Genecological variation corresponding to Forest Ecosystem Classification vegetation and soil types for jack pine and black spruce from northwestern Ontario.

A preliminary study was undertaken to reveal ecotypic differentiation in jack pine and black spruce corresponding to ecological land classification groups. Seed sources of jack pine (64) and black spruce (68) from northwestern Ontario were classified according to Vegetation Types (V-Types) and Soil Types (S-Types) defined by the Forest Ecosystem Classification (FEC) developed by the Ontario Ministry of Natural Resources and Forestry Canada for northwestern Ontario. Two short-term common garden field trials and a greenhouse trial were established for each species. Significant differences were present among ecological groupings of seed sources for both species. These differences were expressed according to V-Types and S-Types based on first, second, and third year heights as well as needle flushing dates for jack pine and second year growth increments for black spruce. Rank differences among the groups based on FEC V-Types and S-Types were generally consistent for each of the two species although certain groups showed rank reversals at the two field trials. Apparently, selection pressures corresponding to different FEC V-Types and S-Types have resulted in a detectable pattern of adaptive variation for both jack pine and black spruce in northwestern Ontario. However, the management implications for these two species are uncertain since additional tests are required to verify these results.