Light-growth responses of coastal Douglas-fir and western redcedar saplings under different regimes of soil moisture and nutrients

2001 ◽  
Vol 31 (12) ◽  
pp. 2124-2133 ◽  
Author(s):  
C Ronnie Drever ◽  
Kenneth P Lertzman
Keyword(s):  
Soil Moisture ◽  
Growth Rates ◽  
Growth Response ◽  
Height Growth ◽  
Douglas Fir ◽  
Site Quality ◽  
Thuja Plicata ◽  
Growth Responses ◽  
Western Redcedar ◽  
Light Levels

We characterized the radial and height growth response to light for coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) and western redcedar (Thuja plicata Donn ex D. Don) saplings growing in sites of different regimes of soil moisture and nutrients on the east coast of Vancouver Island, British Columbia. We determined that at low light levels, site quality has little effect on the growth response of Douglas-fir saplings. At light levels above approximately 40 and 60% full sun, Douglas-fir saplings show statistically significant differences in height and radial growth, respectively, that reflect the differences in soil moisture and nutrient regimes of the sites we examined. Western redcedar approaches its maximum radial and height growth rates at about 30% full sun. Our data suggest that partial-cutting treatments need to create light environments greater than about 40% full sun to achieve growth that represents a high proportion of the site growing potential for Douglas-fir at full sun, while the high shade tolerance of western redcedar allows silvicultural treatments that retain a high amount of forest structure without compromising growth rates of young trees.

Short- and Long-Term (Final Height) Growth Responses to Growth Hormone (GH) Therapy in Patients with Turner Syndrome: Correlation of Growth Response to Stimulated GH Levels, Spontaneous GH Secretion, and Karyotype

1997 ◽  
Vol 47 (2) ◽  
pp. 67-72 ◽  
Author(s):  
Klaus Schmitt ◽  
Gabriele Haeusler ◽  
Peter Blümel ◽  
Engelbert Plöchl ◽  
Herwig Frisch
Keyword(s):  
Growth Hormone ◽  
Turner Syndrome ◽  
Growth Response ◽  
Final Height ◽  
Height Growth ◽  
Growth Responses ◽  
Gh Therapy ◽  
Gh Secretion ◽  
Short And Long Term

scholarly journals Laminated Root Rot and Fumigant Injection Affect Survival and Growth of Douglas-Fir

2007 ◽  
Vol 22 (3) ◽  
pp. 220-227 ◽  
Author(s):  
Constance A. Harrington ◽  
Walter G. Thies
Keyword(s):  
Tree Growth ◽  
Growth Rates ◽  
Root Rot ◽  
Survival Rates ◽  
Height Growth ◽  
Douglas Fir ◽  
Infection Level ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Tree Survival

Abstract Laminated root rot caused by Phellinus weirii is a significant disease of western conifers; it is important to understand the effects of the disease on tree growth and survival and, for some management objectives, to develop treatments that will reduce those effects. This study was conducted in a 47-year-old Douglas-fir (Pseudotsuga menziesii) stand in northwest Oregon. First, we evaluated the effects of root system infection on diameter and height growth. Growth rates were lowest in trees with high infection levels; root infection level affected diameter growth more than height growth. Second, we evaluated the effects of fumigation treatments on tree growth. The nine treatments were as follows: three dosages of methylisothiocyanate (MITC), four dosages of chloropicrin (trichloronitromethane), one dosage of Vorlex [20% MITC, 80% chlorinated C3 hydrocarbons (v/v)], and a control. The fumigants were applied by inserting them into holes drilled into the base of live trees. After nine growing seasons, all three of the treatments applying different dosages of MITC and the treatment applying the lowest dosage of chloropicrin had higher tree survival rates than the untreated control, and the growth rates in those four fumigation treatments were not significantly different from growth in the surviving control trees.

Ionic balance and organic acids in western redcedar, western hemlock, and Douglas-fir seedlings grown in low- and high-N soils

1999 ◽  
Vol 29 (6) ◽  
pp. 669-678 ◽  
Author(s):  
J E Graff, Jr. ◽  
R K Hermann ◽  
J B Zaerr
Keyword(s):  
Organic Acids ◽  
Quinic Acid ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
N Availability ◽  
Ionic Balance ◽  
Total N ◽  
Western Redcedar

Seedlings of western redcedar (Thuja plicata Donn ex. D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were transplanted into soils with low and high levels of available NO3-(and total N). Current-year foliage was sampled after 10 weeks to determine the effect of N availability on foliar cation-anion balance (C-A) and the concentrations of low molecular weight organic acids of the three species. Carboxylate concentrations were estimated by using the difference between sums of cations and anions (C-A): 750 mequiv.·kg-1for western redcedar, 351 mequiv.·kg-1for western hemlock, and 266 mequiv.·kg-1for Douglas-fir. Quinic acid was a primary constituent, accounting for 40% of the total for western redcedar and 75% for western hemlock and Douglas-fir. Oxalic acid was present in greatest concentration in the foliage of western redcedar (65 mequiv.·kg-1) but was a minor constituent in western hemlock and Douglas-fir. The quantified acids accounted for only 15% of the C-A of western redcedar but >80% of the C-A of western hemlock and Douglas-fir. A considerable portion of the C-A balance not accounted for in redcedar may be associated with the accumulation of CaCO3. Litterfall deposition of CaCO3may lead to the consumption of H+ions and enrichment of exchangeable soil Ca in the rooting zone of long-lived western redcedar trees. No statistically significant differences among the soils were detected with regard to C-A or the concentration of organic acids.

Stand development following precommercial thinning and fertilization treatments in a western redcedar (Thuja plicata) dominated forest

2011 ◽  
Vol 41 (1) ◽  
pp. 151-164 ◽  
Author(s):  
Constance A. Harrington ◽  
Warren D. Devine
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Site Quality ◽  
Thuja Plicata ◽  
Nitrogen And Phosphorus ◽  
Western Redcedar ◽  
Large Trees ◽  
Wide Range ◽  
Individual Trees ◽  
Area And Volume

Western redcedar (Thuja plicata Donn ex D. Don.) is an important North American tree species, but little information is available on its long-term responses to silvicultural treatments. Stand responses (mortality, ingrowth, basal area and volume growth, and distributions of trees by diameter and height classes) were followed for 25 years after thinning and fertilization treatments (alone and in combination) were applied to a naturally regenerated, low site quality western redcedar stand on the Olympic Peninsula in western Washington, USA. Mortality was low overall, but the densest stands experienced competition-related mortality. Thinning resulted in additional stem recruitment; after 25 years, the number of ingrowth trees exceeded the number of trees in the cohort left after thinning. Fertilization (with nitrogen and phosphorus) flattened size distributions and skewed them to larger size classes. Thinning plus fertilization resulted in the largest individual trees and the most large trees, but also many trees in a wide range of diameter classes. The recruitment of a second cohort did not result in a two-storied stand. Fertilization without thinning resulted in the greatest stand basal area and volume, as well as trees with fewer live lower branches.

scholarly journals Ten-Year Survival and Growth of Planted Douglas-Fir and Western Redcedar After Seven Site-Preparation Treatments

1997 ◽  
Vol 12 (3) ◽  
pp. 74-80 ◽  
Author(s):  
William I. Stein
Keyword(s):  
Pseudotsuga Menziesii ◽  
Site Preparation ◽  
Douglas Fir ◽  
Thuja Plicata ◽  
Alnus Rubra ◽  
Red Alder ◽  
Preparation Methods ◽  
Western Redcedar ◽  
Oregon Coast ◽  
Survival And Growth

Abstract Western redcedar (Thuja plicata) and Douglas-fir (Pseudotsuga menziesii) were planted together after applying seven site-preparation methods at one site in the Oregon Coast Ranges. Survival and growth of cedar were markedly less than Douglas-fir on this favorable site where both species were components of the original stand. Repeated browsing severely impeded the cedar. Site preparation by broadcast burning generally yielded the best results, but sowing grass after broadcast burning produced Douglas-fir responses similar to those for no site preparation. Where grass was sown, herbaceous cover was more abundant and taller, salmonberry differed little in density but was slightly taller, and development of red alder (Alnus rubra) was delayed. Red alder is currently overtopping conifers in all treatments, and release is needed to ensure sufficient conifer survival. This single example illustrates that much more effort than just planting a mix of species is required to establish a desired mixed stand. West. J. Appl. For. 12(3):74-80.

scholarly journals Thirteen-Year Height and Diameter Growth of Douglas-Fir Seedlings under Alternative Regeneration Cuts in Pacific Northwest

2011 ◽  
Vol 26 (2) ◽  
pp. 57-63 ◽  
Author(s):  
Tzeng Yih Lam ◽  
Douglas A. Maguire
Keyword(s):  
Pacific Northwest ◽  
Treatment Effects ◽  
Basal Area ◽  
Height Growth ◽  
Douglas Fir ◽  
Diameter Growth ◽  
Treatment Level ◽  
Growth Responses ◽  
Significant Treatment ◽  
Ecosystem Responses

Abstract Interest in managing Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) forests in the Pacific Northwest under silvicultural systems other than traditional clearcutting has prompted research on the efficacy of alternative systems for successful regeneration and sustained timber productivity of Douglas-fir. The College of Forestry Integrated Research Project, implemented by Oregon State University, was established to compare various ecosystem responses and public perceptions among treatments implemented under clearcutting, shelterwood-with-reserves, and group selection silvicultural systems. The objective of this analysis was to quantify the following three responses of planted Douglas-fir seedlings to initial regeneration cuts: cumulative 13-year height growth (H13yr; 1992–2004), cumulative 13-year diameter growth (D13yr; 1992–2004), and most recent 5-year height growth (ΔH5yr; 2000–2004). Differences in variability of overstory density at the treatment level led to significant differences in the variance of understory growth responses. After accounting for heterogeneous variance, analysis of variance indicated significant treatment effects for all three responses. Treatment effects were explained by the decline in H13yr, D13yr, and ΔH5yr with increasing overstory competition as represented by basal area of residual trees immediately after harvesting (initial basal area). Predicted height:diameter ratio of Douglas-fir seedlings increased as IBA increased. Under regeneration methods that retain a portion of the overstory, a residual overstory with basal area <80 ft2/ac allows establishment, growth, and continued survival of Douglas-fir regeneration during the 13 years following harvest.

scholarly journals Growth of Young Douglas-Fir Plantations Across a Gradient in Swiss Needle Cast Severity

2002 ◽  
Vol 17 (2) ◽  
pp. 86-95 ◽  
Author(s):  
Douglas A. Maguire ◽  
Alan Kanaskie ◽  
William Voelker ◽  
Randy Johnson ◽  
Greg Johnson
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Height Growth ◽  
Douglas Fir ◽  
Site Quality ◽  
North Coast ◽  
Needle Cast ◽  
Basal Area Growth ◽  
Area Growth ◽  
Swiss Needle Cast

Abstract During the past decade, Swiss needle cast (SNC) damage has intensified in many Douglas-fir plantations in the Coast Range of Oregon, particularly along the immediate north coast. In plantations with severe symptoms, growth losses and reduced tree vigor are evident, but the magnitude of growth losses associated with varying intensities of damage is not known. A growth impact study was conducted in 1997 to quantify retrospectively the relationship between growth losses and visual symptoms in 10- to 30-yr-old Douglas-fir plantations in coastal northwestern Oregon, a population totaling 75,700 ha. A random sample of 70 Douglas-fir plantations was selected from the population and evaluated for Swiss needle cast severity. One 0.02 ha plot was destructively sampled in each plantation to reconstruct past height and basal area growth trends and to characterize foliage loss and distribution. The SNC “effect” was assessed by comparing growth of plantations with varying degrees of Swiss needle cast to growth of those that retained maximal amounts of foliage, after correcting for initial stand density, Douglas-fir growing stock, age, and site index. Of numerous possible SNC indices, mean needle retention (yr) explained the largest amount of variation in both basal area and top height growth. Prior to 1990, top height growth was similar across all plantations after correcting for site quality and plantation age; but, by 1992, top height growth losses appeared and were proportional to apparent foliage losses. In 1996, top height growth was reduced by up to 25% relative to plantations with little or no SNC. Basal area growth reductions began to appear around 1990, and in 1996 basal area growth of the most heavily damaged plantations was 35% less than the growth that would be expected in absence of SNC damage. The inferred volume growth loss for 1996 averaged 23% for the 75,700 ha target population, but this loss averaged as high as 52% for the most severely impacted plantations. West. J. Appl. For. 17(2):86ߝ95.

scholarly journals Eastern White Pine (Pinus strobus) Growth Response to Partial Hardwood Overstory Release

2000 ◽  
Vol 17 (3) ◽  
pp. 89-94 ◽  
Author(s):  
Klaus.J. Puettmann ◽  
Mike R. Saunders
Keyword(s):  
Growth Response ◽  
Pinus Strobus ◽  
Height Growth ◽  
The Other ◽  
Diameter Growth ◽  
Growth Responses ◽  
White Pine ◽  
Initial Size ◽  
Initial Height ◽  
Partial Release

Abstract We measured the response of white pine (Pinus strobus L.) saplings after partial release of a hardwood overstory on three sites in central Minnesota. Both height and diameter growth increased quickly after release compared to prerelease growth. Diameter growth response was related to prerelease diameter growth, but not to initial size of the sapling (diameter at time of release). On the other hand, height growth response was strongly influenced by the initial height of all trees, but not related to prerelease height growth in the largest saplings (initial heights > 8.76 m). Increased release intensity (i.e., difference between prerelease and postrelease overstory densities) resulted in higher diameter and height growth responses. The height/diameter ratios decreased after release, indicating that stability as well as growth increased after the release. North. J. Appl. For. 17(3):89–94.

Four-year Basal Area Growth Response of a 25-year-old Douglas-fir Stand to Thinning and Urea Fertilization

1974 ◽  
Vol 4 (4) ◽  
pp. 568-571 ◽  
Author(s):  
Y. Jim Lee
Keyword(s):  
Nitrogen Fertilization ◽  
Growth Response ◽  
Basal Area ◽  
Douglas Fir ◽  
Site Quality ◽  
Growing Period ◽  
Basal Area Growth ◽  
Area Growth ◽  
Four Levels ◽  
Urea Fertilization

Four-year growth response to nitrogen fertilization and thinning is reported for an experiment established in a 25-year-old Douglas-fir stand of medium site quality. Four levels of nitrogen (0, 112, 224, and 336 kg N/ha), in the form of urea, were tested at two thinning levels in a randomized 4 × 2 × 2 factorial design replicated in 2 Blocks. Fertilizer was applied in spring or fall. Basal area growth per hectare in the thinned stand significantly surpassed that of the unthinned stand in the fourth growing period. Increased rate of nitrogen fertilization resulted in increased growth 1 year after fertilization. Urea applied in the fall resulted in greater growth response than that applied in the spring for the first growing period and over a 4-year period. Increased rate of fertilization increased mortality significantly in the fourth growing period, but had no prior effect. Thinning decreased mortality in all four growing periods.

Influence of millipedes on litter decomposition, N mineralization, and microbial communities in a coastal forest in British Columbia, Canada

2000 ◽  
Vol 30 (5) ◽  
pp. 817-826 ◽  
Author(s):  
H A Cárcamo ◽  
T A Abe ◽  
C E Prescott ◽  
F B Holl ◽  
C P Chanway
Keyword(s):  
Litter Decomposition ◽  
N Mineralization ◽  
Sitka Spruce ◽  
Douglas Fir ◽  
Picea Sitchensis ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Coastal Forests ◽  
Western Redcedar ◽  
Litter Consumption

Laboratory experiments were conducted with the millipede Harpaphe haydeniana haydeniana Wood (Polydesmida: Xystodesmidae) to determine (i) its litter feeding preferences, (ii) rates of leaf litter consumption, (iii) feeding effects on available nitrogen, and (iv) functional microbial diversity. The millipede exhibited a preference for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and, to a lesser extent, Sitka spruce (Picea sitchensis (Bong.) Carrière) litter compared with western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn ex D. Don) litter when given a choice. When only one litter type was provided, millipedes consumed considerably more western redcedar than Douglas-fir, Sitka spruce, or western hemlock. Among the six broadleaf species tested, paper birch (Betula papyrifera Marsh.), bigleaf maple (Acer macrophyllum Pursh), vine maple (Acer circinatum Pursh), and red alder (Alnus rubra Bong.) were consumed at much higher rates than swordfern (Polystichum munitum (Kaulf.) Presl.) or salal (Gaultheria shallon Pursh). Daily rates of conifer litter consumption ranged between 10 and 20% of the millipede's fresh biomass and may translate to 36% of the annual litter fall. Our results suggest that transformation of conifer litter into millipede frass can increase rates of litter decomposition and N mineralization, as well as influence microbial activity and diversity in coastal forests.

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