scholarly journals Effect of Leader Clipping on Height Growth of Young Coastal Douglas-Fir (Pseudotsuga menziesii var. menziesii)

2002 ◽  
Vol 17 (2) ◽  
pp. 75-77 ◽  
Author(s):  
Frank C. Sorensen
Keyword(s):  
Pseudotsuga Menziesii ◽  
Height Growth ◽  
Douglas Fir ◽  
Height Increment ◽  
Depressing Effect ◽  
Linear Fashion ◽  
Diameter Increment ◽  
Reduced Height

Abstract Leaders of 3- through 7-yr-old Douglas-fir seedlings were left unclipped or were clipped for 1 to 4 consecutive years. Terminal removal reduced height increment in a significantly linear fashion and was about 19 cm for each year clipped. All treatments had comparable height increment in the 4 yr after clipping, and the initial depressing effect on height was still present at age 23. Diameter increment was reduced but not significantly. West. J. Appl. For. 17(2):75–77

Effects of mechanical stimulus, shade, and nitrogen fertilization on morphology and bending resistance in Douglas-fir seedlings

2003 ◽  
Vol 33 (9) ◽  
pp. 1602-1609 ◽  
Author(s):  
Stephen J Mitchell
Keyword(s):  
Nitrogen Fertilization ◽  
Mechanical Stimulus ◽  
Douglas Fir ◽  
Height Increment ◽  
Stem Form ◽  
Diameter Increment ◽  
Reduced Height ◽  
Bending Resistance ◽  
Volume Increment ◽  
Bending Stresses

Three-year-old coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were planted in a factorial experiment with three levels of shading (0, 30, and 60%), three levels of mechanical stimulus (staked, freestanding, and bent), and two levels of nitrogen fertilization (0 and 200 kg/ha) to investigate the separate and combined effects of these factors on morphology and bending resistance. Fertilization increased branch angle and increased the sensitivity of branch and leader extension to bending stresses but did not affect volume increment, stem form, or bending resistance. The effects of shading and mechanical treatments on morphology were independent and additive. Shading reduced stem diameter and volume increment, but did not affect height increment, producing more slender trees. Bending produced less slender trees through a combination of reduced height increment and increased diameter increment. Staking did not affect tree morphology. Trees under heavy shade were responsive to bending but were more slender and had lower bending resistance than unshaded trees with the same mechanical stimulus. These results point towards the biological basis for the development of tree instability in high density stands.

scholarly journals Soil texture and other site-level factors differentially affect growth of Scotch broom (Cytisus scoparius) and Douglas-fir (Pseudotsuga menziesii) seedlings in the western Pacific Northwest

2021 ◽  
Author(s):  
David Carter ◽  
Robert A. Slesak ◽  
Timothy B. Harrington ◽  
Anthony W. D’Amato
Keyword(s):  
Pacific Northwest ◽  
Pseudotsuga Menziesii ◽  
Height Growth ◽  
Douglas Fir ◽  
Western Pacific ◽  
Limiting Factor ◽  
Cytisus Scoparius ◽  
Invasive Shrub ◽  
Scotch Broom ◽  
The Western Pacific

The invasive shrub Scotch broom (Cytisus scoparius (L.) Link) is a pervasive threat to regenerating Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) stands in the Pacific Northwest, USA. Field observations indicate that the susceptibility of areas to Scotch broom invasion and dominance can vary by site. We selected ten sites throughout the western Pacific Northwest that spanned a gradient of soil textures and other factors to test the site-specific susceptibility of Douglas-fir to overtopping by Scotch broom. We expected to find that the ability of Scotch broom to dominate a site was mediated by site-level factors, particularly those influencing soil water – the most limiting factor to growth in the region. We found Scotch broom and Douglas-fir were inversely affected by site-level factors. In general, Douglas-fir absolute height growth rates were more competitive with those of Scotch broom on fine-textured soils than on more coarsely textured soils. We also found Douglas-fir to have a more dramatic response to increasing down woody material than Scotch broom. Scotch broom height growth approached an asymptote at 3 m. Sites with fast-growing Douglas-fir were able to surpass this height six to seven years after planting and appear likely to avoid suppression by Scotch broom.

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.

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.

HEIGHT GROWTH LOSSES DUE TO ANIMAL FEEDING IN DOUGLAS FIR PLANTATIONS, VANCOUVER ISLAND, B.C.

1964 ◽  
Vol 40 (3) ◽  
pp. 298-307 ◽  
Author(s):  
K. J. Mitchell
Keyword(s):  
Pseudotsuga Menziesii ◽  
East Coast ◽  
Growth Curves ◽  
Tree Height ◽  
Vancouver Island ◽  
Height Growth ◽  
Douglas Fir ◽  
Average Height ◽  
Animal Feeding ◽  
Rotation Age

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations on the east coast of Vancouver Island, British Columbia, were examined to determine the effect of animal feeding upon height growth.Length of internodes and evidence of past leader damage were recorded and cumulative average height-age growth curves compared for undamaged trees and for trees suffering various intensities of damage.The average reduction in tree height attributable to animal feeding in heavily browsed plantations varied from one-half to two feet over a period of 8 to 10 years. It is unlikely that either tree volume or quality at rotation age would be seriously affected.Exposed trees were browsed more heavily than those protected by vegetation or logging slash.

Seed lot, nursery, and bud dormancy effects on root electrolyte leakage of Douglas-fir (Pseudotsuga menziesii) seedlings

1999 ◽  
Vol 29 (8) ◽  
pp. 1269-1281 ◽  
Author(s):  
Raymund S Folk ◽  
Steven C Grossnickle ◽  
Paige Axelrood ◽  
Dave Trotter
Keyword(s):  
Pseudotsuga Menziesii ◽  
Height Growth ◽  
Douglas Fir ◽  
Bud Dormancy ◽  
Root Damage ◽  
Relative Height ◽  
Nursery Culture ◽  
Terminal Bud ◽  
Root Electrolyte Leakage ◽  
The Relationship

The effects of seed lot, nursery culture, and seedling bud dormancy status on root electrolyte leakage (REL) of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were assessed to determine if these factors should be considered when interpreting REL for seedling quality. The relationships of REL to survival, net photosynthesis (Pn), stomatal conductance (gwv), mid-day shoot water potential (Ψmid), root growth capacity (RGC), and relative height growth were determined for each factor. Nursery culture had no effect on the relationship between REL and all other measured attributes. Seed lot affected the relationship between REL and Pn, Ψmid, and survival. However, critical REL (i.e., lowest value associated with detectable root damage) and PS80 REL (i.e., level associated with an 80% probability for survival) were similar between seed lots. Bud dormancy status affected the relationship between REL and survival, RGC, and relative height growth. Control levels of REL, critical REL, and PS80 REL decreased as the number of days required for 50% terminal bud break declined. Thus, terminal bud dormancy status must be known before REL can be used to assess seedling quality. If the bud dormancy status of Douglas-fir populations is known, then critical and PS80 REL levels may be useful as indices of root damage.

Growth patterns in a young western hemlock plantation infested with dwarf mistletoe

1983 ◽  
Vol 13 (5) ◽  
pp. 972-978 ◽  
Author(s):  
A. J. Thomson ◽  
R. B. Smith
Keyword(s):  
Root Systems ◽  
Height Growth ◽  
Growth Patterns ◽  
Western Hemlock ◽  
Height Increment ◽  
Relative Height ◽  
Dwarf Mistletoe ◽  
Diameter Increment ◽  
Breast Height ◽  
Individual Trees

Relative height and diameter values of 22-year-old western hemlock trees (Tsugaheterophylla (Raf.) Sarg.) were normally distributed, with a constant standard deviation from year to year. Ranking of individual trees in the distribution changed with time, presumably because the root systems encountered successively more favourable or unfavourable microsites. Competition effects were detectable on height and diameter at breast height (dbh), although these effects were considerably masked by the microsite effect. Dwarf mistletoe (Arceuthobiumtsugense (Rosendahl) G. N. Jones) effects were detectable on height growth, but not dbh growth. Height increment in a particular year varied in a pattern similar to February precipitation, while diameter increment varied in a pattern similar to March–May precipitation. This may account for the observation that the degree of correlation of height and diameter increments in a particular year varied from low to high.

Comparison of indicator variables for estimating growth reduction associated with Phellinusweirii root rot in Douglas-fir plantations

1979 ◽  
Vol 9 (1) ◽  
pp. 76-81 ◽  
Author(s):  
W. J. Bloomberg ◽  
G. W. Wallis
Keyword(s):  
Root Rot ◽  
Height Growth ◽  
Douglas Fir ◽  
The Other ◽  
Height Increment ◽  
Growth Reduction ◽  
Total Height ◽  
Breast Height ◽  
Indicator Variables ◽  
Increment Ratio

Total height, annual height increment, annual diameter at breast height (dbh) increment, ratio of total height to dbh, and ratio of annual height increment to annual dbh increment were assessed as indicator variables for estimating growth reduction associated with Phellinusweirii root rot of Douglas-fir (Pseudotsugamenziesii). Generally, height variables were more sensitive indicators than dbh. Total height by 2-cm-dbh classes, ratio of total height to dbh, and ratio of annual height increment to annual dbh increment were more sensitive and less variable than the other indicators. Ratio of total height to dbh was a more consistent and sensitive indicator of growth reduction than all other variables. Application of this ratio in estimating height growth reduction in three plantations indicated reductions in infected trees of 1 to 8 m over periods of 2 to 24 years, averaging 0.9 to 1.7% annually.

PATTERNS IN GROWTH OF EARLYWOOD, LATEWOOD, AND PERCENTAGE LATEWOOD DETERMINED BY COMPLETE ANALYSIS OF 18 DOUGLAS-FIR TREES

1966 ◽  
Vol 44 (4) ◽  
pp. 453-466 ◽  
Author(s):  
J. H. G. Smith ◽  
L. Heger ◽  
J. Hejjas
Keyword(s):  
Pseudotsuga Menziesii ◽  
Radial Growth ◽  
Annual Ring ◽  
Ring Width ◽  
Height Growth ◽  
Douglas Fir ◽  
Growth Patterns ◽  
Complete Analysis ◽  
Annual Rings ◽  
Breast Height

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.

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