Successful under-planting of red oak and black cherry in early-successional deciduous shelterwoods of North America

Abstract

-Underplanting early-successional forest stands with red oak and black cherry was tested as a way of improving productivity on abandoned agricultural land of North American temperate deciduous forests. A partial release treatment was applied during the third growing season and compared to a control. The growth increment after six years is analyzed with respect to treatment and competition layers. Although the release treatment reduced competition at all vegetation layers, growth was mostly determined by the density of the upper layer. Deer herbivory was not increased by the release. The release treatment succeeded in significantly increasing available light for the duration of the study, while the understory recovered quickly. Planted trees, particularly red oak, responded well to the release treatment. Results substantiate the need for dynamic silviculture in sensitive, rural landscapes, where conservation of forest structure is important.under-planting / light / early-successional forests / deer herbivory / thinning treatment Résumé -Plantation sous-couvert de chêne rouge et cerisier tardif en forêt décidue pionnière d'Amérique du Nord. Des chênes rouges et cerisiers tardifs ont été introduits sous couvert de jeunes peuplements d'origine agricole dans une étude visant l'amélioration de la productivité de peuplements pionniers de la forêt décidue tempérée d'Amérique du Nord. Un dégagement partiel appliqué au cours de la troisième saison de croissance est comparé à un témoin. La croissance après six ans est analysée en fonction du traitement et des strates de compétition. Alors que le traitement avait significativement diminué la compétition à tous les niveaux, la croissance était surtout fonction de la densité de la strate supérieure. L'herbivorie par le cerf n'a pas été augmentée par le dégagement. Le traitement de dégagement a significativement accru la lumière disponible pour toute la durée de l'étude, alors que le sous-étage s'est reconstitué rapidement. Les plants, particulièrement les chênes rouges, ont bien répondu au dégagement. Les résultats supportent une sylviculture plus dynamique dans les paysages ruraux sensibles, où la conservation des structures forestières est importante. plantation sous-couvert / lumière / forêt pionnière / herbivorie par le cerf / traitement de dégagement

Light-dependent development of two competitive species (Rubus idaeus, Cytisus scoparius) colonizing gaps in temperate forest

“…Even if shade-tolerant species are able to survive in very low light availability, they grow better with increasing light [5,6,24]. Therefore a compromise is to be found between a light value that sufficiently reduces competitive vegetation development while allowing a non negligible growth of tree regeneration [20]. Accordingly, our findings suggest that light availability in forests should be reduced to below 30% to prevent more than 20% Cytisus scoparius cover (about 50 cm height).…”

Morphological plasticity in seedlings of three deciduous species under shelterwood under-planting management does not correspond to shade tolerance ranks

“…Bouchard and Domon, 1997;Brisson and Bouchard, 2003), as well as methods of forest rehabilitation (e.g. Cogliastro et al, 2003Cogliastro et al, , 2006Paquette et al, 2006a). Natural regeneration of several species of hardwood trees, once abundant in the region's forests, is now rare after two centuries of severe deforestation resulting in the loss of seed trees (Simard and Bouchard, 1996;Brisson and Bouchard, 2003).…”

Unexpected seedling growth in the understory of post-agricultural forests from Eastern Canada

“…The strong negative correlation found between red maple height growth rate and the height of the understory layer confirms its ability to persist in low-light environments. The correlations between black cherry growth and different plant groups could be explained by unmeasured factors such as competition for water or nutrients, although the association with the thorny Rubus genus could give a certain degree of protection from browsing, as was suggested by Paquette et al (2006) to explain similar results. The results suggest that the levels of available light are not limiting for the very shadetolerant sugar maple.…”