Modeling percent stocking changes for lodgepole pine stands in Alberta

2008 ◽  
Vol 38 (5) ◽  
pp. 1042-1052 ◽  
Author(s):  
Yuqing Yang ◽  
Shongming Huang
Keyword(s):  
Pinus Contorta ◽  
Sustainable Forest Management ◽  
Lodgepole Pine ◽  
Model Fitting ◽  
Covariance Structure ◽  
Site Index ◽  
Logistic Function ◽  
Correlated Errors ◽  
Validation Data ◽  
Pine Stands

A percent stocking change model was developed for lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) in Alberta based on spatially mapped permanent sample plot data. Percent stocking was defined as the percentage of 10 m2 subplots occupied by at least one tree with a minimum height of 1.3 m. The difference equation technique was employed to fit the model. Three model forms were examined and the logistic function was chosen as the final model. Site index was found to be a significant predictor and incorporated into the model. Analyses revealed that the model had correlated, but homoskedastic errors and the correlated errors were modeled by spherical covariance structure using NLINMIX macro in SAS. A percent stocking index, defined as the percent stocking at 50 years total age, was introduced and derived from the developed model. The percent stocking model had both forward and backward projection capabilities. It was demonstrated, both on model fitting and validation data, that the model adequately portrayed the percent stocking dynamics of lodgepole pine stands in Alberta. The model also provided an important basis for creating linkages between reforestation survey results and future yield, which is crucial for sustainable forest management.

scholarly journals Early Height Growth and Site Index of Lodgepole Pine Under Wet and Dry Soil Moisture Regimes in British Columbia

1997 ◽  
Vol 12 (1) ◽  
pp. 5-8
Author(s):  
Gordon D. Nigh
Keyword(s):  
Soil Moisture ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Site Index ◽  
Height Growth ◽  
Moisture Regimes ◽  
Indicator Variables ◽  
Soil Moisture Availability ◽  
A Site ◽  
Growth Intercept

Abstract The objective of this study was to determine whether the relationship between site index and early height growth of lodgepole pine (Pinus contorta var. latifolia) is the same on wet and dry sites. If the height growth/site index relationship is the same for different site types, then only one growth intercept model is required to estimate site index. Indicator variables in nonlinear regression were used to incorporate soil moisture availability into a growth intercept model. One set of parameters in a site index/early height growth model was adequate for both wet and dry sites. This result was supported graphically. Therefore, only one growth intercept model is necessary for the sites examined in this study. West. J. Appl. For. 12(1):5-8.

A Lodgepole Pine Density Management Diagram

1986 ◽  
Vol 1 (1) ◽  
pp. 6-11 ◽  
Author(s):  
James B. McCarter ◽  
James N. Long
Keyword(s):  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Site Index ◽  
Management Regimes

Abstract A diagram is presented that can greatly facilitate density management of lodgepole pine (Pinus contorta) stands. Together with site index tables or curves, the diagram can be used to estimate average tree sizes and total yields produced under various density management regimes. Its use is illustrated with three alternative regimes. West. J. Appl. For. 1:6-11, Jan. 1986

Predicting survival of lodgepole pine stands infected with western gall rust

2006 ◽  
Vol 36 (4) ◽  
pp. 878-885 ◽  
Author(s):  
J M Wolken ◽  
P V Blenis ◽  
I Duncan
Keyword(s):  
Pinus Contorta ◽  
Management Strategy ◽  
Tree Mortality ◽  
Lodgepole Pine ◽  
Main Stem ◽  
Iteratively Reweighted Least Squares ◽  
Risk Of Mortality ◽  
Endocronartium Harknessii ◽  
Stem Gall ◽  
Pine Stands

The probability of lodgepole pine (Pinus contorta Dougl. ex Loud.) having main-stem galls caused by western gall rust, Endocronartium harknessii (J.P. Moore) Y. Hiratsuka, surviving to rotation is unknown. To evaluate survival, 400 galled trees with at least one stem gall and 400 trees without stem galls were measured in 1992 in two precommercially thinned stands approximately 20 years old. The survival of trees was assessed in 2003. Nonlinear regression using iteratively reweighted least squares was employed to estimate the survival of galled trees as a function of the proportion of the main stem encircled by galls. Galls encircling >79% and >91% of the stem in the two stands increased the risk of mortality relative to non-galled trees, with the risk increasing steeply with percent gall encirclement; smaller stem galls did not cause tree mortality. The 11-year pattern of survival of galled trees was similar for infections that occurred on the main stem and those that had reached the stem from a nearby branch infection. Based on an earlier model of gall expansion, 38%–43% of stem-galled trees would be expected to survive until age 80. Scribing of stem galls to prevent their expansion does not appear to be a feasible management strategy.

How well can we select undamaged site trees for estimating site index?

1999 ◽  
Vol 29 (12) ◽  
pp. 1989-1992 ◽  
Author(s):  
Gordon D Nigh ◽  
Bobby A Love
Keyword(s):  
Picea Glauca ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
White Spruce ◽  
Site Index ◽  
Height Growth ◽  
Sufficient Data ◽  
Terminal Bud ◽  
Pine Trees ◽  
Unbiased Estimates

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.

scholarly journals Winter Habitat Use by Moose, Alces alces, in Central Interior British Columbia

2005 ◽  
Vol 119 (2) ◽  
pp. 186 ◽  
Author(s):  
Gilbert Proulx ◽  
Rhonda M. Kariz
Keyword(s):  
British Columbia ◽  
Habitat Use ◽  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Alces Alces ◽  
Late Winter ◽  
Winter Habitat ◽  
Pine Beetle ◽  
Pine Stands

In central British Columbia, recent epidemics of Mountain Pine Beetle (Dendroctonus ponderosae) have resulted in the use of expansive clearcut areas to remove infested mature and old Lodgepole Pine (Pinus contorta) stands. This study aimed to determine if Moose (Alces alces) use late-successional Lodgepole Pine stands in mid- to late-winter. Moose activity and habitat use was determined during February-March track surveys in 2000 (60 km) and 2001 (55.7 km). In 2000 (69 tracks) and 2001 (313 tracks), Moose track distribution differed significantly (P < 0.05) from random. They were significantly more abundant than predicted in young stands (dominated by Picea spp.), or early seral stages; they were less abundant than predicted in mature and old Lodgepole Pine stands. It is unlikely that harvesting late-successional Lodgepole Pine stands would affect Moose winter habitat supply.

Plant community attributes 12 to 14 years following precommercial thinning in a young lodgepole pine forest

2006 ◽  
Vol 36 (1) ◽  
pp. 48-61 ◽  
Author(s):  
P M.F Lindgren ◽  
D B Ransome ◽  
D S Sullivan ◽  
T P Sullivan
Keyword(s):  
Species Diversity ◽  
Plant Community ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Structural Diversity ◽  
Old Growth ◽  
Precommercial Thinning ◽  
Tree Layer ◽  
Moss Layer ◽  
Pine Stands

We investigated plant community responses (abundance, species diversity, and structural diversity) to a range of precommercial thinning densities in young lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands 12 to 14 years after thinning, with both unthinned and old-growth stands for comparison. Abundance of understory plants, especially herbs, appeared to increase dramatically in the thinned stands. The moss layer was significantly more abundant in old-growth stands than in the young pine stands. Of a total of 108 species sampled, only three were introduced species, all of which occurred more frequently in the low-density stands than in any of the other stands. Thinning treatments appeared to increase the abundance of late-seral species. Our results suggest that by disrupting canopy closure, thinning decreased the dominance of tall trees and increased the abundance of herbs, shrubs, and trees in the understory height classes. As a result, thinning to low densities significantly increased the structural richness of the tree layer and caused an increase in total structural diversity, which, although only marginally significant (p = 0.06), was likely biologically important. Our results suggest that thinning will enhance the abundance, species diversity, and structural diversity of the plant community 12 to 14 years postthinning.

scholarly journals Genetic control of transition from juvenile to mature wood with respect to microfibril angle (MFA) in Norway spruce (Picea abies) and lodgepole pine (Pinus contorta)

2018 ◽  
Author(s):  
Haleh Hayatgheibi ◽  
Nils Forsberg ◽  
Sven-Olof Lundqvist ◽  
Tommy Mörling ◽  
Ewa J. Mellerowicz ◽  
...  
Keyword(s):  
Genetic Control ◽  
Norway Spruce ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Microfibril Angle ◽  
Threshold Level ◽  
Logistic Function ◽  
Direct Selection ◽  
Narrow Sense Heritability ◽  
Slope Function

AbstractGenetic control of microfibril angle (MFA) transition from juvenile to mature was evaluated in Norway spruce and lodgepole pine. Increment cores were collected at breast height from 5,618 trees in two 21-year-old Norway spruce progeny trials in southern Sweden, and from 823 trees in two 34-35 – year-old lodgepole pine progeny trials in northern Sweden. Radial variations in MFA from pith to bark were measured for each core using SilviScan. To estimate MFA transition from juvenile to mature, 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 to mature in Norway spruce and lodgepole pine selective breeding programs, as the genetic gains (∆G) obtained in direct selection of this trait were very high in both species.

scholarly journals Height Growth Models for High-Elevation Subalpine Fir, Engelmann Spruce, and Lodgepole Pine in British Columbia

2000 ◽  
Vol 15 (2) ◽  
pp. 62-69 ◽  
Author(s):  
Han Y. H. Chen ◽  
Karel Klinka
Keyword(s):  
British Columbia ◽  
Growth Models ◽  
Lodgepole Pine ◽  
Site Index ◽  
High Elevation ◽  
Logistic Function ◽  
Height Growth ◽  
Potential Productivity ◽  
Subalpine Fir ◽  
Engelmann Spruce

Abstract To estimate potential productivity of the high-elevation Engelmann Spruce and Subalpine Fir (ESSF) zone of British Columbia forests, the height growth models developed from low-elevation forests are currently used to estimate site indices of subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii), and lodgepole pine (Pinus contorta). Whether these models are adequate to describe height growth of high-elevation forests is of concern. We sampled a total of 319 naturally established, even-aged, and undamaged stands with breast height age ≥50 yr (165 for subalpine fir, 87 for Engelmann spruce, and 67 for lodgepole pine) ranging widely in climate and available soil moisture and nutrients. In each sampled stand, three dominant trees were destructively sampled for stem analysis. Height growth models developed from fitting data to a conditioned logistic function explained > 97% variation in height for all three study species. Examined by residual analysis, no models showed lack of fit. These models provided more accurate estimates of site index than the currently used models developed from low-elevation stands or different species. It is recommended that the models developed in this study be applied to estimate site index of the three species in the ESSF zone in British Columbia. West. J. Appl. For. 15(2):62-69.

scholarly journals Commercial thinning effects on growth, yield and mortality in natural lodgepole pine stands in Alberta

2020 ◽  
Vol 96 (02) ◽  
pp. 111-120
Author(s):  
Sanatan Das Gupta ◽  
Bradley D. Pinno ◽  
Tim McCready
Keyword(s):  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Growth Yield ◽  
Timber Supply ◽  
Individual Tree ◽  
Growth And Survival ◽  
Commercial Thinning ◽  
Pine Stands ◽  
Individual Trees

There is an expected decrease in the short to mid-term timber supply of lodgepole pine (Pinus contorta var. latifolia) in Alberta, Canada due to the impacts of past fires and the mountain pine beetle outbreak. Commercial thinning is a potential option for increasing mid-term sawlog timber supply by decreasing the time needed for individual trees to reach merchantable size, through providing access to fiber earlier in the rotation, and from the ability to keep mature stands on the stump longer. In the current study, we evaluated the effects of commercial thinning in stands of different ages. Stands less than 70 years old at thinning were classified as commercial thinning (CT), whereas stands greater than 70 years at thinning were classified as salvage thinning (ST). Tree growth and survival were measured every five years from 1996 to 2016 in both thinned and unthinned stands. Fifteen years post-thinning, stand volume was less in the thinned stands relative to the unthinned controls. However, when volume removed at thinning was considered, volume gain from thinned stands was greater than that from the controls in both thinning treatments. Individual tree DBH and live crown ratio were also greater in thinned stands relative to controls. Thinning favored diameter gain mostly in the medium-sized trees in CT but both small to medium-sized trees in ST. Thinning reduced mortality in all stands relative to the controls and a maximum of 50% reduction in mortality was observed in CT. Overall, the findings suggest that natural lodgepole pine stands may respond to commercial thinning with a net gain in cumulative volume at final harvest.

Monoterpene and morphological variation and hybridization of Pinus contorta and P. banksiana in Alberta

1985 ◽  
Vol 63 (2) ◽  
pp. 201-210 ◽  
Author(s):  
John C. Pollack ◽  
Bruce P. Dancik
Keyword(s):  
Multivariate Analysis ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Morphological Characters ◽  
Jack Pine ◽  
Putative Hybrid ◽  
Front Range ◽  
Needle Length ◽  
Pine Stands ◽  
Monoterpene Composition

Five xylem oleoresin monoterpenes and 17 morphological characters of trees in four pine stands in Alberta were measured to delineate pure lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) from jack pine (P. banksiana Lamb.) in a region where hybridization commonly has been reported. Multivariate analysis determined α-pinene, β-phellandrene, and needle length best separated the taxa. The monoterpene composition of two putative hybrid stands at Onoway and Devon closely resembled that of jack pine. Analysis of the four major monoterpenes in an additional 10 stands allowed the identification of a transition zone between jack pine and lodgepole pine stands, which occurred farther west than previously reported and contained stands of highly variable monoterpene types. Trees in this region morphologically resembled lodgepole pine. The presence of variant monoterpene types in Front Range lodgepole pine stands and their absence from the Cypress Hills provide evidence for introgression of jack pine into lodgepole pine. No evidence of gene flow from lodgepole pine to jack pine was found. The two putative hybrid stands at Onoway and Devon probably consisted mostly of jack pine, with a small complement of hybrids.

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