Recovery of Douglas-fir seedlings and saplings wounded during overstory removal

1993 ◽  
Vol 23 (8) ◽  
pp. 1684-1694 ◽  
Author(s):  
Steven D. Tesch ◽  
Kathryn Baker-Katz ◽  
Ed J. Korpela ◽  
John W. Mann
Keyword(s):  
Discriminant Analysis ◽  
Height Growth ◽  
Douglas Fir ◽  
Upright Position ◽  
Size Classes ◽  
Lateral Branches

Damaged and undamaged Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings and saplings, ranging in height from 15 to 450 cm, were monitored for 6 years after overstory removal to evaluate recovery from an assortment of logging wounds. Mortality (26%) was concentrated in seedlings less than 75 cm tall and was not related to damage. Surviving trees recovered from most wounds within the 6-year period. In most cases, lateral branches turned up to replace broken terminal leaders or stems; bole wounds healed over; and trees that had been pushed over returned to an upright position. A combination of a bole wound and being pushed to the ground resulted in the poorest recovery, especially for larger trees. With discriminant analysis, initial crown ratio alone enabled correct reclassification of sample trees as crop trees from 64 to 71% of the time; small trees were the most difficult to classify correctly. The addition of preharvest height growth and percentage of bole girdled variables improved the reclassification slightly. Across all three size classes analyzed, damaged trees with initial crown ratios of at least 0.66 were classified as crop trees a minimum of 75% of the time after 6 years. Significant height growth reductions were found only for damaged trees taller than 150 cm.

Patterns of above- and below-ground response of understory conifer release 6 years after partial cutting

2002 ◽  
Vol 32 (2) ◽  
pp. 255-265 ◽  
Author(s):  
Daniel D Kneeshaw ◽  
Harry Williams ◽  
Eero Nikinmaa ◽  
Christian Messier
Keyword(s):  
Root Growth ◽  
Height Growth ◽  
Douglas Fir ◽  
Stem Growth ◽  
Radial Increment ◽  
Growth Responses ◽  
Partial Cutting ◽  
Size Classes ◽  
Clear Cutting ◽  
Advance Regeneration

An increased pressure to use silvicultural techniques not based on clear-cutting followed by planting has led to an interest in systems that take advantage of existing understory seedlings (advance regeneration). Earlier studies have suggested that following harvesting, understory seedlings may experience growth reductions before responding with growth increases. We hypothesize that this "growth shock" following release results because seedlings are ill adjusted to the new growing conditions and that this can be investigated through a comparison of growth in different parts of the tree over a 6-year period. This study compares the growth response of three size classes of lodgepole pine (Pinus contorta Dougl. ex Loud.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings to a partial overstory removal in relatively dry conifer forests of central British Columbia. Growth was evaluated in four parts of the studied trees: radial increment in roots, in the base of the stem, and in branches, as well as leader height growth extension. Our findings show that following release from the overstory, early growth increases were largest in the roots and stems irrespective of the species or the size class. Differences between the species were observed in greater absolute height growth for pine, whereas Douglas-fir invested in greater stem growth, especially in the larger individuals. Important differences also occurred temporally. Both species (and all size classes) responded with an immediate increase in root growth followed, after a 1-year delay, by an increase in stem growth. Branch radial increment (for pine) and leader height growth (both species), however, experienced 2 to 3 year growth reductions before responding. It is therefore suggested that individuals restore the root–shoot balance by greater initial investments to root growth to offset the increased transpiration losses associated with the greater light and higher temperature conditions and the relative changes in the photosynthetic versus nutrient uptake capacity following the canopy opening. Foresters may therefore be able to manipulate tree growth responses by using an appropriate degree of overstory removal or opening size.

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.

Boron and Magnesium Fertilization of a Coastal Douglas-Fir Plantation

1993 ◽  
Vol 8 (2) ◽  
pp. 48-53 ◽  
Author(s):  
R. N. Green ◽  
R. E. Carter
Keyword(s):  
Height Growth ◽  
Douglas Fir ◽  
Boron Deficiency ◽  
Growing Seasons ◽  
Foliar Symptoms ◽  
Foliar Concentrations ◽  
A Site ◽  
Coastal British Columbia ◽  
Severe Growth

Abstract This study examines the role of boron and magnesium nutrition in the occurrence of severe growth distortion symptoms in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in the Skwawka River valley of south coastal British Columbia. Four fertilizer treatments including boron (2.25 kg B/ha), magnesium (42 kg Mg/ha), boron plus magnesium, and a control, were applied in conjunction with planting on a site believed to be deficient in these nutrients. After 5 growing seasons, only treatments containing boron (B and B+Mg) showed improved height growth over the control trees. The incidence of leader dieback, swollen leading shoots, and foliage distortion was significantly related to treatment with virtually no occurrence in plots treated with boron. Seedling uptake of applied boron was high, with foliar concentrations of 45 ppm found after the second growing season. Foliar B levels declined to 13-15 ppm after 5 growing seasons. No significant increase in foliar magnesium levels was detected for either of the magnesium treatments. The reduction in the incidence of leader dieback and shoot and foliar symptoms in seedlings treated with B indicate that these symptoms were the result of boron deficiencies. This is the first study to verify boron deficiency in coastal Douglas-fir through fertilizer trials. West. J. Appl. For. 8(2):48-53.

Sitka alder, a candidate for mixed stands

1982 ◽  
Vol 12 (1) ◽  
pp. 108-111 ◽  
Author(s):  
Constance A. Harrington ◽  
Robert L. Deal
Keyword(s):  
Organic Matter ◽  
Head Start ◽  
Growth Curves ◽  
Poor Quality ◽  
Height Growth ◽  
Douglas Fir ◽  
Nitrogen Fixing ◽  
Mixed Stands

Juvenile height growth of Sitka alder (Alnussinuata (Regel) Rydb.), a nitrogen-fixing shrub, was examined on eight sites. The potential compatibility of mixed stands of Sitka alder and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) was then assessed by comparing height-growth curves of the two species at early ages. Based on Sitka alder's low height and early slowdown in height growth, it appears to be a reasonable candidate for mixed stands on sites where additions of nitrogen or organic matter are desirable. On poor quality Douglas-fir sites, however, Douglas-fir should be given a head start to insure that it is not suppressed.

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.

Motion-induced growth effects in Douglas fir

1977 ◽  
Vol 7 (1) ◽  
pp. 94-99 ◽  
Author(s):  
R. M. Kellogg ◽  
G. L. Steucek
Keyword(s):  
Height Growth ◽  
Douglas Fir ◽  
Considerable Reduction ◽  
Marked Influence ◽  
Wind Action ◽  
Growth Effects ◽  
Xylem Growth ◽  
Significant Change

Daily brief intervals (30 s) of relatively mild shaking had a marked influence on leader growth of young Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stems grown in a greenhouse. When the treatment was applied to naturally wind-loaded stems, there was some suggestion that height growth was reduced more than the considerable reduction from wind action alone. Neither the pattern nor magnitude of xylem growth appeared to be affected by the treatment, whereas wind action produced a significant change in the pattern. It is suggested that the response to wind and shaking stimuli may differ.

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.

Effect of seed weight on height growth of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) seedlings in a nursery

1985 ◽  
Vol 15 (6) ◽  
pp. 1109-1115 ◽  
Author(s):  
Frank C. Sorensen ◽  
Robert K. Campbell
Keyword(s):  
Seed Size ◽  
Seed Weight ◽  
Germination Rate ◽  
Plant Size ◽  
Height Growth ◽  
Douglas Fir ◽  
Genetic Makeup ◽  
Practical Implications ◽  
Filled Seeds

Different mean seed weights were produced within each of 10 young Douglas-fir trees by leaving some developing cones unbagged and enclosing others in Kraft paper bags for two different durations. On the average, 10 days in the bag increased filled-seed weight by about 1%. Unbagged cones and cones from the 117-day bagging duration were wind pollinated. Seeds from these cones were, therefore, of comparable genetic makeup and were used in further nursery growth tests. To eliminate the effect of germination rate or time, samples of filled seeds from each treatment on each parent tree were sown as germinant seedlings on one date. Cotyledon number was counted and 1st-year epicotyl lengths and 2nd-year total heights were measured on all seedlings. Seedling volumes were estimated by assuming diameters were proportional to heights. On the average, bagging cones for 117 days increased seed weight by 10.7%, 1st-year epicotyl length by 9.1%, and 2-year total height by 4.0%. All differences were statistically significant. Results were compared with other reports of the relations between seed weight and growth and reasons for inconsistencies were discussed. Size differences were projected to later ages with a growth model and practical implications of long-term seed effects on plant size, of increasing seed size through cultural techniques, and of grading seed lots by size were considered.

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