Modelling current annual height increment of young Douglas-fir stands at different sites.

2009 ◽  
pp. 249-257
Author(s):  
P. J. Radonja ◽  
M. J. Koprivica ◽  
V. S. Lavadinovic
Keyword(s):  
Douglas Fir ◽  
Height Increment

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.

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.

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

Lateral Root Pruning – A Promising Forest Nursery Practice

1968 ◽  
Vol 44 (5) ◽  
pp. 12-13 ◽  
Author(s):  
S. Eis
Keyword(s):  
Lateral Root ◽  
Root Systems ◽  
Douglas Fir ◽  
Root Pruning ◽  
Height Increment ◽  
Forest Nursery

The regeneration and growth of pruned roots of Douglas-fir seedlings were studied under nursery conditions. Root pruning did not decrease the height increment of seedlings. For the best development of dense and compact root systems, the bottom pruning should be done early in spring and the side pruning around the middle of June, on both sides of the row simultaneously.

Effects of Nitrogen Fertilization on Growth of Grand Fir and Douglas-Fir Stands in Northern Idaho

1989 ◽  
Vol 4 (2) ◽  
pp. 54-57 ◽  
Author(s):  
Bahman Shafii ◽  
James A. Moore ◽  
John R. Olson
Keyword(s):  
Pseudotsuga Menziesii ◽  
Nitrogen Fertilization ◽  
Basal Area ◽  
Douglas Fir ◽  
Tree Size ◽  
Stand Development ◽  
Height Increment ◽  
Area Growth ◽  
Nitrogen Treatment ◽  
Northern Idaho

Abstract A study of nitrogen fertilization response in thinned and unthinned stands of grand fir (Abies grandis) and Douglas-fir (Pseudotsuga menziesii) in northern Idaho showed that the application of one urea nitrogen treatment applied at a rate of 200 lb N/ac resulted in a significantly higher average basal area growth over a 6-year post-treatment period. Nitrogen fertilization also resulted in a significant height increment increase over the same period. Fourteen years after treatment, fertilization had increased average tree size, in terms of total cubic volume, by 14% in unthinned and by 23% in thinned stands. A comparison of thinned and unthinned stands suggested an increase in tree size (>300%) over the same period without significant reduction in average total cubic volume per acre. Patterns of stand development were altered by nitrogen fertilization. West. J. Appl. For. 4(2):54-57, April 1989.

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