Structural Properties of Second-Growth Douglas-Fir Logging Spars

1987 ◽  
Vol 30 (1) ◽  
pp. 0065-0069 ◽  
Author(s):  
Marvin R. Pyles
Keyword(s):  
Structural Properties ◽  
Douglas Fir ◽  
Second Growth

Fungal deterioration of second-growth Douglas-fir logs in coastal British Columbia

1970 ◽  
Vol 48 (9) ◽  
pp. 1541-1551 ◽  
Author(s):  
R. B. Smith ◽  
H. M. Craig ◽  
D. Chu
Keyword(s):  
Seasonal Pattern ◽  
Wood Decay ◽  
Late Summer ◽  
Douglas Fir ◽  
White Rot ◽  
Decay Fungi ◽  
Deterioration Rate ◽  
Second Growth ◽  
Autumn And Winter ◽  
Fungal Deterioration

Fungal deterioration of second-growth Douglas-fir logs, felled each month from August 1961 to May 1962, was studied 2, 4, and 6 years after felling. Decay increased from 10% of log volumes after 2 years to 47% after 6 years. The rate of decay, particularly for the brown cubical type, was greater for autumn- and winter-felled logs than for those felled in the spring and late summer, and closely paralleled the seasonal pattern of ambrosia beetle attack.Decay rates increased with decreasing log size, increasing percentage of sapwood, and increasing height of log above ground. For the same diameter of log, base logs decayed less rapidly than second logs, possibly because of their lower proportion of sapwood in relation to heartwood.Decay expressed as a percentage of total log volume (Y) may be estimated (R2 = 0.71) with the following equation: Y = 13.2 + 10.7X1 − 3.2X2, where X1 = years elapsed and X2 = d.i.b. (diameter inside bark) top of log.Of 30 wood-decay fungi isolated, Naematoloma sp. (N. capnoides or N. fasciculare), which causes a white rot, was associated with the most decay. Fomes pinicola was mainly responsible for brown cubical sap rot, while Poria monticola and P. carbonica caused a brown cubical heart rot at the ends of logs.The significance of variations in deterioration rate and fungal associates is discussed in relation to log durability and salvability.

Load-Carrying Capacity of Second-Growth Douglas-Fir Stump Anchors

1987 ◽  
Vol 2 (3) ◽  
pp. 77-80 ◽  
Author(s):  
Marvin R. Pyles ◽  
Joan Stoupa
Keyword(s):  
Carrying Capacity ◽  
Deformation Behavior ◽  
Ultimate Load ◽  
Douglas Fir ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Tree Diameter ◽  
Second Growth ◽  
Load Carrying ◽  
Load Tests

Abstract In order to quantify the stump anchor capacity of small second-growth Douglas-fir (Pseudotsuga menziesii [Mirb]. Franco) trees, load tests to failure were conducted on 18 stumps from trees 7 to 16.5 in dbh. The tests produced ultimate loads that varied as the square of the tree diameter. However, the ultimate load typically occurred at stump system deformations that were far in excess of that which would be considered failure of a stump anchor. A hyperbolic equation was used to describe the load-deformation behavior of each stump tested and was generalized to describe all the test results. West. J. Appl. For. 2(3):72-80, July 1987.

Douglas-fir soil C and N properties a decade after termination of urea fertilization

2001 ◽  
Vol 31 (12) ◽  
pp. 2225-2236 ◽  
Author(s):  
Peter S Homann ◽  
Bruce A Caldwell ◽  
H N Chappell ◽  
Phillip Sollins ◽  
Chris W Swanston
Keyword(s):  
Mineral Soil ◽  
Cellulase Activity ◽  
Douglas Fir ◽  
Soil Organic C ◽  
Total N ◽  
Organic C ◽  
Soil C ◽  
Second Growth ◽  
Heavy Fractions ◽  
Urea Fertilization

Chemical and microbial soil properties were assessed in paired unfertilized and urea fertilized (>89 g N·m–2) plots in 13 second-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands distributed throughout western Washington and Oregon. A decade following the termination of fertilization, fertilized plots averaged 28% higher total N in the O layer than unfertilized plots, 24% higher total N in surface (0–5 cm) mineral soil, and up to four times the amount of extractable ammonium and nitrate. Decreased pH (0.2 pH units) caused by fertilization may have been due to nitrification or enhanced cation uptake. In some soil layers, fertilization decreased cellulase activity and soil respiration but increased wood decomposition. There was no effect of fertilization on concentrations of light and heavy fractions, labile carbohydrates, and phosphatase and xylanase activities. No increase in soil organic C was detected, although variability precluded observing an increase of less than ~15%. Lack of a regionwide fertilization influence on soil organic C contrasts with several site-specific forest and agricultural studies that have shown C increases resulting from fertilization. Overall, the results indicate a substantial residual influence on soil N a decade after urea fertilization but much more limited influence on soil C processes and pools.

scholarly journals Effect of Plot Size on Estimates of Top Height in Douglas-Fir

1999 ◽  
Vol 14 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Steen Magnussen
Keyword(s):  
Douglas Fir ◽  
Growth Potential ◽  
Site Quality ◽  
Plot Size ◽  
Height Estimates ◽  
Second Growth ◽  
Height Predictions ◽  
Relationship Of ◽  
Simulated Sampling ◽  
The Impact

Abstract Top height is frequently used to estimate site quality and growth potential of forest stands. Top height estimates are quantile estimators and thus sensitive to scaling. If top height is defined as the height of the largest dbh tree per 0.01 ha of area, then it follows that any estimate based on ntop trees in a ntop · 0.01 plot will be a function of ntop, the distribution of dbh values, and the height-diameter relationship of the stand. This study quantifies for second-growth Douglas-fir (Pseudotsuga menziesii) stands along the west coast of British Columbia top height estimates derived from plots of size 0.01, 0.03, 0.05, and 1.0 ha. A pool of 635 permanent and remeasured sample plots allowed the estimation of expected stand-level diameter distributions (Weibull) and height-diameter relationships. Simulated sampling from these distributions quantified the impact of plot size. Top height, derived from plots of 0.01 ha, 0.03 ha and 0.05 ha were 5.6%, 3.0%, and 2.5% lower, respectively, than the estimates based on 1.0 ha plots. Yield predictions based on top heights from 0.01 ha plots were, on average, 8% lower than predictions from 1.0 ha plots. Three of four top height predictions based on 0.01 ha plots were significantly (P < 0.05) lower than predictions from a 1.0 ha plot. West. J. Appl. For. 14(1):17-27.

Estimating probability of intertree root contact in second-growth Douglas-fir

1982 ◽  
Vol 12 (3) ◽  
pp. 493-498 ◽  
Author(s):  
K. M. Reynolds ◽  
W. J. Bloomberg
Keyword(s):  
Douglas Fir ◽  
Rooting Depth ◽  
Tree Stand ◽  
Site Factors ◽  
Root Volume ◽  
Cross Sectional ◽  
Second Growth ◽  
Root Contact

The relationships of root attributes and tree, stand, and site factors to root contact between second-growth Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were studied in excavated root systems. Type 1 contacts (tenuous) were positively related to root length and inversely related to root volume. Type 2–3 contacts (with slight to severe root deformation) were positively related to number of roots. Type 4 contacts (apparent grafts) were positively related to root number and cross-sectional area. Differentiation among groups containing no contacts. Type 1 contacts only or all contact types showed that intertree distance, tree diameter, rooting depth, soil gravel content, and percent slope were significant in determining probability of root contact.

Fungal and arboreal biomass in a western Oregon Douglas-fir ecosystem: distribution patterns and turnover

1979 ◽  
Vol 9 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Robert Fogel ◽  
Gary Hunt
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Forest Floor ◽  
Distribution Patterns ◽  
Turnover Time ◽  
Douglas Fir ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Second Growth ◽  
Soil Hyphae

The allocation of biomass and the turnover time of various components were measured from August 1976 to August 1977 in a young, second-growth Douglas-fir stand in the Oregon Coast Range. Allocation of biomass among the tree components was 14 732 kg foliage ha−1, 30 455 kg branches ha−1, 212 941 kg boles ha−1, 49 289 kg nonmycorrhizal roots ha−1, and 15 015 kg host portion of mycorrhizae ha−1. Biomass allocation of fungal components was 10 009 kg mycorrhizal mantles ha−1, 2785 kg Cenococcumgeophilum sclerotia ha−1, 65 kg sporocarps ha−1, 369 kg litter hyphae ha−1, and 6666 kg soil hyphae ha−1. The forest floor was composed of 6970 kg fine (<2 mm) litter ha−1, 6564 kg coarse (2–25 mm) litter ha−1, and 5500 kg log (>25 mm) litter ha−1. Soil organic matter (<0.494 mm) was 87 600 kg ha−1. Total annual stand throughput was 30 324 kg ha−1, excluding soil organic matter throughput. Of this total, 50.5% was accounted for by fungal throughput, 39.5% by tree throughput, and 10.0% by forest floor throughput.

scholarly journals THE EFFECT OF SEVERAL VARIABLES ON THE SPECIFIC GRAVITY OF SECOND-GROWTH DOUGLAS FIR

1952 ◽  
Vol 28 (3) ◽  
pp. 34-44 ◽  
Author(s):  
R. W. Wellwood
Keyword(s):  
Specific Gravity ◽  
Site Index ◽  
Douglas Fir ◽  
Several Variables ◽  
Second Growth ◽  
Significant Difference ◽  
Thinning Operation ◽  
The Mean ◽  
Individual Trees ◽  
The University

Second-growth stands of mixed Douglas fir and western hemlock produce wood that varies considerably in quality, expressed as specific gravity, depending upon the factors of position in the stem, crown class and site index. Data were obtained from sample Douglas fir trees removed in a thinning operation on the University Research Forest, Haney, British Columbia. Samples represent three levels in the stem (stump, one-third total height and merchantable top), three major crown classes (Dominant, Codominant and Intermediate) and site indices from 93 to 160.It was determined that wood at the base of the tree was more dense than at the higher levels, although this difference failed to show significance for the better sites. Considering the differences, at the same levels, between trees of the three crown classes, Dominants had significantly lower values of specific gravity than either the Codominants or the Intermediates. No significant differences occurred between the latter two classes. When the variable of site is tested, it is found that the "Good" sites have significantly lower specific gravities than do the "Average" sites, for comparable sections. The interaction between site and crown class reveals that the differences above hold for the mean of all sites, and for "Average" sites, but that on "Good" sites no significant difference exists between any of the crown classes.In managing second-growth stands of this nature the forester should keep in mind the variation in specific gravity that will occur. He can regulate rate of growth of individual trees and of stands, within limits, so as to produce wood of the desired quality.

Lateral variability of forest floor properties under second-growth Douglas-fir stands and the usefulness of composite sampling techniques

1986 ◽  
Vol 16 (5) ◽  
pp. 1128-1132 ◽  
Author(s):  
R. E. Carter ◽  
L. E. Lowe
Keyword(s):  
Bulk Density ◽  
Forest Floor ◽  
Chemical Properties ◽  
Mean Value ◽  
Douglas Fir ◽  
Mean Values ◽  
Weighted Arithmetic ◽  
Second Growth ◽  
The Mean ◽  
Composite Samples

Lateral variability of forest floor physical and chemical properties is examined in LF and H horizons under six naturally regenerated, second-growth Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands in coastal southwestern British Columbia. The number of samples required to predict a mean value at two confidence levels (P = 0.01 and 0.05) and two allowable errors (10 and 20%) are given for each variable. Total C, N, P, S, Zn, pH, and lipids were the least variable, requiring 2–13 samples to estimate a plot mean with a 10% allowable error at the 95% confidence level in LF horizons and 3–51 samples per lot in H horizons. Total K, Cu, and Mn were found to have moderately high lateral variability, while total Ca, Mn, Al, and Fe all required large numbers of samples to estimate the plot mean. In the second part of the paper, composite samples weighted by field depth and bulk density are compared with the depth and bulk density–weighted arithmetic mean of subsamples analyzed individually. Values from analysis of composite samples were within one standard deviation of the mean, with the exception of P and Cu in the LF horizons and lipids in both horizons. Composite values and mean values were significantly correlated across the six sites for all variables except lipids in LF horizons and total C and Mn in both horizons. Composite samples are suggested to provide an adequate estimate of the mean value of subsamples analyzed individually for most purposes and, for some variables (i.e., Ca, Fe, Al, and Mn), the only feasible method of obtaining an estimate of the mean.

Diversity of ectomycorrhizae on experimentally planted Douglas-fir seedlings in variable retention forestry sites on southern Vancouver Island

2004 ◽  
Vol 82 (11) ◽  
pp. 1671-1681 ◽  
Author(s):  
R A Outerbridge ◽  
J A Trofymow
Keyword(s):  
Root Colonization ◽  
Distance Effect ◽  
Vancouver Island ◽  
Douglas Fir ◽  
Stand Age ◽  
Mature Trees ◽  
Old Growth ◽  
Variable Retention ◽  
Second Growth ◽  
Retention Forestry

Studies were done on Vancouver Island of ectomycorrhizal (EM) communities at four distances (5–45 m) from isolated forest patches in three second-growth (SG) and three old-growth (OG) Douglas-fir sites subject to variable retention harvesting. We tested the hypothesis that retention of mature trees enhances colonization and diversity of EM fungi on seedlings planted in adjacent areas. In total 41 EM morphotypes were described, with mean diversity of 3.47 morphotypes and root colonization of 62% per seedling. Overall, root colonization declined with distance (72% at 5 m vs. 52% at 45 m), as did EM diversity (4.7 at 5 m vs. 2.9 at 45 m). For individual sites, the distance effect was significant for root colonization at four sites and for EM diversity at three to four sites. This suggests that variable retention is important for the recovery of ectomycorrhizal biota in harvested sites. Seedling root colonization was significantly lower in SG sites than in OG sites. Though EM diversity did not differ with stand age, OG sites had potentially more total (34) and unique (14) EM morphotypes than did SG sites (total 27, unique 7). Differences with stand age might be related to the relative abilities of EM fungi to disperse to regenerating second-growth forests.Key words: variable retention silviculture, ectomycorrhizae ecology, Douglas-fir seedlings, old growth, second-growth forests.

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