Douglas-fir Provenance Survival and Growth in the British Columbia South Submaritime Seed Planning Zone

In southwestern British Columbia, the South Submaritime (ssm) seed planning zone is a geographically and ecologically complex transition zone between the Pacific coast and the interior plateaus. The ssm follows a long, narrow band along the Coast Range (Figure 1), and is characterized by steep, incised valleys. The highly variable climate is strongly influenced by prevailing warm, moist maritime air masses, and towards the east it is characterized by a cool, dry continental climate. Throughout the ssm, survival rates of the 1.3 million annually planted Douglas-fir seedlings are far below those that are typical or expected for post-harvest plantations: below 8% by age 3, declining to under 7% by age 5 (Ministry seedling survival database; Hunt ), compared to typically over 95% at comparable ages for most operational areas. Douglas-fir is approximately 4% of the harvested volume (biogeoclimatic subzone averages within the ssm range from 36 to 65%) and is the preferred species on most sites. Most of the seedlings currently planted in the ssm originate from seed orchard #181 that produces Class A seed bred to increase yields and maintain adaptability to the planting site throughout the ssm (Forest Genetics Council 1). Current seed transfer standards in the ssm are based on the principle that local seed is best adapted to a site and specify that seedlings used for reforestation must be used within °N, 1°S, °E, no limit west, and 35 m up or down from its origin (Snetsinger 5). However, recent trials suggest these standards could be overly restrictive and may limit performance of planted Douglas-fir (Hunt 3). In 1996, a long-term series of provenance trials (e.p. 1) was established to: (1) describe patterns of genetic variation for Douglas-fir in the ssm; () compare the growth performance of ssm seed sources with coastal, interior, and intra-specific hybrids in the ssm; and (3) provide data to refine seed transfer guidelines in the region. This report presents 1-year results and attempts to determine whether current restrictions on seed transfer are aligned with adaptive patterns of Douglas-fir for this region, or whether the standards should be revisited.