Genetic variation and structure at three spatial scales for Acersaccharum (sugar maple) in Canada and the implications for conservation

Abstract

Genetic (allozyme) variation and genetic structure in Acersaccharum Marsh. (sugar maple) were examined at three spatial scales: among populations across the species' range in Canada, among populations within a single region, and among individuals within populations. Levels of genetic variation were slightly lower than for other North American angiosperm trees and shrubs; however, genetic structure was observed at all three scales. Possible processes associated with the patterns of variation at different scales ranged from post-Pleistocene glacial migration to flowering ecology. Genetic conservation strategies for A. saccharum should aim to maintain a spatial hierarchy of populations and individuals throughout the species' range in Canada. This approach should encompass that genetic variation already in existance, and provide the range of spatial and organizational scales necessary for processes such as selection, gene flow, and genetic drift to continue to operate.