The continued influx of refugees into Uganda confronts people and hosting landscapes with severe challenges. Vast volumes of biomass resources are required for energy and building materials. Consequently, woodlands have come under pressure as the key source within refugee-receiving regions. This raises the question of how to simultaneously achieve a higher standard of living and energy autonomy for the population while reducing primary resource demand and safeguarding nature. We propose that nature-based and/or technological adaptions can ameliorate this dramatic and deteriorating situation. We thus evaluated the impact of: (i) building autonomy by growing biomass resources on scale via approaches such as agroforestry and ii) enhancing energy efficiency through use of improved cook stoves (ICS) and switching toward renewable energy sources. Focusing on four Ugandan districts, we analyzed the energy and land demand of households and districts in three scenarios. Our results show all districts running into shortages of biomass resources and cultivable land and two districts already reaching their limits. An efficient use of woodfuel combined with solar energy could reduce primary energy demand by up to 37%. The remaining wood demand could be realized by agroforestry systems thereby ensuring household energy autonomy and access to reliable energy sources. We recommend combining energy efficiency measures and technology to reduce firewood demand with agroforestry solutions to satisfy the remaining necessities. Both are needed to reduce the essistential pressure on woodlands and increase the energy autonomy of refugee-hosting landscapes while respecting stakeholder needs.

Urban landscapes are now the most inhabited places by the majority of global population. The rapid and large-scale land use land cover (LULC) changes induced by urbanization are declining the ecosystem services (ESs) provisioning capacity of natural and semi-natural ecosystems of urban landscapes. The main aim of the study was to assess the ecological changes caused by LULC change in the urbanized capital of the Central India, Bhopal. This study relied on satellite images (from 1988 to 2018) for generation of spatio-temporal LULC database and direct benefit transfer ecosystem service valuation scheme for quantifying the ecosystem service value (ESV). The results showed decline in total ESs by US $ 2.00 million. Though water body covers least area out of 5 LULC types of the city, it remains the top contributor to total ESV in each reference year. The ecosystem service function analysis aided in identifying, regulating and provisioning services as the key contributors. In addition, assessment of ESs under two alternate future urban growth scenarios highlights the importance of conservation of natural ecosystems within the urban area. The results of this study can provide insights to the urban planners in effective decision making about how the ecosystems and their ecosystem service functions can be sustainably managed and strategically developed for the overall well-being of the growing urban population.

Decreasing biocapacity, accompanied by increasing ecological footprint (EF) and urbanization, is the core environmental challenge that the G7 countries have to contend with, despite enjoying tremendous growth for decades. As such, this study scrutinizes the influence of biocapacity, human capital, and urbanization on the EF with an advance technique that addresses core panel data issues with the ability to show country-specific results. The findings suggest that biocapacity, economic growth, and urbanization increase the EF, while human capital reduces it. Also, the coefficient of the interaction between urbanization and economic growth turns out negative inferring that as economic growth persists, urbanization attains the desired level required to decrease the EF. Biocapacity increases the EF in all the countries except in Canada. Further findings showed that urbanization is not particularly harmful in Canada, Japan, and the UK; however, its impact remains devastating in the USA, Germany, Italy, and France. A feedback causality exists between human capital, EF, urbanization, and economic growth. Relevant policy recommendations, directions for future research, limitations of the study, as well as potential lessons for emerging economies, are discussed.

In the present paper, the Hastings and Powell model of three species food chain model is modified incorporating Allee effect. Additive type Allee effect has been used in order to modify the three-species food chain model. We investigate the impact of Allee in the food chain model. Dynamical behaviours such as existence of steady states and their local stability analysis, bifurcation analysis of the proposed three species model have been discussed. Numerical examples are provided to justify the analytical results. Regions of stability of different equilibrium points have been plotted which are in coherence with the results derived analytically. From this study, we find that chaos in the three species food chain can be controlled when prey is subject to the strength of the Allee effect. Bifurcation diagrams show that the model turns from stable to periodic doubling and periodic doubling to chaos due to the strength of Allee effect. We observe that this modified HP model is lesser chaotic in case of increase in severity of Allee effect.

In this study, a packed bed was used to remove pathogenic bacteria from synthetic contaminated water. Two types of packing material substrates, sand and zeolite, were used. These substrates were coated with silver nanoparticles (AgNPs), which were prepared by decomposition of Ag ions from AgNO₃ solution. The prepared coated packings were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy and transmission electron microscopy. The packed column consisted of a PVC cylinder of 2 cm diameter and 20 cm in length. The column was packed with silver nanoparticle-coated substrates (sand or zeolite) at a depth of 10 cm. Four types of bacteria were studied: Escherichia coli, Shigella dysenteriae, Pseudomonas aeruginosa and Vibrio cholera. The parameters studied were feed inlet flow rate (1.5, 2, 3 and 4 L/h) and AgNO₃ concentration (0.02, 0.04, 0.07 and 0.1 mM), which were used to coat the packing substrates. The best results for removal efficiency of bacteria were obtained at the feed flow rate of 1.5 L/h with AgNO₃ concentration 0.1 mM. Likewise, the percent of bacterial removal from contaminated water was found to be 99% for V. cholera, 93.7% for E. coli, 85% for S. dysenteriae and 77.5% for P. aeruginosa.

Olive mill wastewater is one of the environmental problems in semiarid regions. The main goals of this study were to investigate the impacts of different olive mill wastewater levels on durum wheat (Triticum aestivum var. Douma1) production and soil microbial activities (i.e., bacteria and fungi). A pot experiment was conducted during the growing seasons 2015/2017 to evaluate the effect of three levels of olive mill wastewater on both growth and productivity attributes of wheat. Vertisol soil samples were collected from southern Syria. Two months before wheat cultivation, three levels of olive mill wastewater: T5 (5 L/m ²), T10 (10 L/m²) and T15 (15 L/m ²) were added to pots filled with the collected soil samples. Also, a control (T0) free of olive mill wastewater was considered as a reference. Results showed a significant increase (p < 0.05) in germination rate (%), plant height (cm), ear length (cm), kernels number, kernels weight per ear (g) and grain yield (g/m²) compared to control. However, T5 treatment did not induce a significant increase in terms of ear length, kernels weight per ear or yield (in the second season). On the other hand, T10 treatment had recorded the best results compared with the other two treatments (T5, T15). Similarly, the results showed a significant increase in the number of bacterial and fungi cells by increasing olive mill wastewater concentration. This research provides promising results toward using olive mill wastewater in an eco-friendly way under Syrian conditions.