A total of 100 informants (74 male and 26 female) whose ages ranged from 21 to 76 years (average age 52) were participated. Participant educational status was as follows: illiterate (cannot read and write), 72%, and literate (read and write), 28%. Various variables were selected to determine the influence of socioeconomic and other factors on the indigenous knowledge of people including gender, age, and socioeconomic factors such as distance to the forest, education, and income. There was a significant difference (p < 0.05) between men and women on the average number of plants reported and compared using an independent t test. According to this, more useful plants were reported by men than women. In the same way, statistically significant differences were observed (p < 0.05) among age categories, with elderly and adult holding the most knowledge of plant uses.

The distance of the informants, residence from the forest, also showed a significant impact on the number of useful plants reported (t (83) = 3.96 t (83) = 3.96, p < 0.001. Informants living near the forest reported a higher mean number of useful plants (Mean = 9.83) compared to those living farther away (Mean = 5.65). The other factor influencing knowledge was education, which was negatively correlated with the informant knowledge of plants. The same is true; income was another negatively correlated with the informant knowledge of plants. The study found that low-income individuals possessed more traditional ecological knowledge compared to wealthier individuals.

Diversity of useful plants

The present study documented 90 useful plant species found in the Wof Ayzurish Forest, representing 50 plant families (Table 8). The 6 most dominant plant families, Asteraceae (7 species), Lamiaceae (6 species), Rubiaceae, Fabaceae, Euphorbiaceae, and Solanaceae (4 species each), were identified. Conversely, 25 families exhibited the lowest levels of representation, with only a single species (27.8%) documented per family. In terms of habits, shrubs were highly dominant (35 spp., 39%), followed by trees (26 spp., 29%), herbs (19 spp., 21%), and climbers (10 spp., 11%). The uses of plants were grouped into ten use categories (Table 8). A substantial proportion of respondents reported using forest resources primarily for traditional medicine (50 species, 55.5%), followed by firewood (44 species, 49%), fencing (40 species, 44.4%), and materials use (37 species, 41.1%). Environmental role (23 species, 25.6%), farm tools (17 species, 19%), charcoal production (19 species, 21.1%), and animal fodder (21 species, 23.3%) were also notable uses. Additionally, social applications (8 species, 9%) and wild edibles (7 species, 7.8%) were reported (Fig. 2).

Fig. 2

Major use categories and number species around Wof Ayzurish Forest

TM plants

A total of 55 species (61%) belonging to 33 families were reported as TM plants. Of the 19 identified herbs in the forest, 84% possessed medicinal properties. Trees were the least common in terms of medicinal properties. The highest number of medicinal species was recorded within Asteraceae and Lamiaceae each (5 species), Euphorbiaceae (4 species) and each Cucurbitaceae and Solanaceae (3 species). Leaves represented the largest proportion (62.3%), followed by root (19%). The most common and highly preferred medicinal plants for treating various diseases of humans and livestock were: Osyris quadripartita, Asparagus africanus, Justicia schimperiana, Gymnanthemum amygdalinum, Withania somnifera, Euclea divinorum, Acmella caulirhiza, Aloe pulcherrima, Cucumis ficifolius, Cynoglossum coeruleum, Jasminum abyssinicum, Croton macrostachyus, Verbascum sinaiticum, Rumex nepalensis, and Ehretia cymosa. Of all, Osyris quadripartita was cited most frequently for its medicinal properties and its use in treating various ailments.

Firewood

Firewood was the second most common use in the study area. There were 44 firewood plants belonging to 30 botanical families, accounting for 49% of the total. The highest numbers of firewood plants were trees. The most preferred species were Dodonaea viscosa subsp. angustifolia, Carissa spinarum, Searsia pyroides var. pyroides, Eucalyptus camaldulensis, Eucalyptus globulus, and Vachellia abyssinica.

Live fencing

Fencing was also in high demand by the communities in the vicinity of the forest. Although cutting plants is forbidden, people collect them illegally. A total of 40 plants for fencing purposes were recorded, accounting for 44.4% of the total useful plants. The greatest percentages of fenced plants (52.5%) were trees. Among these, Vachellia abyssinica, Carissa spinarum, Searsia pyroides var. pyroides, Searsia retinorrhoea, Rosa abyssinica, and Rubus volkensii were common and preferred fencing plants.

Charcoal

In the study area, there were 20 charcoal-producing plants belonging to 15 botanical families, accounting for 22.2% of the total. Of these, 84% were trees and 216% were shrubs. Dodonaea viscosa subsp. angustifolia, Carissa spinarum, Eucalyptus camaldulensis, Eucalyptus globulus, Olea europaea subsp. cuspidata, and Searsia retinorrhoea were highly preferred for charcoal production. In addition, Vachellia abyssinica, Vachellia seyal, Galiniera saxifraga, Maytenus senegalensis, and Nuxia congesta were commonly mentioned as charcoal-producing plants. However, these plants were not abundant in the forest. No herbs or climbers were recorded for charcoal.

Farm tools

It was found that 17 (19%) useful plants were identified for manufacturing farm tools. The largest number of plant species used for farm tool purposes were trees (10 species, 59%), followed by shrubs (6 species, 35.3%) and climbers (1 species, 5.8%). Olea europaea subsp. Cuspidata (for plow handle), Ehretia cymosa (for Yoke), Eucalyptus camaldulensis, Eucalyptus globulus (for beam of plow), and Croton macrostachyus and Searsia retinorrhoea were the preferred species for crafting traditional plowing tools. Plant such as Vachellia abyssinica was also used for making broad blades for farm tools, but its abundance in the forest was limited. The sole climbing plant observed was Jasminum abyssinicum, which is occasionally employed for tying farm implements.

Fodder

The Wof Ayzurish Forest is surrounded by agriculturalist peoples, who use a variety of plant species for livestock feed. Twenty useful plants were identified as animal fodder which belonging to 16 botanical families, accounting for trees (7), shrubs (11), herbs (2), and climbers (1). Poaceae, Anacardiaceae, Asteraceae, and Rosaceae each with 2 species were the dominant families.

Material use

Plants were also reported for making construction and/or furniture, and handicrafts such as baskets, barns, and walking sticks, and other locally available materials. Thirty-seven plant species representing 26 families, accounting for 41.1% of the total useful species, were recorded as material plants. Most of these plant materials (30 species) were used for local construction and furniture (Fig. 3). The most common plant species employed to manufacture locally sourced materials for furniture and construction were Eucalyptus spp., Carissa spinarum, and Juniperus procera and Searsia pyroides var. pyroides,. Juniperus procera was used extensively as a building and furnishing material. In addition, Olea europaea subsp. cuspidata, Dodonaea viscosa subsp. angustifolia, Myrsine africana, and Jasminum abyssinicum were commonly used for making baskets (locally known as “Kirchat”). Olea europaea subsp. cuspidata and Dodonaea viscosa subsp. angustifolia also preferred to make barns (locally known as “Gotera”). Dodonaea viscosa subsp. angustifolia, Olea europaea subsp. cuspidata, Searsia retinorrhoea, and Eucalyptus spp. were the preferred sources for making walking sticks. Additionally, the leaves of Maesa lanceolata were used for baking bread. The stems of Euclea divinorum and Sida schimperiana were employed as toothbrushes. Furthermore, rural women utilized the leaves of Bersama abyssinica to provide shade and protection from the sun. While Vachellia abyssinica and Cordia africana are less diverse in forests [21], few respondents mention them as useful material plants.

Fig. 3

Types of material uses and the percentage of species used in the Wof Ayzurish Forest. The category "Others" includes uses such as rifle-making and fabric cleaning

Wild edible

Seven wild edible species (7.6% of the useful plants) were identified including Carissa spinarum, Ficus sur, Searsia pyroides var. pyroides, Rosa abyssinica, Rubus volkensii, Solanum physalis, and Syzygium guineense var. guineense. Carissa spinarum was the most commonly known edible wild plant. Among the edible wild plants, Syzygium guineense var. guineense posed the greatest threat.

Social uses

Plants approximately 9% (8 species) reported to have social uses were those utilized for ritual and holidays, as well as for fumigation and mastication. Trees and herbs were the dominant plants in social use. The study reported that Ficus vasta, and Juniperus procera were noted for their use in traditional ritual activities within the local community. Furthermore, grass was the preferred choice for public holidays. Additionally, Olea europaea subsp. cuspidata was utilized to fumigate containers of local alcoholic beverages, such as Tella and Katikala. Dodonaea viscosa subsp. angustifolia was used as a fumigant, being used in and around homes to ward off evil spirits and certain pathogenic microorganisms.

Environmental uses of plants

More than 95% of the respondents reported that all plants in the forest are used for environmental protection. Specifically, environmentally useful plants were identified for their utility as shading, ornamental, and enhancing soil fertility. Of the useful plants, 23 plants (25%) were specifically mentioned for the following environmental roles. For example, H. hirta, A. abyssinicus, C. macrostachyus, V. abyssinica, A. pulcherrima, and R. prinoides were highly preferred for soil erosion; V. abyssinica, C. macrostachyus, and F. sur were preferred for shading; J. procera, C. spinarum, C. macrostachyus, F. sur, O. europaea subsp. cuspidata, G. robusta, J. mimosifolia, M. salicifolia, O. quadripartita, and J. abyssinicum were preferred for their ornamental role. All respondents answered that Eucalyptus spp. was not as good as ornamental, shading, or soil fertility. The most common plant habits used for environmental improvement and protection were trees (65%).

Culturally Important plant species

Of the identified 90 useful plants, approximately 61% had 2 or more uses, whereas 39% were had one use. Only 34% of the species were reported to have more than 3 uses. Consequently, considering the use citations and FGD, 15 plant species were identified for additional analysis using various quantitative measures (Table 3). In general, for this study, URs were grouped into the 10 use categories shown in Table 2.

Table 2 Number of use reports (UR) and percentage of use categories

The maximum value for FC per species was the total number of informants (NC = 100). The maximum value for both NU per species and the CI index is the total number of use categories (NC = 10). The rankings of the 15 most culturally significant native species according to the cultural importance index (CI), frequency of citations (FC), and number of uses (NU) are shown in Table 3.

Table 3 Highest-ranking species according to the quantitative indices

Material use was the most culturally significant (CI = 1.56), followed by firewood (CI = 1.51) and live fencing (CI = 1.36), while social use and human edible plants were the least important. According to the CI score, Olea europaea subsp. cuspidata (locally known as Weira) has the most citations (FC = 53) and was the most versatile plant according to the CI index (CI = 1.77), with nine uses out of the ten categories (NU). It is mainly used for charcoal production (CI CH = 0.29), followed by firewood (CI FW = 0.13) and materials (CI MU = 0.12).). The second most common species was Juniperus procera according to the CI (CI = 0.97), with six use (NU) 97 use reports (UR) and 33 (FC). It is mainly used as a material (CI MU = 0.48), followed by environmental use (for shading and ornamental purposes) (CI: ER = 0.19). The third most important species was Carissa spinarum (CI = 0.96); informants cited it in nine of the 10 categories used. The most important uses were fencing (CI = 0.24), followed by firewood (CI = 0.19) and edible (CI = 0.16) (Table 4).

Table 4 Cultural importance (CI) of each use category for the 15 most significant species

In addition, the results showed that there was a low correlation between the practical and cultural values of species: Some species that were frequently used were rarely mentioned. These plants, such as Galiniera saxifraga, Myrsine africana, and Nuxia congesta, were mentioned as the most important plants (during FGD) but their use report was low.

Comprehensive analyses of ethnobotanical indices

Other indices, such as RFC, CV, and CI, indicate the ranking of different plants based on each index, that is, the frequency of citations, number of use reports, and number of uses for each species (Table 3). The RFC directly depends on the number of informants mentioning the use of a plant (FC). In comparison with all indices, Olea europaea subsp. cuspidata ranked first in terms of the number of citations, use categories, and multiplicity of uses according to the CI, RFC, and CV rankings. Juniperus procera ranked second position according to the CI. O. europaea subsp. cuspidata, Juniperus procera, and Carissa spinarum rank 1st, 2nd, and 3rd in position, respectively, according to the CI reference. In other words, Olea europaea subsp. cuspidata, Dodonaea viscosa subsp. angustifolia, and Juniperus procera rank 1st, 2nd, and 3rd in position, respectively, according to the RFC reference. Furthermore, O. europaea subsp. cuspidata, Carissa spinarum, and Juniperus procera rank 1st, 2nd, and 3rd in position, respectively, according to the CV reference.

The role of Wof Ayzurish Forest

Key informants highlight the ecological functions of the forest, emphasizing its role in water reservoir, climate regulation, soil erosion prevention, and flood protection. These vital functions exceed its contribution to local subsistence needs. The forest is also home to variety wildlife, including potentially dangerous animals like pythons, snakes, hyenas, porcupines, tigers, apes, and harmful insects, which may pose risks to the local population’s well-being. The Wof Ayzurish Forest borders agricultural land where farmers cultivate diverse plant species and crops (Fig. 4). Additionally, home gardens are practiced, providing income through the production of fruits, vegetables, and spices. The primary cultivated crops included Sorghum bicolor, Eragrostis tef, Lens culinaris, Triticum aestivum, and Vigna radiata. Furthermore, the most prominent marketed fruits trees and spices by the local population include Carica papaya, Catha edulis, Citrus sinensis, Citrus aurantiifolia, Coffea arabica, Saccharum officinarum, Musa acuminata, Allium sativum, Allium cepa, Ruta chalepensis, Ocimum basilicum, Capsicum annuum, and Rhamnus prinoides.

Fig. 4

A partial view of the Wof Ayzurish Forest and surrounding (Photo courtesy: Yirefu Tefera, 2022)

Threats to indigenous plant knowledge and conservation strategies

The research revealed various threats compromising the survival of useful plants in their native ecosystems. The expansion of agricultural practices, grazing, and cutting for construction, charcoal and farm tools were identified as major human-induced disturbances to plant composition and diversity (Fig. 5). Trampling can also have detrimental effects on natural environments, causing vegetation loss and degradation of plant communities by inhibiting seedling growth.

Fig. 5

Overgrazing (left), expansion of agriculture (middle), and selective cutting (right) of anthropogenic activities around Wof Ayzurish Forest

Local communities in this study employ various strategies to ensure the sustainable use of forest resources. Key informants indicated that the forest was revered as sacred and thus protected from logging activities. A local proverb, “ERTIB AYKORETEM” (meaning “preserving the plants”), underscores this deep-rooted respect. Additionally, the communities along with water and irrigation committee have implemented eco-friendly resource management practices, including the construction of terraced landscapes around the forests. These terraces, composed of stones and plant species like Rhamnus prinoides (above terraces) and Croton macrostachyus (below terraces), contribute to soil conservation and water retention (Fig. 6). Furthermore, efforts have been made to prevent grazing animals from entering the forest and making charcoal. For instance, due to their importance in the local community, Juniperus procera and Olea europaea subsp. cuspidata are protected against being cut down. If occasional cutting is necessary, the local population employs a selective approach to harvesting, prioritizing species with abundant populations. Moreover, it is important to note that the locations where medicinal plants grow are well known, and as a result, free grazing and walking near these plants are not allowed. Besides, it is crucial that if a plant has not completed its life cycle, it should not be harvested for firewood.

Fig. 6

Terrace partial view (A, B), Farming system (C) (Photo courtesy: Yirefu Tefera, 2022)

Jaccard similarity index

Jaccard index was used to compare the results of the current study with those of other related studies conducted in Ethiopia. The species richness of these medicinal plants was comparatively lower in this study than in other forest ecosystems. To assess the degree of species similarity, the Jaccard similarity index was calculated. The highest similarity in medicinal plant species was observed between the current study and those conducted in Tara-gedam and Amba Remnant Forests (30%), followed by selected church forest (25%), Wejig-Mahgo-Waren Massif Forest (24%), and Desa’a Forest (20%). In contrast, the similarity was lower with the study conducted in Bale Mountain (12%) (Table 5).

Table 5 Jaccard’s similarity index (JS) between the current study and other similar studies conducted in EthiopiaComparison with previous studies in Ethiopia

This comparative analysis reviewed 50 prior studies focusing on the ethnomedicinal knowledge of 15 culturally significant plant species within the study area, where medicinal plants accounted for more than half of the forest’s biodiversity (Table 6). These ethnomedicinal studies have focused on multipurpose plants, employing direct matrix analysis to evaluate their various uses. These comparison documented how indigenous and local communities across different regions of the Ethiopia have utilized these plants. C. spinarum, O. europaea subsp. cuspidata, C. macrostachyus, J. procera, and V. abyssinica have been reported to have the highest number of use categories (Fig. 7), while, in the present study, O. europaea subsp. cuspidata, C. spinarum, C. macrostachyus, and D. viscosa subsp. angustifolia were found to have the highest number of use categories. A comparable number of uses were documented in the current and previous studies for plant of M. salicifolia, E. globulus, S. retinorrhoea, and F. sur.

Fig. 7

The reported ethnobotanical use categories of fifteen culturally significant plants in previous studies (represented in blue) to the findings from the current research (represented in orange)

Table 6 Comparison of reported ethnobotanical studies on the top 15 culturally significant useful plant species in Wof Ayzurish Forests with previous studies in Ethiopia

The bar plot in Fig. 8 illustrates also how the number of reports significantly (p < 0.05) varies by plant species and region. Amhara region has the widest spread in the data, indicating high variability in the number of Reports. Oromia region also shows substantial variability next to Amhara region, whereas Benishangul-Gumuz, SNNRP, and Tigray regions have smaller interquartile ranges, indicating lower variability in reports. Figure 8 shows C. macrostachyus, O. europaea subsp. cuspidata, E. globulus, and V. abyssinica as the most frequently encountered plant species. It is evident that different plant species have varying levels of reports across regions, confirming the results from the Chi-Square Test that plant species and region are associated.

Fig. 8

The bar plot illustrates how the number of reports varies by plant species and region