Every wood anatomist knows that the wood near the center of a tree (juvenile wood) differs from the wood laid down at some distance from the pith (mature wood), and that the wood produced during the spring (earlywood) differs from the wood produced during the summer (latewood). There is a...
The objective of this project was to investigate the fate of ponderosa pine regeneration from seed to established seedling, and to determine the relative influences of several important stand elements on those fates. The project was carried out in a series of observational and experimental recruitment studies in central Oregon....
Basal area and height growth were analyzed for individual trees in uneven-aged ponderosa and lodgepole pine stands in central Oregon. Basal area growth was modeled as a function of other stand and tree variables to address five general objectives: 1) to compare the predictive ability of distance-dependent versus distance-independent stand...
The relationship between annual foliage production and nitrogen and water stress was examined in 14 naturally regenerated, mid-rotation ponderosa pine stands in central Oregon. Current-year and older foliage masses, and foliage nitrogen contents and concentration were estimated from 132 destructively sampled trees. Litterfall mass and nitrogen retranslocation rates from senescing...
Exotic ponderosa pine (Pinus ponderosa Doug. ex Lawson) plantations are being planted within the natural distribution area of cordilleran cypress (Austrocedrus chilensis (D.Don) Pic. Ser. et Bizzarri) in Patagonia, Argentina. The productivity of these exotic plantations is much greater than that of native forests, suggesting greater water use. Before these...
Without the natural occurrence of fire in ponderosa pine forests of the western US, lodgepole pine has started to dominate regeneration in many forest stands and may be gradually replacing ponderosa pine over time. This development, however, conflicts with recent efforts in this region to restore old-aged, open ponderosa pine...
Healthy-appearing 1-0 ponderosa and lodgepole pine seedlings were assayed for root infection and colonization by potentially-pathogenic fungi following pre-sowing soil treatments which included methyl bromide/chloropicrin (MBC) fumigation, fallowing with or/without periodic cultivation, and amending soil with mushroom composts or undecomposed sawdust. Levels of root colonization by Fusarium spp. on both...
This dissertation describes arthropod responses to and effects on decay processes in ponderosa pine, a dominant forest canopy tree in northern California. We used both descriptive and experimental field techniques to establish how arthropod assemblages depend on and are important to the disintegration of woody structures in forests of this...
Ultrasonic wave attenuation and velocity in the transverse direction were used to detect defects in ponderosa pine (Pinus Ponderosa) lumber previously dried from green to 9% moisture content. After ultrasonic testing the boards were visually inspected for defects and classified according to the defects present. An ANOVA with Bonferroni pairwise...
Although previous research in central Oregon has shown soil compaction can lead to a decline in site productivity, the subject is not understood well enough to predict the growth changes resulting from a given level of soil compaction. A study was initiated to relate the basal area, height and volume...