Influence of forest road, road surfacing material and stand age on floristic diversity and composition in a nutrient-poor environment
Influences de la route forestière, du type de matériau de la route et de l'âge du peuplement sur la diversité et la composition floristique en milieu acide
Bergès, L. ; Chevalier, R. ; Avon, C.
Type de document
Article de revue scientifique à comité de lecture
Affiliation de l'auteur
IRSTEA AIX EN PROVENCE UR EMAX FRA ; IRSTEA NOGENT SUR VERNISSON UR EFNO FRA ; IRSTEA AIX EN PROVENCE UR EMAX FRA
Résumé / Abstract
Questions. How did the presence of forest roads modify plant diversity and composition in a nutrient-poor environment? What was the effect of the use of limestone gravel as road surfacing material? How did floristic succession vary between roadside and forest interior? Location. State Forest of Orléans, Loiret, Northern France. Methods. We sampled thirty pairs of 2000-m² plots, one on road and the other 30 m inside forest, on two road surfacing materials (limestone gravel and bare soil) and three stand ages (young, middle-aged, and mature) in Scots and Corsican pine stands in a large managed forest. Plant diversity was analysed according to life-history traits (protection status, indigenousness, life form, habitat and ecological preferences). We tested the effects of plot position, road type and stand age on species richness, species composition and individual species response. Results. The species richness of all plant groups was always higher on roads compared to forest stands, and the forest plot communities were nearly completely nested within the roadside plot communities. Seven protected species and four non-native potentially invasive species were observed on roadsides. Limestone gravelled roads hosted more species than bare soil roads, but acidophilous forest and grassland species richness was higher on bare soil roads. Plant composition similarity between the roadside and forest were higher at early successional stages and lower in older stages. Conclusions. Roads have inseparable positive and negative effects on plant communities, but the negative ones are of great concern. To prevent further damage in these nutrient-poor ecosystems, we recommend monitoring road sections hosting protected acidophilous species, not increasing road density, and replacing limestone gravel by a low-pH endogenous material.
Applied Vegetation Science, vol. 16, num. 3, p. 470 - 479