Southern pine seed sources

The purpose of this handbook is to guide landowners and consulting foresters in selecting appropriate seed sources for planting southern pines. It replaces the booklet “A Guide to Southern Pine Seed Sources” written by Clark Lantz and John Kraus (1987). Both are now retired from USDA Forest Service. Important changes based on more recent research have been made. The biggest changes are in the seed movement guidelines themselves. The new guidelines avoid the term “zones” because it implies distinct boundaries. North-south variation in growth and survival traits is considered continuous (clinal), and east-west movement to areas of similar climate is generally permissible, with some major exceptions for loblolly pine.