Dead wood plays a vital role in forest biodiversity

Dead wood, including fallen branches, old stumps, and decaying trees, serves as a vital component for ecosystem health and biodiversity. These elements facilitate the organic matter cycle by balancing carbon-to-nitrogen ratios, which enhances soil fertility through the decomposition of lignin and cellulose into humus.

Dead wood provides essential habitats, food sources, and breeding grounds for a wide variety of organisms, including xylophagous insects, fungi, bacteria, mosses, lichens, amphibians, small mammals, and birds. Some rare beetle species depend exclusively on dead wood for survival.

In France, the Office National des Forêts (ONF) identifies and geolocates specific trees essential for biodiversity, referred to as ‘bio trees’. These include dead trees standing or on the ground, senescent trees, and those with cavities or large nests. To distinguish them, foresters mark these trees with an inverted yellow triangle painted on the trunk. Approximately one-quarter of forest animal and fungal species rely on dead wood and the micro-habitats provided by tree cavities.