Human–forest interaction of useful plants in the Wof Ayzurish Forest, North Showa Zone, Ethiopia: cultural significance index, conservation, and threats

Abstract

Background

Indigenous communities have historically engaged in harvesting and management practices that have significantly influenced the state of forests globally. The Wof Ayzurish Forest community is almost entirely an agricultural society, familiar with the native flora, which has been integrated into their culture. Due to that, local communities have relied on these plants for centuries, passing down knowledge about their importance through generations. Therefore, this study aimed to investigate the interaction between humans and useful plants in the Wof Ayzurish Forest, North Showa Zone, Ethiopia, with a focus on their cultural significance, conservation status, and the threats they face.

Methods

A snowball sampling technique was employed to select 100 informants and the data were collected through free listing, field walk, open-ended and semi-structured interviews, and focus group discussions. To evaluate the cultural importance (CI) of the plant species, three quantitative indices, namely, the relative frequency of citations (RFC), use reports (UR), and the cultural value index (CV), were employed. Each index aims to assess the CI of plant taxa statistically. Spearman’s correlation coefficient was used to compare the correlations among various indices since all the variables considered are not distributed normally. The Jaccard similarity index (JI) was calculated to assess the proportion of plant species shared between the study area and other regions within Ethiopia.

Results

This study identified a total of 90 useful plants in the Wof Ayzurish Forest, categorized into ten groups based on their uses. The medicinal use category was the most represented (55 taxa), followed by firewood (44 taxa), fencing (40 taxa), and construction and furniture (37 taxa). Consequently, considering the use citations and key informant discussion, 15 plant species were identified for additional analysis using various quantitative measures including cultural importance index (CI). Based on CI score, Olea europaea subsp. cuspidata, Juniperus procera, Carissa spinarum, Croton macrostachyus, Dodonaea viscosa subsp. angustifolia, and Eucalyptus globulus were identified and reflecting their relative cultural importance and frequent utilization. Among these, Olea europaea subsp. cuspidata was the most versatile plant and ranked first due to its greater number of citations and diverse use categories.

Conclusions

The frequency with which a species is mentioned provides relevant information about its cultural significance. More versatile plants are generally more familiar to people than those with only one purpose and are often subject to high pressure due to overutilization. Thus, this information can aid in establishing sustainable use of Wof Ayzurish Forest without depletion of resources by informing community-based strategies that incorporate ethnobotanical knowledge.

Background

Indigenous communities have historically engaged in harvesting and management practices that have significantly influenced the sates of forests globally [1]. The connection between indigenous communities and forests is multidimensional, encompassing social, economic, and spiritual aspects. The destruction of the forests inevitably leads to the decline of these intimacies, as they are inextricably linked [2]. Isolating local populations from their forests is a critical step not only toward the erosion of their identity and survival as distinct peoples, but also toward the degradation of the forests themselves [3]. Therefore, studying floristic composition and species diversity is useful for identifying ecologically and economically significant plants and protecting threatened plants [4].

Traditional Ecological Knowledge (here after TEK) comprises the accumulated wisdom, beliefs, culture, and practices of indigenous, rural, and local communities, which have been developed and sustained through their interactions with the natural environment [2]. This knowledge system is valuable in addressing climatic, social, and economic challenges faced by these communities, as it provides context-specific insights and strategies for sustainable resource management and adaptation [5]. Thus, ethnobotanical studies can provide an understanding of how indigenous society integrates local and scientific knowledge to achieve biocultural conservation [6]. One key issue related to these studies is the use of quantitative techniques to evaluate the relative importance and cultural significance of plants in a given culture [7]. In ethnobotany, various indices have been constructed to measure the use value of plant species [8].

The cultural significance index (CSI) is a tool that is defined as the sum of different values obtained for each plant [9, 10]. This index determines a relation between the number of uses mentioned in interviews and the number of interviews conducted. Plants mentioned more frequently were assigned greater use value than plants mentioned less frequently [10]. Keeping in view this, researchers have calculated various indices using data on the number of participants who mentioned a plant species during interviews [11].

It is evident that natural forests offer a multitude of resources and ecosystem services that are indispensable to global human well-being. They provide a broad range of sustenance, including food, medicinal plants, timber, and materials for shelter and other necessities [12]. Nevertheless, deforestation and other human activities are rapidly depleting these forests, jeopardizing their long-term sustainability and the communities that rely on them [13]. In light of this consideration, this study aimed to i) collect, identify, and document the diversity and types of useful plants utilized by local communities in the Wof Ayzurish Forest, North Showa Zone, Ethiopia, ii) determine the cultural significance index (CSI) of key plant species and analyze their role in the socio-cultural well-being of local communities, iii) assess current conservation practices and strategies used to protect useful plants in the Wof Ayzurish Forest, with an emphasis on traditional knowledge and community-based initiatives, and iv) identify the key threats facing useful plant species in the forest, including anthropogenic factors and recommend sustainable management and conservation measures.

Materials and methods

Description of the study area

The study was conducted in the Wof Ayzurish Forest 190 km north of Addis Ababa in Tarmaber district. Tarmaber district is found in the north Shewa Zone of Amhara Regional State, 59 km east of Debre Berhan town (the administrative capital of the North Shewa Zone) (Fig. 1). The total area of the district is 609.26 km², and it has 19 Kebeles, the smallest administrative units [14]. Wof Ayzurish Forest is situated between 9°45′N and 10°N, 39°45′E and 40°E. Based on Ethiopian agroecological zones, the climate is divided into three: warmest zone, which is locally known as Kolla (warm semi-arid), the cold climate zone locally known as Dega (cool and humid), and medium/intermediate zone, which is locally known as Woina-Dega (cool sub-humid) [14]; each accounting for 50.2%, 36.2% and 13.6%, respectively. The average altitude of the district is 2318 m a. s. l. The topography of the study area is characterized by 47.21% mountainous areas, 33.37% rolling terrain, 15.74% valleys, and 3.68% plains. The average annual precipitation in the district ranges from 1100–1400 ml. The average minimum annual temperature is 7.9 °C, while the highest annual temperature is 25 °C, as reported by Ethiopian National Meteorology Agency (ENMA).

Fig. 1

Map of Ethiopia showing the Amhara region and the location of study district and the Wof Ayzurish Forest and subkebeles

Data sampling and collection

Before data collection, a preliminary reconnaissance survey was conducted in the study forest and its environs, from May 28 to June 15, 2021. The purpose of this survey was to identify suitable study sites and become acquainted with the local environment. The researchers obtained formal letter from the Department of Plant Biology and Biodiversity Management at Addis Ababa University and verbal consent from each participant. Four study sites (Mosebit, Many_Amba, Woyne_Wuha, and Jana_Amorie) were purposively selected based on proximity, accessibility, potential human–forest interactions, and recommendations from knowledgeable elders (Table 1).

Table 1 Demographic characteristic of the informants and description of subkebeles

A snowball sampling technique [15] was employed to select 100 informants. The informants included farmers, herdsmen, forest rangers, housewives, and knowledgeable elders who had knowledge of useful plants. The data were collected through free listing, field walk, open-ended and semi-structured interviews, and focus group discussions [16, 17]. A free listing approach was employed, whereby informants were asked to enumerate the useful plants they were familiar with and/or had utilized [15]. After explaining the purpose of our research, a questionnaire prepared in the local Amharic language was subjected to the informants. We asked each informant: “Can you tell me the names of all the useful plants you know?” and “How do you employ these plants?” [18].

To inventor the cultural value of useful plants in the forest, ten broad categories (Table 3) were identified following emic categories which include traditional medicine (here after TM), firewood, fencing, materials use, charcoal, farm tools, wild edibles, animal fodder, and environmental and social use [10]. The “TM” category encompasses plants used to treat human and animal ailments. “Material use” covers plants used for making furniture, construction, and handicrafts (e.g., basketry, barns, walking stick etc.). “Environmental use” includes ornamental, shading and improving soil fertility plants. “Social use” includes plants used in holydays, rituals, and fumigating and masticatory. “Firewood” includes any locally available dried plants material that is gathered and used for fuel as cooking and heating at homes. “Charcoal” making covers fuel for cooking heating including income source and sales. “Fodders plants” includes for animal feed. “Fencing” uses plants as part of the live fence. The plants utilized in making “farm tools” encompass the construction of plow beams, broad blades, and plowing tools. Then, the CS of the plant species was determined, the interviewees listed the useful species in each ethnobotany use category, and their frequency of being mentioned was calculated by adding the number of times each species was mentioned [19].

Focus group discussion (FGD)

Three focus group discussions (here after FGD) were held: one at the district level and two within selected subkebeles, involving an average number of five to seven key informants [20]. Two FGDs were held, representing each study site, to collect information on forest conservation management, utilization, and associated threats. The member of group includes development agents for natural resource, key informants, male and female headed households. Specifically, to study the forest threats, human disturbance such as grazing, agricultural expansion, and other activities such as cutting and trampling in the vegetation was recorded in the forest [21]. A total of 14 key informants were interviewed to rank the four most prevalent threats to the study forest. The highest threat was indicated by a value of 5, while the least threat was denoted by a value of 1. An overall ranking of the threats was determined by summing the values provided by the key informants, following the methods by [16].

Voucher plant specimen collection and identification

Vegetation surveys prior were systematically predetermined in the study forest [21]. The study participants were asked to enumerate the useful plant species they know from the forests and describe how they utilize. The researchers then tallied and documented these local plant names and traditional uses. Voucher specimens were collected, identified using standard methods, and verified by experts at the National Herbarium, Addis Ababa University.

Data analysis

Descriptive statistics, including frequencies and percentages, were calculated using Microsoft Excel and visualized through graphs, charts, and tables. A t test was utilized to determine if differences existed in plant knowledge between demographic groups, including gender, age, education level, and other socioeconomic information (income, and proximity to the forest).

Jaccard similarity index (JS)

The Jaccard similarity of index was employed to assess the degree of species overlap with other ten ethnobotanical studies on medicinal plants conducted in forest ecosystems in Ethiopia. The JS was calculated using the formula

$${\text{JCS}} = { }\frac{c}{{\left( {a + b + c} \right)}}$$

Here, JCS represents the Jaccard Coefficient of Similarity, where a denotes the number of species found in habitat A (Wof Ayzurish Forest), b represents the number of species in habitat B (other study areas), and c is the number of species common to both habitats A and B. This method has been widely utilized in various studies, including those by [20, 22]. The percentage JCS is obtained by multiplying by 100.

Quantitative ethnobotanical data analysis

To assess and compare the cultural significance of the useful plant species, established quantitative indices such as the Cultural Value Index (CV), Use Value Index (UV), Relative Frequency of Citation (RFC), and Cultural Importance Index (CI) were employed [23]. All the ethnobotanical indices were computed from ethnobotanical data, specifically referring to the “use of species in a specified use category u mentioned by an informant i.” All the outcomes formed by these three factors are referred to as a use report [19]. In a specific investigation involving NS species (s1, s2,…,sNS), with a total count of use categories NC (u1, u2…, uNC) and N informants (i1, i2…, iN), URsui equals 1 if the combination exists or 0 if it is not mentioned. Consequently, the total number of use reports (UR) is one of the most widely used methods for assessing each species. This can be expressed mathematically as [10]:

$${\text{URs}} = \mathop \sum \limits_{{{\text{i}} = {\text{i}}1}} {\text{URui}}$$

First, the UR of all the informants (from i1 to iN) within each use category for that species (s) summed up, that is, the number of informants who mentioned each use category for the species. Second, we summed all the URs of each use category (from u1 to uNC). The importance of each species was discussed using the following indices: relative frequency of citations (RFC), cultural value index (CV), and cultural importance index (CI).

Relative frequency of citation (RFC) This index is obtained by dividing the number of informants who mention the use of the species, also known as the frequency of citation (FC), by the number of informants participating in the survey (N) and is expressed by [19] using the following formula:

$${\text{RFCs}} = { }\left[ {{\text{FC}}/N} \right]$$

Cultural value index (CV) The cultural value index is developed by [24] using the following formula:

$${\text{CVs }} = \left[ {\frac{{{\text{NUs}}}}{{{\text{NC}}}}} \right] \times \left[ {\frac{{{\text{FCs}}}}{N}} \right] \times { }\left[ {\frac{{{\text{URui}}}}{N}} \right]$$

The first factor was the relationship between the number of different uses reported for the species (“ethnospecies” in the original work) and the total number of use categories considered in the study (NUs divided by NC). The second factor was the relative frequency of citations of the species. Finally, the third factor was the sum of all the URs for the species, that is, the sum of the number of participants who mentioned each use of the species divided by N. These three factors were then multiplied.

Cultural importance index (CI) The CI is defined [10] by the following formula:

$${\text{CI}} = \mathop \sum \limits_{u = 1}^{NC} \mathop \sum \limits_{i = 1}^{N} \begin{array}{*{20}c} \frac{URui}{N} \\ \end{array}$$

It is a part of CV and can be calculated by summing the proportion of informants who reported using each plant species. Spearman’s correlation coefficient was employed to examine the relationships among these indices, as the variables under consideration do not follow a normal distribution [10].

Results

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 Ethiopia

Comparison 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

Discussion

The plants in the study forest were assessed for their traditional uses. Certain variables were selected to determine the influence of socioeconomic and other factors on the indigenous people, including gender, age, and distance to the forest, education, and income. In this context, more useful plants were reported by men than women, aligning with previous research [36, 37]. In contrast, other studies have shown that females significantly identified and reported more plants [25, 35]. Regarding age, it is evident that older individuals and other knowledgeable community members possess a more extensive knowledge of local flora [25, 36].

Other socioeconomic factors such as proximity to the forest likely increases close interaction with and knowledge of local flora, leading to a higher reported number of useful plants and this in line with study by [25]. It has been found that individuals with lower levels of education, including those who are illiterate, possess more, traditional knowledge than educated individuals [79, 80]. This is particularly true for those engaged in traditional livelihoods such as agriculture, resource extraction, and other rural activities [24]. The study also found that low-income individuals possess more traditional ecological knowledge compared to wealthier individuals. For these low-income individuals, traditional knowledge serves as a resource for their livelihoods and contributes to their healthcare, while also fostering their engagement with the surrounding environment. This aligns with the findings of [73], which indicate that a person’s ethnobotanical knowledge is not influenced by their income or education level.

The current investigation documented the presence of 90 useful plant species in the Wof Ayzurish Forest. Asteraceae, Fabaceae, Lamiaceae, Rubiaceae, Euphorbiaceae, and Solanaceae were the richest plant families. These families were highly dominant in the dry Afromontane forest. For example, similar dominant plant families were reported in dry Afromontane forest by [81] in Gelawoldie community forest, [35] in Habru district forest patch, and [82] in Guard dry Afromontane forest. Thus, species of those listed families might be very familiar, and easily accessible in the local environment compared to other few species represented families [83].

In the current study, the uses of plants were grouped into ten use categories including traditional medicine, firewood, fencing, materials use, environmental role, farm tools, charcoal production, animal fodder, social use, and wild edibles. Indigenous and local communities have a wealth of traditional knowledge about using plants for different purposes [84]. This traditional knowledge is not often documented but has been handed down through generations as an essential part of the culture and natural heritage of certain communities [84, 85]. Ethnobotany, the interdisciplinary study of human–plant relationships, has significant implications for contemporary global challenges. Its applications extend to areas such as food security, climate change mitigation, biodiversity conservation, and human health [86].

CSI studies primarily target plants that are important to traditional medicine systems. These plants serve a critical role in meeting healthcare needs, particularly in regions where access to modern medical services is limited [87]. These plants are integral to traditional medicine systems, particularly in regions where access to formal healthcare is limited [88]. In the present study, the local communities still possess strong botanical knowledge on the medicinal plants utilization for health care needs. This privileged botanical knowledge is maintained by their culture for conserving the plants and good practices in their uses [89]. In this circumference, Osyris quadripartita is the most preferred medicinal plant for treating various diseases. It is primarily used to treat wounds, swelling, febrile illness, and herpes zoster. Asparagus africanus and Olea europaea subsp. cuspidata have been identified as commonly used medicinal plants for the treatment of swelling. Satureja abyssinica is also widely regarded as an effective remedy for alleviating headaches.

Ethnobotanical investigations have been instrumental in elucidating the immense botanical knowledge on the diverse use of food plants. The comprehensive documentation of food plant diversity in various studies provides valuable information on the potential of these plants for future development, including the development of plant-based food products [30]. Besides, CSI highlights culturally significant plants that are staples in local diets. These plants often include indigenous or underutilized species that are resilient to environmental changes and can diversify diets [90]. However, in the present study area, agriculture was the main pillar of economic activity and livelihood source [14]. Meanwhile, a wild edibles plants were not well consume, and almost all food plants are cultivated. Even when wild plants grow nearby, shepherds and young children often eat them. Indeed, other study has shown that the erosion TEK surrounding the use of wild edible plants has played a substantial role in their reduced consumption [91].

CSI aids in identifying plants of cultural importance that are essential to local communities [92]. These species often serve as keystone components within their ecosystems, contributing significantly to ecological stability. Conservation strategies that prioritize these species promote both cultural preservation and ecological resilience [93,94,95]. In the present study, more than 95% of the respondents reported that all plants in the forest are used for environmental protection. However, specifically, 23 plant species with multiple uses, including shade provision, ornamental value, and soil fertility enhancement, were identified by respondents. Previous studies have investigated the diverse benefits of forests, encompassing biodiversity conservation, soil and water retention, mitigation of air and water pollution, economic development, and their critical role in climate regulation [96].

Preserving and revitalizing traditional knowledge in a study area requires a multifaceted approach that integrates education, community engagement, and local economic activities. Integrating traditional knowledge into school curricula can be achieved by incorporating it into subjects such as history, culture, and environmental science [97, 98]. This approach may include teaching lessons on local crafts, traditional agricultural techniques, and indigenous medicinal practices. Additionally, organizing workshops or seminars led by community elders and knowledgeable persons can provide students with hands-on and interactive learning experiences [99]. Moreover, educational field trips to local sites, such as natural forests, can further enable students to observe the surrounding environment of traditional methods in real-world contexts [100]. Additionally, implement training programs for artisans that integrate traditional ethnobotanical knowledge and techniques with contemporary business practices [84]. These programs could include instruction in small-scale marketing strategies alongside the application of sustainable conservation methods [101]. Finally, conduct skill development workshops for community members and students to teach skills like traditional hand crafts [102], herbal medicine mode of preparation, or sustainable harvesting techniques. The consecutive paragraphs will provide a detailed discussion on the various use categories of forest resources and their applications in supporting local livelihoods.

The use of certain materials is another significant category for making construction, furniture, and handicrafts, such as barns, baskets, walking sticks, and toothbrushes, among others. Juniperus procera is the predominant choice for construction and furniture making due to its desirable properties, aligning with previous research (Table 5). Furthermore, the species Olea europaea subsp. cuspidata and Dodonaea viscosa subsp. angustifolia are commonly utilized to make baskets and barns, which are locally referred to as “Kirchat” and “Gotera,” respectively. However, people are aware that cutting trees is prohibited; they continue to do so, especially for making furniture, farm tools, and building materials. However, it is important to acknowledge that the primary use of wood in the study area is for personal consumption, rather than commercial purposes.

The use of firewood constitutes another common category of plant utilization, with individuals preferring dried and fallen plants over young, growing ones. This practice is significant for plant conservation. Within the study area, the dominant fencing plants such as Rosa abyssinica, Searsia pyroides var. pyroides, and Carissa spinarum exhibit spines and thorns those are crucial for deterring livestock [103, 104] and preventing unauthorized entry across boundaries.

The forest also serves as a source of materials for farm tools, with plant species selected based on their simplicity and durability. Olea europaea subsp. Cuspidata (Plow handle), Ehretia cymosa (Yoke), Eucalyptus camaldulensis, Eucalyptus globulus (beam of plow), Croton macrostachyus, and Searsia retinorrhoea were favored for making plowing tools. Eucalyptus globulus, Olea europaea subsp. cuspidata, and Croton macrostachyus were also identified as preferred materials for agricultural tools by [38] and see more Table 5. Furthermore, Searsia retinorrhoea, Eucalyptus globulus, Olea europaea subsp. cuspidata, and Croton macrostachyus were reported as preferred materials for agricultural tools [35].

The most frequently cited fodder species included Olea europaea subsp. cuspidata, F. sur, and Vachellia abyssinica, consistent with prior research (Table 5). Olea europaea subsp. cuspidata and Myrica salicifolia were also identified as suitable forage for young livestock. Vachellia spp and Olea europaea subsp. cuspidata were mentioned as preferred fodder plants by [105].

Charcoal production was also another use category. Some forest plants like Dodonaea viscosa subsp. angustifolia, Carissa spinarum, Eucalyptus camaldulensis, Eucalyptus globulus, Olea europaea subsp. cuspidata, and Searsia retinorrhoea were highly preferred. Previous studies have highlighted the role of these plants in the charcoal-making process (Table 5). Additionally, the present study identified Vachellia abyssinica, Vachellia seyal, Galiniera saxifraga, Maytenus senegalensis, and Nuxia congesta as species utilized for charcoal production. However, these species were found to be least abundant within the Wof Ayzurish Forest, as reported by [21].

The study area’s plants have various social uses, including ceremonial, ritualistic, and holidays celebration, and fumigation. Notable examples include large trees like Juniperus procera, Vachellia abyssinica, Ficus sur, and Ficus vasta, which are associated with ritual practices. Certain plants (Table 5), including F. sur, F. vasta, and P. africana, are employed by local populations in the region for a range of ritualistic and religious practices, as identified by [106].

The findings of this study reveal novel reports for certain medicinal plants within the Wof Ayzurish Forest in Ethiopia. Helichrysum spp is widely acknowledged in South African traditional medicine for its therapeutic benefits [107] and renowned for its essential oils [108]. The species Helichrysum splendidum, however, remains largely underexplored in the context of Ethiopian phytomedicine and pharmacology. Indeed, this species is reported in areas of Ethiopia such as the Menz-Guassa community conservation zone of the Afroalpine ecosystem [109]. However, there is limited documentation on its TM uses within Ethiopian communities. In this study, the plant was reported employed by the local community to treat ailments such as febrile illnesses and vomiting. This finding highlights the need for further ethnobotanical and pharmacological investigations to explicate its full therapeutic potential in Ethiopia.

Additionally, Cynoglossum coeruleum, herbaceous plant, has now been identified as a medicinal resource used to address conditions such as swelling illnesses. Despite its apparent utility, the pharmacological and phytomedicinal properties of this plant remain underexplored in Ethiopia. Nevertheless, research on Cynoglossum amplifolium has demonstrated broad-spectrum antimicrobial activity in leaf extracts, a closely related species. While direct studies on C. coeruleum in Ethiopia are scarce, the pharmacological potential of related species suggests promising antimicrobial and therapeutic applications. Therefore, comprehensive scientific investigations are essential to fully characterize the pharmacological efficacy and safety profile of both species of C. coeruleum and H. splendidum in the Ethiopian context. Thus, the documented medicinal plant species and the associated traditional knowledge hold significant potential to support future public health initiatives and promote the development of sustainable herbal medicine practices in the Wof Ayzurish Forest, Tarmaber district.

In terms of the multiple uses of categories, this study revealed new uses for certain useful plants. Notably, in addition to the well-documented uses of Searsia pyroides var. pyroides for food and medicine, the findings highlighted its utility across diverse categories, including construction and furniture, firewood, fodder, environmental purposes, and fencing (Fig. 5). Similarly, while Olinia rochetiana has traditionally been recognized primarily for its medicinal properties, this study expands its documented applications to include roles in medicine, firewood, environmental benefits, fencing, and construction and furniture, as illustrated in Fig. 5.

Cultural significance index implications

The CI is used to compare the relative importance of plants and offers reliable information about their benefits [9, 110]. According to the present data, material use, firewood, fencing, and TM are paramount to cultural significance (CI score) around the forests. Although plants exhibit high species richness, e.g., TM, their cultural significance, as measured by the CI score, is relatively low in local daily practices. Therefore, there were few very important useful plants that were mentioned frequently by respondents; conversely, they were numerous in number but less frequently mentioned.

The CI also provides reliable information about the usefulness of plants and can be used to compare the importance of plants on site or off site [110]. For example, Dodonaea viscosa subsp. angustifolia and Olinia rochetiana had the same CI (0.45), but their FC differed, at 32 and 21, respectively. In this regard, it is possible to say that Dodonaea viscosa subsp. angustifolia is more important for various uses than Olinia rochetiana.

Table 7 shows the Spearman correlations among all the variables. All the correlations are significant at P < 0.05, with some being stronger than others. Most importantly, the frequency of citations is not totally independent of the use category. According to the results, there was a strong correlation (0.73) between the NU and FC, indicating that more versatile species are likely to be reported by more informants. This relationship is also illustrated in the scatter plot of Fig. 9. Table 6 displays nearly strong correlations (0.74) between the CI and FC indices. It is possible that the fit of many species into a single use category may be the cause of this strong association, which results in the FC and CI indices having the same values.

Fig. 9

A correlation between the number of use categories for every species (NU) and the frequency of citations (FC), i.e., the number of informants mentioning the species as useful. The dot represents the most important species

Table 7 Spearman correlations values among various variables

Jaccard similarity of index

The results highlight the varying degrees of similarity in medicinal plant species among different forest types in Ethiopia, as measured by Jaccard’s index. The highest similarity (30%) with the Tara-gedam and Amba remnant forests [25] suggests that these forests share ecological and environmental characteristics, such as climate, soil type, and vegetation structure, with the forest under study. This could be indicative of a comparable historical land use, conservation status, or floristic composition.

The moderate similarity observed with three selected church forests (Assela Teklehaymanot, Etisa Teklehaymanot, and Saramba Kidanemhret) (25%) [31] and the Wejig-Mahgo-Waren massif forest (24%) [27] could reflect differences in forest size, isolation, or human influence, which may contribute to distinct levels of species richness and composition. Church forests, often serving as refuges for biodiversity in fragmented landscapes, may contain unique or locally adapted species, which partially overlap with the study forest.

Conversely, the much lower similarity with the Bale Mountain Forest (7%) [28] and Sirso Natural Forest (14%) [26] indicates significant differences in species composition. These differences could stem from variations in altitude, climate, or forest management practices. The Bale Mountains, for instance, are characterized by their high-altitude environment, which supports unique and often endemic species that are less likely to overlap with lowland or mid-altitude forests.

Overall, the findings underscore the influence of ecological, geographical, and anthropogenic factors on the distribution of medicinal plant species in Ethiopian forests. They also suggest the importance of localized conservation strategies to preserve the unique plant biodiversity of each forest type.

Comparison with previous studies

As highlighted in the comparative results discussed earlier, even within a single geographic region, distinct ethnic groups have influenced by their unique cultural traditions; developed specialized knowledge regarding the use of plants [111]. Similarities in plants utilization including medicinal plant species by various ethnolinguistic groups within a given region can be attributed to several factors. One primary factor is the interaction of cultural knowledge among these groups, leading to the shared adoption of certain plants for certain purposes. Additionally, the geographic distribution and availability of these plant species within the investigated areas also play a significant role in their widespread use [112].

Most importantly, the significant association between plant species and region suggests that the distribution of reports across regions is not random. This might be due to factors such as regional preferences, environmental conditions, or the availability of certain plant species in specific regions. The significant difference in the number of reports between regions suggests that certain regions may be more actively reporting on specific plants. This could be due to factors such as population density, regional interest in biodiversity, or differences in regional policies related to plant conservation. Understanding the patterns in the number of reports by region can provide insights for biodiversity management strategies. For example, regions with fewer reports might benefit from more targeted outreach and awareness programs about the importance of monitoring and reporting on local plant species. The significant variability in Reports for Amhara and Oromia could indicate differing factors influencing the number of reports in these regions, such as population size, infrastructure, or other sociopolitical factors. The low median values for BGR, SNNPR, and Tigray including other regions suggest a need to investigate why these regions have fewer reports. It could be due to underreporting, differences in regional characteristics, or other external factors.

Threats to indigenous forest management and conservation practices

In spite of the forest contributions for sustainable rural livelihoods, TEK and practices related to forest ecosystems are facing a global decline [1]. Human population growth and its associated pressures have led to significant deforestation and increased demand for agricultural land and wood products [12]. Thus, it is unsurprising that agricultural practices are the primary driver of habitat loss, vegetation degradation, and species decline including useful plants [21, 25, 113]. Consistent with these findings, previous vegetation studies have identified agricultural expansion, grazing, and cutting as significant human-induced factors contributing to the alteration of plant composition and diversity within the current forest [21] (Fig. 9). Trampling can also have negative impacts on natural environments, leading to the destruction of vegetation and the degradation of plant communities [114] by inhibiting seedling growth.

Community participation in forest conservation is essential for sustainable resource management [11]. Local communities in this study employ various strategies to ensure the sustainable use of forest resources. Finally, the study suggested that various types of usage, harvesting methods, and parts of the plant being harvested all play a role in the forest conservation efforts.

Conclusion and Recommendations

This study was based entirely on the useful plants of Wof Ayzurish Forest and its environs. We recorded 90 useful plant species and classified into ten use categories. The medicinal use category was the most represented (55 taxa) followed by fire wood (44 taxa), fencing (40 taxa), and material use (37 taxa). The more versatile plants are generally more familiar to people than those with only one purpose and are often under high pressure because of over utilize. However, this does not mean that plants with low indices are always less interesting. Depending on CI index, Olea europaea subsp. cuspidata is the most important plant followed by Juniperus procera. Detail comparison was conducted on 15 culturally important plant species with previously documented studies, taking into account their diverse applications. According to this, the number of reports differs significantly across regions, indicating regional differences in how plant species are reported. These findings highlight the importance of considering regional factors in biodiversity management and conservation strategies. Policymakers might focus on addressing the factors driving the high variability in some regions and also look into the potentially low engagement or underreporting of others regions. Thus, this information can aid in establishing sustainable use of Wof Ayzurish Forest without depletion of resources, by informing community-based conservation strategies that incorporate ethnobotanical knowledge. Human activities, including cutting, agricultural expansion, and grazing, pose significant threats to the survival of the forest. To address these challenges, we recommend integrating wild plants into home gardens, farmlands, and the forest periphery as a conservation strategy. This practices aims to conserve these resources while diversifying household incomes and improving subsistence needs. Therefore, we can conclude that as gardeners who protect the forest and as the owners of farming land and home gardens, communities cannot exploit the forests aggressively.

Appendix

See Table 8

Table 8 List of useful plants in Wof Ayzurish Forest and their detail uses