The angular distribution of diffuse photosynthetically active radiation under different sky conditions in the open and within deciduous and conifer forest stands of Quebec and British Columbia, Canada

Gendron, Fidji; Messier, Christian; Lo, Ernest et Comeau, Philip G. (2006). « The angular distribution of diffuse photosynthetically active radiation under different sky conditions in the open and within deciduous and conifer forest stands of Quebec and British Columbia, Canada ». Annals of Forest Science, 63, pp. 43-53.

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Résumé

The angular distribution of diffuse photosynthetically active radiation (PAR) was characterised in the open and beneath deciduous and conifer forests in Quebec and British Columbia, Canada, under overcast and clear sky conditions, using a restricted field of view light sensor and hemispherical canopy photographs. The angular distribution of PAR was described by the relative light reading (RLR). In the open on overcast days, light was best characterized using the standard overcast sky distribution with the light intensity at the zenith set to four to five times greater than the light intensity at the horizon. RLR under forest stands was found to decrease with decreasing elevation angles under both overcast and clear sky conditions. Aspen (Populus tremuloides Michx.) and Jack pine (Pinus banksiana Lamb.) stands transmitted more light from a relatively wider angle around the zenith than the spruce (Picea glauca (Moench) Voss and Picea mariana (Mill.) BSP) stands, which transmitted light mainly from the zenith. RLR estimated with the hemispherical canopy photographs (RLR hc_corr) generally provided a comparable prediction of the effect of the canopy composition on the angular distribution of PAR.

Type: Article de revue scientifique
Mots-clés ou Sujets: coniferous forest, deciduous forest, diffuse radiation, photosynthetically active radiation
Unité d'appartenance: Faculté des sciences > Département des sciences biologiques
Déposé par: Christian Messier
Date de dépôt: 26 nov. 2008
Dernière modification: 01 nov. 2014 02:07
Adresse URL : http://archipel.uqam.ca/id/eprint/1368

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