Biodiverse Urban Forests – Cities full of Life

Biodiverse Urban Forests – Cities full of Life

Cities are home to more than half of the global population. As urbanisation increases at an unprecedented rate, by 2050, about two thirds of the worldwide population are anticipated to live in cities (UN, 2018). But let’s look a bit closer at who else is calling cities their home: Urban areas also provide shelter to a considerable range of growing, flying and crawling diversity, living in the soil, on street trees, in urban parks, woodlots, urban forests and their surrounding natural habitat. Read on to learn more about the nexus between urban forests and biodiversity and why a healthy, biodiverse city is critical for the future of human societies.

The impact of humanity on our planet is becoming increasingly visible through climate disasters and the global biodiversity crisis. It is a complex relationship of living things and systems and a growing damage towards our planet’s biodiversity that result in significant risks to humankind. Facing this development, it becomes ever more vital to conserve, protect, restore and sustainably manage those places that offer shelter for different species.

The role of urban biodiversity

Photo by Emily Kessler on Unsplash

Efforts to preserve biodiversity often focus on large natural habitats. However, the urban environment, with a landscape that can harbour relatively high amounts of biodiversity (Alvey, 2016), represents a significant potential for the preservation and promotion of species, genetic and ecosystem diversity. Humanity relies on a range of ecosystem services provided by the natural environment, including regulating, cultural, supporting and provisioning services – and a diverse urban forestry landscape is necessary to ensure the long-term provision of those ecosystem services in cities. Safeguarding biodiversity must therefore become an integral part of sustainable urban development. To effectively halt and reverse the loss of nature, the adoption of a transformative post-2020 global biodiversity framework needs to be high on the political agenda. COP 15 is on its way to tackle this challenge.

COP 15 – ‘Ecological Civilization – Building a Shared Future for All Life on Earth’

The UN Biodiversity Conference and the Fifteenth meeting of the Conference of the Parties to the Convention on Biological Diversity (COP 15) kicked off online on 11 October 2021. While the first phase of the summit is being held virtually from 11 to 15 October 2021, the second phase is inviting for an in-person meeting from 25 April to 8 May 2022 in the Chinese city of Kunming. The two-part conference will further host the Tenth meeting of the Conference of the Parties serving as the meeting of the Parties to the Cartagena Protocol on Biosafety (CP-MOP 10), and Fourth meeting of the Conference of the Parties serving as the meeting of the Parties to the Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilisation (NP-MOP 4).

COP 15 will shed light on the delivery and achievements of the CBD’s Strategic Plan for Biodiversity 2011-2020. The summit aims to finalise the post-2020 global biodiversity framework and establish mid-century long-term goals and short-term targets for 2030 to fight biodiversity loss. Looking back to the previous global targets set, objectives were largely missed. More than ever, it is of utmost importance to agree on clear, measurable targets to boost nature preservation and ensure those targets are anchored within national policies. Read more about the conference and registration here.

The importance of SDG 15 – Life on Land – Urban green matters

Forests provide shelter to more than 80% of all terrestrial animal, plant and insect species. With plant life itself providing 80% of the human diet, the intact functioning of a diverse natural environment is crucial to support food and water security while helping to adapt to and mitigate climate change and fostering peace and security (UNDP). In this context, food security is closely tied to the role of insect pollinators – and those also live in urban areas. Initiatives to promote bee-friendly urban green area management exist beyond Europe. By choosing the right plants, applying appropriate mowing and pruning practices, promoting the creation of planted road margins, flowering green roofs, vertical gardens or by harnessing the potential of urban agriculture initiatives, cities can contribute a significant part to supporting human livelihood based on nature – with potential for upscaling (Van der Slujis & Vaage, 2016).

Urban Forests & Biodiversity

About healthy trees, planting trees in the right places and planting the right trees

Fortunately, urban forests provide critical ecosystem services to sustain human health and well-being and support environmental quality in and around urban areas. As a vital part of the city infrastructure, urban forests also face numerous threats due to climatic changes, conflict over land use, strong anthropogenic influence as well as pests and diseases. To ensure that people can rely on benefits provided by urban forests in the future, it is crucial to understand those threats and foster a healthy and resilient urban forestry landscape.

Biodiversity of Urban Forests

Photo by Sophie Nito on Unsplash

The long-term provision of ecosystem services provided by healthy urban forests counts on species diversity, diversity within species, age and structural diversity. The many different regulating, cultural, supporting or provisioning services we obtain from urban forests are related to the tree’s characteristics – with some species providing a single ecosystem service better than others due to their individual characteristics.

“To optimise one ecosystem service, diversity is unnecessary. But in order to optimise multiple ecosystem services, high urban tree diversity is essential.”

Urban Tree Diversity for Sustainable Cities’, Nordic Forest Research

In many European cities, urban areas harbour high species richness but are often dominated by few species, especially on stressed sites. To work towards a resilient future city, efforts to decrease the dominance of a small number of species are needed. But which species are best suited for a changing urban environment? And what is the role of non-native species? The wide range of site-adapted species growing (and dying) in urban environments comprises both native and introduced species. While the potentials and risks of non-native species are passionately discussed among scientists, the suitability of long-term resilient tree species appears to be a topic far from black and white. In this context, the role of non-native species remains an understudied topic (Schwarz et al., 2017).

Biodiversity of Fauna supported by Urban Forests

Urban forests also provide shelter for adapted species, including insects and birds. Trees and forests in cities can be regarded as extreme habitats due to their high anthropogenic influences. Looking at urban forests as faunal biodiversity habitats, studies show the important role of native trees for bird species richness and abundance. However, also exotic trees can harbour interesting habitats invertebrates, being an important food resource for insect-eating animals. Newer suburbs are anticipated to provide high-quality habitats with native tree species able to promote faunal biodiversity, albeit non-native trees also form part of cities now and in the future (Livesley et al., 2016).

Since the city lives of being a shared place, the coexistence of nature and people does not come without challenges. Overcrowded urban green areas and recreational overuse can disturb urban biodiversity. The considerable potential of urban forests to increase and hold biodiversity needs to be taken into account when balancing different interests and promoting nature in cities for all beings. In this context, planting trees in the right places provides an important opportunity to create connections between urban biodiversity and surrounding forests and ecosystems.

Improving environmental quality = Improving quality of life?

Photo by Kristi Simko on Unsplash

Preserving biodiversity in urban areas brings more than the inherent value of biodiversity conservation itself. It also presents significant societal benefits, such as environmental awareness and improvements for mental health and well-being through interacting with a biodiverse natural environment (Morgenroth & Nielsen, 2016). Recent studies suggest that daily contact to nature through street trees close to residents’ homes may reduce the risk of depression (Marselle et al., 2020), while older studies also hint at the fact that improved health may derive from an area perceived as highly biodiverse by residents, without necessarily being highly biodiverse (Qiu et al. 2013). Read more about the nexus between functional biodiversity and a healthy society here.

It remains – diversity is key. Strategic planning, decision-making and management will be crucial in an increasingly urbanising world, with urban forests as a promising stage for the fight against biodiversity loss.

Learn more about Urban Forests and their potential for rehabilitating, reconnecting and restoring urban ecosystems in the Sino-European H2020 CLEARING HOUSE project.

Urban Forests as Nature-based Solutions: Local Actions for Resilient Cities

Urban Forests as Nature-based Solutions: Local Actions for Resilient Cities

Think global, act local.

(Patrick Geddes)

Functional biodiversity, healthy society

Thriving communities need healthy ecosystems. The conservation of biodiversity is closely tied to the health and well-being of people. In recent years, increasing worldwide recognition of this interrelatedness emphasises the need for preserving and enhancing functional biodiversity. We depend on nature as our substantial infrastructure. Especially in expanding urban and peri-urban areas, living with the pandemic has revealed how healthy, biodiverse green spaces are increasingly frequented by urban dwellers and help foster societal resilience. Biodiversity conservation is therefore high on the international agenda.

The IUCN World Conservation Congress 2021 – Managing landscapes for nature and people

The International Union for Conservation of Nature (IUCN) and the French government are holding the IUCN World Conservation Congress from September 3 to 11 2021 in Marseille.

Bringing together the global nature conservation community, the Congress opens the stage to leading conservation scientists, policy experts and practitioners and invites 1,400 Member organisations. Among those organisations, states, civil society and Indigenous Peoples exchange views about pressing issues in nature conservation and ways to tackle them. As one of the main Congress themes, attendees discuss how to manage landscapes for nature and people.

Urban Forests as Nature-based Solutions

As defined by IUCN, Nature-based solutions are “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”.

The Sino-European CLEARING HOUSE Horizon2020 project is developing a novel typology for urban forests, urban green and urban trees. In this context, Urban Forests as Nature-based Solutions (UF-NBS) are built on tree-based ecosystems in urban areas and play a fundamental role in providing ecosystem services for biodiversity benefits, human health and well-being. Focussing on Europe and China, the project’s diverse typology assumes a broad perspective and intends to provide grounding knowledge on UF-NBS beyond the project scope. On the way towards sustainable urbanisation, UF-NBS connect urban and peri-urban ecosystem services with societal demands. Do you want to learn more about the typology and its role to gather and exchange knowledge and integrate models and data on UF-NBS? Join the Humboldt University Berlin, the European Forest Institute (EFI) and the CLEARING HOUSE project in an Online Workshop on October 7th (8:15 – 11:15 CEST) – click here to register.

Urban trees and green spaces provide multiple benefits for people. Through CO2 sequestration and pollutant absorption, urban forests improve air quality. The rapid worldwide urbanisation entails increasing extensive ranges of impermeable hard surfaces in the built-environment, exacerbating the urban heat-island effect. Through shade provisioning and the process of evapotranspiration, urban trees and forests mitigate heat stress whilst saving energy through less use of air-conditioning and increasing urban liveability. Urban green spaces further reduce stormwater runoff, improve water filtration and water storage and reduce soil erosion. No less crucial, urban forests shelter numerous species, serving as a biodiversity hub for declining flora and fauna.

UF-NBS: A focus on health, well-being and inclusivity

Photo by Alan Healy on Pexels

Trees and forests in cities invite urban dwellers to connect with nature and provide an open space for physical activities and interactions with others. Why is this increasingly relevant? While projections assume a global urban population of 68% by 2050, nearly 85% of the worldwide population will live in cities by 2100 (UN, 2018). This trend is associated with rising levels of illnesses, stress and anxiety. Peoples’ nowadays communication patterns, characterised mainly by less direct contact and more screen-to-screen interaction, tend to bring communities further away from nature.

Reconnection with nature plays a vital role in preventing the development of illnesses, treating developed illnesses and ultimately in helping to reduce costs of health care. The positive effects of nature on health and well-being are rapidly becoming recognised on a broader scale. To better align stakeholders in the healthcare sector, the last IUCN World Conservation Congress, which took place in Hawaii in 2016, brought the IUCN Resolution 064 ‘Strengthening cross-sector partnerships to recognise the contributions of nature to health, well-being and quality of life’ to life. This resolution includes the urban context as: “Recognising that places, including urban areas, with a rich natural heritage, improve physical and mental health and spiritual well-being, and can increase the appreciation of nature including by the elderly”. 

Biodiversity and UF-NBS enhance the health and well-being of urban dwellers in different environments, be it urban forests, parks or trees, public gardens, urban gardening projects or green spaces around health institutions allowing for nature encounters and boosting the well-being of patients and staff. However, it deserves mentioning that to build a flourishing connection to nature for all, inclusivity is essential. In many urban scenarios, opportunities to engage with nature leave out those who may benefit most, resulting in green gentrification and social exclusion. The IUCN World Conservation Congress 2021 invites attendees to discuss initiatives designed to deliver social justice together with benefits for people and the environment. See the latest news from the Congress.

Think global, act local

Looking at how pressing environmental threats such as the global biodiversity crisis evolve and how devastating those effects turn on a global scale, one can easily get frustrated and some of the challenges can appear as very remote. What can be done to drive change? How can individuals contribute to a sustainable transition that acknowledges the importance of biodiversity protection and human well-being? The concept “Think global, act local” has been introduced in 1915 by Patrick Geddes, a Scottish pioneering town planner and conservationist. Following a strong belief to work with the environment, rather than against it, Geddes’ concept shaped the idea in architecture and planning. Putting a spotlight on the impact urban development has on its surrounding environment, Geddes makes an important point that becomes increasingly meaningful in the face of a globalised world. Whilst a local action may not directly lead to saving the Amazon rainforest from deforestation or saving species on the brink of extinction, showing solidarity through local activities must not be underestimated. Enhancing consciousness about pressing environmental topics starts on a local scale.

Photo by Anna Earl on Unsplash

All around the globe, local communities take initiatives to improve the liveability of their urban neighbourhoods. This development enhances cooperation among urban dwellers such as bottom-up and citizen engagement approaches, grassroots movements and urban agriculture initiatives. The positive effect of shaping common spaces in a community is shown through manifold benefits: shaping and meeting in urban green areas has a catalysing impact on social cohesion and social capital, fosters personal and societal resilience and enables early development of landscape stewardship through educational networks.

Life on earth relies on intact ecosystems. However, to collectively shape the healthy planet we want to live on, change does not emerge out of political agendas but also needs to be driven actively from the bottom. Turning ambition into science-informed action, engaging in volunteer programs, harnessing opportunities of citizen science and getting to know the ecosystems in front of your own door are important and impactful steps on the way towards creating environmental consciousness and tackling the biodiversity crisis.

Save the Date: 24th EFUF – City of Belgrade, Serbia (17-21 May 2022)

Save the Date: 24th EFUF – City of Belgrade, Serbia (17-21 May 2022)

The City of Belgrade is pleased to announce the 24th European Forum on Urban Forestry (EFUF). The Forum will be held from 17-21 May 2022 in Belgrade, Serbia. The Forum theme is adaptive measures in urban forests.

EFUF 2022 will be a great opportunity to learn about new and cutting-edge research on adaptive measures in urban forest and an opportunity to discuss with inspiring practitioners, advanced researchers and sector-leading policymakers on how to improve urban forest management in a rapidly changing world.

Mark your calendars to experience the Urban Forests of Serbia and meet and greet urban forestry colleagues you may have not seen since the 2019 in person EFUF in Germany.

Further details and details of the registration process will be issued in autumn 2021.

Check the EFUF website for further announcements.

Welcome to the 24th EFUF, City of Belgrade, 17 – 21 May 2022.

EFUF 2022 is supported by EFI and the EU funded H2020 CLEARING HOUSE project.

Sponsorship opportunities will be available – details later in 2021.

A tree awakening – Call for Action

A tree awakening – Call for Action

Click here for the full recording of the tree awakening.

Did you know that urban trees and forests provide vital infrastructure for healthy and happy people? Are you aware that they are protecting and enhancing biodiversity and co-creating a climate-adapted built environment?

Three recently awarded ‘Tree Cities of the World’; City of Ljubljana, Barcelona Metropolitan Area (AMB) and Brussels Capital Region are taking the lead on promoting the crucial role of urban trees towards greener and more resilient cities and urban regions. The three cities and regions differ in character but have demonstrated a commitment to urban trees within the framework of urban forestry, green infrastructure and the enhancement of local ecosystem services. 

The ‘tree awakening’ is a partner event of the EU Green Week. The  European Forum on Urban Forestry (EFUF), European Forest Institute (EFI) and CLEARING HOUSE project, brought together these three cities and regions to kick-off anactivity – focus – celebration of trees and to build and strengthen existing relationships across Europe. The ‘tree awakening’ event invited practitioners, researchers, policymakers, journalists and citizens eager to explore ways to work together towards a greener and more resilient future in cities.

Christophe Vanoerbeek, the Brussels Mobility CEO said:

Brussels is regularly cited as one of the greenest cities in Europe, with an impressive surface area of 4,000 hectares of green spaces. Brussels Mobility manages 30,000 trees along the main roads. To increase the ecosystemic benefits (landscape, biodiversity, water infiltration, shading, heat reduction, CO2 capture, etc.), we encourage the development of high trees. The management of plantations has evolved enormously to take into account biodiversity and new methods. For example, Brussels Mobility takes care of +/- 15 hectares of ecological zones and flower meadows.”

Antoni Farrero, General Coordinator of the Technical Office of Management of the Metropolitan Area of Barcelona (AMB), added:

“Belonging to international networks, such as the European Forum on Urban Forestry (EFUF) or the Tree Cities of the World, encourages us to continue working towards the renaturation of urban fabrics, the reinforcement of green infrastructure and the promotion of ecosystem services.”

Nataša Jazbinšek Seršen, Head of Department for Environmental Protection at the City of Ljubljana, continued:

“Looking at Ljubljana is looking at a city of the future! Numerous city trees and forests connect us, contribute to the health and well-being of citizens and give a unique backdrop to the Green capital.”

Call for Action:

We urge citizens and local leaders and decision-makers across urban regions in Europe to be inspired and step up towards recognising, building awareness, communicating and taking ownership of the benefits of urban trees for all living being in a city.
  • It’s not just planting but caring: There’s much more to enhancing urban green then just planting trees – caring for, respecting, and ensuring a long lifetime of an urban tree is crucial to ensure it develops its ecosystem potential. However, urban tree care remains a great challenge for those managing urban regions.
  • Caring for life – from seed to soil: Brought up in nurseries, going through adolescence and calling for pruning from time to time, dispersing seeds and finally returning back to the soil. A tree’s life is not that different from ours – and calls for a lifetime of care.
  • Trees – you get more than you see: Green space planning needs to focus on the benefits of trees both individually and when growing together. Considering trees as an ecological umbrella covering an urban region is fundamental to understanding their overall benefit to society.
  • Big Trees Matter: Urban regions need veteran trees as these provide the most ecosystem services and are the most important to people. Whilst planting new trees is important the loss of a mature tree before its lifetime is over takes generations to recover.

Elisabeth Pötzelsberger, Head of Resilience at the European Forest Institute (EFI) and Chris Baines, environmental campaigner, award-winning writer and broadcaster opened up the event, joined by high-level representatives from the European Union, the ‘Tree Cities of the World’ representatives from Slovenia, Spain, Belgium and international urban forestry experts.

Chris Baines reported:

“Mature trees have been breathing life into our towns and cities for centuries. Now, in the face of climate change, increasingly extreme weather patterns, relentless development pressure and stressful urban living, the moderating role they play is more important than ever.”

Speaker Session

Please click on the titles to have a look at the detailed presentations:

Thomas Randrup, professor in Urban Open Space Management and Head of Subject for Landscape Governance and Management at the Swedish University of Agricultural Sciences (SLU) shed light on the importance of moving from Nature-Based Solutions to Nature-Based Thinking. He emphasised:

“Nature-based Thinking is a way to address Nature-based Solutions as places in their own right rather than installations, helping them to become more resilient and sustainable.”

Simone Borelli, Agroforestry and Urban/Periurban Forestry Officer at the Forestry Division of the Food and Agriculture Organization of the United Nations (FAO), presented the ‘Tree Cities of the World’ and stated:

“It is time to shift paradigm. Urban forests and trees should no longer be seen as a cost, but as an investment in the future of cities. The Tree Cities of the World programme celebrates the achievements of the cities that are taking steps in the right direction.”

Cecil. C. Konijnendijk van den Bosch, global urban forester and director of the Nature-Based Solutions Insitute (NBSI) introduced the 3-30-300 rule, shared his experience on the importance of trees in cities and explained:

 “For someone who has worked in urban forestry for almost three decades, it is exciting to see the current ‘tree awakening’ across Europe, as we have come to realise how important trees are for our health, wellbeing, and happiness.”

During an interactive Q&A session, participants had the opportunity to engage in discussions with the speakers, moderated by John Parker, CEO at the Arboricultural Association. This was followed by a technical panel discussion moderated by Clive Davies, Convenor of the EFUF International Steering Group, Senior Researcher, Advisor and Facilitator at European Forest Institute (EFI) Governance and Resilience Programmes and CLEARING HOUSE project, which explored the opportunities and challenges of managing trees in urban regions. The virtual stage featured insights by Nejc Praznik, Consulting arborist at JP VOKA SNAGA, Ljubljana, Valérie Decoux, Bio-Engineer at the Brussels Mobility, Public Service of the Brussels Capital Region and Antoni Farrero, General Coordinator of the Technical Office of Management of the Metropolitan Area of Barcelona (AMB).

The ‘tree awakening’ opened an inspiring and positive discourse about the manifold benefits and challenges of managing trees in urban regions without dodging difficult questions. The insights and discussions serve as an impulse and starting point to awake consciousness and activate decision-makers to take practical action on transforming concrete jungles towards liveable shared spaces with multifunctional, interconnected and open, accessible green spaces for all.

As part of the ‘tree awakening’ self-guided tree discovery walks have been created for the City of Ljubljana, the Barcelona Metropolitan Area (AMB) and the Brussels Capital Region. These walks are designed to help the public explore the trees in these areas, whether as residents in-situ, virtual or actual visitors.

The self-guided tree discovery walks are presented through the ActionBound app and are intended as an inspiration to other urban regions to produce further walks.

The walks can be explored at any time through the ActionBound app.

Download the app by clicking on this link or scanning the QR-Code:

Access the tree discovery walks by clicking on the links below or by scanning the QR-Codes:

Brussels Capital Region

English version:

Dutch version:

French version:

Barcelona Metropolitan Area

English version:

Catalan version:

Spanish version:

City of Ljubljana

English version:

Slovenian version:

Further contact:

A tree awakening – 11 June

A tree awakening – 11 June

Partner Event of the #EUGreenWeek, European Forum on Urban Forestry (EFUF), European Forest Institute (EFI) and CLEARING HOUSE project

A tree on your doorstep is a forest in your mind.

Register here to be part of the tree awakening.

The City of Ljubljana, the Barcelona Metropolitan Area (AMB) and the Brussels Capital Region have all recently been awarded Tree Cities of the World status (TCoW). Bringing together the three cities as a partner event of the EU Green Week, European Forum on Urban Forestry (EFUF), European Forest Institute (EFI) and CLEARING HOUSE project, invite you to join an online ‘tree awakening’ activity – focus – celebration of trees to build and strengthen existing relationships at a continental level.

The 2-hour interactive online event is targeted at practitioners, researchers, policymakers and everyone eager to explore ways to work together towards a greener and more resilient future in cities around Europe and beyond.

The ‘tree awakening’ will follow the main theme of the life of a tree in the city, which will be explored by a range of high-level speakers and throughout a technical panel discussion, where participants have the opportunity to engage in an interactive Q&A session.

To round off the ‘tree awakening’, attendees and urban adventurers are invited to explore trees and forests around the City of Ljubljana, the Barcelona Metropolitan Area (AMB) and the Brussels Capital Region from anywhere around the globe or in-situ to as a self-guided tree discovery excursion to learn about the manifold opportunities and challenges urban green encompasses in these three areas.


11 June, 10:30-12:30 CEST

10:30 Opening

10:50 Speaker Session

Moderator: John ParkerArboricultural Association

  • Moving from Nature Based Solutions to Nature Based Thinking – Thomas Randrup (SLU)
  • Tree cities of the world – Simone Borelli (FAO)
  • The 3-30-300 rule – Cecil. C. Konijnendijk van den Bosch (NBSI)
  • Q&A Session with speakers

10-minutes comfort break

11:40 Technical Panel Discussion

Opportunities and Challenges of Managing Trees in Cities

Moderator and Interviewer: Clive Davies (EFIEFUFCH)

12:15 Introducing the ActionBound Discovery Walks in the City of Ljubljana, Brussels Capital Region and Barcelona Metropolitan Area & Closing

  • ActionBound Introduction – Vera Franziska Knill (EFI/EFUF) and brief introduction of discovery walks by city representatives
  • Closing Words by Clive Davies (EFIEFUFCH)

We are looking forward to seeing you online.