Cities need forests. The network of woodlands, groups of trees and individual trees in a city and on its fringes performs a huge range of functions – such as regulating climate; storing carbon; removing air pollutants; reducing the risk of flooding; assisting in food, energy and water security; and improving the physical and mental health of citizens. Forests enhance the look of cities and play important roles in social cohesion; they may even reduce crime. This edition of Unasylva takes a close look at urban and peri-urban forestry – its benefits, pitfalls, governance and challenges.

Water – drinkable, usable water – is likely to be one of the most limiting resources in the future, given the growing global population, the high water demand of most agricultural production systems, and the confounding effects of climate change. We need to manage water wisely – efficiently, cost-effectively and equitably – if we are to avoid the calamity of a lack of usable water supply. Forested watersheds provide an estimated 75 percent of the world’s accessible freshwater resources, on which more than half the Earth’s people depend for domestic, agricultural, industrial and environmental purposes. Forests therefore, are vital natural infrastructure, and their management can provide “nature-based solutions” for a range of water-related societal challenges. This edition of Unasylva explores that potential.

Nature-Based Solutions for More Sustainable Cities makes a clear case of performances, impacts, and benefits generated by NBS in cities providing a comprehensive framework approach to understand the real and full potential of NBS at the urban level.

The book addresses the challenges of urban water security and adaptive management in Sub-Saharan Africa, exploring and interlinking novel concepts of ecosystems services, watershed investments, and boundary work. Specifically, the book’s goals are to (i) present a conceptual framework for the urban water sector from an ecosystem services perspective, highlighting the specificities of the Sub-Saharan context; (ii) develop an operational approach to designing and assessing the impacts of watershed investments, based on ecosystem services and boundary work; and (iii) test the approach through a case study in Asmara, Eritrea, and discuss the findings and lessons learned that can be applied in other contexts. Through a fully worked out case study, from identification of water challenges and opportunities to spatially explicit modelling, the book offers a sound and accessible, coverage of issues and proposed solutions to better operationalize ecosystem services, watershed investments and boundary work, to promote adaptive management, and achieve water security in the context of rapidly developing cities in Sub-Saharan Africa. The book is an effective tool for capacity building of diverse stakeholders on the urban water sector, including water managers, local and national policy-makers as well as a suitable resource for both undergraduate and post-graduate courses in planning and geography.

Accessibility to clean and sufficient water resources for agriculture is key in feeding the steadily increasing world population in a sustainable manner. Nature-Based Solutions (NBS) offer a promising contribution to enhance availability and quality of water for productive purposes and human consumption, while simultaneously striving to preserve the integrity and intrinsic value of the ecosystems. Implementing successful NBS for water management, however, is not an easy task, since many ecosystems are already severely degraded and exploited beyond their regenerative capacity. Furthermore, ecosystems are large and complex and the many stakeholders involved may have conflicting interests. Hence, implementation of NBS requires a structured and comprehensive approach that starts with the valuation of the services provided by the ecosystem. The whole set of use and non-use values, in monetary terms, provides a factual basis to guide the implementation of NBS, which is ideally based on transdisciplinary principles, i.e. complemented with scientific and case-specific knowledge of the ecosystem in an adaptive decision-making process that involves the relevant stakeholders. This discussion paper evaluated twenty-one NBS case studies using a non-representative sample, to learn from successful and failed experiences and to identify possible causalities among factors that characterize the implementation of NBS. The case studies give a minor role to valuation of ecosystem services, an area for which the literature is still developing guidance. Less successful water management projects tend to suffer from inadequate factual and scientific basis and uncoordinated or insufficient stakeholder involvement and lack of long term planning. Successful case studies point to satisfactory understanding of the functioning of ecosystems and importance of multi-stakeholder platforms, well-identified funding schemes, realistic monitoring and evaluation systems and endurance of its promoters.

The 2nd Universitas Kuningan International Conference on System, Engineering, and Technology (UNISET) will be an annual event hosted by Universitas Kuningan. This year (2021), will be the second UNISET will be held on 2 December 2021 at Universitas Kuningan, Kuningan, West Java, Indonesia. “Opportunity and challenge in environmental, social science and humanity research during the pandemic Covid-19 era and afterward” has been chosen at the main theme for the conference, with a focus on the latest research and trends, as well as future outlook of the field of Call for paper fields to be included in UNISET 2021 are: natural science, education, social science and humanity, environmental science, and technology. The conference invites delegates from across Indonesian and South East Asian region and beyond, and is usually attended by more than 100 participants from university academics, researchers, practitioners, and professionals across a wide range of industries.