Bark Thickness and Bark Volume in Southwestern Oregon Douglas-Fir

1990 ◽  
Vol 5 (1) ◽  
pp. 5-8 ◽  
Author(s):  
Douglas A. Maguire ◽  
David W. Hann

Abstract A segmented polynomial taper equation for southwestern Oregon Douglas-fir (Pseudotsuga menziesii) predicts double bark thickness (dbt) at any point above breast height. Below breast height predictions assume conformity to a neiloid frustrum. The equations facilitate estimation of inside bark diameter (dib) given outside bark (dob) measurements. Bark volume and bark biomass can also be estimated when supplemented with existing dib taper equations developed for southwestern Oregon. West J. Appl. For. 5(1):5-8.

2008 ◽  
Vol 54 (No. 7) ◽  
pp. 321-332 ◽  
Author(s):  
P. Kantor

: The study evaluates production parameters (height, diameter at breast height, volume) of Douglas fir (<I>Pseudotsuga menziesii</I> [Mirb.] Franco) at mesotrophic sites of the Křtiny Training Forest Enterprise in mature stands. In total, 29 mixed stands were assessed with the registered proportion of Douglas fir at an age of 85 to 136 years. Comparing the 10 largest Douglas firs with the 10 largest spruces or larches higher, and as a rule markedly higher, production potential of introduced Douglas fir was found in all assessed stands. There were also groups of trees where the volume of Douglas fir was twice to 3 times higher than the volume of spruce or larch (see Tabs. 5 to 10). For example, in stand 177B11, the mean volume of 9.12 m<sup>3</sup> was recorded in the 10 largest Douglas fir trees but the volume of spruce reached only 3.17 m<sup>3</sup> and the volume of larch was 3.70 m<sup>3</sup>. Differences in mensurational parameters of Douglas fir found on the one hand and of Norway spruce (<I>Picea abies</I> [L.] Karst.) or European larch (<I>Larix decidua</I> Mill.) on the other hand compared by ANOVA tests were statistically highly significant. Annual ring analyses have shown that at present the volume increment of particular Douglas fir trees ranges from 0.12 to 0.16 m<sup>3</sup> per year in mature stands (i.e. about 1.5 m<sup>3</sup> every 10 years).


1989 ◽  
Vol 4 (4) ◽  
pp. 116-119 ◽  
Author(s):  
Linda S. Heath ◽  
H. N. Chappell

Abstract Response surface methodology was used to estimate six-year volume growth response to 1 application of 200 lb nitrogen per acre in unthinned and thinned Douglas-fir (Pseudotsuga menziesii) stands of breast height age (bha) 25 years or less. Regional mean fertilizer response was 16% in unthinned stands and 20% in thinned stands. Site index had an increasingly inverse effect on response as basal area increased in both unthinned and thinned stands. Response varied little over site index in regions of low basal area, decreased moderately as site index increased in the intermediate region, and decreased rapidly in the high basal area region. West. J. Appl. For. 4(4):116-119, October 1989.


2012 ◽  
Vol 42 (2) ◽  
pp. 382-399 ◽  
Author(s):  
Ulrich Kohnle ◽  
Sebastian Hein ◽  
Frank C. Sorensen ◽  
Aaron R. Weiskittel

2000 ◽  
Vol 15 (1) ◽  
pp. 34-36 ◽  
Author(s):  
James S. Hadfield ◽  
Paul T. Flanagan

Abstract Fresh attacks of Douglas-firs (Pseudotsuga menziesii) by Douglas-fir beetles (Dendroctonus pseudotsugae) were found in a campground that had trees pruned to remove Douglas-fir dwarf mistletoe (Arceuthobium douglasii) infections. All Douglas-firs with a diameter at breast height (dbh) of at least 12.7 cm were examined. Beetle attacks were found on 41% of the pruned trees and 5% of the unpruned trees. Among pruned trees, both the average number of branches pruned and the average dbh were greater in trees attacked by Douglas-fir beetles than in unattacked trees. West. J. Appl. For. 15(1):34-36.


IAWA Journal ◽  
2000 ◽  
Vol 21 (4) ◽  
pp. 389-401 ◽  
Author(s):  
Barbara L. Gartner ◽  
David C. Baker ◽  
Rachel Spicer

The factors that determine sapwood width and volume in a tree are not known. This study asked whether sapwood width is related to a need for stem storage sites. Experiments were conducted on 12 34-year-old Douglas-fir [(Pseudotsuga menziesii (Mirb.) Franco] trees with a 6-7 fold range of leaf areas and leaf area/sapwood volumes. Because of declining ray frequency but constant average ray area, ray volume declined for the first 6-10 growth rings, then remained constant, and did not vary with height (breast height vs. 10 nodes from the top). Fewer of the ray parenchyma cells had nuclei in inner than outer sapwood. Inner sapwood had ray parenchyma with smaller rounder nuclei than did outer sapwood, and there was no effect of height. There was a positive relationship between leaf area and the relative volume of ray in outer sapwood at breast height (r = 0.646, p = 0.02), supporting the hypothesis that Douglas-fir trees with larger leaf areas have higher ray volume than do trees with smaller leaf areas. However, correlations of leaf area I sapwood volume with leaf area at either height were not significant, nor were correlations of either leaf area or leaf area/sapwood volume with measures of ray vitality (nuclear frequency in outer sapwood, or the ratio of nuclear frequency in the middle I outer sapwood or in inner I outer sapwood). These latter correlations give no evidence that Douglas-fir trees determine their sapwood volume based on a need for quantity of vital xylem rays.


2011 ◽  
Vol 41 (2) ◽  
pp. 300-308 ◽  
Author(s):  
Alexa K. Michel ◽  
Susanne Winter ◽  
Andreas Linde

The focus of this study was to investigate the role of tree dimension and associated bark structures for high structural complexity and high natural biodiversity in forest ecosystems. Two-hundred and ninety-one Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirbel) Franco) trees in two regions of the US Pacific Northwest were investigated for the relationship between tree diameter and bark thickness (measured as bark fissure depth) and the relationships of both to bark microhabitats and signs of bark use. Our results emphasize the habitat function of tree bark of large-diameter Douglas-fir trees. Many bark microhabitat types and their total abundance significantly increased with increasing tree diameter and bark thickness. These were bark pockets with and without decaying substrate, bowls in the bark, and signs of bark use, e.g., small holes from woodpecker drillings and large insects, large bark excavations from woodpeckers, spider funnel webs, natural cavities at the stem base without decay, and the occurrence of herb vegetation at the tree base. In forest monitoring, tree diameter may be a good indicator of the number of bark microhabitats and of bark thickness because it is strongly related to both of these variables. However, because of the high variability of bark thickness in large-diameter trees, we suggest monitoring bark fissure depth if an ecological evaluation of Douglas-fir forests is needed.


1966 ◽  
Vol 44 (4) ◽  
pp. 453-466 ◽  
Author(s):  
J. H. G. Smith ◽  
L. Heger ◽  
J. Hejjas

Widths of earlywood and latewood in each annual ring, measured on an average radius on a disk taken halfway between each branch whorl, were analyzed to define their variation in 18 Douglas-fir trees (Pseudotsuga menziesii (Mirb.) Franco). Distribution of ring width and percentage latewood also was investigated in these trees which had from 20 to 50 whorls above stump height. Multiple regression and correlation analyses showed that number of rings from pith, and its reciprocal, square, or logarithm accounted for most of the variation in radial growth. Number of rings from pith influenced thickness of both earlywood and latewood much more than the climatic differences reflected by variations in annual height growth and in widths of earlywood and latewood formed at breast height in the same calendar year. Since earlywood and latewood are distributed differently and controlled by different factors, they should be studied separately within annual rings. The statistical methods used in this study provide a simple, efficient, and comprehensive basis for thoroughly describing growth patterns, and for objectively analyzing factors that govern growth.


1998 ◽  
Vol 28 (7) ◽  
pp. 1078-1083 ◽  
Author(s):  
Antal Kozak

Like several other taper equations, the predictive ability of Kozak's (1988. Can. J. For. Res. 18: 1363-1368) variable-exponent taper equations can also be improved by an additional upper stem outside bark diameter measurement. This study indicated that improvements were small and were mainly restricted to increasing the precision of the estimates. Also, it was demonstrated that if additional diameter measurements are justified, they should be taken between 40 and 50% of the height above breast height for greatest improvement. Measurement errors in upper stem diameters and in their heights above breast height affected both the precision and bias of predictions.


1991 ◽  
Vol 6 (4) ◽  
pp. 105-108 ◽  
Author(s):  
Rene I. Alfaro ◽  
Liang Qiwei ◽  
John Vallentgoed

Abstract The diameter growth of western larch, Larix occidentalis, was studied in two stands defoliated by the larch casebearer, Coleophora laricella. Before defoliation, the growth pattern of larch was highly synchronized (correlation coefficient ≥0.82) with that of Douglas-fir, Pseudotsuga menziesii, a nonhost for the casebearer on the same site, indicating that both species were under the influence of the same environmental factors. During the defoliation years, the growth of larch was only loosely related to the growth of Douglas-fir. A model which predicted growth of larch based on growth of Douglas-fir indicated that defoliation caused a loss of approximately 29% in the breast height diameter growth of larch. West. J. Appl. For. 6(4):105-108.


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