Light-mediated influence of three understorey species (Calluna vulgaris, Pteridium aquilinum, Molinia caerulea) on growth and morphology of Pinus sylvestris seedlings

Noémie Gaudio (1) , Philippe Balandier (1) , Gwenaël Philippe (1) , Yann Dumas (1) , F. Jean (1) , Christian Ginisty (1)

1 UR EFNO - Écosystèmes forestiers

Pinus sylvestris is a pioneer species and as such is relatively light-demanding. Therefore, its natural regeneration may be inhibited by some forest understorey species that develop with light and can then reduce light as well as soil resources (i.e. nutrients and water) availability for the pine seedlings. To better quantify these effects, we designed two experiments in a nursery. The first one aimed at studying the influence of density of three common understorey species in temperate forests (Calluna vulgaris, Pteridium aquilinum and Molinia caerulea) on pine seedlings survival and growth. The purpose of the second experiment was to quantify the development of these three species relatively to light that varied in our experiment from 6 to 100% of relative light. An increase in weed density, i.e. a concomitant decrease of light availability and soil moisture content, resulted in reduced pine seedlings growth (diameter and biomass) and higher stem height/diameter ratio but had no significant effect on seedlings survival. Height and cover of the three weedy species followed a non linear relationship relative to light availability. Results are discussed according to the quantity of available light as well as its quality assessed through the red/far red ratio, both for the pine seedlings development and weed species height and cover, and their interactions.

Mots clés: PLANT FORESTIER; SEMIS; PINUS SYLVESTRIS; SURVIE; CROISSANCE EN HAUTEUR; CROISSANCE EN DIAMETRE; MORPHOLOGIE; CONCURRENCE VEGETALE; LUMIERE; CALLUNA VULGARIS; PTERIDIUM AQUILINUM; MOLINIA CAERULEA; REGENERATION NATURELLE; DISPOSITIF EXPERIMENTAL; EXPERIMENTATION; FORET; ARBRE FORESTIER; MAUVAISE HERBE; VEGETATION; SOUS ETAGE FORESTIER; DISPONIBILITE EN LUMIERE; INTERCEPTION LUMINEUSE; ARBRE; REGENERATION; ADVENTICES; MOLINIE; CALLUNE; FOUGERE; PIN

Domaines: Sciences et techniques de l'agriculture; Botanique; Amélioration des plantes; Biodiversité et Ecologie; Etudes de l'environnement; Ecosystèmes

Noémie Gaudio, Philippe Balandier, Gwenaël Philippe, Yann Dumas, F. Jean, et al.. Light-mediated influence of three understorey species (Calluna vulgaris, Pteridium aquilinum, Molinia caerulea) on growth and morphology of Pinus sylvestris seedlings. Final COST E47 conference Forest vegetation management towards environmental sustainability, May 2009, Vejle, Denmark. p. 70 - p. 72. ⟨hal-00468648⟩