scholarly journals A closer look at site index - biogeoclimatic site series correlations: Douglas-fir in the Coastal Western Hemlock Zone, xm2 variant, 01 site series

2010 ◽  
Vol 86 (4) ◽  
pp. 477-483 ◽  
Author(s):  
Gord Nigh
Keyword(s):  
Site Index ◽  
Douglas Fir ◽  
Stem Analysis ◽  
Data Set ◽  
Site Specific ◽  
Index Site ◽  
Ecosystem Classification ◽  
Age Model ◽  
A Site ◽  
Index Estimate

The Site Index - Biogeoclimatic Ecosystem Classification (SIBEC) model predicts site index from species and biogeoclimatic site series. The purpose of this project was, for Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) in the CWHxm2/01 site series, to: 1) verify that the current SIBEC site index estimate of 32.90 m is accurate, 2) create a more site-specific SIBEC model by including additional variables in the model to capture within-site series variation, and 3) compare the SIBEC site index estimates and their variability when the estimates are obtained using stem analysis data versus data from Bruce’s (1981) height-age model. The data set consisted of 40 Douglas-fir plots established in the CWHxm2/01 site series. The analysis shows that the current SIBEC site index estimate should be changed to 34.68 m. No relationship was found between site index and ecological variables within this site series, hence the model could not be made more site-specific. The BEC system aggregates sites into relatively homogeneous units with respect to productivity. The comparison of the SIBEC site index estimates and their variances when estimated using stem analysis and a height-age model were not statistically different. Obtaining a site index estimate from Bruce’s model is as accurate as obtaining a site index estimate from stem analysis when the Douglas-fir sample trees are between 50 and 80 years of age.Key words: Biogeoclimatic Ecosystem Classification, Douglas-fir, model error, site index, site series, stem analysis

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 A site index system for redwood and Douglas-fir in California's North Coast Forest

Hilgardia ◽  
1986 ◽  
Vol 54 (8) ◽  
pp. 1-14 ◽  
Author(s):  
Lee C. Wensel ◽  
Bruce Krumland
Keyword(s):  
Index System ◽  
Site Index ◽  
Douglas Fir ◽  
North Coast ◽  
A Site

scholarly journals Radiocarbon Results from a 13-Kyr BP Coral from the Huon Peninsula, Papua New Guinea

Radiocarbon ◽  
2004 ◽  
Vol 46 (3) ◽  
pp. 1211-1224 ◽  
Author(s):  
G S Burr ◽  
Chrystie Galang ◽  
F W Taylor ◽  
Christina Gallup ◽  
R Lawrence Edwards ◽  
...  
Keyword(s):  
Papua New Guinea ◽  
New Guinea ◽  
Individual Growth ◽  
Time Range ◽  
Drill Core ◽  
Seasonal Growth ◽  
Data Set ◽  
Site Specific ◽  
A Site ◽  
Resolution Data

This paper presents radiocarbon results from a single Goniastrea favulus coral from Papua New Guinea which lived continuously between 13.0 and 13.1 kyr BP. The specimen was collected from a drill core on the Huon Peninsula and has been independently dated with 230Th. A site-specific reservoir correction has been applied to the results, and coral growth bands were used to calibrate individual growth years. Alternating density bands, which are the result of seasonal growth variations, were subsampled to provide 2 integrated 6-month 14C measurements per year. This allows for 20 independent measurements to be averaged for each decadal value of the 14C calibration, making these results the highest resolution data set available for this brief time range. The finestructure of the data set exhibits 14C oscillations with frequencies on the order of 4 to 10 yr, similar to those observed in modern coral 14C records.

scholarly journals Production and soil restoration effect of pioneer tree species in a region of allochthonous Norway spruce dieback

2017 ◽  
Vol 63 (No. 1) ◽  
pp. 34-44
Author(s):  
Martiník Antonín ◽  
Adamec Zdeněk ◽  
Houška Jakub
Keyword(s):  
Norway Spruce ◽  
Tree Species ◽  
Site Index ◽  
Soil Restoration ◽  
Soil Reaction ◽  
Al Content ◽  
Index Site ◽  
Spruce Stands ◽  
A Site ◽  
Mg Content

The paper analyses the growth, structure, production and soil chemistry of different tree species stands 20 years after allochthonous spruce dieback. The experiment was carried out at lower altitudes (300 m a.s.l.) at rich sites of the Central Europe region. Norway spruce (Picea abies Linnaeus) and beech (Fagus sylvatica Linnaeus) stands established by artificial regeneration were compared with silver birch (Betula pendula Roth), aspen (Populus tremula Linnaeus) and birch-aspen stands, which were regenerated naturally. Spruce stands showed a decrease of site index (site index 3), compared with the previous generation (site index 2). This leads to an expected lower production at the age of 100 years, compared to mature beech stands, which showed a site index of 1. The highest production (tree overbark volume) was found out in the aspen stand – 294 m<sup>3</sup>·ha<sup>–1</sup>. The production (tree overbark volume) of other monoculture stands was comparable and reached 201–222 m<sup>3</sup>·ha<sup>–1</sup>. Most of the soil chemical characteristics under the compared stands (Ca and Mg content, Al content and active and potential soil reaction) were significantly better under aspen and decreased in the following trend: birch – beech – spruce.

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.

A Sitka spruce height-age model with improved extrapolation properties

1997 ◽  
Vol 73 (3) ◽  
pp. 363-369 ◽  
Author(s):  
Gordon D. Nigh
Keyword(s):  
British Columbia ◽  
Serial Correlation ◽  
Sitka Spruce ◽  
Analysis Data ◽  
Site Index ◽  
Picea Sitchensis ◽  
Stem Analysis ◽  
Queen Charlotte Islands ◽  
Extrapolation Model ◽  
Age Model

The height-age model for Sitka spruce (Picea sitchensis (Bong.) Carr.) currently recommended for use in British Columbia has poor extrapolation properties. Therefore, a new height-age model for Sitka spruce using stem analysis data collected from the Queen Charlotte Islands was developed. Care was taken to meet the standard regression assumptions. In particular, accounting for within-plot serial correlation improved the extrapolation abilities of the model by eliminating the crossing-over effect. The new model is being recommended for use in British Columbia because it offers better extrapolated height and site index estimates without sacrificing accuracy at young ages. Key words: Sitka spruce, site index, height-age model, serial correlation, nonlinear regression, extrapolation, model properties

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.

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.

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