mouth to a family member. The finding further indicated that the present knowledge transfer system followed the inheritance based transfer system where most traditional healers pass their knowledge to the elder/eldest/son/daughter. The selection of the elect was based upon his/her good conduct and ability to keep the secret with regard to the ethnobotanical plant use knowledge. The knowledge transfer system is bounded by traditional rules and can only happen through cultural ceremony. Most of the healers confirmed that, during transfer of the knowledge, they also received obligation. Similarly it was also reported that, at family level, it is restricted to the elders (men and women), followed by elder son or daughter or their trustworthy person when the mother or the father is getting old or near to die [14, 27, 28].

3.5. Medicinal Plants in Gozamin Wereda

3.5.2. Diversity of Medicinal Plants in Natural Habitat and Home-Garden

Most medicinal plants were collected in their natural habitat which account for 42 (45%) whereas 28 (30%) medicinal plants were from home-garden and 23 (25%) were from both home-garden and the wild (Figure 4). Various studies conducted in Ethiopia as well as other countries in the world reported that majority of MPs were harvested from the wild [32–34]. Here, our findings revealed that many MPs were also collected from home-gardens. This indicated that the people and the local healers have started cultivating many MPs in their gardens.

3.5.3. Plant Parts Used in the Study Area

Every part of different plant species is used against a variety of ailments. As per the informant’s response, the most commonly used part is the leaf (39), followed by root (16), seed (13), fruit, latex, leaf/or fruit, and stem (4, each) (Figure 5). In some cases, more than one organ of the same plant species, particularly a combination of parts, is used in the preparation of different therapies (see also Tables 2 and 3). It was also observed that the indigenous people have deep knowledge and age-old experience in the right mix of different plant parts to get better treatment of the given ailment. In this study, leaves are the most frequently utilized part of plant organs. Analogous results on different ethnobotanical studies by Giday et al. [12], Megersa et al. [23], Kefalew et al. [24], Gebeyehu et al. [31], Tolasa [32], and Lulekal et al. [33] were reported in Ethiopia.

It was reported that the ease of accessibility to leaves explains their frequent inclusion in most of the preparations [35]. It was also observed that residents have been using leaves to identify MPs. Additionally, leaves are the main photosynthetic organs in plants, and photosynthates are translocated to other parts, such as the root, stem, fruit, and seed. These can act as toxins for protection of predators and some are of medicinal value to humans.

On the other hand, the results of the study showed that harvesting of roots has great impact on the plants and leads to the dearth of the MPs. Fortunately, the plant parts which are mostly used for the preparation of the remedies in the study area were leaves and harvesting of leaves has less impact on the plant than harvesting of roots.

3.6. Disease Categories in the Study Area

Diseases can be categorized in different ways as dermatological, respiratory, gastrointestinal, and so on. Based on the information obtained in the study site, the most prevalent diseases are related to skin (dermatology) and gastrointestinal ones (31%, each) followed by livestock (19%) and other diseases (15%) (Figure 6). The study showed that dermatological diseases such as wound, skin rush, itching, and eczema are prevalent and a number of MPs were found to be cited so as to treat these skin diseases. Similarly, gastrointestinal diseases like stomachache, gastritis, abdominal pain, intestinal parasite, dysentery, diarrhea, vomiting, hepatitis, and other related diseases were treated by many MPs. Respiratory and other diseases were also treated by various MPs (Figure 6; Tables 2 and 3).

The health problems could be as inverse as the MPs and associated ecological zones. For example, Tolasa [32] reported 49 human health problems, which have been treated by 85 different MPs. Awas and Demissew [36] and Gebeyehu et al. [31] identified skin disease as the most commonly reported health problems in Kafficho people, Menjarna Shenkora and Mecha districts, respectively. On one hand Belayneh et al. [37] and Lulekal et al. [27] reported gastrointestinal diseases as the major human health problems. On the other hand, Mesfin et al. [34] reported malaria as the most common human health problem of Wonago district.

3.7. Diversity of Medicinal Plants in terms of Families

In this study different families of MPs were recorded. Among them Asteraceae is the most dominant family that holds 9 (9.68%) plant species followed by Solanaceae having 7 (7.53%) species. Other taxa commonly used are Cucurbitaceae and Lamiaceae (each 5 spp.), Euphorbiaceae and Fabaceae (each 4 spp.), Brassicaceae, Poaceae, and Rosaceae (each 3). The remaining forty-two (42) families hold fifty plant species. Eight of them account for two species. The rest of the families signify one species (Figure 7; Tables 2 and 3). Our finding agreed with the finding of Gebeyehu et al. [31] in which Asteraceae is the dominant family followed by Solanaceae. Etana [38] also reported that Asteraceae is the dominant family followed by Fabaceae. This may be because the weedy nature of the family Asteraceae takes advantage of disturbance.

3.8. Habits of Medicinal Plants Which Treat Diseases

The finding shows that the most widely used MPs habits in the different Kebeles of the study areas were herbs, 42 (45%), followed by shrubs 29 (31%). Trees and climbers account for 15 (16%) and 7 (8%), respectively (see Figure 8). Herbs are largest in number; this may be because the plant species exhibit high level of abundance and it is easy to access them. The results of this finding agreed with the findings of other indigenous researchers including Berhan et al. [15], Giday et al. [12], and Teklehaymanot and Giday [39]. On the contrary, the findings of Hunde et al. [14], Giday and Ameni [9], Lulekal et al. [33], and Mesfin et al. [34] revealed that shrubs are the most commonly used habits in their respective different study sites of Ethiopia.

3.9. Traditional Methods of Preparation, Condition, and Route of Application

The popular method of preparation of traditional medicine is crushing and squeezing accounting for 54 (45%) followed by powdering (powder form), 22 (18%). It was also recorded that 13 (11%) were prepared in juice form, 9 (8%) in boiling form, 8 (7%) in chewing form, and 4 (3%) in the form of fumigation and immersion (each). Other methods such as paste form, raw form, and the like accounted for 6 (5%) (Figure 9). Methods can be used for human and livestock problem except chewing which is used only for humans.

Based on the informants’ information the most popular method of preparation of remedy in the study area was crushing. This finding is in line with the results of Yineger and Yewhalaw [16], Getaneh [30], and Amsalu et al. [28]. However, Mesfin et al. [34], in a similar study on people of Wonago Wereda, reported that powdering was dominant method of preparation of remedy.

The result in the conditions of plant part used indicated that most medicines (about 61%) of traditional MPs were prepared from fresh plant materials in the study site whereas 30% and 9% of medicinal plants were reported to be used dry and in both dry or fresh form, respectively (Figure 10). The most common use employs fresh (intact or pounded/crushed) leaves for external administration.

This finding is also consistent with the finding of [23, 26, 28–30, 32, 34, 36, 40] that reported that the majority of the remedy preparations were in fresh form. In contrast with this, Tolasa [32] stated that 60% of the preparations are fresh or dried followed by fresh, 36.47%, and dried, 14%.

Respondents argued that they use fresh plant parts mostly because they believe that using fresh materials increases efficacy as compared to the dry ones. This is because of the fact that the ingredients may be lost or reduced when the plants became dry. Nevertheless, this contributes much a lot to the threats of MPs given that local people have no practice of preserving dry form of traditional medicine.

On the other hand, the most common route of administration is internal particularly oral that accounted for 51.61% followed by dermal, 24.73%. The oral/dermal, nasal, and nasal/oral ones and others are indicated in Figure 11. This result is being in agreement with the findings made by Megersa et al. [23] and Amsalu et al. [28], who reported that the leading route of application used by the given community in their respective study areas of remedies is taking orally.

3.10. Ranking of Medicinal Plants

3.11. Jaccard’s Coefficient of Similarity (JCS)

Jaccard’s Coefficient of Similarity (JCS) revealed that the study area has the highest similarity with 45 common species (34.66%) to the study conducted around Wonago Wereda, followed by 40 common species (28%) with Debre Libanos Wereda, followed by 39 common species (21.91) with Chelya Wereda, followed by 30 common species (17.65) having similarity to Gimbi Wereda, followed by 23 common species (17.16%) having similarity to Zegie. The least similarity was linked with the study conducted on Bale Mountain National Park (Table 7).

3.12. Fidelity Level

Fidelity levels were calculated for Plumbago zeylanica, Prunus africanus, Solanum anguivi Lam., and Withania somnifera having highest scores (100%) which treat diseases like wounds, eczema, and fibril illness (Table 8). On the other hand, Rhamnus prinoides which treats tonsillitis, skin infection, and dysentery has the least score (50%) (Table 8). Plants that are known as remedies of a single ailment have 100% fidelity level as compared to those that are used as remedies for more than one type of aliment. Most of the plants with high FL values have pharmacological effects that have been proven scientifically. On the other hand, the lowest one indicated less preferred species for treating specific ailments. In contrast, these plants have been widely used against several diseases. Plants with highest fidelity level values could also be targeted for further photochemical investigation to prove the bioactive components that are responsible for their high healing potential [42].

3.13. Nutraceuticals

Of the total MPs collected, twenty (21.51%) of them are used as a source of both medicine and food (nutraceuticals). The ethnobotanical information revealed that many food crops have medicinal effects (Table 9). The following plants like Allium sativum, Brassica carinata, Brassica nigra, and so on are directly used as a source of medicine and food in the study area of the given community. From this one can easily understand that the local people have IK and age-old experience in the use of plants as a source of medicine and nutrition. Similar findings were reported by Reta [43]. Most TMPs are safe, some are nutraceuticals, some are functional foods (wild fruits, vegetables, and other crops), and hence they are preferred.

3.14. Threatened and Endemic Medicinal Plants in the Study Area

In the study area, ethnobotanical information disclosed that MPs like Hagenia abyssinica, Olea europaea subsp. cuspidata, Podocarpus falcatus, Juniperus procera, Euphorbia abyssinica, Myrica salicifolia, Cucumis ficifolius, Withania somnifera, Cordia africana, Brucea antidysenterica, Ficus sur, and Millettia ferruginea are highly threatened. Medicinal plants documented as endemic from Ethiopia to the study site were Brassica carinata, Eragrostis tef, Cynoglossum coeruleum, Echinops kebericho, Erythrina brucei, Guizotia abyssinica, Inula confertiflora, Lippia adoensis, Lobelia rhynchopetalum, Millettia ferruginea, Solanecio gigas, and Urtica simensis which accounted for 13% (12 plant species) of the total collected MPs. Out of these, Cynoglossum coeruleum, Inula confertiflora, Laggera tomentosa, and Lobelia rhynchopetalum are nearly threatened while Lippia adoensis, Solanecio gigas, and Urtica simensis were under least concern (LN) [44]. This list could be used for collection of the rare plants of Ethiopia and contribute to national plant conservation target.

3.15. Threats and Conservation of Medicinal Plants in the Study Area

3.16. Conservation and Management Practices

In Gozamin Wereda, irregular remnants of aged dry Afromontane evergreen forests that contain many MPs can be found mainly around the Ethiopian Orthodox Tewahedo Churches. Hence, someone sees a patch of indigenous old-aged trees in the study area; he/she can be sure that there is an Orthodox Church in the middle. Patches of forests are visible from a great distance. Similar findings were reported in Chekole et al. [25]. This shows that culture, belief, and religion contribute much a lot to the conservation of MPs.

Some traditional practitioners in the study area have brought the different curative plans from different corners and started to conserve these MPs by cultivating at home-gardens. On the topic of this, Asfaw [11] in his findings reported that the home-garden is a strategic and ideal farming system for conservation, production, and enhancement of MPs and valuable IK. The same information was also documented by Etana [38].

Likewise, few management practices are carried out in the home-gardens of Gozamin’s indigenous people. One of the practices is to the make an effort for maintaining diverse plant species in the garden as much as possible. Diversity is achieved through planting and protecting annual and perennial herbs and woody perennials in combinations. Management practices like intercropping and crop rotation were observed among very few farmers of the study area. In doing so, herbal remedies continued to exist because of the existence of other plant species. As a result, indigenous people can be excellent conservators of plant diversity. However, according to the informants, in most cases attempts regarding conservation were weak. Similarly, Lulekal et al. [27] reported that although traditional practitioners and local communities in their study sites mainly depend on the natural environment for collecting MPs, the effort to conserve and sustainably utilize resources was frail.