Actualités

How are France's forests faring?

28 / 08 / 2024
Knowledge & data
Terrestrial environment
Credit : Philippe Massit / OFB

What is the current state of forest biodiversity in France? What pressures are being exerted on it? To mark International Forest Day, the French Biodiversity Agency (OFB) presents an overview of the current situation, in conjunction with the new thematic publication on forests from the French Biodiversity Observatory.

Home and refuge to a vast number of species, forests are among the richest terrestrial ecosystems in terms of biodiversity. Appreciated for their landscapes, heritage and cultural values, forests are rooted in the collective imagination and have been shaped by human activity.

As early as the Neolithic era, farming and pastoral practices led to numerous forest clearings. This dynamic intensified from Antiquity onwards, as the human population expanded.

After reaching its minimum area in the 1830s, the forest area in France has doubled since the mid-19th century. The reasons for this positive trend include agricultural abandonment, the development of alternative energy sources and the implementation of massive reforestation programs.

Today, French forests cover 31% of France (2018) and 84% of the French overseas territories (2020). The Guiana rainforest alone represents 7.5 million hectares, or 85% of the department.

What is a forest?

According to the official definition of the Food and Agriculture Organization (FAO), a forest is defined as an area of at least 5,000 m² and 20 meters in width, with trees that can reach heights of more than 5 meters at maturity and a tree crown cover of more than 10%. Woodlands whose main use is agricultural or urban are excluded.

For areas smaller than 5,000 m², the term “forest” is replaced by “grove”.

Although forests are gaining ground in France every year, they are still subject to numerous human-induced pressures:

  • Land artificialization: between 1990 and 2018, more than 40,000 hectares of forest were destroyed in France for urban development or human infrastructure. Over the same period, 1,400 hectares of hardwoods were destroyed in the French overseas territories.
  • Climate change: the increase and combination of natural hazards linked to climate change are causing a general deterioration in the health and vitality of trees. Increasing mortality has already been observed, estimated at +54% over the last decade.
  • Light pollution: artificial light sources are harmful to the biological rhythms of forest species and affect plant growth. In 2020, 85% of our territory was affected by light pollution.
  • Invasive alien species: accidentally or deliberately transported outside their natural range, these species are likely to harm existing biodiversity by altering ecosystem balances. This is a particularly important issue in overseas island territories such as French Polynesia, where Miconia calvescens is now nicknamed the “green cancer” due to its rapid colonization of the island's rainforests, threatening many endemic plant species with extinction.

In many cases, the various past and present pressures add up to a cocktail that is particularly damaging to forest ecosystems and the species that inhabit them.

Although the situation seems alarming, there are some encouraging signs.

Despite significant declines in certain bird populations in France, the numbers of specialist forest birds are virtually stable (-2%), unlike those in urban and agricultural areas.

What's more, the volume of dead wood and very large trees in forests, essential elements for the existence of certain forest species, increased by an average of 7% between the periods 2008-2012 and 2013-2017.

Finally, the regular presence of large predators (brown bear, wolf, lynx), which contribute to the ecosystem balance of forests, is on the rise in France: territory coverage by at least one large predator has risen from 2% in 2001 to almost 9% in 2020.