2023-06-03 11:57:00
With global warming, fires like the one that took place in the Fagnes are likely to be repeated often in the coming years. With what impact on our biodiversity and vegetation?
One would think that after a fire, no more vegetation will grow back. This is false: a few months later, some plants will reappear. “We are going to have the installation of species that we call ruderal species, such as nettle, umbelligera, geranium…”explains Grégory Mahy, professor of ecology and biodiversity management at the faculty of Gembloux. “These are very generalist species that colonize degraded areas.”
Last year near Wavre, a brush fire broke out in August along the E411. All the vegetation had been burned. Today, the green is back even if the trees still standing are still dead. Many grasses have actually grown back in a year: this will allow trees and vegetation to grow back with small shrubs at first.
Fires are actually part of natural cycles, especially in the Fagnes, where the flora will quickly return. “Wherever there are grasses, it will be green again in six or seven weeks, if we don’t have extreme drought,” notes René Dahmen, cantonment chief of the Department of Nature and Forests (DNF).
Some favored species
This will become more problematic in the event of a larger and/or more frequent fire. “In our ecosystems which are highly degraded, this is a problem”, continues Professor Grégory Mahy. “It will contribute to the degradation of the soil, to the degradation of forest regeneration which is already not easy.”
The first species to regrow will therefore be herbaceous species which are qualified as aggressive and which have prevented other more specific plantations from growing. Another problem: they catch fire very easily…