Adaptive variation and seed transfer for Ponderosa pine in Central Idaho

When planted and compared in the same environments, populations from elevationally or geographically mild sites demonstrated the most growth, mainly because of the long duration and rapid rate of shoot elongation. Populations from relatively cold sites were comparatively shorter largely because growth ceased early. Populations from the South Fork of the Salmon River, however, combined a high rate of shoot elongation with a short duration of growth and thereby were capable of high productivity while maintaining adaptability for severe sites. In artificial reforestation, seed transfer from most opoulations should be limited to +/- 650 feet of the elevation at the source. Test should be established to determine if South Fork populations can be moved beyond the recommended limits in an attempt to increase productivitiy on harsh, cold sites.