Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia: Diversity, structure and spatial distribution

ISSN: 2224-0616 Int. J. Agril. Res. Innov. Tech. 13(2): 6-13, Dec 2023 DOI: https://doi.org/10.3329/ijarit.v13i2.70848 Available online at https://ijarit.online https://www.banglajol.info/index.php/IJARIT Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia: Diversity, structure and spatial distribution Nesibu Yahya1, Abdu Abdelkadir3* , Busha Teshome2, Mister Abebe2 and Habtemariam Kassa3 Received 15 July 2023, Revised 15 November 2023, Accepted 25 December 2023, Published online 31 December 2023 ABSTRACT Despite their ecological and socio-economic contributions, the lowland dry forests of Ethiopia have largely been neglected and hence experience severe deforestation and degradation challenges. It is, therefore, crucial to assess the status of the dry forest resources to formulate appropriate management strategies that facilitate their sustainable utilization. This study was undertaken to determine spatial distribution, species composition, structure, and regeneration of gum and resin-producing species in the dry forests of the Somali Regional State of Ethiopia. The recent Sentinel-2A image was procured and used to classify the area, using a supervised Random Forest Algorithm, into different land covers and vegetation types. Inside the two key vegetation types (Acacia dominated woodland and Mixed woodland), forest inventory was conducted by establishing 30 m x 30 m size quadratic sample plots. The results revealed that the study area was divided into settlement (0.2%), bare land (6.0%), undifferentiated forest (0.5%), acacia woodland (36.3%), mixed woodland (54.1%) and scrubland (2.9%). Thirty-four woody species were identified and recorded with a Shannon diversity of 3.03. The population structure showed a lack of sufficient natural regeneration. This shows that the forest containing the gum and resinbearing species is not replacing itself as well as it should. On the other hand, if managed properly, the forest has the potential to produce various types of oleo-gum resins. Thus, implementing appropriate restoration measures is urgent to enhance natural regeneration. Moreover, formulating sustainable utilization while creating a product market of gum and resins are important consideration to ensure the conservation and sustainable use of dry forests in the region. Keywords: Somali, Horn of Africa, Gum and Resin 1 WeForest Ethiopia, Addis Ababa, Ethiopia 2 Ethiopian Forestry Development, Addis Ababa, Ethiopia Center for International Forestry Research (CIFOR), Addis Ababa, Ethiopia *Corresponding author’s email: aabdelkadir@yahoo.com (Abdu Abdelkadir) 3 Cite this article as: Yahya, N., Abdelkadir, A., Teshome, B., Abebe, M. and Kassa, H. 2023. Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia: Diversity, structure and spatial distribution. Int. J. Agril. Res. Innov. Tech. 13(2): 6-13. https://doi.org/10.3329/ijarit.v13i2.70848 Introduction Dry forests in the tropics are important forest biomes that support the livelihood of millions of people around the globe (Djoudi et al., 2015). In addition, it provides multiple ecosystem services (Cortés-Calderón et al., 2021). The dry forest covers about 42% of tropical and subtropical forests (Hasnat and Hossain, 2019). Compared with other biomes, it is much more prone to loss of biodiversity and habitat fragmentation due to the high rate of deforestation and forest degradation (Maass, 2010; Rivas et al., 2020). While it comprises extensive distribution, it receives less research attention as compared to the moist tropical forests (Sunderland et al., 2015). The Combreterm – Terminalia and the Acacia Commiphora are the two widely distributed forest ecosystems in the dry lowlands of Ethiopia. The resources are significant in biodiversity as they are endowed with numerous endemic plants and animals (Bareke, 2018). The woodland is also a source of various gum and resin products such as frankincense, myrrh, opopanax, and gum. It plays an important role economically, from enhancing household income (Berhanu et al., 2021; Walle and Nayak, 2021; Worku et al., 2014) to improving the GDP of the country (Mekonnen et al., 2013). Somali Regional State of Ethiopia is one of the regional states in Ethiopia where dry forests are the dominant vegetation types. El – Weyni district of Somali, region is known to have much of its areas covered with dry forests comprising large number of gum and resin-bearing species. However, this economically important resource has not properly managed and effectively utilized due to lack of adequate information on biodiversity aspects as well as on the distribution International Journal of Agricultural Research Innovation & Technology An open access article under Yahya et al. (2023) Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia and production potential of gums and resin producing species and under development of markets. Hence, evidence-based planning and implementation of sustainable utilization is constrained by lack of adequate information. Forest inventory, which can reveal the existing diversity and structure of the forest, is an important phase in forest management. Understanding the regeneration status of woody species in general, and gum and resin-bearing species in particular, is fundamental in formulating appropriate policy and strategy both at a national and regional level. In addition, knowledge and information in these areas are crucial for the sustainable utilization of the resources. Previous studies on gum and resin-bearing dry forests in Ethiopia have emphasized on the western and northwestern dry lowlands, providing critical information on their proper utilization and ecological sustainability (Addisalem et al., 2016; Bekele, 2016; Mokria et al., 2017; Yilma et al., 2016), and socio-economic aspects (Eshete et al., 2005; Tilahun et al., 2015). On the other hand, there is scarce information on the forest resources of the Somali region of the southeastern lowlands. Limited work has been conducted in Somali Region on the current forest composition structure and the spatial distribution of the dry woodlands in general and gum and resin-bearing species in particular. The objective of this study was, therefore, to fill in the gap of information and determine the species composition, structure, and regeneration of gum and resin species. At the same time, it quantifies the spatial distribution of gum and resin-bearing species in the El-Weyni district of the Somali Regional State of Ethiopia. Materials and Methods The study area The study was conducted in the El-Weyni district in the Somali Regional State of Ethiopia. It is located between 42° 45' to 43° 25' East and 6° 20' to 6° 45' north. El–Weyni was selected for the study because its resource endowment in terms of gum and resin bearing species in the region. The total area of the district is estimated at 242,030 hectares. The altitude ranges from 331 to 1035 m.a.s.l through an average value of 482 m.a.sl. The landform of the study area is mainly characterized by a smooth plain with some rugged topography in the northeastern section of the district. The climatic condition of the district is described as dryland affected by recurrent drought. The site has an annual average precipitation of 200 mm, and the mean maximum and minimum temperature is 28°C and 40°C, respectively (Hussein et al., 2021). The vegetation types of the study area are the dry woodland ecosystem types of AcaciaCommiphora woodland and scrubland (Friis et al., 2010). In this ecosystem, gum and resinbearing tree species are widely distributed. The woodland usually coexists with grasslands and pastureland. The pastoral system is the common livelihood means of the community in the area. Figure 1. Location map of the study area and forest inventory plots. Vegetation data collection and analysis A reconnaissance survey was conducted before undertaking the forest inventory. A systematic random sampling technique was employed to lay sampling plots. Thirty quadratic plots of 30 x 30 meters were established to record the seedlings, saplings, and adults of all woody species. For the adult, the diameter at breast height (DBH) and height were measured using standard diameter tape and a True-pulse height meter, respectively. The total number of seedlings and saplings was counted and recorded within each plot. Environmental data such as location (latitude and longitude), altitude, slope and aspect were recorded from the center of each sample plot. For the present study, different growth stages were Int. J. Agril. Res. Innov. Tech. 13(2): 6-13, December 2023 7 Yahya et al. (2023) Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia pre-defined as an adult (height greater than 1.5 meters), sapling (height between 0.5 and 1.5 meters), and seedling (height less than 0.5 meters). In order to describe the woody species diversity, the Shannon-Wiener Diversity Index (H) and Evenness (E) were employed using the following equations: 𝑠 𝐻 = − ∑ 𝑝𝑖 ln 𝑝𝑖 𝑖=1 Where: H = Shannon–Wiener diversity index and Pi = the proportion of individuals found in the i th species. 𝐻 𝐻 = 𝐸= ln 𝑆 ′ 𝐻𝑚𝑎𝑥 Where: E = Evenness, Hmax= the maximum level of diversity possible within a given population, which equals ln (number of species). The absolute density (number of stems per hectare), frequency (number of plots with a species presence) and dominance (basal area of a species in m2 per hectare) were calculated for all woody species in the study area using the standard methods. Then, relative density, relative frequency, and relative dominance were calculated using the following equations: 𝑅𝑒𝑙𝑎𝑡𝑖𝑣𝑒 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 (𝑅𝐷) 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑖𝑛𝑑𝑖𝑣𝑖𝑑𝑢𝑎𝑙𝑠 𝑜𝑓 𝑠𝑝𝑒𝑐𝑖𝑒𝑠 = 𝑥 100 𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑖𝑛𝑑𝑖𝑣𝑖𝑑𝑢𝑎𝑙𝑠 𝑅𝑒𝑙𝑎𝑡𝑖𝑣𝑒 𝑓𝑟𝑒𝑞𝑢𝑎𝑛𝑐𝑦 (𝑅𝐹) 𝐹𝑟𝑒𝑞𝑢𝑎𝑛𝑐𝑦 𝑜𝑓 𝑎 𝑠𝑝𝑒𝑐𝑖𝑒𝑠 𝑥 100 = 𝐹𝑟𝑒𝑞𝑢𝑎𝑛𝑐𝑦 𝑜𝑓 𝑎𝑙𝑙 𝑠𝑝𝑒𝑐𝑖𝑒𝑠 𝑅𝑒𝑙𝑎𝑡𝑖𝑣𝑒 𝑑𝑜𝑚𝑖𝑛𝑎𝑛𝑐𝑒 (𝑅𝐷𝑂) 𝐷𝑜𝑚𝑖𝑛𝑎𝑛𝑐𝑒 𝑜𝑓 𝑎 𝑠𝑝𝑒𝑐𝑖𝑒𝑠 𝑥 100 = 𝐷𝑜𝑚𝑖𝑛𝑎𝑛𝑐𝑒 𝑜𝑓 𝑎𝑙𝑙 𝑠𝑝𝑒𝑐𝑖𝑒𝑠 𝑰𝒎𝒑𝒐𝒓𝒕𝒂𝒏𝒕 𝒗𝒂𝒍𝒖𝒆 𝒊𝒏𝒅𝒆𝒙 = 𝑹𝑫 + 𝑹𝑭 + 𝑹𝑫𝑶 With the purpose of understanding the community and population structure, a population frequency diagram was generated based on different diameter sizes. The vegetation analysis was conducted on the R software program using the “vegan” and the “BiodiversityR” packages (Dixon, 2003; Kindt, 2018; Team, 2021). Spatial data collection and analysis Several spatial databases were collected to quantify the current distribution of different forest communities in the study area. The freely available Sentinel 2A satellite images with 10 meter spatial resolution was downloaded. A better cloud-free image was selected from the available list of images. Two tiles (T38 NKN and T38 NLN) encompassed the entire study area. The selected satellite image was acquired in the late dry season (January – February 2022) to allow for clear separation of the different vegetation types. Only the spectral bands of the satellite images (Sentinel L2A) covering the Blue (Band - 2), Green (Band - 3), Red (Band - 4) and Near Infrared (Band - 8) were selected for the study. Table 1. Description of different types of land cover classes. No. 1 land cover classes Bare land 2 Settlement 3 Acacia dominated woodland Commiphora dominated woodland Scrubland 4 5 6 Undifferentiated forest Description Areas with no vegetation cover consisting of exposed soil and/or bedrock Land covered by residences, road networks, buildings and small industrial areas in both rural and urban areas. Land covered by Acacia-Commiphora woodland but Acacia is a dominant species than Boswellia and Commiphora Land covered by Acacia-Commiphora woodland but Boswellia and Commiphora species are dominant than Acacia species Land covered by small trees, shrubs and herbs, which may be succulent, geophytic or annual. Areas that were inaccessible for the team to differentiate physically and hence categorized as undifferentiated forest The images were geometrically and radiometrically (i.e., top of the atmosphere) corrected. Image pre-processing techniques such as subsetting, layer stacking and image enhancement were conducted for the downloaded images. The Random Forest algorithm of the supervised classification technique was implemented to classify the image into the aforementioned classes (Table 1). The spatial analysis was conducted on R software and ArcGIS software programs. Results and Discussion Woody species distribution, diversity and composition The vegetation distribution map of the study area (Figure 2) shows that the Acacia woodland (36.3%) and mixed woodland (54.1%) are the two dominant vegetation types. The proportion of the other land cover categories was bare land (5.9%), (14416.9 ha), scrubland (2.9%) (7193.7 ha), (2.9%), undifferentiated forest (0.5%) (1165.1 ha) and settlement (0.2%) (510.2 ha). The undifferentiated forest was found in remote and inaccessible areas where the altitude is relatively higher. This result gives clues to the need to reassess of the previously reported national spatial coverage of Gum arabic (399,700 ha) and Gum Commiphora (171,300 ha) (Fitwi, 2000). Int. J. Agril. Res. Innov. Tech. 13(2): 6-13, December 2023 8 Yahya et al. (2023) Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia Figure 2. Spatial distribution map of vegetation types of the study area. Table 2. The area coverage and density of predominant woody species in the study area. No. Land cover types Area (ha) 1 2 3 4 5 Settlement Undifferentiated forest Scrubland Bare land Acacia dominated woodland (n = 15) 510.24 1165.11 7193.71 14416.89 87864.94 Proportion (%) 0.21 0.48 2.97 5.96 36.30 6 Mixed woodland (n = 15) 130879.46 54.08 Total 242,030.35 100.00 A total of 34 woody species were recorded from the study area of which Acacia, Boswellia, and Commiphora are the three genera producing gums and resins. The mean pooled diversity of the study area is 3.03 and 0.93 for the Shannon and Simpson diversity indices, respectively (Table 3). Acacia senegal, Commiphora Botanical name Acacia senegal Commlphora gowlello Commiphora myrrha Commiphora truncata Commiphora erythraea Boswellia neglecta Boswellia rivae Boswellia neglecta Commlphora gowlello Acacia senegal Commiphora truncata Commipbora hodai Commiphora erythraea Commipbora samharensis Density of dominant tree species (stem/ha) 49.6 13.3 12.6 6.7 5.9 5.2 5.2 18.5 14.8 13.3 13.3 11.9 11.1 10.4 erythraea, Commlphora gowlello, Acacia asak and Commiphora myrrha, are the five most frequently found species in the study area. The most dominant gum and resin bearing species in the study area include Commiphora guidotii, Commiphora erythraea, Commiphora myrrha, Boswellia rivae and Acacia senegal. Table 3. Woody species diversity of the study. Diversity indices Richness Shannon diversity Simpson diversity Evenness The spatial distribution, together with composition and density of the gum and resin species (Table 3) indicate that there is a huge potential in the study area to produce several types of oleo-gum resins such as gum arabic from Pooled values 34.00 3.03 0.93 0.61 A. senegal, frankincense from B. neglecta and B. rivae, myrrh from C. myrrha and C. truncate, opopanax from C. guidotii, Hager from C. africana. Int. J. Agril. Res. Innov. Tech. 13(2): 6-13, December 2023 9 Yahya et al. (2023) Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia Table 4. Estimated gum and resin production potential of the study area. Product name Gum arabic Myrrh Frankincense Density (stems/ha) Acacia woodland 49.6 34.1 10.4 Mean production kg/tree/yr* Mixed woodland 13.3 48.9 24.4 2.0630a 0.5000b 0.2610c Estimated production gum/resins in kg/ha/yr Acacia Mixed woodland woodland 102.32 27.44 17.05 24.45 2.71 6.37 a: (Zeleke et al., 2021); b: (Lemeneh and Kassa., 2011); c: (Eshete et al., 2012) The estimated production (Table 4) shows variation between the two types of vegetation. In the Acacia woodland, higher production potential of gum Arabic is expected as compared to the mixed woodland. Myrrh and frankincense are expected to be produced more from the mixed woodland vegetation type. Thus, the resource potential of the study area is huge and is an indication of the need for a better utilization of the resource. With this estimation, the study area has an area-wise extrapolated total production potential of 18351.5 tons (58.5% from Acacia woodland and 41.5% from mixed woodland). Indeed, actual production may vary from the potential by several factors such as species, growth stage, weather conditions, implemented harvesting techniques and tools and many other related factors. The results are also consistent with a study that claims the underutilization of gum and resin resources in Ethiopia (Tadesse et al., 2007). It should be noted that these products are internationally demanded commodities for various applications such as food, beverages, pharmacology, adhesives and cosmetics industries and can be sources of much needed hard currencies (Başer et al., 2003; Lemenih and Teketay, 2005; Sambawa et al., 2016; Hamad et al., 2017; Efferth and Oesch, 2022). Structure and regeneration status The diameter class distribution of the entire community showed “reverse J-shaped” which is regarded as a higher density of individuals found at the lower diameter classes and gradually decreasing their density with increasing diameter class (Figure 3). The first diameter class (< 5 cm DBH) shows a slight decrease that indicates insufficient regeneration of woody species at the community level. The regeneration status also indicates a “J-shape” which shows the unhealthy status of the regeneration of woody species (Figure 3). Figure 3. Diameter class distribution (diameter class in cm: class 1.5 ≤ 5 cm, 2 =5 – 10 cm, 3 = 10 – 15 cm, 4 = 15 – 20 cm, 5 = 20 – 25 cm, 6 ≥ 25 cm) of adults (A) and density of regenerates and adults of woody species (B) in the entire community. The population structure of some of the species (most of them are gum and resin-bearing species) shows an irregular pattern and is bell-shaped (Figure 4). The bell-shaped pattern is described by the larger density of individuals in the middle diameter class (DBH = 5-20 cm). Except for Acacia asak, the population structure of the dominant and/or abundant woody species lacks the density of individuals at the lower diameter class (particularly in the first and second classes), which strongly suggests the problem of regeneration and recruitment. This pattern is consistent with previous studies in the lowland dry forest of Ethiopia (Adem et al., 2014; Hido et al., 2020). Int. J. Agril. Res. Innov. Tech. 13(2): 6-13, December 2023 10 Yahya et al. (2023) Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia Figure 4. Diameter class distribution (diameter class in cm: class 1.5 < 5 cm, 2 =5 – 10 cm, 3 = 10 – 15 cm, 4 = 15 – 20 cm, 5 = 20 – 25 cm, 6 ≥ 25 cm) of dominant and/or abundant species. The results also showed that the vegetation resources of the study area are relatively less affected by urbanization and agricultural expansion, unlike the western and Northwestern lowland forests of Ethiopia. Moreover, it was observed that there was relatively less charcoal production and marketing in the study area. However, the vegetation might be affected by over-grazing activities since the livelihood of the community depends primarily on livestock production. The free grazing practice in the dry forests of Ethiopia’s lowlands has been reported as a major factor that hampers the natural regeneration of gum and resin species (Lemeneh and Kassa, 2011). Climate variability and frequent drought could also be another factor for the loss of regeneration of the woody plants in general and gum and resin-bearing species in particular. The findings of the study highlight the potential contribution of dry forests to support livelihoods of local communities and to halt the decline of biodiversity, which are the two most challenging global sustainability issues (Wei et al., 2018). However, little attention is given to research and development of dry forests in the lowlands of Ethiopia as compared to the montane forest. For Int. J. Agril. Res. Innov. Tech. 13(2): 6-13, December 2023 11 Yahya et al. (2023) Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia instance, the quasi absence of nurseries that propagate and raise lowland tree species is one of the justifications to substantiate the low level of attention being paid to the lowland dry forests. Moreover, the soil is highly susceptible to erosion and degradation and hence forest restoration is crucial and cost-effective (Crouzeilles et al., 2020). With a slight reduction in human pressures, the restoration of such areas may require little effort to achieve results that are more significant before the degradation reaches the stage of no return. Finally, it is suggested that research and development in these ecologically and economically useful lowland dry forests would be very helpful to effectively restore the landscapes by selecting appropriate restoration techniques and available propagation mechanisms. Implementing appropriate restoration is urgent to enhance and aid natural regeneration while formulating sustainable utilization and marketing of gum and resin species, which would be crucial to the well-being of the surrounding community and the country at large. Acknowledgements The authors sincerely thank the Ethiopian Forestry Development, SIDA and UNDP as the costs of the study were covered by a Catalyzing Forest Sector Development Project of Ethiopian Forestry Development, funded by the Swedish International Development Agency (SIDA) and UNDP. The authors are also grateful to experts at Regional and district levels, as well as to community members who were involved in the data collection process. The Kebele, district, zonal, and regional administrative bodies were highly acknowledged for their permission and support of the research. Our thanks also go to community members who shared their time and kindly agreed to respond to the questions of the research team. The authors also thank field assistants and drivers for their support. References Addisalem, A.B., Bongers, F., Kassahun, T. and Smulders, M.J.M. 2016. Genetic diversity and differentiation of the frankincense tree (Boswellia papyrifera (Del.) Hochst) across Ethiopia and implications for its conservation. Forest Ecol. Manage. 360: 253-260. https://doi.org/10.1016/j.foreco.2015.10.038 Adem, M., Worku, A., Lemenih, M., Tadesse, W. and Pretzsch, J. 2014. Diversity, regeneration status and population structure of gum- and resin-bearing woody species in south Omo zone, southern Ethiopia. J. Forest. Res. 25: 319-328. https://doi.org/10.1007/s11676-014-0461-2 Bareke, T. 2018. Lowland semi–evergreen forest of Ethiopia. Forest. Res. Engin. Int. J. 2(5): 244-248. https://doi.org/10.15406/freij.2018.02.00057 Başer, K.H.C., Demirci, B., Dekebo, A. and Dagne, E. 2003. Essential oils of some Boswellia spp., myrrh and opopanax. Flavour Fragr. J. 18(2): 153-156. https://doi.org/10.1002/ffj.1166 Bekele, A.A. 2016. Conservation genetics of the frankincense tree. PhD thesis, Wageningen University, Wageningen, The Netherland. https://edepot.wur.nl/382024. Berhanu, Y., Vedeld, P., Angassa, A. and Aune, J.B. 2021. The contribution of frankincense to the agro-pastoral household economy and its potential for commercialization - A case from Borana, southern Ethiopia. J. Arid Environ. 186: 104423. https://doi.org/10.1016/J.JARIDENV.2020.104423 Cortés-Calderón, S., Mora, F., Arreola-Villa, F. and Balvanera, P. 2021. Ecosystem services supply and interactions along secondary tropical dry forests succession. Forest Ecol. Manage. 482: 118858. https://doi.org/10.1016/j.foreco.2020.118858 Crouzeilles, R., Beyer, H.L., Monteiro, L.M., Feltran-Barbieri, R., Pessôa, A.C.M., Barros, F.S.M., Lindenmayer, D.B., Lino, E.D.S.M., Grelle, C.E.V., Chazdon, R.L., Matsumoto, M., Rosa, M., Latawiec, A.E. and Strassburg, B.B.N. 2020. Achieving cost-effective landscape-scale forest restoration through targeted natural regeneration. Conserv. Lett. 13(3): e12709. https://doi.org/10.1111/conl.12709 Dixon, P. 2003. VEGAN, a package of R functions for community ecology. J. Vege. Sci. 14(6): 927-930. https://doi.org/10.1111/j.1654- 1103.2003.tb02228.x Djoudi, H., Vergles, E., Blackie, R.R., Koame, C.K. and Gautier, D. 2015. Dry forests, livelihoods and poverty alleviation: understanding current trends. Int. Forest. Rev. 17(2): 54-69. https://doi.org/10.1505/146554815815834868 Efferth, T. and Oesch, F. 2022. Antiinflammatory and anti-cancer activities of frankincense: Targets, treatments and toxicities. Seminar Cancer Biol. 80: 39-57. https://doi.org/10.1016/j.semcancer.2020.01.015 Eshete, A., Sterck, F.J. and Bongers, F. 2012. Frankincense production is determined by tree size and tapping frequency and intensity. For. Ecol. Manage. 274: 136-142. https://doi.org/10.1016/j.foreco.2012.02.024 Eshete, A., Teketay, D. and Hulten, H. 2005. The socio-economic importance and status of populations of Boswellia papyrifera (Del.) Hochst. in Northern Ethiopia: The case of north gonder zone. Forests Trees Livelihoods. 15(1): 55-74. https://doi.org/10.1080/14728028.2005.9752507 Fitwi, G. 2000. The status of gum arabic and resins in Ethiopia. In: B.N. Chikamai, S. S. Mbiru, E. Casadei (Eds.), Report of the Meeting of the Network of Natural Gums and Resins in Africa (NGARA). Kenya College of Communications Technology, Nairobi, Kenya. pp. 29–31. Friis, I., Demissew, S. and Breugel, P. van. 2010. Atlas of the potential vegetation of Ethiopia. Copenhagen: The Royal Danish Academy of Sciences and Letters in Biologiske Skrifter 58. 307p. https://doi.org/10.1017/S0960428611000448 Hamad, G.M., Taha, T.H., Alshehri, A. and ElDeeb, N.M. 2017. Myrrh as a functional food with therapeutic properties against colon cancer in traditional meals. J. Food Process Preserv. 41(1): e12963. https://doi.org/10.1111/jfpp.12963 Int. J. Agril. Res. Innov. Tech. 13(2): 6-13, December 2023 12 Yahya et al. (2023) Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia Hasnat, G.N.T. and Hossain, M.K. 2019. Global Overview of Tropical Dry Forests. pp. 1-23. (eds. Bhadouria et al.) In: Handbook of Research on the Conservation and Restoration of Tropical Dry Forests. IGI Global, Hershey, Pennsylvania. https://doi.org/10.4018/978-1-7998-00149.ch001 Hido, A., Tolera, M., Lemma, B. and Evangelista, P.H. 2020. Population status and resin quality of Frankincense Boswellia neglecta (Burseraceae) growing in South Omo, Southwestern Ethiopia. J. Sustain. Forest. 39(6): 620-634. https://doi.org/10.1080/10549811.2020.1721302 Hussein, B.A., Tsegaye, A.A. and Abdulahi, A. 2021. Assessment of the environmental and health impacts of disposal plastics in Gode town, Somali regional state, Eastern Ethiopia. J. Material. Environ. Sci. 12(3): 455-471. Kindt, R. 2018. Package ‘BiodiversityR’. Package for community ecology and suitability analysis. Version 1.10-1. Lemenih, M. and Teketay, D. 2005. Frankincense and myrrh resources of Ethiopia: II. Medicinal and industrial uses. SINET: Ethiopian J. Sci. 26(2): 161-172. https://doi.org/10.4314/sinet.v26i2.18213 Lemeneh, A. and Kassa, H. (eds). 2011. Opportunities and challenges for sustainable production and marketing of gums and resins in Ethiopia: In Opportunities and challenges for sustainable production and marketing of gums and resins in Ethiopia. Center for International Forestry Research (CIFOR). 106p. https://doi.org/10.17528/cifor/003478 Maass, J.M. 2010. Conversion of tropical dry forest to pasture and agriculture. pp. 399 – 422. In: Bullock et al. Seasonally Dry Tropical Forests, Cambridge University Press, London, United Kingdom. https://doi.org/10.1017/cbo9780511753398.017 Mekonnen, Z., Worku, A., Yohannes, T., Bahru, T., Mebratu, T. and Teketay, D. 2013. Economic contribution of gum and resin resources to household livelihoods in selected regions and the national economy of Ethiopia. Ethnobot. Res. Appl. 11: 273– 288. https://ethnobotanyjournal.org/index.php/ era/article/view/847 Mokria, M., Tolera, M., Sterck, F.J., Gebrekirstos, A., Bongers, F., Decuyper, M. and SassKlaassen, U. 2017. The frankincense tree Boswellianeglecta reveals high potential for restoration of woodlands in the Horn of Africa. Forest Ecol. Manage. 385: 16-24. https://doi.org/10.1016/j.foreco.2016.11.020 Rivas, C.A., Navarro-Cerillo, R.M., Johnston, J.C. and Guerrero-Casado, J. 2020. Dry forest is more threatened but less protected than evergreen forest in Ecuador’s coastal region. Environ. Conserv. 47(2): 79-83. https://doi.org/10.1017/S0376892920000077 Sambawa, Z.M., Alkahtani, F.H., Aleanizy, F.S. and Alqahtani, F.Y. 2016. Comparison of antibacterial efficacy chlorohexidine gluconate and Saudi Myrrh mouthwashes in the oral cavity. Oriental J. Chem. 32(5): 2605-2610. https://doi.org/10.13005/ojc/320532 Sunderland, T., Apgaua, D., Baldauf, C., Blackie, R., Colfer, C., Cunningham, A.B., Dexter, K., Djoudi, H., Gautier, D., Gumbo, D., Ickowitz, A., Kassa, H., Parthasarathy, N., Pennington, R.T., Paumgarten, F., Pulla, S., Sola, P., Tng, D., Waeber, P. and Wilm, L. 2015. Global dry forests: a prologue. Int. Forest. Rev. 17(2): 1-9. https://doi.org/10.1505/146554815815834813 Tadesse, W., Desalegn, G. and Alia, R. 2007. Natural Gum and Resin Bearing Species of Ethiopia and Their Potential Applications. Investigación Agraria: Sistemas y Recursos Forestales. 16: 211-221. http://doi.org/10.5424/srf/2007163-01010 Team, R.C. 2021. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna. https://www.R-project.org Tilahun, M., Vranken, L., Muys, B., Deckers, J., Gebregziabher, K., Gebrehiwot, K., Bauer, H. and Mathijs, E. 2015. Rural Households’ Demand for Frankincense Forest Conservation in Tigray, Ethiopia: A Contingent Valuation Analysis. Land Degrad. Dev. 26(7): 642-653. https://doi.org/10.1002/ldr.2207 Walle, Y. and Nayak, D. 2021. Analyzing Households’ Dependency on Non-timber Forest Products, Poverty Alleviation Potential, and Socioeconomic Drivers: Evidence from Metema and Quara Districts in the Dry Forests of Amhara Region, Ethiopia. J. Sustain. Forest. 41(8): 678-705. https://doi.org/10.1080/10549811.2020.1867185 Wei, F., Wang, S., Fu, B., Zhang, L., Fu, C. and Kanga, E.M. 2018. Balancing community livelihoods and biodiversity conservation of protected areas in East Africa. Curr. Opin. Environ. Sustain. 33: 26-33. https://doi.org/10.1016/j.cosust.2018.03.013 Worku, A., Pretzsch, J., Kassa, H. and Auch, E. 2014. The significance of dry forest income for livelihood resilience: The case of the pastoralists and agro-pastoralists in the drylands of southeastern Ethiopia. Forest. Policy Econ. 41: 51–59. https://doi.org/10.1016/J.FORPOL.2014.01.001 Yilma, Z., Worku, A., Mohammed, O., Girma, A., Dejene, T., Eshete, A., Teketay, D., Teshome, M. and Tadesse, W. 2016. Status of populations of gum and resin bearing and associated woody species in BenishangulGumuz National Regional State, western Ethiopia: Implications for their sustainable management. Forests Trees and Livelihoods. 25(1): 1-15. https://doi.org/10.1080/14728028.2015.10 67153 Zeleke, G., Dejene, T., Tadesse, W., Martín-Pinto, P., 2021. Gum arabic production and population status of Senegalia senegal (L.) britton in dryland forests in south omo zone, Ethiopia. Sustainability. 13(21): 11671. https://doi.org/10.3390/su132111671 Int. J. Agril. Res. Innov. Tech. 13(2): 6-13, December 2023 13