Relationships Between Sapwood Amount, Latewood Percentage, Moisture Content and Crown Vitality of Douglas Fir, Pseudotsuga Menziesii

IAWA Journal ◽  
1993 ◽  
Vol 14 (4) ◽  
pp. 413-427 ◽  
Author(s):  
Ingrid de Kort
Keyword(s):  
The Netherlands ◽  
Moisture Content ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir

Relationships between sapwood amount, latewood percentage, moisture content and crown vitality were studied in 171 Douglas firs [Pseudotsuga menziesii (Mirb.) Franco] belonging to different vitality classes. The trees originated from 10 stands in the Netherlands varying in age from 25-70 years.

Drying characteristics and equilibrium moisture content of steam-treated Douglas fir (Pseudotsuga menziesii L.)

2012 ◽  
Vol 116 ◽  
pp. 396-402 ◽  
Author(s):  
Pak Sui Lam ◽  
Shahab Sokhansanj ◽  
Xiaotao T. Bi ◽  
C. Jim Lim ◽  
Sylvia H. Larsson
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Drying Characteristics

scholarly journals FACTORS AFFECTING THE VIABILITY AND GERMINATION BEHAVIOR OF CONIFEROUS SEED. V. SEED MOISTURE CONTENT DURING STRATIFICATION AND SECONDARY STORAGE, PSEUDOTSUGA MENZIESII (MIRB.) FRANCO

1962 ◽  
Vol 38 (3) ◽  
pp. 303-312 ◽  
Author(s):  
G. S. Allen
Keyword(s):  
Moisture Content ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Secondary Storage ◽  
Seed Moisture Content ◽  
Factors Affecting ◽  
Seed Moisture ◽  
And Storage ◽  
Post Stratification

Two seedlots of Douglas fir were each soaked to two levels of moisture content, stratified for 20-120 days at 0-2 °C., subjected to post-stratification storage, and incubated at 10°, 15°, and 25 °C. The higher moisture content (60-70 per cent) was superior for both seedlots particularly when the seed was subjected to drying and storage after stratification. The ability of Douglas fir seed to withstand stratification, drying, and storage for a total time of 240 days, without loss of germinative capacity or vigor, is shown.

Tracheid Length in Vital and Non Vital Douglas Fir (Pseudotsuga Menziesii) in the Netherlands

IAWA Journal ◽  
1990 ◽  
Vol 11 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Ingrid de Kort
Keyword(s):  
The Netherlands ◽  
Pseudotsuga Menziesii ◽  
Growth Ring ◽  
Ring Width ◽  
Douglas Fir ◽  
Growth Reduction ◽  
Tracheid Length ◽  
Growth Ring Width ◽  
Temporary Growth

Tracheid length in relation to growth ring width is recorded for five Douglas firs from different sites in the Netherlands. The investigated trees differed in vitality assessed by crown appearance. Non vital trees showed a growth reduction which coincides with a decrease in tracheid length. Temporary growth reductions in vital trees did not result in a decrease of tracheid length. The relations hip between tracheid length and ring width is discussed.

scholarly journals Stand development and stem form of the Douglas Fir (Pseudotsuga taxifolia Britt.) in the Netherlands.

1954 ◽  
Vol 2 (4) ◽  
pp. 265-272
Author(s):  
A. van Laar
Keyword(s):  
The Netherlands ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Japanese Larch ◽  
Stand Development ◽  
Stem Form

Increment measurements on 65 heavily thinned trial plantations are used to show the development of stands in the Netherlands up to 30 years. Yields compare satisfactorily with Kanzow's yield tables for Prussia (1937), but are considerably below those of Grandjean and Soest [cf. F.A. 15 No. 567]. A taper table was derived from 801 trees measured after felling. At heights below 20 m. the stem forms of Douglas Fir and Japanese Larch, as shown in figures obtained by Schober [cf. F.A. 15 No. 1656], correspond closely with each other, but above 20 m. the former tapers more rapidly. KEYWORDS: Increment \ mensuration \ forests \ Pseudotsuga taxifolia \ Pseudotsuga menziesii \ aggr. form \ stem \ Pseudotsuga taxifolia \ Pseudotsuga menziesii \ aggr. yield \ taper \ tables \ stem form \ s \ yield tables (Abstract retrieved from CAB Abstracts by CABI’s permission)

Drying and storage of prechilled Douglas fir, Pseudotsuga menziesii, seeds

1999 ◽  
Vol 29 (2) ◽  
pp. 172-177 ◽  
Author(s):  
C Muller ◽  
E Falleri ◽  
E Laroppe ◽  
M Bonnet-Masimbert
Keyword(s):  
Moisture Content ◽  
Pseudotsuga Menziesii ◽  
Traditional Method ◽  
Detrimental Effect ◽  
Seedling Emergence ◽  
Douglas Fir ◽  
Dormancy Release ◽  
Optimal Temperature ◽  
Germination Speed ◽  
And Storage

Douglas fir, Pseudotsuga menziesii (Mirb.) Franco, seeds exhibit relative dormancy as they do not germinate at suboptimal temperature (15°C), whereas at optimal temperature (20°C) some germination occurred. Thus, germination at 15°C was chosen to estimate dormancy release. In the first experiment, seeds were prechilled at 32% moisture content (MC) for 0-34 weeks at 3°C. Long chilling treatments enhanced germinability and, more markedly, germination speed both at 20°C and at 15°C. Seeds pretreated for the longest periods were then dried to 6.7% MC and stored up to 6 months without any detrimental effect on germination at 15°C. In the second experiment, seeds from a second seedlot were prechilled for 18 weeks and then stored at three different MCs over a period of 17 months. Seeds stored at the lowest MC (6.7%) germinated fastest and to the highest percentage both at 15 and 20°C. In the nursery, seedling emergence tests confirmed results from this experiment. In most cases, comparisons between seeds prechilled at controlled MC before storage and those stratified with the traditional method resulted in better performance of the first ones, both in the laboratory and in the nursery.

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.

Sign in / Sign up

Export Citation Format

Share Document