Nutrient, moisture, and light relations in 5-year-old Douglas-fir plantations under variable competition

1986 ◽  
Vol 16 (4) ◽  
pp. 727-732 ◽  
Author(s):  
Elizabeth C. Cole ◽  
Michael Newton
Keyword(s):  
Nitrogen Concentration ◽  
Moisture Stress ◽  
Douglas Fir ◽  
Coast Range ◽  
Nitrogen And Phosphorus ◽  
Red Alder ◽  
Oregon Coast Range ◽  
Foliar Nitrogen ◽  
Foliar Phosphorus ◽  
Crown Closure

Competition for soil nutrients, moisture, and light was examined in 5-year-old plantations of young coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) growing at 17- to 123-cm spacings, alone or with either of two competitors, grass (Elymus spp. and Agrostistenuis L.) or red alder (Alnusrubra Bong.), on three different site types in the Oregon Coast Range. Douglas-fir foliar nitrogen concentration and total and available soil nitrogen did not differ significantly by competitor species; however, foliar phosphorus was higher in the grass treatments. Both foliar nitrogen and phosphorus concentrations were significantly lower at high planting densities. Predawn moisture stress varied with site, competitor, and density, the lowest stresses occurring at low densities where Douglas-fir was growing alone. Canopy light penetration varied with competitor, density, and height above ground, the lowest values occurring under the red alder canopy. Grass competed with Douglas-fir seedlings primarily for moisture until crown closure eliminated the grass. Nodulated red alder did not increase soil or Douglas-fir foliar nitrogen on any site or at any density, but competition from red alder trees reduced available light and moisture for Douglas-fir. Regardless of competitor type, high density resulted in increased demands on resources.

Fifth-year responses of Douglas-fir to crowding and nonconiferous competition

1987 ◽  
Vol 17 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Elizabeth C. Cole ◽  
Michael Newton
Keyword(s):  
Basal Area ◽  
Primary Objective ◽  
Douglas Fir ◽  
Coast Range ◽  
Growth Responses ◽  
Coastal Site ◽  
Red Alder ◽  
Oregon Coast Range ◽  
Management Alternatives ◽  
Site Types

Growth responses from crowding and interspecific competition were examined in 5-year-old plantations of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) spaced 17 to 123 cm apart, alone or with either grass or red alder (Alnusrubra Bong.) on three site types in the Oregon Coast Range. Grass and red alder competition and crowding adversely affected growth and standing biomass on a per tree basis. Basal area per hectare and volume per hectare were higher at high densities but these relations are expected to change with time as the larger trees at low densities form fully stocked stands. Grass competition showed greatest effects on growth at the driest site. Although the presence of red alder decreased growth on all sites, the effect was most significant at the coastal site where light is most limiting and moisture is least limiting. If the production of maximum tree size is the primary objective, then low stocking with control of competing vegetation will produce larger trees faster than will other management alternatives.

Germination, survival, and early growth of red alder seedlings in the central Coast Range of Oregon

1995 ◽  
Vol 25 (10) ◽  
pp. 1639-1651 ◽  
Author(s):  
Sybille Haeussler ◽  
John C. Tappeiner II ◽  
Brian J. Greber
Keyword(s):  
Soil Moisture ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Mineral Soil ◽  
Survival Rates ◽  
Moisture Stress ◽  
Coast Range ◽  
Seedling Mortality ◽  
Central Coast ◽  
Red Alder

Effects of forest disturbance and soil moisture levels on establishment of red alder (Alnusrubra Bong.) seedlings were studied at four sites representing a climatic moisture gradient within the central Coast Range of Oregon. On average, there was no difference in seedling emergence between recent clearcuts and second-growth forests, but emergence was much higher on mineral soil than on organic seedbeds. Emergence, on both types of seedbed, was positively correlated with spring soil moisture conditions (R2 = 0.60). Seedling survival, on the other hand, differed greatly between clearcut and forest. In clearcuts, heat and drought injuries were the primary causes of seedling mortality. In the forest, seedlings had poor vigour and quickly succumbed to pathogens, herbivores, and rain splash. First-year survival rates were strongly correlated with minimum summer soil moisture levels (R2 = 0.71). Height growth of seedlings on clearcuts (2–5 cm after 1 year; 8–23 cm after 2 years) was much slower than rates typically described for red alder. Best establishment occurred on skid trails and landings, suggesting that young seedlings may suffer less from heat or moisture stress on these heavily disturbed microenvironments.

Correlations Between Overtopping Vegetation and Development of Douglas-Fir Saplings in the Oregon Coast Range

1987 ◽  
Vol 2 (4) ◽  
pp. 117-119 ◽  
Author(s):  
Samuel S. Chan ◽  
John D. Walstad
Keyword(s):  
Pseudotsuga Menziesii ◽  
Tree Height ◽  
Douglas Fir ◽  
Morphological Features ◽  
Diameter Growth ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Sapling Growth ◽  
Stem Diameter Growth

Abstract The response of Douglas-fir (Pseudotsuga menziesii) saplings to overtopping vegetation on three northeast-facing sites in the Oregon Coast Range was studied for two years. As amount of overtopping brush increased, sapling growth (as indicated by size) generally decreased. Basal stem diameter growth was most reduced, but similar reductions in growth occurred for tree height and other morphological features. West. J. Appl. For. 2(4):117-119, October 1987.

scholarly journals Douglas-Fir Beetle Response to Artificial Creation of Down Wood in the Oregon Coast Range

2006 ◽  
Vol 21 (3) ◽  
pp. 117-122 ◽  
Author(s):  
Darrell W. Ross ◽  
Bruce B. Hostetler ◽  
John Johansen
Keyword(s):  
Tree Mortality ◽  
Large Diameter ◽  
Douglas Fir ◽  
Coast Range ◽  
Managed Forests ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Management Objectives ◽  
Baited Traps ◽  
Before And After

Abstract Douglas-fir beetle populations were monitored before and after thinning and felling of trees to create down wood in an 88-year-old Douglas-fir plantation in the Oregon Coast Range. Treatments included an unthinned control, thinning to a target of 75 trees/ha, and thinning to a target of 150 trees/ha. Actual mean tree densities on the plots after thinning were 406, 102, and 154, for the control, 75 trees/ha, and 150 trees/ha treatments, respectively. Fifty trees/ha were felled and left on all thinned plots to create down wood for ecological values. Catches in pheromone-baited traps indicated that the local beetle population increased for 1 year in response to felling and leaving large diameter trees in partial shade. Douglas-fir beetle entrance holes and brood were significantly more abundant on the sides of felled trees and wood borers were significantly more abundant on the upper surface suggesting that treatments that provide maximum exposure of felled trees will create the least favorable habitat for Douglas-fir beetles. However, there were no differences in Douglas-fir beetle entrance holes or brood densities in felled trees between the two thinning intensities. Douglas-fir beetle-caused tree mortality was significantly higher on thinned plots with residual felled trees compared with unthinned controls, although infestation levels were low on all plots (<2 trees/ha). The small increase in beetle-caused tree mortality associated with leaving felled trees would be unlikely to interfere with resource management objectives. These results are applicable to mature, managed forests west of the Cascades with relatively low Douglas-fir beetle populations. In different regions and stand types, or under different environmental conditions, beetle populations could increase to higher densities, remain at high densities longer, and cause higher levels of tree mortality. West. J. Appl. For. 21(3):117–122.

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 Effects of Swiss Needle Cast on Three Douglas-Fir Seed Sources on a Low-Elevation Site in the Northern Oregon Coast Range: Results after Five Growing Seasons

2001 ◽  
Vol 16 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Walter W. Kastner ◽  
Steve M. Dutton ◽  
David M. Roché
Keyword(s):  
Douglas Fir ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Needle Cast ◽  
Growing Seasons ◽  
Seed Sources ◽  
Coastal Fog ◽  
Swiss Needle Cast ◽  
Natural Stands

Abstract Douglas-fir (Pseudotsuga menziesii var. menziesii) seedlings grown from three seed sources were evaluated for 5 yr on a high-disease-hazard site for their relative tolerance to Swiss needle cast. The seed sources were: (1) seed collected from trees showing an apparent degree of tolerance to Swiss needle cast in natural stands in the coastal fog belt, (2) open-pollinated seed orchard seed collected from random single-pair crosses of parent trees in natural stands outside of the coastal fog belt, but west of the Oregon Coast Range summit, whose progeny demonstrated an apparent degree of disease tolerance in coastal Douglas-fir progeny test sites, and (3) standard reforestation seed purchased from a commercial vendor. There were no significant differences among seed sources in basal diameter and total height for all five growing seasons. Needle retention varied among seed sources over the 5 yr period, but current-year needle retention did not vary significantly after the fifth growing season, and retention of 1- and 2-yr-old needles was relatively low for all seed sources. The intense disease pressure on this site may have overwhelmed expression of disease tolerance among seed sources. We do not recommend planting Douglas-fir on such high-hazard sites. West J. Appl. For. 16(1):31–34.

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