Methods for describing light capture by understorey weeds in temperate forests: consequences for tree regeneration
Résumé
Light quantity and light quality are two of the main environmental factors controlling the success of seed germination, seedling establishment and growth of trees in the understorey of our temperate forests. Increasing light availability by the practice of thinning also promotes the development of the ground vegetation, graminoids, forbs and shrubs, which may affect tree regeneration. These plants can intercept a significant fraction of the available light in the understorey and thus the resulting amount of light available for tree seedlings can vary greatly depending on species and composition of ground vegetation. Assessing light capture within such complex distribution of vegetation still faces many technical challenges. Measuring light directly in the understorey of forest stands, taking into account the ground vegetation, can be very tedious and expensive. Therefore mathematical methods, dealing with plant architecture, are being developed to resolve light capture by tree seedlings in contrasting understorey situations. Many models have dealt with light transmission through forest overstorey whereas the understorey vegetation is often not taken into consideration. We will synthesize results on light measurement under different understorey species (Rubus fruticosus, Rubus idaeus, Epilobium angustifolium, Cytisus scoparius, Calluna vulgaris, Molinia caerulea, Pteridium aquilinum), provide some modeling options for light capture computations, and discuss potential consequences for tree regeneration.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...