The effects of crown ratio on the transition from juvenile to mature wood production in lodgepole pine in western Canada

2007 ◽  
Vol 37 (8) ◽  
pp. 1450-1459 ◽  
Author(s):  
Shawn D. Mansfield ◽  
Roberta Parish ◽  
James W. Goudie ◽  
Kyu-Young Kang ◽  
Peter Ott

Crown depth, tree spacing, and stand density have major effects on wood quality and fibre characteristics of trees. Lodgepole pine ( Pinus contorta Doug. ex Loud.) trees from a mixture of plantation and fire origin stands were employed to determine how crown ratio, a surrogate for stand density, affected mature wood production. In total, 104 trees were sampled, ranging from 24 to 110 years of age, from stands in western Alberta and interior British Columbia, Canada. Samples taken along the bole were measured for wood density, which was subject to segmented regression analysis to identify the transition point from juvenile to mature wood production. On average, the lodgepole pine trees were 31 (±17 SD) years old before mature wood production began. A mixed-effects model, in which combination of fixed effects (tree age, height of the sample disc relative to crown base, and crown length) and random effects (site, trees nested in sites, and discs nested in both trees and sites) proved to be the best predictor of years of mature wood production along the bole. The transition from juvenile to mature wood was shown to be below the crown base in trees <50 years old with deep crowns, and above the crown base otherwise.

2005 ◽  
Vol 83 (8) ◽  
pp. 983-988 ◽  
Author(s):  
Erin C Fraser ◽  
Victor J Lieffers ◽  
Simon M Landhäusser

This study investigated stand factors associated with the rate of root graft formation in lodgepole pine stands. Forty plot areas, each containing 10 trees, were excavated in pure, even-aged pine stands in western Alberta. Exposed root systems were examined for grafts and various stand measurements were recorded at each plot. Results indicate that the number of grafts per square metre is controlled by plot tree density and tree diameter. Also, the percentage of grafted trees increased with both increasing tree age and decreasing distance between trees. Grafts also appear to form relatively early in stand development; the majority of grafts in the present study had formed by the time roots were 20 years old and 50 mm in diameter. These results suggest that grafting is a common occurrence in lodgepole pine stands where trees are <109 cm apart, which translates to a density of approximately 8500 stems/ha (based on even tree distribution). However, even clumps within relatively low density stands are likely to be grafted from a relatively early stage of development.Key words: Pinus contorta, graft formation, stand dynamics.


2000 ◽  
Vol 30 (3) ◽  
pp. 476-481 ◽  
Author(s):  
Alex J Woods ◽  
Albert Nussbaum ◽  
Bill Golding

We developed two models to predict volume loss due to western gall rust (Endocronartium harknessii (J.P. Moore) Y. Hiratsuka) and comandra blister rust (Cronartium comandrae Peck) on juvenile lodgepole pine (Pinus contorta Dougl. ex Loud.) dominated stands in central British Columbia. The models suggest that volume loss is significantly and positively correlated to the incidence of comandra blister rust. The relationship between volume loss and western gall rust incidence was weak. The addition of stand density data improved the statistical fit of the model. We used the growth and yield model Tree and stand simulator (TASS) to predict volume at culmination age (age at which the merchantable mean annual increment was maximized) in thirty 1-ha stem-mapped stands. The lodgepole pine trees we stem mapped were also assessed for hard pine stem rust incidence. We developed our volume loss functions assuming that trees with stem infections of both comandra blister rust and western gall rust were lethal, and that infected trees would die from ages 21 to 40. In areas where comandra blister rust is common, the losses due to the disease can be considerable. We predict that the volume losses due to hard pine stem rusts in lodgepole pine dominated stands are as high as 7.2% by culmination age.


2005 ◽  
Vol 35 (6) ◽  
pp. 1314-1318 ◽  
Author(s):  
Peter V Blenis ◽  
Wuhan Li

Infection of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) by western gall rust has been shown to decrease with tree height and age, but the effects of those two factors have not been separated. Five replicate artificial inoculations were done on a total of 327 trees of different ages in two height classes. Temperature and percentage of spore germination at the height of inoculation, shoot development (stem elongation at the time of inoculation as a proportion of final shoot elongation), main stem leader length at the time of inoculation, tree height, and tree age were measured. Modeled percentages of infected trees and the number of galls per 10 cm of shoot length decreased by 85% and 88%, respectively, as tree age increased between 2 and 10 years, indicating the undesirability of early, aggressive precommercial thinning of lodgepole pine stands in areas where western gall rust is common. By controlling and (or) statistically accounting for inoculum, microclimate, and phenological factors, it was possible to demonstrate that changes in susceptibility with tree age are sufficient to account for the reduction in infection with tree height.


2017 ◽  
Vol 47 (8) ◽  
pp. 1123-1130 ◽  
Author(s):  
Pontus M.F. Lindgren ◽  
Thomas P. Sullivan ◽  
Douglas B. Ransome ◽  
Druscilla S. Sullivan ◽  
Lisa Zabek

Integration of trees with forage and livestock production as silvopastoralism is another potential component of intensive forest management. Stand thinning and fertilization may enhance growth of crop trees and understory forage for livestock. We tested the hypothesis that large-scale precommercial thinning (PCT) (particularly heavy thinning to ≤1000 stems·ha−1) and repeated fertilization, up to 20 years after the onset of treatments, would enhance production of graminoids, forbs, and shrubs as cattle (Bos taurus L.) forage. Results are from two long-term studies: (1) PCT (1988–2013) and (2) PCT with fertilization (PCT–FERT) (1993–2013) of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands in south-central British Columbia, Canada. Mean biomass estimates of graminoids, forbs, total herbs, and shrubs were not affected by stand density. However, fertilization enhanced mean biomass estimates of graminoids, forbs, and total herbs, but not shrubs. Thus, the density part of our hypothesis was not supported, but the nutrient addition part was supported at least for the herbaceous components. Biomass of the herbaceous understory was maintained as a silvopasture component for up to 20 years (stand age 13 to 33 years) in fertilized heavily thinned stands prior to canopy closure.


2004 ◽  
Vol 118 (4) ◽  
pp. 595 ◽  
Author(s):  
Brock Epp ◽  
Jacques C. Tardif

The Lodgepole Pine Dwarf Mistletoe (Arceuthobium americanum Nutt. ex Engelm.) is an important pathogen of Jack Pine (Pinus banksiana Lamb.). Dwarf Mistletoe alters tree form, suppresses growth, and reduces volume and overall wood quality of its host. Stem analysis and a 3-parameter logistic regression model were used to compare the growth of heavily and lightly to non infected Jack Pine trees. At the time of sampling, no significant reduction in diameter at breast height and basal area were observed in heavily infected trees. However, a significant reduction in height and volume and an increase in taper were observed in heavily infected trees. Growth models predicted a 21.1% lower basal area, 23.4% lower height and 42.1% lower volume by age 60 for the high infection group.


2014 ◽  
Vol 44 (11) ◽  
pp. 1312-1319 ◽  
Author(s):  
Eleanor C. Lahr ◽  
Anna Sala

Stored resources in trees reflect physiological and environmental variables and affect life history traits, including growth, reproduction, resistance to abiotic stress, and defense. However, less attention has been paid to the fact that stored resources also determine tissue nutritional quality and may have direct consequences for the success of herbivores and pathogens. Here, we investigated whether stored resources differed between two hosts of the mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902): lodgepole pine (Pinus contorta Douglas ex. Loudon), a common host, and whitebark pine (Pinus albicaulis Engelmann), a more naïve host that grows at higher altitudes. Phloem and sapwood were sampled in small- and large-diameter trees at two elevations, and nitrogen, phosphorus, nonstructural carbohydrates, and lipids were measured. We found that concentrations of stored resources increased with elevation and tree diameter for both species and that whitebark pine had thicker phloem than lodgepole pine. Overall, stored resources were higher in whitebark pine such that small-diameter whitebark pine trees often had resource concentrations higher than large-diameter lodgepole pines. These results suggest that whitebark pine is of higher nutritional quality than lodgepole pine, which could have implications for the current expansion of mountain pine beetles into higher altitude and latitude forests in response to climate warming.


1998 ◽  
Vol 76 (2) ◽  
pp. 218-227 ◽  
Author(s):  
S M Bradbury ◽  
R M Danielson ◽  
S Visser

The ectomycorrhizal community associated with regenerating lodgepole pine (Pinus contorta Loud.) after clear-cutting in southwestern Alberta was investigated in 6-, 10-, and 19-year-old cut blocks and their adjacent 90-year-old undisturbed control stands. Twenty different mycorrhizal taxa were found in the 90-year-old undisturbed stands. Of these 20, 13 mycorrhizal taxa were found in the 6-year-old cut blocks, and 15 mycorrhizal taxa were found in both the 10- and 19-year-old cut blocks. The most common associate of all stand ages was Mycelium radicis atrovirens Melin (MRA), which overall colonized 29% (weighted average) of the root tips. Species or groups accounting for greater than 10% of the mycorrhizas in one or more age classes included Piloderma fallax (Karst.) Jül. (15% overall), Piloderma byssinum (Karst.) Jül. (11%), Cenococcum geophilum L. (8%), Russula-like (8%), Suillus brevipes (Pk.) Kuntze (5%), Suillus tomentosus (Kauff.) Sing., Snell & Dick (5%), and Lactarius deliciosus (L.:Fr.) S.F. Gray (2%). Although several mycorrhizal fungi exhibited significant differences in percent relative abundance of root tips colonized, when comparing cut blocks to their controls, there was no evidence to suggest that the suite of mycorrhizal fungi colonizing roots of young lodgepole pine trees was replaced by a different suite of mycorrhizal fungi in mature stands. Extensive fruit body collections, totalling 43 species of ectomycorrhizal fungi, throughout the study sites support this contention.Key words: Pinus contorta ectomycorrhizas, clear-cutting, second-rotation forests, succession.


1999 ◽  
Vol 29 (12) ◽  
pp. 1989-1992 ◽  
Author(s):  
Gordon D Nigh ◽  
Bobby A Love

The best estimates of site index, an indicator of site productivity, are obtained from site trees. Undamaged site trees should be sampled to obtain unbiased estimates of site index. Two juvenile height growth modelling projects provided us with sufficient data to assess our ability to select undamaged lodgepole pine (Pinus contorta var. latifolia Dougl.) and white spruce (Picea glauca (Moench) Voss) site trees. The sample trees were split open to measure height growth from the terminal bud scars. Splitting the stems also revealed damage that was not visible from the outside of the tree. Over 50% of the lodgepole pine trees and 75% of the white spruce trees had damage, which was much higher than expected. Possible causes of damage are frost and insects. The damage does not significantly reduce the height of the spruce trees, but there is evidence that the heights of the lodgepole pine trees are reduced.


2018 ◽  
Vol 48 (11) ◽  
pp. 1358-1365 ◽  
Author(s):  
Haleh Hayatgheibi ◽  
Nils Erik Gustaf Forsberg ◽  
Sven-Olof Lundqvist ◽  
Tommy Mörling ◽  
Ewa J. Mellerowicz ◽  
...  

Genetic control of microfibril angle (MFA) transition from juvenile wood to mature wood was evaluated in Norway spruce (Picea abies (L.) Karst) and lodgepole pine (Pinus contorta Douglas ex Loudon). Increment cores were collected at breast height (1.3 m) from 5664 trees in two 21-year-old Norway spruce progeny trials in southern Sweden and from 823 trees in two lodgepole pine progeny trials, aged 34–35 years, in northern Sweden. Radial variations in MFA from pith to bark were measured for each core using SilviScan. To estimate MFA transition from juvenile wood to mature wood, a threshold level of MFA 20° was considered, and six different regression functions were fitted to the MFA profile of each tree after exclusion of outliers, following three steps. The narrow-sense heritability estimates (h2) obtained for MFA transition were highest based on the slope function, ranging from 0.21 to 0.23 for Norway spruce and from 0.34 to 0.53 for lodgepole pine, while h2 were mostly non-significant based on the logistic function, under all exclusion methods. Results of this study indicate that it is possible to select for an earlier MFA transition from juvenile wood to mature wood in Norway spruce and lodgepole pine selective breeding programs, as the genetic gains (ΔG) obtained in direct selection of this trait were very high in both species.


1990 ◽  
Vol 5 (2) ◽  
pp. 40-42 ◽  
Author(s):  
A. D. Yanchuk ◽  
M. R. Carlson ◽  
J. C. Murphy

Abstract Two 8-year-old grafted ramets from 12 lodgepole pine (Pinus contorta var. latifolia) ortets (wild stand parent trees) were sampled at each of three sites and were assessed for specific gravity with small diameter cores. The broad-sense heritability estimate from the analysis of variance was 0.62, but estimates derived by regressing clone means from ramets on ortet values were 0.49 and 0.54 for juvenile and mature wood, respectively. This relatively high repeatability for specific gravity suggests wild-stand ortet values may be useful for identifying low specific gravity clones in seed orchards, or potential low specific gravity families in breeding populations of lodgepole pine. West. J. Appl. For. 5(2):40-42, April 1990.


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