Genetic diversity in Canadian Hardwoods: Implications for conservation

Abstract

Hardwoods are diverse, and they are important components in several forest regions of Canada. Yet low demand from the pulp and paper sector, abundant natural regeneration for several species, and high costs associated with seedling production and plantation establishment have restrained industries and governments from investing intensively into basic biological and genetic research of hardwoods. Recently, new interests have emerged for the utilization and conservation of hardwood species. To devise efficient gene conservation and breeding strategies for hardwoods, knowledge is needed about their genetic structure, genecology, and mating systems. Here we review information on the organization of genetic diversity in the few Canadian hardwood species that have been studied. Results derived from analyses of quantitative characters showed extensive genetic variation among populations and among individuals within populations in all species. Genetic variation among populations was found to be associated with environmental factors, especially for adaptive traits. Levels of genetic diversity were also found high in allozyme genetic markers. The application of molecular genetic markers at the DNA level in monitoring genetic diversity of hardwoods is also discussed. Information available regarding genetic diversity of Canadian hardwoods is insufficient to design efficient gene conservation strategies. Several programs investigating genetic diversity of hardwoods have been initiated in Canada, and should yield urgently needed data.