Early growth performance of salal (Gaultheria shallon) from various North American west-coast locations

Salal is a native perennial evergreen shrub occurring from the panhandle of Alaska along the entire coast of British Columbia to southern California. In the North American west coast industrial forest it is considered a weed because it is a persistent, serious competitor with coniferous species. Intraspecific genotypic and phenotypic diversity of salal is not well known despite of its ecological and economic significance. A morphometric analyses within and among populations was performed in a statistically appropriate manner. Two-year-old container grown seedlings of 24 collections of salal from throughout the natural area of distribution in western North America were planted in a randomized complete blocks design (6 blocks) on a cleared 0.7 ha plot on Vancouver Island. Each of the 24 seedlots was planted once in each block with 24 plants per seedlot in April 1990. Shoot height and the number of buds prior to planting, the plant spatial volume (product of plant height and plant width on two perpendicular axes) in 1992 and 1993, the relative growth increment (1992-1993) and the number of dead plants in 1992 and 1993 were subjected to analysis of variance. No differences among seedlots were detected for the relative growth increment and the number of dead plants in 1992 and 1993. Conversely, shoot height and the number of buds prior to planting as well as the plant volume in 1992 and 1993 showed statistically significant seedlot effects. Cluster analysis of these effects revealed greatest differences in plant response among the eastern- and southernmost collection and the remainder of the collections; i.e. three geographical races of salal may exist. Potentiel de croissance initiale du Salal (Gaultheria shallon) de diverses régions de la côte ouest de l'Amérique du Nord. Le Salal est un arbuste autochtone pérenne à feuilles persistantes réparti depuis la péninsule de l'Alaska tout au long de la côte de la Colombie Britannique jusqu'au sud de la Californie. Dans les forêts industrielles de la côte ouest de l'Amérique du Nord, il est considéré comme une mauvaise herbe parce qu'il est persistant et un compétiteur sérieux des espèces de conifères. La diversité intra spécifique génotypique et phénotypique du Salal n'est pas bien connue malgré son importance écologique et économique. Une analyse morphométrique parmi ses populations a été réalisée selon les règles statistiques. Des semis de 2 ans, ayant poussé en conteneurs, provenant de 24 collections de Salal ori