European Commission logo
English English
CORDIS - EU research results

CLEARING HOUSE - Collaborative Learning in Research, Information-sharing and Governance on How Urban tree-based solutions support Sino-European urban futures

Periodic Reporting for period 2 - CLEARING HOUSE (CLEARING HOUSE - Collaborative Learning in Research, Information-sharing and Governance on How Urban tree-based solutions support Sino-European urban futures)

Reporting period: 2021-03-01 to 2022-08-31

CLEARING HOUSE is focussing on “Urban Forests as nature-based solutions” (UF-NBS) which are a subset of nature-based solutions (NBS) that build on tree-based urban ecosystems. They address societal challenges, simultaneously providing ecosystem services for human well-being and biodiversity benefits. UF-NBS include peri-urban and urban forests, forested parks, small woods in urban areas, and trees in public and private spaces. UF-NBS are an integral and traditional part of urban landscapes, supporting attractive environments for living, working and business investments.

Trees and forests are a proven nature-based solution that contribute to sustainable urban development. Their potential for delivering ecosystem services, enhancing biodiversity, mitigating negative impacts of climate change and urban growth and contributing to the wellbeing of urban societies is often underestimated and underused. CLEARING HOUSE aims to unite Chinese and European cities in their quest to finding pathways for an effective tree-based restoration of degraded urban environments in order to improve human well-being. Cities and researchers in China and EU are experimenting with UF-NBS at different urban scales, implementing different UF-NBS types and working in diverging economic, governance and institutional contexts. This creates an interesting living laboratory for comparative research on how to plan, establish, govern, manage and monitor tree-rich landscapes for the benefit of urban societies at large.

Therefore, the main objective of CLEARING HOUSE is to analyse and develop – across China and Europe – the potential of NBS in general, and UF-NBS in particular, for enhancing the resilience of cities facing major ecological, socio-economic, and human wellbeing challenges.
CLEARING HOUSE started by reviewing the existing literature and knowledge on urban forests as nature-based solutions (UF-NBS) in Europe and China. An academic literature review identified 422 articles, resulting in a dashboard of academic knowledge ( An analysis of 22 case histories in Europe and China demonstrated the importance of urban forests in practice; these case histories are the empirical ground for analysing governance, institutional and economic frameworks for UF-NBS in Europe and China (see In both China and Europe, the engagement of the civil society in the selected case studies is relatively low, with the main actor being local authorities. There seems to be room for more active civic engagement, both in planning and implementation of UF-NBS, as in providing funding. There is a need to explore alternative economic arrangements, which can be also a starting point for new governmental and institutional arrangements. A new typology for UF-NBS has been developed based on web ontology language. This innovative approach allows for interactive browsing and querying of knowledge, and for providing means of building UF-NBS inventories, databases and models.

The work in the case study cities and regions started with an exploratory analysis. A GIS analysis mapped the UF-NBS potential in the European cases, and compared this to the broader regional and national forest availability. A qualitative in-depth analysis looked at communalities, differences, and challenges in the case studies. These include densification; land development; renaturing cities; fragmentation through infrastructure; institutional silo thinking; challenges related to stakeholder and public involvement; diverging scales, resources (HR, financial) and timelines between ecosystem processes on the one hand and administrative and policy processes on the other hand.

Five local co-design workshops in selected European cases (Barcelona, Brussels, Gelsenkirchen, Halle-Leipzig, Krakow), one Chinese co-design workshop and a joint Sino-European co-design workshop has lead to the research questions and the analytical research framework for the second comparative research phase of the project, structured along 4 workstreams
1. Governance analysis: UF-NBS and transdisciplinarity
2. Cultural Ecosystem Services & citizen appreciation of UF-NBS
3. Sustainable funding mechanisms of UF-NBS
4. Geography of UF-NBS & multifunctionalities

To integrate stakeholders' perspectives, CLEARING HOUSE has been implementing a citizen science tool for collecting perceptions and use related to urban forests and urban trees in the case study cities. Further, a very appealing inspirational package to UF-NBS to teenagers (10 – 14 years) has been developed ( This package is available in English, Catalan, Italian and Mandarin, and has been implemented in schools in Belgium and Spain. Work has started on developing four guidelines for local authorities, civic organisations and consultancies on how to implement UF-NBS.

Communication and dissemination work supported the project by building a community of interested stakeholders, prospective users, and potential multipliers for the outcomes of the project. Successful social media accounts (see have been initiated. The project hosts a successful blog on UF-NBS, including a blog series on the impact of COVID-19 on the use of urban forests. Twenty-five academic articles have been published (see with in total over 400 citations by October 2022.
The innovative typology of UF-NBS has the potential to become a new standard, as it integrates diverging actual typologies with different viewpoints into a holistic approach that combines form, physical perspectives, function and institutional perspectives. The academic review, the review of case studies, and the governance, economic and institutional analyses gave interesting insights in commonalities and differences within and between Europe and China, in terms of urban forest types, ecosystem services focused at and solutions implemented. These comparative cross-continent analyses are novel, and generate interesting new insights on UF-NBS delivery under diverging systems and institutions in both continents.

Very interesting insights are expected to emerge from a Europe- and China-wide societal representative survey on use and perceptions towards urban forests in Europe and China. Multiple local, regional and national studies have been done in this field, but comparing between and within China and Europe will provide a novel and representative perspective.

Upcoming tools include a citizen science tool, a spatial impact assessment and a classification tool, and spatial information and knowledge hub. These tools will facilitate locally embedded research and planning that support urban forest implementation in cities and urban regions. These tools will be combined with a targeted communication and dissemination approach, including guidelines for implementation and an education package, to increase impact and uptake by cities and its citizens.