Why is the productivity of Douglas-fir higher in New Zealand than in its native range in the Pacific Northwest, USA?

2008 ◽  
Vol 255 (12) ◽  
pp. 4040-4046 ◽  
Author(s):  
Richard Waring ◽  
Alan Nordmeyer ◽  
David Whitehead ◽  
John Hunt ◽  
Michael Newton ◽  
...  
Keyword(s):  
New Zealand ◽  
Pacific Northwest ◽  
Douglas Fir ◽  
Native Range ◽  
The Pacific

scholarly journals Contrasting the Pathogen Loads in Co-Existing Populations of Phytophthora pluvialis and Nothophaeocryptopus gaeumannii in Douglas Fir Plantations in New Zealand and the Pacific Northwest United States

2019 ◽  
Vol 109 (11) ◽  
pp. 1908-1921 ◽  
Author(s):  
Mireia Gómez-Gallego ◽  
Jared M. LeBoldus ◽  
Martin Karl-Friedrich Bader ◽  
Everett Hansen ◽  
Lloyd Donaldson ◽  
...  
Keyword(s):  
United States ◽  
New Zealand ◽  
Pacific Northwest ◽  
Spatial Scales ◽  
Douglas Fir ◽  
The Pacific ◽  
Foliar Pathogen ◽  
Swiss Needle Cast ◽  
Phytophthora Pluvialis ◽  
Foliar Pathogens

The emergence of Phytophthora pluvialis as a foliar pathogen of Douglas fir in New Zealand and the Pacific Northwest United States has raised questions about its interaction with the widespread Swiss needle cast (SNC) disease. During Spring 2017, we repeatedly sampled 30 trees along an environmental gradient in each region and 292 additional trees in a longitudinal transect to assess the P. pluvialis epidemic and the association between P. pluvialis and Nothophaeocryptopus gaeumannii, which are causal agents of SNC. Both pathogens were consistently more abundant in the host’s exotic environment in New Zealand. In both areas, the two pathogens co-exist in different spatial scales for regions and needles. The relative abundance of both pathogens was negatively correlated in the Pacific Northwest, where both presumably have co-existed for longer. Our findings confirmed the interaction of P. pluvialis and N. gaeumannii as foliar pathogens of Douglas fir and suggest a within-site spatial variation in the Pacific Northwest.

scholarly journals Phytophthora pluvialis Studies on Douglas-fir Require Swiss Needle Cast Suppression

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1259-1262 ◽  
Author(s):  
Mireia Gómez-Gallego ◽  
Martin Karl-Friedrich Bader ◽  
Peter Matthew Scott ◽  
Sebastian Leuzinger ◽  
Nari Michelle Williams
Keyword(s):  
New Zealand ◽  
Pacific Northwest ◽  
Radiata Pine ◽  
Douglas Fir ◽  
Needle Cast ◽  
The Pacific ◽  
Swiss Needle Cast ◽  
Phytophthora Pluvialis ◽  
Red Needle Cast ◽  
Ubiquitous Presence

Phytophthora pluvialis is associated with early defoliation and shoot dieback in Douglas-fir in Oregon and New Zealand. In 2013, P. pluvialis was described from mixed tanoak-Douglas-fir forests in the Pacific Northwest and concurrently recognized as the main causal agent of red needle cast (RNC) in New Zealand radiata pine plantations. Little is known about its infection cycle and impact on host physiology. P. pluvialis studies in Douglas-fir are challenging due to the ubiquitous presence of the endophyte Phaeocryptopus gaeumannii, which produces similar symptoms and premature defoliation with persistent needle wetness, known as Swiss needle cast (SNC). Nonetheless, our study showed P. pluvialis infection in the presence of SNC. Exclusive expression of P. pluvialis is difficult to achieve as both diseases are promoted by high humidity. Here we established a ‘dry leaf’ strategy to suppress SNC when inoculating Douglas-fir needles for RNC studies. Sheltering plants along with drip irrigation to avoid needle wetness during the P. gaeumannii sporulation period suppressed its development in the new season flush. The diminished endophyte inoculum enabled bias-reduced studies of P. pluvialis impacts on Douglas-fir without the confounding effects of stomatal blockage and premature defoliation caused by P. gaeumannii.

Invasive scotch broom alters soil chemical properties in Douglas-fir forests of the Pacific Northwest, USA

2015 ◽  
Vol 398 (1-2) ◽  
pp. 281-289 ◽  
Author(s):  
Robert A. Slesak ◽  
Timothy B. Harrington ◽  
Anthony W. D’Amato
Keyword(s):  
Pacific Northwest ◽  
Chemical Properties ◽  
Douglas Fir ◽  
Soil Chemical Properties ◽  
Scotch Broom ◽  
The Pacific

Canopy disturbances over the five-century lifetime of an old-growth Douglas-fir stand in the Pacific Northwest

2002 ◽  
Vol 32 (6) ◽  
pp. 1057-1070 ◽  
Author(s):  
Linda E Winter ◽  
Linda B Brubaker ◽  
Jerry F Franklin ◽  
Eric A Miller ◽  
Donald Q DeWitt
Keyword(s):  
Pacific Northwest ◽  
Variable Density ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Old Growth ◽  
The Pacific ◽  
History Of ◽  
Horizontal Heterogeneity ◽  
Restoration Strategies

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.

Keepability of Pennsylvania versus West Coast Grown Douglas-Fir Christmas Trees: Genotypic Variation in Relation to Subfreezing Temperatures

1990 ◽  
Vol 7 (2) ◽  
pp. 86-89 ◽  
Author(s):  
Mark E. Kubiske ◽  
Marc D. Abrams ◽  
James C. Finley
Keyword(s):  
Pacific Northwest ◽  
Genotypic Variation ◽  
Rocky Mountain ◽  
Douglas Fir ◽  
Seed Sources ◽  
Christmas Trees ◽  
Display Area ◽  
The Pacific ◽  
Significant Difference ◽  
Needle Loss

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.

scholarly journals Soil phosphorus fractions vary with harvest intensity and vegetation control at two contrasting Douglas-fir sites in the Pacific northwest

Geoderma ◽  
2019 ◽  
Vol 350 ◽  
pp. 73-83 ◽  
Author(s):  
Daniel G. DeBruler ◽  
Stephen H. Schoenholtz ◽  
Robert A. Slesak ◽  
Brian D. Strahm ◽  
Timothy B. Harrington
Keyword(s):  
Pacific Northwest ◽  
Soil Phosphorus ◽  
Douglas Fir ◽  
Phosphorus Fractions ◽  
Vegetation Control ◽  
Soil Phosphorus Fractions ◽  
Harvest Intensity ◽  
The Pacific

Astrosclereids In Needles Of Old-Growth Douglas-Fir Trees

1999 ◽  
Vol 5 (S2) ◽  
pp. 1240-1241
Author(s):  
M. Apple ◽  
A. Soeldner ◽  
R. Hamill ◽  
K. Tiekotfer
Keyword(s):  
Pacific Northwest ◽  
Cell Walls ◽  
Douglas Fir ◽  
Old Growth ◽  
Mesophyll Cells ◽  
Mesophyll Tissue ◽  
The Pacific ◽  
And Function ◽  
Development Structure

Old-growth Douglas-fir trees in the Pacific Northwest are venerable giants that often live for 500 years and reach heights of over 75 meters. Their needles are relatively ephemeral and small but have the important role of interacting with the atmosphere in order to transpire and photosynthesize. Within the photosynthetic mesophyll tissue of Douglas-fir needles, there are large, non-living cells with lignified secondary cell walls that are known as astrosclereids. Apparent channels in the secondary wall may provide a route for exchange or transport of materials between the astrosclereid lumen and mesophyll cells or the vascular cylinder. Astrosclereids may be involvev d in storage of secondary metabolites such as tannin and may develop in response to fungi, mistletoe, or other pathogens. More knowledge is needed about the development, structure and function of astrosclereids.Needles were collected from sapling and old-growth Douglas-fir, Pseudotsuga menziesii, (Mirb.) Franco, trees at the Wind River Canopy Crane in Carson, Washington and from three sites in the Cascade Mountains of Oregon in 1997 and 1998.

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