Focal point seed zones: site-specific seed zone delineation using geographic information systems

A new site-specific approach to defining seed zones in North American conifers is described. Using focal point seed zones, an individual site to be reforested becomes the focal point, and a unique seed zone is established for that site as needed. This approach depends upon (i) obtaining good comparative data in adaptive characteristics from throughout the range to beregenerated based upon a series of short-term growth tests in a common garden and (or) greenhouse and (ii) graphic analysis of multivariate summary scores by geographic information systems software to delimit boundaries of unique seed zones for any location to be reforested. A sample focal point seed zone is delineated for jack pine (Pinusbanksiana Lamb.) reforestation of a site in northern Ontario. This approach has considerable potential to help prevent decreased growth and yield due to the planting of maladapted seed.