Urban Forest-Based Solutions for Resilient Cities

Planting trees is a longstanding traditional urban planning approach for improving liveability in cities. Dating back from the earliest urban societies such as the Roman Empire, urban planners have applied trees for bringing shade, mitigating temperature, rainfall and wind, and providing food and fodder for animals. Providing urban trees, parks and urban forests is probably one of the earliest applications of what is now termed “nature-based solutions”. Nature-based solutions are defined by the International Union for Conservation of Nature (IUCN) as “actions to protect, sustainably manage, and restore natural or modified ecosystems, that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits”.

Urban Forest-Based Solutions (UFBS) are a subset of nature-based solutions that build on tree-based urban ecosystems to address societal perceptions and demands, simultaneously providing ecosystem services for human well-being and biodiversity benefits (see Figure). An example of how an urban tree provides multiple benefits is showen in the figure below: the tree is sequestring CO2, absorbing pollutants, providing shade (resulting in less airconditioning and hence electricity use), reducing stormwater runoff, providing shelter and habitat for birds and insects etc.

UFBS refers to all measures a city can take to address urban sustainable development challenges by planting and managing trees and their associated vegetation and environs. In addition to these rather technical aspects, UFBS encompass societal perceptions and resulting demands for ecosystem services generated by UFBS, and the larger socio-economic and governance framework. Both the technical and socio-economic aspects relate to the entire (cycle) process of planning, designing, deploying, governing, managing and monitoring UFBS, including feedback, (re-)planning, re-designing and adaptive management. Importantly, UFBS become a solution for sustainable urbanisation through the interaction between urban and peri-urban ecosystems, society and economy. They connect the ecosystems and socio-economic systems of a city. These interlinkages can be assessed as ecosystem services, connecting the provision of services and goods from urban forests with societal demands. Consequently, UFBS are socio-ecological interventions that combine human management with nature’s functionality within (peri-)urban settings, offering great potential for more sustainable urban development.
UFBS include peri-urban and urban forests, forested parks, small woods in urban areas, and trees in public and private spaces. UFBS are efficient and cost-effective tools to improve the urban environment. However, urban trees are under constant pressure from urbanisation and decreasing budgets for management. Whilst trees are a proven nature-based solution, their potential for delivering ecosystem services, enhancing biodiversity and contributing to the resilience of cities, including both the urban ecosystem and society, is frequently underestimated. This may lead to decisions in urban plan­ning that miss opportunities to exploit synergies between ecosystem regeneration and sustainable urban develop­ment.
Although trees are considered important by all populations around the world, there is still a large unexploited potential of applying trees in the rapidly growing metropolis in Asia, Africa and Latin-America. This is the ground for a recently submitted project proposal that – coordinated by the European Forest Institute and the Urban forest Research Centre at the Chinese Academy of Forestry – will facilitate research cooperation and collaborative learning between European and Chinese researchers, NGOs, city departments and metropolitan regions. In China, urban forest establishment is one of the goals in the country’s 13^th Five-Year Plan. The Chinese government aims at planting more than 60,000 hectares of new trees in urban areas by 2025, but there are still challenges to overcome (as we have noticed during a study visit in January 2018). In Europe, maintaining and enhancing green infrastructure (of which UFBS are a crucial element) is part of Target 2 of the EU2020 Biodiversity Strategy and Action 7 of the EU Strategy on Climate Change Adaptation.
By bringing together two major arenas of urban development, Europe and China, the motivation is to learn across local experiences and to improve the development of what is collectively termed the “urban forest” at a larger scale. Based on reviewing the available knowledge and comparative analysis of existing and new UFBS in ten case studies in China and Europe, new user-oriented tools will be developed that will support planners, practitioners and decision-makers to plan, design, implement, manage and monitor UFBS at different scales. The tools will be co-defined by actors from the case studies and by national and continental stakeholders. The tools and new UFBS will be tested in urban forest field laboratories The laboratories include citizen-science monitoring and working with engaged citizens, less-privileged groups and school children to raise their awareness on UFBS.
The project is answering actual and concrete questions that decision-makers, practitioners and planners have. We touch (urban) wood for a positive evaluation.