Voir en


Environmental awareness: exploring CERN’s biodiversity

Take a walk around CERN to discover the rich flora and fauna that surround us

Flora inventory May 2022
A lizard orchid (Himantoglossum Hircinum) and a marbled white butterfly (Melanargia galathea) on the Prévessin site (Image: CERN)

It’s morning. You’re walking to your workplace. The sun is shining, and you look down at the greenery along the path. What do you see? Is that wild thyme? Sorrel? And look, a pyramidal orchid! You might know that CERN has several sites, but what you might not know is that the Organization spans 625 hectares, 415 of which are non-built environments. This land hosts a variety of species and ecosystems, including endangered species of wild orchid.

Over time, the Laboratory has implemented several measures to promote biodiversity on its land, with an approach based on low-intensity maintenance to foster biodiversity preservation, keeping watering to a minimum and eliminating fertilisers and chemicals wherever possible. CERN delays grass mowing and uses sheep grazing to allow the flora’s full life cycle to complete. In addition to its fenced sites, CERN also owns 136 hectares of woodland, mainly located along the surface path of the SPS accelerator. These forests, most of which are located in France, are jointly managed by CERN and the French forestry commission (Office National des Forêts – ONF). To ensure minimum mechanical intervention, be more respectful of the land and reduce damage to woodland soil, horse logging is used to remove fallen trees, a forest management measure in regular use since 2012.

In 2020, the Organization set up a working group on biodiversity with four key objectives: conserving and protecting natural spaces in the CERN domain; developing biodiversity in fenced and unfenced areas; establishing measures for biodiversity for new development projects on CERN sites; and defining indicators to monitor biodiversity at CERN. The proposed action plan for 2021–2025 identified several measures to be approved, funded and implemented by the CERN Environmental Protection Steering board (CEPS), two of which have already been set in motion.

The first one is to draw up guidelines for biodiversity considerations concerning new construction at CERN. These 11 guidelines aim to align CERN with the French and Swiss regulations on biodiversity protection. They cover a range of subjects, such as new plantations, invasive species, green roofs and tree compensation. An example of the latter is the recent planting of 200 trees on the Meyrin site over three years, compensating for previously felled trees due to ageing and construction work. This measure is aligned with CERN’s Masterplan 2040, released at the end of 2021, which adopts principles and standards to promote biodiversity when developing the site. Specific measures have been developed not only to preserve CERN’s natural heritage, but also to strengthen biodiversity on the land managed by CERN.

The second measure that has been launched involves surveys of various species of fauna and flora on the CERN sites. Conducting surveys is crucial to monitor populations and will enable CERN to identify zones of biological interest and their importance and help put in place concrete protection measures. Based on expert recommendations, the inventories will focus on flora, amphibians, insects and birds. The first surveys have already started: during the inventory of amphibians, two species of frog as well as two protected species of newt were found. A first inventory of the flora led to the identification of a new orchid species on the CERN site, the burnt-tip orchid. The inventory of birds is still under way.

CERN’s biodiversity working group will continue to investigate other issues, such as light pollution, which can negatively impact night wildlife, as well as urban heat islands. Planting more trees and vegetation on site will help mitigate this phenomenon, which occurs in areas with high artificial infrastructure and little to no greenery. While concrete and asphalt absorb heat, vegetation helps cool the air and thus keeps the temperature stable.

The Organization is also committed to improving biodiversity downstream of its activities. In 2020, CERN co-signed a charter initiated by WWF Geneva for the revitalisation of the Nant d’Avril, the second largest affluent to the Rhône in the Geneva basin. In addition to improving water quality, the project will boost the biodiversity of the entire watershed. The project will run until 2033 and the actions taken will promote recolonisation by some target species, namely the brown trout, the fire salamander and the grass snake.

Next time you take a walk on the CERN site, engage your senses and notice the many species that surround you. Meanwhile, you can catch a glimpse of CERN’s biodiversity in this short video.

(Video: CERN)


This article is a part of the series “CERN’s Year of Environmental Awareness”.