Reproductive ecology of the Sitka willow (Salix sitchensis ).

Salix sitchensis, Sanson ex Bong, was shown to be ...pollinated by both wind and insect vectors in this study. Vector reliance and efficiency were variable by site as well as year, and pollen limitation was also observed. Asexual propagules had a higher survival rate and abundance compared to seedlings. Low seedling survival, an abundance of asexual propagules, and the presence of linkage disequilibrium suggested that asexual reproduction was occurring. However, all sampled individuals had a unique multilocus genotype and populations had a high level of genetic and genotypic diversity. These factors suggested that sexual reproduction is the dominant strategy in the observed populations of S. sitchensis. High gene flow and non-significant isolation by distance suggested that S. sitchensis exists as a large, continuous, interbreeding population along the sampled waterways in central British Columbia. Successful restoration of riparian habitat is dependent on species specific reproductive information and knowledge of how species interact with other riparian species. The data determined in this study may help future riparian restoration efforts, as the reproductive strategy of a common riparian willow and how it interacted with beavers (Castor canadensis Kuhl) was quantified.