scholarly journals Douglas-fir provenance phenology observations

2013 ◽  
Vol 32 (4) ◽  
Author(s):  
Vera Lavadinović ◽  
Vasilije Isajev ◽  
Ljubinko Rakonjac ◽  
Vladan Popović ◽  
Aleksandar Lučić

AbstractLavadinović V., Isajev V., Rakonjac L., Popović V., Lučić A.: Douglas-fir provenance phenology observations. Ekologia (Bratislava), Vol. 32, No. 4, p. 376-382, 2013.Introduction of species involves adaptation, productivity and success in new types of environmental conditions. The introduction also includes confirmation to bring in only species which are superior on their natural habitat. In Canada and western North America, Douglas fir (Pseudotsuga menziesii/Mirb./Franco) is one of the most ecologically and economically value trees. In Europe, New Zealand, Australia and Chile, Douglas fir is important as an exotic fast-growing timber species. Douglas fir has one of the widest natural ranges of any tree species, extending from the Pacific Coast to the eastern slope of the Rocky Mountains and from 19°N in Mexico to 55°N in western Canada. In Serbia, from the original seeds introduced from British Columbia and Canada, the experimental Douglas-fir provenance is established in a few locations. One of the main dangers for the Douglas fir is its sensitivity to the occurrence of late frost in spring and early occurrence of frost in the autumn. The aim of the paper is to test the effect of environment on the expression of Douglas-fir seed transfer. Bud burst phenology is closely related to genecology of introduced species. Douglas fir is susceptible to cold climate and most of its genetic structure and ability depends on its ecological adaptability. In order to avoid errors introduction of Douglas-fir provenances that are sensitive to the occurrence of extreme temperature, applied are researching for buds phenological changes Douglas fir, as an introduced species, has to be tested at the provenance level before its introduction to the new sites in Serbia.

2015 ◽  
Vol 398 (1-2) ◽  
pp. 281-289 ◽  
Author(s):  
Robert A. Slesak ◽  
Timothy B. Harrington ◽  
Anthony W. D’Amato

1975 ◽  
Vol 136 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Robert K. Campbell ◽  
Albert I. Sugano
Keyword(s):  

1979 ◽  
Vol 57 (5) ◽  
pp. 534-538 ◽  
Author(s):  
Joe E. Webber ◽  
Murray L. Laver ◽  
Joe B. Zaerr ◽  
Denis P. Lavender

The occurrence of abscisic acid (ABA) in the dormant shoots of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) was confirmed by bioassay, thin-layer chromatography, gas–liquid chromatography, and gas–liquid chromatography – mass spectrometry. Seasonal variation of ABA in the buds, leaves, and stems was then determined using 2-trans-ABA as an internal standard. Concentrations of ABA were highest in the autumn for buds (2.1 μg/g) and needles (0.79 μg/g) and highest in January for stems (0.34 μg/g). The lowest concentrations for all tissues were in February and March, before bud burst. Close correlation of levels of ABA with previously measured physiological evidence of growth and metabolic activity suggests a possible role in the dormancy cycle of Douglas-fir.


2002 ◽  
Vol 32 (6) ◽  
pp. 1057-1070 ◽  
Author(s):  
Linda E Winter ◽  
Linda B Brubaker ◽  
Jerry F Franklin ◽  
Eric A Miller ◽  
Donald Q DeWitt

The history of canopy disturbances over the lifetime of an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand in the western Cascade Range of southern Washington was reconstructed using tree-ring records of cross-dated samples from a 3.3-ha mapped plot. The reconstruction detected pulses in which many western hemlock (Tsuga heterophylla (Raf.) Sarg.) synchronously experienced abrupt and sustained increases in ringwidth, i.e., "growth-increases", and focused on medium-sized or larger ([Formula: see text]0.8 ha) events. The results show that the stand experienced at least three canopy disturbances that each thinned, but did not clear, the canopy over areas [Formula: see text]0.8 ha, occurring approximately in the late 1500s, the 1760s, and the 1930s. None of these promoted regeneration of the shade-intolerant Douglas-fir, all of which established 1500–1521. The disturbances may have promoted regeneration of western hemlock, but their strongest effect on tree dynamics was to elicit western hemlock growth-increases. Canopy disturbances are known to create patchiness, or horizontal heterogeneity, an important characteristic of old-growth forests. This reconstructed history provides one model for restoration strategies to create horizontal heterogeneity in young Douglas-fir stands, for example, by suggesting sizes of areas to thin in variable-density thinnings.


1990 ◽  
Vol 7 (2) ◽  
pp. 86-89 ◽  
Author(s):  
Mark E. Kubiske ◽  
Marc D. Abrams ◽  
James C. Finley

Abstract Cut Douglas-fir Christmas trees grown in Pennsylvania from Rocky Mountain seed sources and coastal trees grown in the Pacific Northwest and shipped into Pennsylvania were compared for keepability. Following various cold treatments, the cut ends of trees were placed in water in an indoor display area. Coastal trees placed in a freezer at - 29°C for 24 h had 89 ± 5.1% (mean ± standard error) needle loss after one day of display, while Rocky Mountain origin trees exhibited only 3 ± 2.0% needle loss after 1 day and 50 ± 5.6% needle loss after 18 days. Coastal produced trees exposed to temperatures > - 12°C had 50 ± 9.8% needle loss at the end of the experiment, while Rocky Mountain trees ended with 22 ± 3.2% needle loss. Four additional treatments consisted of trees placed on an outdoor lot and periodically moved indoors to simulate Christmas tree market activity. Again, there was a significant difference between trees from coastal and Rocky Mountain sources, with 57.2 ± 4.3% and 11.8 ± 1.2% needle loss after 3 days, respectively. By the end of the 23 day experiment, the coastal trees were essentially devoid of needles, whereas Rocky Mountain trees had an average of only 20% needle loss. Coastal trees also exhibited a very noticeable loss of color and lustre. North. J. Appl. For. 7:86-89, June 1990.


Author(s):  
R. F. Castañeda Ruíz

Abstract A description is provided for Ulocladium sorghi. Nothing is known about the natural habitat of this fungus, the only record being in association with a widely cultivated introduced species (Sorghum bicolor). Some information on its dispersal and transmission, and conservation status is given, along with details of its geographical distribution (Asia (China (Anhui))).


Author(s):  
Thomas N. Sherratt ◽  
David M. Wilkinson

One answer to this chapter’s question is straightforward and based on high-school physics. The early SCUBA divers quickly discovered that if they took underwater colour photographs, even if they were only a few metres down, their pictures had a strong blue cast to them. However, if they illuminated their subjects with a flash, then a more colourful world emerged in their pictures—especially if they were photographing the rich diversity of highly coloured fish that can be found in some parts of the tropics. The reason for the blueness is that as sunlight passes through water the colours of the spectrum are absorbed at different rates, with the long wavelengths (e.g. red) absorbed first and the higher-energy shorter wavelengths (e.g. blue) penetrating deeper into the depths. It follows that underwater available light is predominantly blue and that any light reflected from within the water body is more likely to be from the bluer end of the spectrum of visible light. So, light coming from the sea to our eyes is mainly blue because these wavelengths are least absorbed; indeed oceanographers who have studied some of the cleanest waters describe them as looking ‘violet blue’. As biologists we are interested in a more ecological answer to the question, ‘Why is the sea blue’? The physics explanation only works if seawater is reasonably clear, and it is this clarity that biologists need to explain. Consider our opening quotation, which comes from Peter Matthiessen’s book describing early attempts to film the great white shark in its natural habitat. It raises an interesting ecological question—why can a SCUBA diver or snorkeler see where they are going in the ocean? Put another way, why is the sea blue rather than green? The upper layer of the ocean with enough light for photosynthesis is called the euphotic zone (defined as extending down to the point where only 1% of photosynthetically usable light is present compared with surface light levels); this is often only a few tens of metres deep, but in extremely clear water near Easter Island in the Pacific it has recently been found to extend down to 170 m depth.


Geoderma ◽  
2019 ◽  
Vol 350 ◽  
pp. 73-83 ◽  
Author(s):  
Daniel G. DeBruler ◽  
Stephen H. Schoenholtz ◽  
Robert A. Slesak ◽  
Brian D. Strahm ◽  
Timothy B. Harrington

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