Ecological Adaptations in Douglas-fir (Pseudotsuga menziesii var. glauca). IV. Montana and Idaho Near the Continental Divide

1988 ◽  
Vol 3 (4) ◽  
pp. 101-105 ◽  
Author(s):  
G. E. Rehfeldt

Abstract Seventy-seven seedling populations of Douglas-fir (Pseudotsuga menziesii var. glauca) sampled from near the Continental Divide in Idaho and Montana exhibited pronounced genetic differences when compared in three common environments. Differentiation involved several traits that are components of an annual developmental cycle that must be completed within a growing season of finite length. Consequently, the elevational and geographic dines of genetic variation tend to parallel variation in the length of the growing season at the seed source. Such clines suggest that maladaptation in artificial reforestation can be controlled by limiting the transfer of seeds. While geographic transfers can be relatively liberal, elevational transfers should be limited to ±90 m (300 ft) from the seed source at elevations below 1,400 m (4,600 ft), to ±125 m (410 ft) for elevations between 1,400 and 2,000 m (4,600 and 6,550 ft), and ±200 m (560 ft) for elevations above 2,000 m (6,550 ft). West. J. Appl. For. 3(4):101-105, October 1988.

2014 ◽  
Vol 21 (2) ◽  
pp. 947-958 ◽  
Author(s):  
Sheel Bansal ◽  
Constance A. Harrington ◽  
Peter J. Gould ◽  
J. Bradley St.Clair

2012 ◽  
Vol 42 (2) ◽  
pp. 382-399 ◽  
Author(s):  
Ulrich Kohnle ◽  
Sebastian Hein ◽  
Frank C. Sorensen ◽  
Aaron R. Weiskittel

1999 ◽  
Vol 14 (4) ◽  
pp. 183-185
Author(s):  
Gladwin Joseph ◽  
Rick G. Kelsey

Abstract To test whether methanol or ethanol stimulated growth of coast Douglas-fir (Pseudotsuga menziesii vat. menziesii) or ponderosa pine (Pinus ponderosa) seedlings, we sprayed concentrations of 1 to 10% (v/v) on the foliage twice a week for 13 wk during the growing season. Foliar applications of methanol and ethanol neither significantly stimulated nor inhibited growth, and signs of damage at these concentrations were lacking. West. J. Appl. For. 14(4):183-185.


1986 ◽  
Vol 1 (4) ◽  
pp. 108-111 ◽  
Author(s):  
Chao-Hsiung Tung ◽  
Jim Batdorff ◽  
David R. DeYoe

Abstract Two vegetation management methods, paper mulching and spot-spraying with glyphosate, were combined with a root-dipping treatment, Terra Sorb®, to test effects on seedling survival and height growth on a harsh site in Oregon. Survival of Douglas-fir (Pseudotsuga menziesii) seedlings was significantly higher after the third growing season when competing vegetation had been controlled with mulch or glyphosate during the first two growing seasons. Seedlings retreated with paper mulch and glyphosate before the second growing season had 36 and 25% higher survival than those that were not retreated. None of the seedlings was retreated before the third season; after this season, survival of seedlings treated twice with glyphosate was 26, 23, and 21% higher than seedlings receiving one glyphosate treatment and one or two mulch applications, respectively. There were no differences in seedling height growth among treatments. Rootdipping with Terra Sorb® did not influence survival or growth. West. J. Appl. For. 1:108-111 Oct. 86.


2007 ◽  
Vol 37 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Marilyn L Cherry ◽  
Thimmappa S Anekonda ◽  
Michael J Albrecht ◽  
Glenn T Howe

We studied flower stimulation in two young miniaturized seed orchards of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) in Oregon. In experiment 1, female and male flowering were substantially enhanced when the trees were treated 2–4 years after grafting with stem girdling plus stem-injected gibberellin A4/7 (GA 0.25× rate = ProCone(tm) at 0.084 µL·mm–2 scion cross-sectional area). Comparable results were obtained the following year when the same trees were retreated with 1× GA. In experiment 2, female and male flowering were significantly enhanced when 3-year-old trees were treated with girdling plus either 1× GA, 1.5× GA, or 2× GA. Some treatments had higher mortality and less height growth than the control in the year of cone development. We recommend using a combination of girdling and 1× GA biennially once trees are large enough to produce large per-hectare seed yields and withstand the stress of flower stimulation. At the study orchards, this seems to be about 5 years postgrafting, just before the sixth growing season. Yields were estimated to be 272 963 seeds·ha–1 at age 4 years, or 143 095 seeds·ha–1 annually with stimulation occurring every 2 years. Yields should increase as orchards age, with full stocking, and with higher planting densities.


IAWA Journal ◽  
2006 ◽  
Vol 27 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Heidi J. Renninger ◽  
Barbara L. Gartner ◽  
Amy T. Grotta

The width of earlywood and latewood in conifer xylem may have a profound effect on water transport and storage, vulnerability to embolism, and wood strength, yet the controls over the timing of latewood formation are unclear. Tracheids differentiating in the cambial zone are influenced by IAA, indole-3 acetic acid, the radial concentration gradient of which appears to either increase cell expansion (earlywood) or increase cell wall deposition (latewood). There are suggestive data that latewood begins to form when the growth of the leader stops, but definitive results are lacking. Height growth was measured in 14 Douglas-fir (Pseudotsuga menziesii) saplings at 10 dates between May and August, from the beginning of the growing season until after height growth had ceased. The cambium was also pinned six times between June and July, to induce xylem scarring at known dates. After height growth ceased, saplings were harvested and transverse sections of the wood were made at the pin insertion points. The date at which 95% of the height growth had occurred and the date at which latewood formation had begun were estimated. Analysis showed no correlation of these data, suggesting that the two phenomena may occur around the same time, but that one is not causal of the other.


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