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. Int raspecific genotypic and phenotypic diversity of salal is not well known de spite of its ecological and economic significance. A morphometric analyses within and among populations was performed in a statistically appropriate m anner. Two-year-old container grown seedlings of 24 collections of salal fr om throughout the natural area of distribution in western North America wer e 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 n umber 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 re lative growth increment (1992-1993) and the number of dead plants in 1992 a nd 1993 were subjected to analysis of variance. No differences among seedlo ts were detected for the relative growth increment and the number of dead p lants in 1992 and 1993. Conversely, shoot height and the number of buds pri or to planting as well as the plant volume in 1992 and 1993 showed statisti cally significant seedlot effects. Cluster analysis of these effects reveal ed greatest differences in plant response among the eastern- and southernmo st collection and the remainder of the collections; i.e. three geographical races of salal may exist.