The project will study ponderosa pine to various planting site conditions in an attempt to develop correlations between ray tracheid area, active sapwood area and drought tolerance. The results of this study will lead to a greater understanding of tree species with varieties adapted to contrasting climates and further refine how trees utilize sapwood
Oregon and Washington are unique in their state-wide climatic variation. The Cascade Crest draws a definitive boundary between the mild and wet west-side and the dry desert of the east-side. Tree species have adapted to survive in both extremes; however several species have developed varieties or ecotypes adapted to one climate or the other. The Willamette Valley (WV) ponderosa pine is a perfect example of ecotypic adaptation. Ponderosa pine has a wide geographic range but is most commonly found in areas with little annual precipitation. WV ponderosa has adapted to areas with higher rainfall, more consistently saturated soils and less extreme temperatures. Studies have shown that the trees from dry-side seed sources do not do well in the wet conditions of the Willamette Valley. This indicates that the WV ponderosa has developed specific physiological and anatomical adaptations that make it well suited for the Willamette Valley. This project will study these adaptations in an attempt to develop correlations between ray tracheid area, active sapwood area and drought tolerance.