Summary
Published in Forest Ecology and Management 255: 3001-3012
Over the last few decades, several phenomena contributed to modify the structure and composition of the eastern North American forests. Along with forest management, disturbances such as insect defoliation, global environmental changes, acid deposition, and rising atmospheric CO2 concentrations, have been identified as phenomena that could affect forest structure and composition. Currently, there is very little quantitative information on the resulting effect of multiple disturbances on the main parameters of forest dynamics (growth, mortality, and recruitment). Using available data from the Québec permanent sample plots network, we analyzed the ecological response of tree species populations to the combined effect of contemporary global environmental changes, disturbance regimes, and forest management practices over the last 30 years in southern Québec. The results indicate that the main parameters of forest dynamics changed considerably over the last three decades. The last spruce budworm outbreak initiated a successional change in coniferous stands. The basal area of Abies balsamea and Picea glauca, the most abundant coniferous species, decreased by 29.7%, while pioneer species abundance increased. For late successional deciduous species, observed changes in forest dynamics appear to be mainly associated with global environmental changes rather than with natural disturbances or forest harvesting. The results indicate that inferring responses of tree population dynamics to global environmental changes can be very complex or even misleading considering the confounding effects of other disturbance agents. The results also suggest that the ecosystem-based management approach promoted by forest ecologists, aimed at maintaining landscape stand composition and structures similar to those characterizing natural environments, will not be easily achieved. Forest ecosystems are highly dynamic and disturbances other than tree harvesting appear to have been the major factors affecting their pattern of change over the last three decades. Forest managers should consider adaptive management approaches that will consider the contemporary evolution of forest ecosystems in a changing environment.
Sector(s):
Forests
Categorie(s):
Scientific Article
Theme(s):
Ecosystems and Environment, Forest Ecology, Forestry Research, Forests
Departmental author(s):
Author(s)
DUCHESNE, Louis and Rock OUIMET
Year of publication :
2008
How to get the publication :
Keywords :
sugar maple, american beech, tree regeneration, dieback, northern hardwood, soil properties, liming, ecosystems and environment, écosystèmes et environnement, Acer saccharum, Fagus grandifolia, écologie écosystèmes et environnement, érable à sucre, hêtre à grandes feuilles, régénération, déclin, feuillu tolérant, propriété du sol, chaulage
