Clonal constitution and sex ratio in northern populations of balsam poplar Populus balsamifera

Abstract

Isozyme analyses performed on balsam poplar stands in subarctic northern Québec indicated polyclonal predominance (76%). This suggests that seed sources were adequate for colonization of new habitats. High variance at the clone and the stand levels did not permit, however, the use of morphological traits for clonal partitioning. A non‐random sex distribution related to habitat conditions was found both at the regional and the local scales, although there is an equal male‐female ratio in the study area. Female stands predominate in regions subject to a maritime climate (1:5) and in fertile and humid habitats (1:7).