Old-growth forests in the temperate deciduous zone of Quebec: Identification and evaluation for conservation and research purposes

摘要

The Quebec Department of Natural Resources (Ministere des ressources naturelles do Quebec) is working to identify and protect old-growth forests in the deciduous forest zone of the province. A total of 88 sites was visited and a multivariate analysis of the main attributes of old growth allowed the development of quantitative definitions and criteria for identifying old-growth sugar maple (Acer saccharum), eastern hemlock (Tsuga canadensis), eastern white pine (Pinus strobus), eastern white-cedar (Thuja occidentalis), and red spruce (Picea rubens) stands. Life expectancy of various species according to environment was determined through a statistical analysis of 21500 study trees taken from the province's forest inventory. Four different identification criteria for old-growth forests were developed that include a number of indicators for old growth. Along with advanced age of forest cover, the criteria that best reflected the nature of old-growth forests were the presence of large dead trees, low cutting intensity, and the importance of shade-tolerant species. Old-growth forests identified during this validation work occupy roughly 60 km(2) in Quebec's deciduous forest zone. Among other things, old-growth sugar maple stands of over 400 years old were discovered, containing stems with a diameter at breast height of 140 cm and a height of over 38 m. The very great potential of many of these exceptional forests for scientific research and biodiversity conservation is illustrated by the work carried out in the Boise des Muir. Despite its small size, this sugar maple stand, which is over 300 years old, has advanced knowledge in fields as varied as forest dynamics, biodiversity, and climate studies, and has also served as a control site for various scientific studies.