From 16 to 24 May, people across Belgium are invited to look more closely at the life around them during Belgium Biodiversity Week, and to help map the country’s wild plants and animals through the National Biodiversity Challenge.
For Brussels residents, this year’s campaign offers a special opportunity. On 17 May, the first of three Sonian Forest Days (FR | NL) will take place in La Hulpe, with the launch of the Grand Bioblitz of the Sonian Forest at the Domaine Régional Solvay, the Walloon gateway to one of Belgium’s most remarkable natural landscapes.
The timing is fitting. On 22 May, the world will mark the International Day for Biological Diversity, a United Nations observance that raises awareness of the importance of protecting the variety of life on Earth. The 2026 theme, “Acting locally for global impact”, is a reminder that biodiversity action can start close to home.
That is exactly the idea behind Biodiversity Week.
Using the free ObsIdentify app (EN | FR | NL), participants can photograph wild plants, animals, insects, fungi and other species they encounter. The app helps identify what they have found, while observations are shared through Observation.org, a global biodiversity platform for citizen science and monitoring established in 2004.
Every observation helps make biodiversity more visible. Together, thousands of small discoveries can contribute to a clearer picture of the species living in Belgium’s forests, parks, streets, gardens and protected areas.
In the Sonian Forest, volunteers and nature experts will be on hand during the launch of the Grand Bioblitz to help visitors make their first observations and use the app. The event is part of the Walloon Day of the Sonian Forest and will include guided walks, nature activities, exchanges with forest managers and partner associations, and a special opportunity to discover the Nysdam nature reserve, which is usually closed to the public.
But you do not have to be deep in the forest to take part.
Biodiversity is often much closer than we think. A pavement edge, a roadside verge, a park wall or a patch of unmown grass can reveal a surprising variety of wild plants and insects. The key is to photograph wild species only — not flowerpots, planted flower beds or cultivated garden plants. Once you start looking carefully, even an ordinary sidewalk can become a small field of discovery.
For those who want to see biodiversity at its richest, Belgium’s Natura 2000 areas are a treasure trove. These protected sites are part of a Europe-wide network that helps safeguard valuable habitats and species. In and around Brussels, they offer some of the best places to observe wild nature while understanding why conservation matters.
The Sonian Forest is one of Belgium’s most important peri-urban forests. Shared by the Brussels, Flemish and Walloon regions, it is a green lung for the capital and a refuge for countless species. The Grand Bioblitz will help build knowledge of this unique forest by encouraging visitors to record as many species as possible.
The forest is also home to the UN Trail, launched in October 2024 by the United Nations, in partnership with the Sonian Forest Foundation and Brussels Environment. The trail invites visitors to learn more about the forest’s biodiversity, its role in ecosystem restoration and the UNESCO recognition of parts of the Sonian Forest as Belgium’s only natural World Heritage site.
Taking part is simple: download the ObsIdentify app, create an account, activate location services and look for the National Biodiversity Challenge 2026 in the “Challenges” tab. Then go outside, take photos of wild species and let the app guide you.
Participants are also asked to respect nature: stay on paths, do not pick plants, do not disturb animals and follow local guidance, including any wildfire risk warnings.
Biodiversity Week is an invitation to rediscover the living world around us — in the forest, in the city and just outside our front door.
Additional links:
- International Day for Biological Diversity, 22 May
- Sonian Forest Days (FR | NL)
- ObsIdentify app (EN | FR | NL)
- Belgium Biodiversity Week
What is LIFE B4B?
LIFE B4B aims to contribute to the protection and restoration of biodiversity in Belgium. The LIFE Belgium for Biodiversity project (LIFE B4B) is one of the first LIFE Strategic Nature Projects (SNaP) of the European LIFE programme (= EU’s funding instrument for the environment and climate action).
