GENETIC-VARIATION AND STRUCTURE AT 3 SPATIAL SCALES FOR ACER-SACCHARUM (SUGAR MAPLE) IN CANADA AND THE IMPLICATIONS FOR CONSERVATION

Genetic (allozyme) variation and genetic structure in Acer saccharum M arsh. (sugar maple) were examined at three spatial scales: among popul ations across the species' range in Canada, among populations within a single region, and among individuals within populations. Levels of ge netic variation were slightly lower than for other North American angi osperm trees and shrubs; however, genetic structure was observed at al l three scales. Possible processes associated with the patterns of var iation at different scales ranged from post-Pleistocene glacial migrat ion to flowering ecology. Genetic conservation strategies for A. sacch arum should aim to maintain a spatial hierarchy of populations and ind ividuals throughout the species' range in Canada. This approach should encompass that genetic variation already in existance, and provide th e range of spatial and organizational scales necessary for processes s uch as selection, gene flow, and genetic drift to continue to operate.