Estimating Dominant Height and Site Index of Even-Aged Interior Douglas-Fir in British Columbia

1992 ◽  
Vol 7 (1) ◽  
pp. 20-25 ◽  
Author(s):  
James S. Thrower ◽  
James W. Goudie
Keyword(s):  
British Columbia ◽  
Linear Model ◽  
Pseudotsuga Menziesii ◽  
Site Index ◽  
Logistic Function ◽  
Height Growth ◽  
Douglas Fir ◽  
Stem Analysis ◽  
Inland Empire ◽  
Dominant Height

Abstract Height-age and site-index curves were developed from stem analysis of 262 Douglas-fir trees (Pseudotsuga menziesii var. glauca) from 68 plots in the Interior Douglas-fir, Interior Cedar-Hemlock, and Sub-boreal Spruce Biogeoclimatic zones in the interior of British Columbia. Plots ranged in site index from about 8 to 30 m and in age from about 60 to 350 years; however, the analyses were limited to data up to 100 years of age. A conditioned logistic function was selected for predicting height, and a linear model was selected for predicting site index. The curves are similar to those developed in comparable studies in the Inland Empire, but differ substantially from curves developed in British Columbia from temporary sample plots. This study supports previous observations that the pattern of height growth for a given site index varies among ecologically different areas. West. J. Appl. For. 7(1):20-25.

Comparison and Development of Height Growth and Site Index urves for Douglas-Fir in the Inland Northwest

1989 ◽  
Vol 4 (3) ◽  
pp. 85-88
Author(s):  
James L. Vander Ploeg ◽  
James A. Moore
Keyword(s):  
Pseudotsuga Menziesii ◽  
Model Development ◽  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
Douglas Fir ◽  
Western Montana ◽  
Stem Analysis ◽  
Inland Northwest ◽  
Central Idaho

Abstract Stem analysis data from Douglas-fir (Pseudotsuga menziesii) collected throughout the inland Northwest were used for testing height growth and site index equations. The equations performed well in northern and central Idaho, northeast Oregon, and northeast Washington on vegetative types similar to those sampled in model development. However, if the equations were applied on drier sites outside the original geographic study area, overestimates of height growth and under-estimates of site index could result. Therefore, revised height growth and site index equations are presented for western Montana and central Washington. West. J. Appl. For. 4(3):85-88, July 1989.

scholarly journals Height growth of black spruce in British Columbia

2002 ◽  
Vol 78 (2) ◽  
pp. 306-313 ◽  
Author(s):  
Gordon D Nigh ◽  
Pavel V Krestov ◽  
Karel Klinka
Keyword(s):  
British Columbia ◽  
Black Spruce ◽  
Site Index ◽  
Logistic Function ◽  
Height Growth ◽  
Growth Patterns ◽  
Growth And Yield ◽  
Stem Analysis ◽  
Yield Information ◽  
Northern Half

Black spruce (Picea mariana (Mill.) B.S.P.) is a boreal species that occurs extensively across the northern half of British Columbia. Forest managers require better growth and yield information for black spruce given the anticipated increase in demand for wood in the northern part of the province. The purpose of this study was to develop height-age models for black spruce. Ninety-one stem analysis plots were established in the BWBS and SBS biogeoclimatic zones. Three black spruce site trees from each plot were stem analyzed and the data were converted into height-age data. A conditioned log-logistic function was fit to the data. Indicator variables were used to test for differences in height growth between the sampled subzones. Although the warm subzones had different height growth patterns than the cool subzones, there was general agreement among the height-age models from British Columbia, Alberta, and New Brunswick up to about age 100. Key words: biogeoclimatic zones, height-age models, logistic function, site index, stem analysis

Assessing the impact of current and projected climates on Douglas-Fir productivity in British Columbia, Canada, using a process-based model (3-PG)

2010 ◽  
Vol 40 (3) ◽  
pp. 511-524 ◽  
Author(s):  
Nicholas C. Coops ◽  
Robbie A. Hember ◽  
Richard H. Waring
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Site Index ◽  
Douglas Fir ◽  
Climatic Variation ◽  
Climate Forecasts ◽  
Fine Spatial Resolution ◽  
Viable Approach ◽  
The Impact ◽  
Process Based Models

Predicted climate change is expected to significantly affect tree growth in many areas. We used a process-based model (Physiological Principles for Predicting Growth, 3-PG) to evaluate how climatic variation might alter growth of Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco and Pseudotsuga menziesii (Mirb.) Franco var. menziesii ) across biogeoclimatic zones in British Columbia. The results indicate that there will be significant changes in site index (defined as the height (in metres) of dominant trees at 50 years) over this century. In the interior, a reduction in site index is likely, particularly in stands with mid-range values of site index (25–30 m), with many of the interior bioecoclimatic zones predicted to experience a gradual mean decrease in site index by up to 10%. Individual sites may decrease by as much as 40% from current values. In contrast, site index along the coast overall is predicted to increase to a maximum of 43 m by 2080. In the Coastal Western Hemlock zone, however, mean site index is likely to increase from 26 m to only 34 m. We believe that combining process-based models with fine-spatial resolution climate forecasts offers a viable approach to assess future changes in forest productivity.

scholarly journals RELATIVE QUALITY OF THE MAJOR FOREST ASSOCIATIONS OF THE SOUTHERN B.C. INTERIOR FOR GROWTH OF LODGEPOLE PINE, ENGELMANN SPRUCE, DOUGLAS-FIR AND ALPINE FIR

1966 ◽  
Vol 42 (3) ◽  
pp. 306-313 ◽  
Author(s):  
Walter Stanek
Keyword(s):  
British Columbia ◽  
Lodgepole Pine ◽  
Site Index ◽  
Height Growth ◽  
Douglas Fir ◽  
Regression Equations ◽  
Common Occurrence ◽  
Engelmann Spruce ◽  
Relative Quality

Height growth of lodgepole pine, Engelmann spruce, Douglas-fir and alpine fir was investigated in the Douglas-fir and Engelmann Spruce-Alpine Fir Zones of the Interior of British Columbia. In the same forest association each species has a characteristic site index at the age of 100 years (SI/100). Regression equations were calculated for predicting SI/100 of several species in different associations. Regression equations were also developed for estimating SI/100 of Engelmann spruce, Douglas-fir and alpine fir from known SI/100 of lodgepole pine. The latter species was selected because of its common occurrence in the two zones. In addition regression equation was calculated for predicting SI/100 of lodgepole pine from known SI/100 of Engelmann spruce. All regression equations apply to naturally established stands in the study area.

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.

Douglas-fir height growth affected by western spruce budworm

1983 ◽  
Vol 13 (3) ◽  
pp. 445-450 ◽  
Author(s):  
G. A. Van Sickle ◽  
R.I. Alfaro ◽  
A.J. Thomson
Keyword(s):  
British Columbia ◽  
Recovery Period ◽  
Spruce Budworm ◽  
Site Index ◽  
Height Growth ◽  
Douglas Fir ◽  
Western Spruce Budworm ◽  
Total Height

Detailed dissections of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) trees repeatedly defoliated by the western spruce budworm (Choristoneuraoccidentalis (Freeman)) in two areas of British Columbia indicated that budworm severely affected height growth. Dissected trees lost an average 7.3 internodes in each infestation, of which 4.2 were destroyed or failed to grow during the budworm feeding and recovery periods, and 3.1 were existing internodes lost to dieback. An average of one internode of subnormal size, produced during the recovery period, was also present. Total height was reduced by 32% (11.4 m) and 19% (5.9 m) in areas that sustained four and two infestations respectively. Budworm infestations lead to an underestimation of the site index for Douglas-fir in the affected areas.

Site Index and Height Growth Curves for Ponderosa Pine, Western Larch, Lodgepole Pine, and Douglas-Fir in Western Montana

1992 ◽  
Vol 7 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Kelsey S. Milner
Keyword(s):  
Ponderosa Pine ◽  
Growth Curves ◽  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
Douglas Fir ◽  
Growth Patterns ◽  
Western Montana ◽  
Stem Analysis ◽  
Western Larch

Abstract Height growth patterns from several published site curve sytems for ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii var glauca), western larch (Larix occidentalis) and lodgepole pine (Pinus contorta var latifolia) were compared to stem analysis data from western Montana. Most of the published curves had height growth patterns that differed significantly from those in the data. The magnitude of the deviations often varied by level of site index; this appeared to be related to differences in the range of site qualities sampled. Those curves constructed from stem analysis data from geographically similar populations compared most closely. Curves constructed using guide curve techniques showed a consistent tendency to underpredict heights at greater ages. New site index and height growth curves are presented for each species. West. J. Appl. For. 7(1):9-14.

Comparison of Douglas-fir site index and height growth curves in the Pacific Northwest

1985 ◽  
Vol 15 (4) ◽  
pp. 673-679 ◽  
Author(s):  
Robert A. Monserud
Keyword(s):  
Pacific Northwest ◽  
Growth Curves ◽  
Site Index ◽  
Height Growth ◽  
Douglas Fir ◽  
Stem Analysis ◽  
The Pacific ◽  
Northern Rockies ◽  
Growth Differences ◽  
Index Curve

Site index and height growth curves produced by the major Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) site index studies in the Pacific Northwest are graphically compared. Results indicate that differences in the height growth pattern of Douglas-fir increase with increasing distance between regions. Height growth differences were extremely small between the northern Rockies and the east side of the Cascades and were rather large between the Rockies and the west side of the Cascades. The relatively small differences between the northern Rockies and the Cascade crest fell between these two extremes. Very small differences were also found between Montana and northern Idaho. A second result of the comparisons is that the type of data and the resulting methodology used to develop the site index curve system are strongly related to the similarity of the resulting curves. Curves derived from felled-tree, stem-analysis studies were quite similar to each other, but differed substantially from curves derived by harmonized guide-curve methods. Furthermore, the guide-curve systems produced curves that were surprisingly similar to each other, even though different varieties of Douglas-fir from different regions were being compared. The magnitude of the differences that could be attributed solely to different methods of site curve construction (stem analysis vs. guide curve) was demonstrated to be quite large by applying both methods to the same data. The often untenable assumptions inherent in guide-curve systems appear to affect the shape of the curves more than real regional height growth differences.

scholarly journals Development of Height-Age Models for Estimating Juvenile Height of Coastal Douglas-Fir in British Columbia

2003 ◽  
Vol 18 (3) ◽  
pp. 207-212 ◽  
Author(s):  
Gordon D. Nigh ◽  
Matthew G.E. Mitchell
Keyword(s):  
British Columbia ◽  
Nonlinear Least Squares ◽  
Site Index ◽  
Height Growth ◽  
Douglas Fir ◽  
Growth Patterns ◽  
Least Squares Regression ◽  
Data Set ◽  
Constant Variance ◽  
Power Models

Abstract Douglas-fir (Pseudotsuga menziesii var. menzeisii) is an important and abundant tree species in coastal British Columbia. Juvenile height estimates are important for management prescriptions and decisions involving regenerating stands. We used 100 plots to investigate the juvenile height growth of coastal Douglas-fir. The growth patterns of the sample trees were observed by felling and splitting them longitudinally and measuring the height of the annual nodes from the point of germination. Sixty-four plots were used to develop a height model as a function of total age and site index. The Chapman-Richards, Gompertz, and modified exponential and power models were fit using nonlinear least squares regression. The models were tested with the remaining 36 plots. The modified exponential and power equation was the best fitting of the three models. None of the models met the regression assumption of independently normally distributed residuals with a mean of zero and a constant variance. The modified exponential and power model was further analyzed using the complete data set by fitting height growth and incorporating a model for serial correlation in the error term to improve the statistical properties of the model. West. J. Appl. For. 18(3):207–212.

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