Fast coppicing plantations like Eucalyptus are becoming an ever increasingly important land use system globally, including the Eucalyptus hotspot highlands of Northwestern Ethiopia. However, comprehensive information regarding species composition is essential for proper planning and policy decisions. The current study mapped the spatial distribution of Eucalyptus globulus (hereafter referred to as Eucalyptus) and identified the key push factors for its expansion. The study used a mapping procedure that uses Landsat imagery together with ground truth data based on supervised training of a pixel-by-pixel classification algorithm within image regions to distinguish areas of Eucalyptus plantations from other classes. High-resolution multispectral and multi-temporal remote-sensing images were combined with ground truth data to produce robust features of Eucalyptus plantation distribution maps. Heckman's Two-Stage econometric model was also employed for determining the major driving factors of Eucalyptus expansion. The results of the mapping algorithm were Eucalyptus plantation distribution maps of 30 × 30 m resolution that showed temporal changes from 1999 to 2021. The findings revealed that Eucalyptus coverage increased by 55% during the period from 1999 to 2010 and the change expressively increased to 69% in 2021 with respect to the reference period. The study also found that a number of push factors influenced the size of land planted with Eucalyptus. The developed maps showing the spatial distribution and expansion of Eucalyptus will help policymakers properly manage the ecosystems and agricultural landscapes of Eucalyptus growing areas.

The northwestern highlands of Ethiopia are characterized by severe land degradation and apparently low agricultural productivity. This situation is continuously threatening the livelihoods of smallholder farmers who mainly sustain their living from the cultivation of annual crops. In recent years, however, smallholder farmers have started converting their croplands to plantations of Eucalyptus, a non-native tree species to Africa, for its rewarding economic contributions. In this study, we aggregated data from 388 smallholder Eucalyptus growers located in three agroecology zones (onwards called farm typologies). We measured the economic impact of Eucalyptus succession on croplands using a farm household model which is provided in the GAMS (General Algebraic Modeling System) platform. The results of the model varied between farm typologies and showed that households’ gross margins increased with a corresponding increase in the conversion of croplands. Results also showed that gross margins from plantations of Eucalyptus were higher than that of cultivation of food crops. Furthermore, evaluation of farm portfolios indicated a higher benefit-cost ratio (BCR) for the plantation of Eucalyptus. We concluded that the conversion of croplands in the study area is an incentive-driven process in a dynamic farming system, which strongly demands bringing policy-emanated livelihood alternatives. With this arena, the expansion of Eucalyptus is recommended for lands of terrain features, high marginality and low suitability for the cultivation of food crops and setting aside fertile arable lands. We generalized that an increase in Eucalyptus plantation pays off given the implementation of proper land resource management and the apparent impacts of Eucalyptus on biodiversity and cultural landscape is managed with sustainability perspectives. However, it demands collaborative policy efforts that can especially meet socioeconomic, environmental and public interests.

Eucalyptus wood products contribute significantly to the income of smallholder growers in many parts of Ethiopia. This has incentivized smallholders to convert arable lands to Eucalyptus plantation. Given the limited attention and availability of empirical evidence, this study examined the Eucalyptus wood products value chain in terms of the actors engaged, the type and importance of channels, margins analysis and the overall value chain governance in the main Eucalyptus growing areas of the Blue Nile highlands of Northwestern Ethiopia in 2019/2020. Sources of data were randomly selected 388 Eucalyptus grower households and 166 Eucalyptus wood traders, complemented by an interview with key informants, group discussions and direct observations. The results reveal that a total of 2,051,114.75 m³ of Eucalyptus wood was produced in the study area and Eucalyptus plantations are expanding over crop lands at a rate of 102.35 ha a year on average. Many actors involved handle a large volume of wood in eight main channels with a high disparity in the shares of the margins. We found that Eucalyptus is the main source of cash earning, contributing about 45.76% to the total annual income of smallholder growers. Little policy attention, a lack of sectoral integration, missing infrastructure and an absence of modern wood processing factories are among the key challenges impeding the performance of the wood sector value chain. There are however existing opportunities for the development of the wood sector value chain such as favorable growing conditions and the spectacular growing demand for wood products. The study provides valuable insights about the wood sector value chain and actions towards ensuring sustainable value chains and the commercialization of the sector.

Today, evaluating ecological wellbeing and ecosystem services is becoming a great concern towards conserving the natural resource base. Healthy functioning ecosystems have fundamental roles for aiding humankind to lead a healthy life and ensure an improved social welfare. Estimating the non-market benefits of ecosystem services can help experts and the public frame policy directions designed for landscape development. The ecosystem of the Eucalyptus hotspot highlands of northwestern Ethiopia, where this study was carried out, provides services that are essential to changes in the life of the society and biodiversity. However, in recent years, the ecosystem is facing a serious threat from intensive monoculture plantations of Eucalyptus. This has resulted in transformation of the cultural landscapes and a loss of biodiversity. The problem in turn calls for designing appropriate ecological improvement programs. Thus, the current study examined the preferences of residents concerning this area and estimated their willingness to pay (WTP) for the proposed ecosystem improvement programs using a Choice Experiment approach. Data were aggregated from 388 residents using a questionnaire survey in January 2020. The survey contained ecological improvement schemes and a hypothetical event by which respondents expressed their willingness to pay a yearly utility fee as a compensation for the improvement programs. Results showed significant differences in resident preferences towards the proposed ecological improvement attributes. The findings also indicated that the socioeconomic backgrounds of residents contributed for the heterogeneity in their WTP for ecological improvement schemes. Accordingly, the marginal willingness to pay of residents was USD 205/person/year for the respective ecological improvement attributes. The findings suggest that policy makers should consider such attribute-based public preferences while planning landscape development and conservation programs. This study can provide vital policy implications and contribute to knowledge as it presents how the non-market valuations of ecosystems help maximize social welfare.

Ocimum, commonly known as basil, is a group of aromatic plants extensively cultivated for their aromatic leaves, flavorful seeds, and essential oils, finding applications in food and herbal medicine. Drought stress is a crucial environmental factor that has a considerable impact on basil growth and the accumulation of bioactive compounds. This study aims to evaluate how drought stress affects biomass production and volatile oil accumulation in selected Ocimum species over two consecutive years in an open-field cultivation setting. Five distinct basil genotypes, O. basilicum L. ‘Ohře,’ O. basilicum L. ‘Genovese,’ O. × africanum Lour., O. americanum L., and O. sanctum L., were evaluated under two levels of water supply, with one group receiving irrigation as a control and the other exposed to non-irrigated conditions to induce drought stress. Consistent negative impacts of drought stress on biomass production were observed in both years. The reduction in fresh herb yield varied from 16.5 g plant⁻¹ (10.3%) for O. sanctum to 118 g plant⁻¹ (41.7%) for O. basilicum ‘Ohre.’ Across the study years, drought stress slightly increased the essential oil content of O. × africanum and O. basilicum ‘Genovese’ by 9.8% and 26%, respectively. The essential oil composition varied considerably among the different Ocimum species and cultivars. Cultivars Ohře and Genovese had linalool as a major component, exceeding 40%. O. americanum was rich in citral compounds—neral and geranial—accounting for 26–37%, which contribute to its strong lemon-like fragrance. The hybrid O. × africanum contained high proportions of 1,8-cineole (32–38%) and limonene (14–16%), while O. sanctum was characterized by its elevated levels of eugenol (36.4–50.3%) and β-caryophyllene (26.4–38.5%). The influence of water availability on essential oil content and composition was inconsistent across species. Similarly, variations were observed in total phenolic content (TPC) and antioxidant capacity (AOC) depending on both species and growing year. Notably, the highest TPC (341.4 mg GAE g⁻¹ DM) and AOC (122.9 mg AAE g⁻¹ DM) were recorded for O. sanctum grown under drought stress during the first experimental year. In conclusion, it is recommended to irrigate the studied basil species at least twice a week under open-field conditions to minimize the negative effects of drought stress.