Introduction: Climate change will either improve, reduce, or shift its appropriate climatic habitat of a particular species, which could result in shifts from its geographical range. Predicting the potential distribution through MaxEnt modeling has been developed as an appropriate tool for assessing habitat distribution and resource conservation to protect bamboo species. Methods: Our objective is to model the current and future distribution of Oxytenanthera abyssinica (A. Richard) based on three representative concentration pathways (RCP) (RCP2.6, RCP4.5, and RCP8.5) for 2050s and 2070s using a maximum entropy model (MaxEnt) in Northern Ethiopia. For modeling procedure, 77 occurrence records and 11 variables were retained to simulate the current and future distributions of Oxytenanthera abyssinica in Northern Ethiopia. To evaluate the performance of the model, the area under the receiver operating characteristic (ROC) curve (AUC) was used. Results: All of the AUCs (area under curves) were greater than 0.900, thereby placing these models in the "excellent" category. The jackknife test also showed that precipitation of the coldest quarter (Bio19) and precipitation of the warmest quarter (Bio18) contributed 66.8% and 54.7% to the model. From the area of current distribution, 1367.51 km 2 (2.52%), 7226.28 km 2 (13.29%), and 5377.26 km 2 (9.89%) of the study area were recognized as high, good, and moderate potential habitats of Oxytenanthera abyssinica in Northern Ethiopia, and the high potential area was mainly concentrated in Tanqua Abergele (0.70%), Kola Temben (0.65%), Tselemti (0.60%), and Tsegede (0.31%). Kafta Humera was also the largest good potential area, which accounts for 2.75%. Compared to the current distribution, the total area of the high potential regions and good potential regions for Oxytenanthera abyssinica under the three RCPs (RCP2.6, RCP4.5, and RCP8.5) would increase in the 2050s and 2070s. However, the total area of the least potential regions under the three RCPs (RCP2.6, RCP4.5, and RCP8.5) in 2050s and 2070s would decrease. Conclusion: This study can provide vital information for the protection, management, and sustainable use of Oxytenanthera abyssinica, the resource to address the global climate challenges.

Nowadays, the conservation of biodiversity is a major environmental challenge globally. Homegarden agroforestry systems (HGAFs) have a large potential for biodiversity conservation. However, little attention has been given to the relative importance of HGAFs in terms of biodiversity conservation. The present study, therefore, aimed to estimate and compare the woody species diversity and structure of HGAFs and adjacent natural forest (NF) in Northern Ethiopia. Three sites were purposively selected based on the presence of HGAFs and NF adjacent to each other. A stratified sampling system was used to select representative homegardens from different wealth categories. In NF, a systematic transect sampling technique was employed. A total of 90 sample plots (10 m  20 m) were used to collect vegetation data. A total of 32 species representing 26 genera and 20 families were identified from the studied HGAFs and NF. Thirty woody species belonging to 24 genera and 20 families were recorded in the HGAFs whereas, 11 species, belonging to 9 genera and 8 families were recorded in the NF. Native woody species accounted for 66% of all woody species recorded in both HGAFs and NF. Stem density, richness, and diversities of woody species were significantly higher in HGAFs than in NF (p 0.05). Trees and shrubs in the HGAFs had significantly lower stem diameters, height, and basal area than the adjacent NF (p 0.05). The results show that HGAFs complements the NF for biodiversity conservation and supports in counteracting the loss of woody species from the natural ecosystem. Hence, promoting HGAFs habitats in human-dominated landscapes should be part of the biodiversity conservation strategy.

Introduction: Dispersed trees such as Oxytenanthera abyssinica (A. Rich.) and Dalbergia melanoxylon (Guill. & Perr.) which are objectively maintained or planted on farmland provide a significant contribution to soil fertility improvement. However, there was no quantitative information on the level of soil nutrient additions of these trees to the soil system. Methods: This study was conducted on the farmers' fields in Kafta Humera district, Tigray region (northern Ethiopia), where mature stands of O. abyssinica and D. melanoxylon trees exist. Radial distance-based soil sampling (under the canopy, near to canopy, and far from canopy) was adopted to quantify the role of these trees on soil fertility improvement. Soil parameters tested were soil reaction (pH), total nitrogen (TN), available phosphorus (AvP), electrical conductivity (EC), cation exchange capacity (CEC), and organic carbon (OC). Results: There was a negative linear relationship between the radial distance of the O. abyssinica tree trunk and soil TN, OC, CEC, and AvP contents but not for pH. Similarly, negative linear relationship between distance from D. melanoxylon and TN, OC, and AvP was obtained. The average total nitrogen (0.26% and 0.13%), available phosphorus (7.21 ppm and 6.37 ppm), and organic carbon (1.73% and 1.02%) contents were respectively higher under the tree canopies of O. abyssinica and D. melanoxylon compared with the adjacent open canopies. The amount of soil OC, TN, AvP, and CEC under O. abyssinica tree species was also significantly higher by 69%, 100%, 13%, and 42% compared to that of D. melanoxylon tree species. However, the amount of EC and soil pH was significantly lower by 57% and 19%, respectively. Conclusion: In general, O. abyssinica and D. melanoxylon added a significant amount of nutrients to the soil. Thus, retaining these important tree species on farmland played a positive role in replenishing soil fertility for resource-constrained households so as to reduce chemical fertilizer amendments.

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In the varying climate and weather environments and fast-growing population, the production of feed that could meet the demand of this ever-growing population will be challenging with limited land, soil, and water resources. In many developing countries, terraces have been constructed in sloppy, hilly and valley areas to rectify their shortage of cultivated land and severe water erosion problems to meet livelihood demands. In the southern zone of Tigray region, various labor-intensive bench terraces (BTs) have been constructed and are on the way of construction. Despite its coverage and labor intensiveness, these terraces are facing problems such as malfunctioning and collapse of structures leading to unsustainability, unproductiveness and additional labor and material costs. Thus, this study was designed to identify the basis of the above-mentioned problems and to put real solutions for the problems. A multi-disciplinary evaluation of BTs from natural resources and socioeconomic researchers was conducted to identify observational gaps in the stability and sustainability of the terraces and to put ways forward. Technical assessment and measurement of BTs were conducted onsite to evaluate and compare the specification with the recommended specification. Inappropriate site selection, water scarcity, free-grazing and neglected maintenance, poor buffer zone, and stone placement were directly or indirectly major reasons for the failure of bench terrace (BT) structures. Most of the BTs were not supported with biological soil and water conservation materials. Site selection and technical standards of BTs should be done based on recommended specifications with continuous follow-up.