Le mélange d'essences est-il favorable à la diversité végétale en forêt?

Abstract

Tree species-richness is thought to be conducive - and conversely pure dominant plots adverse - to the diversity of forest flora. However, a review of the literature shows that very few studies have verified that assumption. In fact, the combination of broadleaved and conifer species is very seldom more conducive to floristic diversity than their pure conifer or broadleaved equivalent. In four forests in the Brie area, we tested the effects of species-richness versus dominant pure effects on floristic diversity. Species-richness turned out to have few significant effects whereas pure dominants did have significant effects on the species-richness of several floristic groups. In particular, it had a positive effect on the species-richness of herbaceous plants. To draw any definite conclusions on this topic, research needs to be conducted elsewhere in French forests.