scholarly journals Ammonium nitrate, urea, and biuret fertilizers increase volume growth of 57-year-old Douglas-fir trees within a gradient of nitrogen deficiency.

1996 ◽  
Author(s):  
Richard E. Miller ◽  
Donald L. Reukema ◽  
John W. Hazard
Keyword(s):  
Ammonium Nitrate ◽  
Nitrogen Deficiency ◽  
Volume Growth ◽  
Douglas Fir

Wachstum und Wertleistung der Douglasie in Abhängigkeit von der Standraumgestaltung

2012 ◽  
Vol 163 (3) ◽  
pp. 96-104 ◽  
Author(s):  
Joachim Klädtke ◽  
Ulrich Kohnle ◽  
Edgar Kublin ◽  
Andreas Ehring ◽  
Hans Pretzsch ◽  
...  
Keyword(s):  
Wood Quality ◽  
Volume Growth ◽  
Static Stability ◽  
Douglas Fir ◽  
Breast Height ◽  
Monetary Analysis ◽  
Starting Conditions ◽  
Tree Number ◽  
Clear Differentiation ◽  
Further Development

Growth and value production of Douglas-fir under varying stand densities The investigation is focused on the effects of initial tree number and thinning on growth and value performance of Douglas-fir stands. Data base is a coordinated Douglas-fir spacing experiment in South Germany, started 40 years ago and comprising variants of tree numbers with 500, 1,000, 2,000 and 4,000 Douglas-firs per hectare. The treatment was performed according to a standardized experiment program. The results show that at low initial tree numbers, the diameter on breast height (DBH) of (pre)dominant trees at the beginning of the observations (with 12 m top height) is bigger than at higher initial plant numbers. Accordingly, the quotient of height (H) to DBH (as an indicator for tree's static stability) is lower. The further development of DBH and H/DBH quotient is decisively determined by stand treatment, which superimposes the effect of the initial tree number. The total volume growth shows a clear differentiation, too, the variants with initially high tree numbers appearing on top. In the monetary analysis, this ranking is reversed: despite a supposed inferior wood quality, the variants with lower initial tree numbers clearly outperform the ones with higher numbers in terms of value. From these results, the following silvicultural recommendations for Douglas-fir can be derived: the initial tree numbers should be in the range from 1,000 to 2,000 plants per hectare. On technically not accessible sites, even lower tree numbers may come into question. The strong influence of stand treatment on DBH and H/DBH development highlights the problem of postponed thinnings, for this causes growth and stability losses even under favorable starting conditions in terms of competition.

scholarly journals Soil disturbance and 10-year growth response of coast Douglas-fir on nontilled and tilled skid trails in the Oregon Cascades

2002 ◽  
Vol 32 (2) ◽  
pp. 233-246 ◽  
Author(s):  
Ronald Heninger ◽  
William Scott ◽  
Alex Dobkowski ◽  
Richard Miller ◽  
Harry Anderson ◽  
...  
Keyword(s):  
Tree Growth ◽  
Volume Growth ◽  
Soil Surface ◽  
Soil Bulk Density ◽  
Soil Disturbance ◽  
Height Growth ◽  
Douglas Fir ◽  
Negative Effects ◽  
Fine Soil ◽  
Reduced Height

We (i) quantified effects of skidder yarding on soil properties and seedling growth in a portion of western Oregon, (ii) determined if tilling skid trails improved tree growth, and (iii) compared results with those from an earlier investigation in coastal Washington. Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were hand planted at eight recent clearcuts in skid ruts in either nontilled or tilled trails, in adjacent soil berms, and in adjacent logged-only portions. Four and 5 years after skidding, rut depths averaged 15 cm below the original soil surface; mean fine-soil bulk density (0–30 cm depth) below ruts of nontilled trails exceeded that on logged-only portions by 14%. Height growth on nontilled trails averaged 24% less than on logged-only portions in year 4 after planting and decreased to 6% less in year 7. For years 8–10, mean height growth was similar for all treatments. Reduced height growth lasted for about 7 years compared with 2 years for coastal Washington. Ten years after planting, trees in skid-trail ruts averaged 10% shorter with 29% less volume than those on logged-only portions. Tillage improved height and volume growth to equal that on logged-only portions. Generalizations about negative effects of skid trails on tree growth have limited geographic scope.

scholarly journals Early Selection of Douglas-Fir across South Central Coastal Oregon, USA

2006 ◽  
Vol 55 (1-6) ◽  
pp. 135-141 ◽  
Author(s):  
C. A. Dean ◽  
R. W. Stonecypher
Keyword(s):  
Genetic Correlations ◽  
Volume Growth ◽  
Douglas Fir ◽  
Early Selection ◽  
Stem Volume ◽  
Direct Selection ◽  
South Central ◽  
Coos Bay ◽  
The Individual ◽  
Age Range

Abstract Details are given of three first-generation progeny tests (CB1, CB2 and CB3) of coastal Douglas-fir (Pseudotsuga menziesii [MIRB.] FRANCO var. menziesii) planted in the Coos Bay region of south-central coastal Oregon in 1973. The three tests included 15 polymix families based on a 10-pollen mix, and 27 families openpollinated on the ortet. The present study gives heritabilities and additive genetic correlations for growth measured between two and 17 years after planting. Correlated responses are estimated for volume at 17 years from early selection for height and diameter. Between four and 17 years after planting the individual heritability (h2) of height of coastal Douglas-fir across the Coos Bay tests was quite stable between h2 = 0.18 and 0.22. The heritability of stem diameter age-forage was consistently much lower than for height. In the critical age range for early selection between five and 10 years the individual heritability of diameter ranged from h2 = 0.07 to 0.10. The additive genetic correlations involving volume-17 and height or diameter increased to high values of rA = 0.80 to 0.84 between eight to 10 years after planting. Before seven years the absolute values of juvenilemature correlations were much lower. The higher heritability of height made this trait the best criterion for early indirect selection to improve mature stem volume growth. Across these Coos Bay tests, early selection on stem height measured at 5-8 years after planting was estimated to produce almost 40% more gain per year in volume-17 compared with direct selection at 17 years on volume-17 itself. The recommendation for maximizing gain per year in mature volume of coastal Douglas-fir at Coos Bay is to select on height at 7-8 years when the mean height of trees in tests should be around 4.5 to 5.5 meters.

Growth Response to Fertilization in Young Douglas-Fir Stands

1989 ◽  
Vol 4 (4) ◽  
pp. 116-119 ◽  
Author(s):  
Linda S. Heath ◽  
H. N. Chappell
Keyword(s):  
Pseudotsuga Menziesii ◽  
Growth Response ◽  
Volume Growth ◽  
Basal Area ◽  
Site Index ◽  
Douglas Fir ◽  
Intermediate Region ◽  
Fertilizer Response ◽  
Breast Height ◽  
Inverse Effect

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.

A Sustained-Yield Scheme for Old-Growth Douglas-fir

1987 ◽  
Vol 2 (1) ◽  
pp. 22-25 ◽  
Author(s):  
Michael Newton ◽  
Elizebeth C. Cole
Keyword(s):  
High Risk ◽  
Pseudotsuga Menziesii ◽  
Volume Growth ◽  
Douglas Fir ◽  
Management Approach ◽  
Old Growth ◽  
Minimal Impact ◽  
Rotation Culture ◽  
Annual Volume ◽  
Sustained Yield

Abstract From analysis of two Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) stands, 120 and 140 years old, we conclude that managed stands can meet established criteria for old-growth Douglas-fir and simultaneously produce near-maximum yields of good-quality timber. With the management approach outlined here, average annual volume growth may approach that of shorter-rotation culture, but in logs of a size and quality normally found only in older stands, and with minimal impact on high-risk watersheds or old-growth habitat. This possibility encourages development of silvicultural systems that can achieve such goals in a variety of timber types. West. J. Appl. For. 2:22-25, Jan. 1987.

Response of coastal Douglas-fir and competing vegetation to repeated and delayed weed control treatments during early plantation development

2009 ◽  
Vol 39 (6) ◽  
pp. 1208-1219 ◽  
Author(s):  
Douglas A. Maguire ◽  
Douglas B. Mainwaring ◽  
Robin Rose ◽  
Sean M. Garber ◽  
Eric J. Dinger
Keyword(s):  
Weed Control ◽  
Seedling Growth ◽  
Volume Growth ◽  
Douglas Fir ◽  
Optimal Regime ◽  
Competitive Effects ◽  
Competing Vegetation ◽  
Plantation Development ◽  
Age Shift

A key silvicultural decision in managing young conifer plantations is determining the number and timing of release treatments to control competing vegetation. Three coastal Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) plantations were treated under eight alternative herbicide regimes during the first 5 years after planting to test treatment effects on vegetation dynamics and seedling growth. After termination of herbicide treatments, competing vegetation developed at a rate similar to that of check plots, reaching 40%–60% cover in the first growing season and approaching 100% by the third. Recovery of competing vegetation was slightly more rapid with greater number of previous releases. Annual volume growth of seedlings was negatively correlated with current cover of competing vegetation, but competitive effects from previous years were fully accounted for by initial tree size. Under 4 years of release, delaying treatment by 1 year reduced volume attained at the end of 5 years by about 15%. Plots receiving 5 consecutive years of weed control reached the 5 year volume of check plots in only 3.9 years, implying an age shift of 1.1 years. Increasing the number of operational release treatments significantly improved seedling growth in the short term, but long-term growth effects must be monitored to determine the economically optimal regime.

Development of old-growth structure and timber volume growth trends in maturing Douglas-fir stands

1998 ◽  
Vol 104 (1-3) ◽  
pp. 265-280 ◽  
Author(s):  
S.A. Acker ◽  
T.E. Sabin ◽  
L.M. Ganio ◽  
W.A. McKee
Keyword(s):  
Volume Growth ◽  
Douglas Fir ◽  
Old Growth ◽  
Timber Volume ◽  
Growth Trends ◽  
Growth Structure

A field test of the accuracy of the Barr and Stroud Type FP-12 optical dendrometer

1971 ◽  
Vol 47 (2) ◽  
pp. 69-74 ◽  
Author(s):  
John F. Bell ◽  
William A. Groman
Keyword(s):  
Field Test ◽  
Volume Growth ◽  
Douglas Fir ◽  
Repeated Measurements ◽  
Field Conditions ◽  
Extended Time ◽  
Chi Square ◽  
Standing Trees ◽  
Chi Square Test ◽  
First Time

Trees in a 55-year-old stand of Douglas-fir were measured with a Barr and Stroud Type FP-12 dendrometer while standing, then measured with tape and caliper after they were felled. The chi-square test of accuracy for diameters, whether determined according to size, elevation, or distance, fell within a range from ±0.222 to ±0.298 inch, and percentage accuracies varied from ±2.12 to ±3.25. The chi-square test of accuracy for stem lengths decreased from ±0.272 foot (±0.991 percent) at an average elevation of 23.30 feet for an 11.40-foot segment to ±0.782 foot (3.96 percent) for a 14.22-foot average segment at an average elevation of 62.91 feet.This study indicates that upper-stem diameters and segment lengths determined by the Barr and Stroud optical dendrometer are highly accurate under field conditions. Thus, the optical dendrometer provides the forester with a means of eliminating tree-volume tables. Results suggest that, for the first time, volume growth of the upper stem can be accurately determined on standing trees by making repeated measurements over an extended time.

Bulldozing stumps and nitrogen fertilization affect growth of Douglas-fir seedlings

1988 ◽  
Vol 18 (6) ◽  
pp. 803-806 ◽  
Author(s):  
W. G. Thies ◽  
E. E. Nelson
Keyword(s):  
Ammonium Nitrate ◽  
Nitrogen Fertilization ◽  
Growing Season ◽  
Douglas Fir ◽  
Olympic Peninsula ◽  
Diameter At Breast Height ◽  
Clear Cut ◽  
Breast Height ◽  
Growing Seasons ◽  
Growth Of Seedlings

Eight treatments involving stump removal by bulldozing in combination with nitrogen fertilization were applied to 0.04-ha circular plots in a clear-cut on the Olympic Peninsula, Washington. Treatments included stump removal (either all stumps removed or the plot left undisturbed) and broadcast fertilization with ammonium nitrate (0, 336, 672, or 1345 kg N ha−1). Diameter at breast height and height of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings, planted several months after treatment, were recorded five and eight seasons after outplanting. The results showed that either bulldozing stumps from the site or fertilizing with ammonium nitrate increased growth of seedlings through their eighth growing season. After eight growing seasons, bulldozing had increased seedling height by 23% and diameter at breast height by 43%; fertilizing produced increases of 13% in height and 17% in diameter at breast height.

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