THE ECONOMICS OF PRUNING

1954 ◽  
Vol 30 (2) ◽  
pp. 197-214 ◽  
Author(s):  
J. H. G. Smith
Keyword(s):  
Shell Thickness ◽  
Tree Mortality ◽  
Douglas Fir ◽  
Early Age ◽  
Clear Wood ◽  
Tools And Techniques ◽  
International Rule

The need for pruning of Douglas fir is urgent. Research has shown that acceptable tools and techniques are available and has evaluated the effects of pruning. This report considers the costs and possible profit in pruning and concludes that for site III Douglas fir, pruning is profitable in all d.b.h. classes from 4" to 22".Volume and growth relationships between clear-shell thickness and diameter at the time of pruning are determined using both the International rule with ¼-inch kerf for board feet and the Smalian formula for cubic feet. A correction is made for slab allowance to give the net clear-wood scale of sawn material.Factors affecting lumber value of pruned trees are illustrated by examples of Douglas fir with and without natural pruning. Pruning profit per tree and per M.f.b.m. are calculated from value comparisons of clear and knotty lumber in pruned and unpruned trees. A formula is presented to aid in the choice of trees and stands to prune in the Douglas fir and other regions. Largest returns may be expected when rapidly growing trees are pruned at an early age. Additional profits may be secured by growing clear shells larger than four inches in diameter. Pruning is shown to be a safe and profitable investment at 2½ per cent without considering increased returns which may come from salvage of pruned-tree mortality and acceleration of growth by thinnings.

A Biodegradable Formulation of MCH (3-Methylcyclohex-2-en-1-one) for Protecting Pseudotsuga menziesii from Dendroctonus pseudotsugae (Coleoptera: Curculionidae) Colonization

2020 ◽  
Vol 113 (4) ◽  
pp. 1858-1863 ◽  
Author(s):  
Gabriel G Foote ◽  
Christopher J Fettig ◽  
Darrell W Ross ◽  
Justin B Runyon ◽  
Tom W Coleman ◽  
...  
Keyword(s):  
New Mexico ◽  
Pseudotsuga Menziesii ◽  
Tree Mortality ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Individual Tree ◽  
Significant Difference ◽  
Antiaggregation Pheromone ◽  
Individual Trees

Abstract Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, trees and stands can be protected from Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (DFB)-caused mortality by application of synthetic formulations of the beetle’s antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH). A biodegradable formulation of MCH, SPLAT MCH, was developed and evaluated for protecting individual Douglas-fir trees and small stands from colonization and mortality by DFB. In an individual-tree experiment in Idaho, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of treated trees colonized and killed by DFB compared to untreated controls. SPLAT MCH was as effective as MCH bubble capsules for protecting individual trees. Both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of trees colonized and killed by DFB within 0.04-ha circular plots surrounding each treated tree compared to untreated controls. In 0.41 ha stands in New Mexico, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of trees colonized and killed by DFB compared to untreated controls, again with no differences observed between MCH treatments. In a similar stand level trial in Idaho, neither MCH treatment significantly reduced the proportion of trees colonized by DFB, and only MCH bubble capsules significantly reduced levels of tree mortality compared to untreated controls, but no significant difference was observed between SPLAT MCH and MCH bubble capsules. Overall, the results indicate that SPLAT MCH is as effective as MCH bubble capsules for protecting individual trees and small stands of Douglas-fir from DFB-caused mortality.

Black Bears Prefer Urea-Fertilized Trees

1989 ◽  
Vol 4 (1) ◽  
pp. 13-15 ◽  
Author(s):  
E. E. Nelson
Keyword(s):  
Pseudotsuga Menziesii ◽  
Dominant Species ◽  
Tree Mortality ◽  
Ursus Americanus ◽  
Douglas Fir ◽  
Black Bears ◽  
National Forest ◽  
Feeding Damage ◽  
Mount Hood ◽  
The Difference

Abstract Feeding damage by black bears (Ursus americanus) to urea-fertilized 25-yr-old Douglas-firs (Pseudotsuga menziesii) in the Mount Hood National Forest, Oregon, resulted in tree mortality four times as severe as among unfertilized trees. Damage was most apparent following application of urea at 448 kg N/ha in 1972, and 224 kg N/ha in 1977. Only Douglas-fir, the dominant species in the stand, was attacked. Attacked trees were somewhat larger than the stand average, but the difference was not significant. Bears appeared to be attracted to the more vigorous trees, which were on fertilized plots. West. J. Appl. For. 4(1):13-15, January 1989.

Changes in the Summer Wild Bee Community Following a Bark Beetle Outbreak in a Douglas-fir Forest

2020 ◽  
Vol 49 (6) ◽  
pp. 1437-1448 ◽  
Author(s):  
Gabriel G Foote ◽  
Nathaniel E Foote ◽  
Justin B Runyon ◽  
Darrell W Ross ◽  
Christopher J Fettig
Keyword(s):  
United States ◽  
Species Richness ◽  
Bark Beetle ◽  
Tree Mortality ◽  
Canopy Cover ◽  
Douglas Fir ◽  
Wild Bee ◽  
Bee Community ◽  
Bee Communities ◽  
Bee Abundance

Abstract The status of wild bees has received increased interest following recent estimates of large-scale declines in their abundances across the United States. However, basic information is limited regarding the factors affecting wild bee communities in temperate coniferous forest ecosystems. To assess the early responses of bees to bark beetle disturbance, we sampled the bee community of a Douglas-fir, Pseudotsuga menziesii (Mirb.), forest in western Idaho, United States during a Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (Coleoptera: Curculionidae), outbreak beginning in summer 2016. We resampled the area in summer 2018 following reductions in forest canopy cover resulting from mortality of dominant and codominant Douglas-fir. Overall, results from rarefaction analyses indicated significant increases in bee diversity (Shannon’s H) in 2018 compared to 2016. Results from ANOVA also showed significant increases in bee abundance and diversity in 2018 compared to 2016. Poisson regression analyses revealed percent tree mortality from Douglas-fir beetle was positively correlated with increases in total bee abundance and species richness, where community response variables displayed a cubic trend with percent tree mortality. Percent reduction in canopy cover from 2016 to 2018 was also correlated with bee species richness and diversity. These findings suggest that wild bee communities may benefit from changes in forest structure following bark beetle outbreaks.

scholarly journals Douglas-Fir Beetle Response to Artificial Creation of Down Wood in the Oregon Coast Range

2006 ◽  
Vol 21 (3) ◽  
pp. 117-122 ◽  
Author(s):  
Darrell W. Ross ◽  
Bruce B. Hostetler ◽  
John Johansen
Keyword(s):  
Tree Mortality ◽  
Large Diameter ◽  
Douglas Fir ◽  
Coast Range ◽  
Managed Forests ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Management Objectives ◽  
Baited Traps ◽  
Before And After

Abstract Douglas-fir beetle populations were monitored before and after thinning and felling of trees to create down wood in an 88-year-old Douglas-fir plantation in the Oregon Coast Range. Treatments included an unthinned control, thinning to a target of 75 trees/ha, and thinning to a target of 150 trees/ha. Actual mean tree densities on the plots after thinning were 406, 102, and 154, for the control, 75 trees/ha, and 150 trees/ha treatments, respectively. Fifty trees/ha were felled and left on all thinned plots to create down wood for ecological values. Catches in pheromone-baited traps indicated that the local beetle population increased for 1 year in response to felling and leaving large diameter trees in partial shade. Douglas-fir beetle entrance holes and brood were significantly more abundant on the sides of felled trees and wood borers were significantly more abundant on the upper surface suggesting that treatments that provide maximum exposure of felled trees will create the least favorable habitat for Douglas-fir beetles. However, there were no differences in Douglas-fir beetle entrance holes or brood densities in felled trees between the two thinning intensities. Douglas-fir beetle-caused tree mortality was significantly higher on thinned plots with residual felled trees compared with unthinned controls, although infestation levels were low on all plots (<2 trees/ha). The small increase in beetle-caused tree mortality associated with leaving felled trees would be unlikely to interfere with resource management objectives. These results are applicable to mature, managed forests west of the Cascades with relatively low Douglas-fir beetle populations. In different regions and stand types, or under different environmental conditions, beetle populations could increase to higher densities, remain at high densities longer, and cause higher levels of tree mortality. West. J. Appl. For. 21(3):117–122.

scholarly journals Predicting postfire Douglas-fir beetle attacks and tree mortality in the northern Rocky Mountains

2007 ◽  
Vol 37 (6) ◽  
pp. 1058-1069 ◽  
Author(s):  
Sharon Hood ◽  
Barbara Bentz
Keyword(s):  
Tree Mortality ◽  
Stand Density ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Northern Rocky Mountains ◽  
Crown Volume ◽  
Crown Scorch ◽  
Predicted Probability ◽  
Attack Trees ◽  
Stand Density Index

Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) were monitored for 4 years following three wildfires. Logistic regression analyses were used to develop models predicting the probability of attack by Douglas-fir beetle ( Dendroctonus pseudotsugae Hopkins, 1905) and the probability of Douglas-fir mortality within 4 years following fire. Percent crown volume scorched (crown scorch), cambium injury, diameter at breast height (DBH), and stand density index for Douglas-fir were most important for predicting Douglas-fir beetle attacks. A nonlinear relationship between crown scorch and cambium injury was observed, suggesting that beetles did not preferentially attack trees with both maximum crown scorch and cambium injury, but rather at some intermediate level. Beetles were attracted to trees with high levels of crown scorch, but not cambium injury, 1 and 2 years following fire. Crown scorch, cambium injury, DBH, and presence/absence of beetle attack were the most important variables for predicting postfire Douglas-fir mortality. As DBH increased, the predicted probability of mortality decreased for unattacked trees but increased for attacked trees. Field sampling suggested that ocular estimates of bark char may not be a reliable predictor of cambium injury. Our results emphasize the important role of Douglas-fir beetle in tree mortality patterns following fire, and the models offer improved prediction of Douglas-fir mortality for use in areas with or without Douglas-fir beetle populations.

Native forest pathogens facilitate persistence of Douglas-fir in old-growth forests of northwestern California

2011 ◽  
Vol 41 (6) ◽  
pp. 1256-1266 ◽  
Author(s):  
Ashley E. Hawkins ◽  
Terry W. Henkel
Keyword(s):  
Bark Beetles ◽  
Tree Mortality ◽  
Douglas Fir ◽  
Native Forest ◽  
Gap Formation ◽  
Old Growth ◽  
Forest Pathogens ◽  
Canopy Trees ◽  
White Fir ◽  
Closed Canopy

Forest pathogens and insects can accelerate tree mortality, increase stand structural heterogeneity, and alter tree community composition. In northern California, the canopy trees Abies concolor var. lowiana (Gord. & Glend.) Lemmon (white fir) and Pseudotsuga menziesii var. menziesii (Mirbel) Franco (Douglas-fir) co-occur but vary in shade tolerance and regenerative abilities following disturbance. Field observations suggested that mortality and turnover of white fir exceeded that of Douglas-fir and that native pathogens may be important drivers in the absence of fire. Pathogens and bark beetles were sampled in old-growth white fir – Douglas-fir stands in northwestern California to assess their contribution to tree mortality, gap formation, and regeneration. We determined abundances and size class distributions of canopy trees, presence of pathogens and bark beetles, and causes of tree mortality. We sampled canopy gaps and closed-canopy forests for overstory species composition, cause of mortality of gap-maker trees, and regeneration of white fir and Douglas-fir. Root-rot fungi accounted for significantly higher mortality and gap formation in white fir than in Douglas-fir. Relative seedling–sapling density of Douglas-fir was higher in pathogen-induced canopy gaps than in closed-canopy forest. In the absence of fire, native forest pathogens enable regeneration and persistence of Douglas-fir by enhancing mortality of white fir, resulting in canopy gap formation.

Effects of species mixtures on growth and stand development of Douglas-fir and red alder

2006 ◽  
Vol 36 (3) ◽  
pp. 768-782 ◽  
Author(s):  
Steven R Radosevich ◽  
David E Hibbs ◽  
Claudio M Ghersa
Keyword(s):  
Pacific Northwest ◽  
Tree Mortality ◽  
Stand Structure ◽  
Stand Density ◽  
Douglas Fir ◽  
Forest Understory ◽  
Red Alder ◽  
Structure Tree ◽  
Species Proportions ◽  
Species Mixtures

In the Pacific Northwest, a mixture of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnus rubra Bong.) often results when red alder regenerates naturally in planted conifer stands. The relationships among stand structure, tree mortality, tree size, and understory development in the two species mixtures were explored at two sites for the first 16 years after planting. Treatments included a range of species proportions, and red alder was either planted simultaneously with Douglas-fir or planting was delayed for 5 years. Red alder was also removed from some simultaneously planted proportions. Both replacement effects (total stand density held constant) and additive effects (stand density doubled) of the interaction were considered. Red alder grew relatively better at Cascade Head Experimental Forest in the Coast Range, while Douglas-fir grew better at H.J. Andrews Experimental Forest in the less temperate Cascade Mountains. Possible production benefits from mixed plantings were examined using two methods of calculation. Potential production benefits from certain planted proportions of the two species occurred at H.J. Andrews Experimental Forest. No planting time or species proportion resulted in yield improvements over monoculture stands at Cascade Head Experimental Forest. Understory species also varied because of differences in site and stand characteristics that resulted from the differences in planting times and species proportions.

Tree mortality and radial growth losses caused by the western spruce budworm in a Douglas-fir stand in British Columbia

1982 ◽  
Vol 12 (4) ◽  
pp. 780-787 ◽  
Author(s):  
R. I. Alfaro ◽  
G. A. Van Sickle ◽  
A. J. Thomson ◽  
E. Wegwitz
Keyword(s):  
Radial Growth ◽  
Tree Mortality ◽  
Small Diameter ◽  
Basal Area ◽  
Spruce Budworm ◽  
Douglas Fir ◽  
Radial Increment ◽  
Western Spruce Budworm ◽  
Number Of Stems ◽  
The Relationship

The effects of defoliation by western spruce budworm (Choristoneuraoccidentalis (Freeman)), on Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) radial growth at breast height and tree mortality are given. Four hundred and twenty trees were marked in an 81-year-old stand, and their defoliation levels were recorded annually from 1970 to 1980 in an outbreak that lasted from 1970 to 1974, inclusive. Forty-one trees were felled and dissected in 1977, 3 years after recovery began. The number of stems per hectare was reduced by 39.3% and basal area by 11.6% through mortality, most occurring among the small diameter, suppressed, and intermediate trees. Relationships were established between mortality and defoliation. Radial increments were examined, and the presence of four outbreaks during the life of the stand was detected. The combined effect of these infestations amounted to a loss of about 12% of the estimated potential diameter had not the insects been active. The most recent outbreak (1970–1974) caused a total of 10 years of subnormal growth, including 5 years due to defoliation and 5 years of recovery. The relationship between radial increment losses and defoliation intensity and duration is studied and quantified.

Effects of a native forest pathogen, Phellinusweirii, on Douglas-fir forest composition in western Oregon

1993 ◽  
Vol 23 (12) ◽  
pp. 2473-2480 ◽  
Author(s):  
Jenny C. Holah ◽  
Mark V. Wilson ◽  
Everett M. Hansen
Keyword(s):  
Tree Mortality ◽  
Vascular Plant ◽  
Douglas Fir ◽  
Forest Composition ◽  
Native Forest ◽  
Forest Pathogen ◽  
Vascular Plant Diversity ◽  
Center Edge ◽  
Ordination Techniques ◽  
Root Grafts

The fungal pathogen Phellinusweirii (Murrill) Gilbertson (Family: Hymenochaetaceae) causes extensive rot in the roots and bole of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and true firs, eventually leading to tree mortality. The native pathogen spreads slowly via root grafts and root contacts between conifers, leaving behind areas of tree mortality commonly called infection centers. This study determines (i) whether the slow, systematic removal of the Douglas-fir overstory by P. weirii changes the community composition of old-growth and mature forests, (ii) if composition is significantly affected, to what degree P. weirii influences the composition, (iii) what effects the disease has on individual populations, and (iv) whether vascular plant diversity is affected by disease presence. The herb, shrub, and tree strata were randomly sampled within and adjacent to six P. weirii infection centers located in the low-elevation Cascade and Coast ranges of western Oregon. Statistically significant (P ≤ 0.05) differences in species composition between infected and adjacent noninfected forest were found across all sites. Ordination techniques showed that the distance of vegetation to the infection center edge was a major factor underlying the forest community's structure. The average cover of all herbaceous species was higher inside infection centers as compared with outside, for all locations, though statistically significant at only two sites. In general, species differed in their responses to disease presence. Changes in diversity due to the presence of the root rot were statistically significant in three of the six cases (P ≤ 0.05) but the patterns of change differed from site to site. The removal of Douglas-fir overstory has strong effects on the plant community, but the specific patterns depend on the species and site involved.

Size effects in defect-free Douglas fir

1990 ◽  
Vol 17 (2) ◽  
pp. 238-242 ◽  
Author(s):  
Borg Madsen
Keyword(s):  
Size Effects ◽  
Volume Effect ◽  
Douglas Fir ◽  
Material Behavior ◽  
Empirical Methods ◽  
Clear Wood ◽  
Weakest Link ◽  
Link Theory ◽  
Structural Engineers ◽  
Free Material

This paper describes experimental work on size effects occurring in defect-free Douglas fir and suggests empirical methods for modelling these. It was found, contrary to present belief, that the size effects could best be described as a volume effect. It was also found that wet and dry materials behaved very differently with respect to size effects. Defect-free material represents the stronger and more expensive range of materials available to the structural engineers. It is, therefore, important that the material behavior be better understood in order to create structures that are both safe and economical. Key words: size effects, clear wood, defect-free wood, volume effect, length effects, load configuration effect, moisture content, weakest link theory.

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