Intraspecific variation in stem growth of western hemlock

Abstract

Fifteen coastal provenances of western hemlock Tsugaheterophylla (Raf.) Sarg. were tested on four sites on Vancouver Island, B.C. Provenance origins and test sites lay within roughly 2° of latitude and at 0–580 m above mean sea level. Mean heights of provenances 10 years after planting varied from roughly 74 to 121% of the plantation mean at each site; plantation means varied from 388 to 493 cm. No interaction between provenance and test site was detected and rankings of provenances remained quite constant from site to site. A large proportion of provenance variation could not be accounted for by descriptors of provenance origin. Results show that for the geographic range tested, faster growing provenances could be planted without constraints imposed by elevation and latitude.