Adaptedness of Noble Fir (Abies procera Rehd.) Beyond Its Northern Limit

Abstract

Abstract The adaptedness of noble fir (Abies procera Rehd.) beyond its northern limit was examined at 12 locations distributed throughout the Maritime, Submaritime, and Subcontinental climates in south coastal British Columbia. Ten-year testing results demonstrated large site effects. Noble fir planted in the Maritime climate survived better, grew faster, entered the period of accelerated growth earlier, and maintained a higher growth rate. In the Maritime climate, the reforestation range of noble fir can be extended considerably north of its current natural distribution and to lower elevations. Low winter temperature and growing-season soil moisture appear to be the major environmental factors limiting the species' expansion into more continental climates, and these factors must be considered in planting site selection. Provenance differences in both growth and survival were significant but small compared to site differences. Adaptive variation showed gentle geographic clines indicating that northern provenances were better adapted in the Maritime climate, whereas inland provenances were superior in the Submaritime climate. Lack of strong geographic patterns suggests that local environmental factors may be important to the adaptive variation of the species. The test results suggest that introduction of noble fir to British Columbia should be limited to the Maritime region, and that northern provenances, such as French Butte, McKinley Lake, and Stevens Pass in Washington are the primary seed sources. For. Sci. 40(3):412-428.