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Green Roofs and wAlls biodiVersITY

Evaluating the contribution of Green Roofs/Walls for cities biodiversity
with the support of citizen science


The Problem


Today, it is generally accepted that Nature-Based Solutions will play an important role in cities regeneration, since they address urban challenges in a multifunctional way. In fact, green spaces provide multiple benefits both for people and nature. Green roofs and green walls are some of the most promising alternatives as urban space is scarce and they can green the grey infrastructure. Yet, their merit is not generally known and accepted, mainly due to difficulties in valuing intangible benefits as biodiversity.

Biodiversity guarantees an important amount of ecosystem services, such as food supply, soil composition, air quality or climate regulation. Therefore, public policies have pursued answers to protect biodiversity, namely on the basis of international agreements, such as the United Nations Sustainable Development Goals. However, despite the growing concern, the loss of biodiversity has continued, particularly in urban areas.

The purpose of GRAVITY is to enhance the knowledge on green roofs/walls contribution to the biodiversity of cities.

Our Approach



The strategy of the project is to:

  1. Define a city case study and catalogue existing green roofs/walls that are already installed in the city;

  2. Collect a comprehensive and systematic data basis of green roofs/walls contributions to the biodiversity of the city, by feeding Biodiversity4all platform and encouraging citizen participation;

  3. Develop a model to assess the contribution of green roofs/walls to the urban biodiversity and to understand the explanatory variables (e.g., how does proximity to other green spaces or type of green roof/wall influence its contribution to urban biodiversity);

  4. Understand how this demonstration project can be up-scaled in other cities and spread out the results.

This methodology is a step forward in knowledge of green roofs/walls biodiversity and crucial for a wide spreading of green roofs/walls in buildings/cities.

Credited to: Sérgio Chozas



  1. Survey of existing studies/works/projects on biodiversity of green roofs and green walls in cities

  2. Survey of main conclusions on biodiversity of green walls in urban centers

Task 1

  1. Identifying existing green roof/walls

  2. Looking for available roofs/walls for greening

Task 2


Task 4

Task 5

  1. Bioblitzes

  2. Workshops

  3. Webpage

  4. Publications in international/national journals and conferences 

  1. Analysing the biodiversity data

  2. Developing a biodiversity model


Task 3

  1. Collecting biodiversity data in green roofs/walls

  2. Empowering citizens to practice citizen science

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