scholarly journals Evidence for red:far red signaling and photomorphogenic growth response in Douglas-fir (Pseudotsuga menziesii) seedlings

1997 ◽  
Vol 17 (3) ◽  
pp. 161-168 ◽  
Author(s):  
G. A. Ritchie
Keyword(s):  
Pseudotsuga Menziesii ◽  
Growth Response ◽  
Douglas Fir

Using decision analysis for stand-level silvicultural decisions

1991 ◽  
Vol 67 (4) ◽  
pp. 384-388
Author(s):  
Peter Marshall
Keyword(s):  
Decision Analysis ◽  
Treatment Response ◽  
Pseudotsuga Menziesii ◽  
Growth Response ◽  
Douglas Fir ◽  
Perfect Information ◽  
Analytic Approach ◽  
Planting Density ◽  
Response Information ◽  
Value Of Perfect Information

A decision analytic approach to assessing stand-level silvicultural decisions is illustrated using planting density and spacing decisions for coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Information from several stand projection procedures was combined into a single analysis. The value of "perfect information" was calculated as an indicator of the value of additional response information. The value of perfect information should not be used as the sole justification for gathering treatment response information because it fluctuated with the economic assumptions made and the alternatives evaluated. However, it provides a relative ranking of treatment response requirements and a means for quantifying the risk associated with silvicultural decisions. The decision analytic approach proved flexible as a means for combining growth response information from several sources into a compromise decision.

Growth Response to Fertilization in Young Douglas-Fir Stands

1989 ◽  
Vol 4 (4) ◽  
pp. 116-119 ◽  
Author(s):  
Linda S. Heath ◽  
H. N. Chappell
Keyword(s):  
Pseudotsuga Menziesii ◽  
Growth Response ◽  
Volume Growth ◽  
Basal Area ◽  
Site Index ◽  
Douglas Fir ◽  
Intermediate Region ◽  
Fertilizer Response ◽  
Breast Height ◽  
Inverse Effect

Abstract Response surface methodology was used to estimate six-year volume growth response to 1 application of 200 lb nitrogen per acre in unthinned and thinned Douglas-fir (Pseudotsuga menziesii) stands of breast height age (bha) 25 years or less. Regional mean fertilizer response was 16% in unthinned stands and 20% in thinned stands. Site index had an increasingly inverse effect on response as basal area increased in both unthinned and thinned stands. Response varied little over site index in regions of low basal area, decreased moderately as site index increased in the intermediate region, and decreased rapidly in the high basal area region. West. J. Appl. For. 4(4):116-119, October 1989.

scholarly journals Ten-Year Growth Response of Young Douglas-Fir to Variable Density Varnishleaf Ceanothus and Herb Competition

1999 ◽  
Vol 14 (4) ◽  
pp. 208-213 ◽  
Author(s):  
V. J. Monleon ◽  
M. Newton ◽  
C. Hooper ◽  
J. C. Tappeiner
Keyword(s):  
Pseudotsuga Menziesii ◽  
Growth Response ◽  
Variable Density ◽  
Douglas Fir ◽  
The Other ◽  
Plantation Establishment ◽  
Single Application ◽  
Herbaceous Vegetation ◽  
Vegetation Control ◽  
Tree Diameter

Abstract The effect of different densities of varnishleaf ceanothus (Ceanothus velutinus var. laevigatus) and herbaceous vegetation control on stem diameter, height, and volume of plantation Douglas-fir (Pseudotsuga menziesii vat. menziesii) seedlings was examined during the 10 yr following planting. Initial densities of ceanothus ranged between 0 and 15,000 seedlings/ha and were obtained by interplanting ceanothus germinants or chemical thinning after clearcutting and broadcast-burning. Herbaceous vegetation control was achieved by a single application of glyphosate following planting, with shrub seedlings covered. Ceanothus density in the range of 0 to 6,750 plants/ha did not have an effect on Douglas-fir diameter, height, or volume at age 10; however, Douglas-fir growth was significantly decreased when ceanothus densities reached 15,000 plants/ha. Ten years after planting, Douglas-fir volume in the treatments with 6,750 ceanothus/ha or less was 1.7 times greater than that in the 15,000 ceanothus/ha treatment. On the other hand, removal of herbaceous vegetation after planting significantly increased tree diameter, height, and volume, regardless of ceanothus density. Even 10 yr after the application of the treatment, trees without early herb competition grew faster and had mean dbh, height, and volume that were 1.02 cm, 0.55 m, and 12.98 dm³/tree greater respectively than those with herbs. Thus, a treatment at plantation establishment to control herbaceous vegetation and to reduce ceanothus density to less than 7,000 plants/ha will ensure an increase in growth and stocking for at least 10 yr. West. J. Appl. For. 14(4):208-213.

scholarly journals Pathogenicity and Virulence of Pythium Species Obtained from Forest Nursery Soils on Douglas-Fir Seedlings

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 744-748 ◽  
Author(s):  
Jerry E. Weiland ◽  
Bryan R. Beck ◽  
Anne Davis
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seedling Survival ◽  
The United States ◽  
Douglas Fir ◽  
Tree Seedlings ◽  
Pythium Species ◽  
Forest Nursery ◽  
Damping Off ◽  
Greenhouse Study ◽  
Forest Nurseries

Pythium species are common soilborne oomycetes that occur in forest nursery soils throughout the United States. Numerous species have been described from nursery soils. However, with the exception of P. aphanidermatum, P. irregulare, P. sylvaticum, and P. ultimum, little is known about the potential for other Pythium species found in nursery soils to cause damping-off of tree seedlings. A greenhouse study was conducted to evaluate the pathogenicity and virulence of 44 Pythium isolates representing 16 species that were originally recovered from soil at three forest nurseries in Washington and Oregon. Seeds of Douglas-fir (Pseudotsuga menziesii) were planted into soil infested with each of the isolates. Seedling survival, the number of surviving seedlings with necrotic root lesions, and taproot length were evaluated 4 weeks later. Responses of Douglas-fir to inoculation varied significantly depending on Pythium species and isolate. Eight species (P. dissotocum, P. irregulare, P. aff. macrosporum, P. mamillatum, P. aff. oopapillum, P. rostratifingens, P. sylvaticum, and P. ultimum var. ultimum) significantly reduced the number of surviving seedlings compared to the noninoculated treatment. However, all Pythium species caused a greater percentage of seedlings to develop root lesions (total mean 40%) than was observed from noninoculated seedlings (17%). Taproot length varied little among Pythium treatments and was not a useful character for evaluating pathogenicity. Results confirm the ability of P. irregulare, P. mamillatum, and P. ultimum var. ultimum to cause damping-off of Douglas-fir seedlings, and are indicative that other species such as P. dissotocum, P. aff. macrosporum, P. aff. oopapillum, P. rostratifingens, and P. sylvaticum may also be responsible for seedling loss.

Cylindrocarpon and Fusarium root colonization of Douglas-fir seedlings from British Columbia reforestation sites

1998 ◽  
Vol 28 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Paige E Axelrood ◽  
William K Chapman ◽  
Keith A Seifert ◽  
David B Trotter ◽  
Gwen Shrimpton
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Root Colonization ◽  
Linear Trend ◽  
Poor Performance ◽  
Douglas Fir ◽  
Root Infection ◽  
Significant Linear Trend ◽  
Conifer Seedlings ◽  
Cylindrocarpon Destructans

Poor performance of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations established in 1987 has occurred in southwestern British Columbia. Affected sites were planted with 1-year-old container stock that exhibited some root dieback in the nursery. A study was initiated in 1991 to assess Cylindrocarpon and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations. Percentages of seedlings harboring Cylindrocarpon spp.and percent root colonization were significantly greater for planted seedlings compared with natural seedlings. A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10cm from that region. This trend in Cylindrocarpon colonization was not observed for natural seedlings. Cylindrocarpon destructans (Zins.) Scholten var. destructans and C.cylindroides Wollenw. var. cylindroides were the only species isolated from planted and natural conifer seedlings. For most sites, percentage of seedlings harboring Fusarium spp.and percent Fusarium root colonization were less than for Cylindrocarpon. Recovery of Fusarium spp.from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.

scholarly journals Growth Response of Bigcone Douglas Fir (Pseudotsuga macrocarpa) to Long-Term Ozone Exposure in Southern California

1995 ◽  
Vol 45 (1) ◽  
pp. 36-45 ◽  
Author(s):  
David L. Peterson ◽  
David G. Silsbee ◽  
Mark Poth ◽  
Michael J. Arbaugh ◽  
Frances E. Biles
Keyword(s):  
Southern California ◽  
Growth Response ◽  
Douglas Fir ◽  
Ozone Exposure

Contarinia pseudotsugae. [Distribution map].

2020 ◽  
Author(s):  
Keyword(s):  
British Columbia ◽  
North America ◽  
Geographical Distribution ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Distribution Map ◽  
New Distribution ◽  
Distribution In Europe

Abstract A new distribution map is provided for Contarinia pseudotsugae Condrashoff (Diptera: Cecidomyiidae). Hosts: Douglas fir (Pseudotsuga menziesii). Information is given on the geographical distribution in Europe (Belgium, France, Germany and Netherlands) and North America (Canada, British Columbia, USA, California, Idaho, Michigan, Montana, Oregon, Pennsylvania and Washington).

Phytophthora pseudotsugae. [Distribution map].

1988 ◽  
Author(s):  
Keyword(s):  
North America ◽  
Geographical Distribution ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Distribution Map ◽  
New Distribution

Abstract A new distribution map is provided for Phytophthora pseudotsugae Hamm & Hansen. Host: douglas fir (Pseudotsuga menziesii). Information is given on the geographical distribution in NORTH AMERICA, USA, OR, WA.

Rhabdocline pseudotsugae. [Distribution map].

1976 ◽  
Author(s):  
Keyword(s):  
British Columbia ◽  
North America ◽  
Geographical Distribution ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Distribution Map ◽  
Irish Republic ◽  
New Distribution ◽  
Distribution In Europe

Abstract A new distribution map is provided for Rhabdocline pseudotsugae Syd. Hosts: Douglas fir (Pseudotsuga menziesii). Information is given on the geographical distribution in EUROPE, Belgium, Britain, Czechoslovakia, Denmark, France, Germany, Irish Republic, Netherlands, Norway, Poland, Romania, Sweden, Switzerland, Yugoslavia, NORTH AMERICA, Canada (Alberta, British Columbia), USA.

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