Present and future focal point seed zones for jack pine in Northwestern region of Ontario

Abstract

Jack pine (Pinus banksiana Lamb.) is among the most widespread and most ecologically and economically important species for planting and direct seeding in the Lake States and throughout much of the boreal forest of Canada. Focal point seed zones for northwestern Ontario jack pine were previously developed in the 1990’s but are in need of revaluation and refinement based upon recent growth and mortality measurements and more current climate models. Updated focal point seed zones created for both present and predicted future climate conditions will provide forest managers with seed transfer guidelines that avoid maladaptation between seed sources and planting sites under a range of current and future climate conditions. To update the existing focal point seed zones and develop future focal point seed zones of jack pine in northwestern Ontario, the newest version o f the climate model OCM2 (1961-1990) was used to update the existing focal point seed zones, while four separate climate change models (CGCM1, CGCM2, HADCM3, CSIRO) were used to develop future focal point seed zones based on predicted future climate conditions. Data obtained from a freezing trial conducted by Davradou (1992), as well as data for additional growth and survival variables collected in recent years (1997, 2003 and 2004) were incorporated when compared with the previous focal point seed zone studies of jack pine in northcentral Ontario and northwestern regions of Ontario. In total 23 and 47 biological variables including growth, phenological and freezing variables were determined for each seed source in these two study areas. Principal components analysis (PCA) was used to summarize the main components of variation patterns. The first two PC axes represented growth potential and phenology, respectively, for these two study areas. PCA axis factor scores for seed sources were regressed against current climatic variables. The significant regression equations were used to model the patterns of adaptive variation. Present and future focal point seed zones were produced through intersecting the two contour maps by GIS. Future focal point seed zones include where seed should go from a given location to best suit future climate conditions (Seed To) and where seed should come from now to be best adapted in the future to its planting location (Seed From). Under these different predicted future climate models, by the middle of this century, seeds will transfer to the north or northeast to match the future climate conditions and seeds should come from areas lying to the south or southeast of the planting location to be best adapted to the future site. By the end of this century, the northward or northeastward shift gradually slows and seed zones will move back under some climate scenarios.