Allometries of coarse tree, stem, and crown measures in Douglas-fir are altered by Armillaria root disease

Botany ◽  
2012 ◽  
Vol 90 (8) ◽  
pp. 711-721 ◽  
Author(s):  
M.G. Cruickshank ◽  
C.N. Filipescu
Keyword(s):  
Wood Quality ◽  
Douglas Fir ◽  
Root Disease ◽  
Stem Diameter ◽  
Light Competition ◽  
Sapwood Area ◽  
Crown Diameter ◽  
Crown Length ◽  
Light Requirements ◽  
Armillaria Root Disease

We used allometric relationships to quantify Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) stem and crown adaptation to Armillaria root disease (caused by Armillaria ostoyae (Romagn.) Herink). At four sites, we measured height, diameter, height to live crown, crown width and length, sapwood area at base of live crown, and infection duration for healthy and infected Douglas-fir trees. Diseased trees were on average smaller than healthy trees for all measured variables, but there were also proportional changes between tree parts suggesting allocation shifts to disease. Infected trees were shorter in relation to stem diameter compared with healthy trees by 4% on average. Crown diameter was positively related to stem diameter (0.24 m·cm–1) but not to disease or competition. Diseased tree crown lengths were on average 0.5 m shorter for a given crown diameter than healthy trees—akin to response to light competition except this also occurred in the upper canopy. Prolonged infection reduced crown length probably through shedding of lower branches and by reducing stem apical growth, possibly related to changed hydraulic architecture or light requirements. Crown surface area was related to stem sapwood area (0.81 m2·cm–2) but unaffected by disease or competition. We discuss how shifting allocation could reveal important implications for life strategies involving whole tree adaptations to disease and tree to tree interactions, and for wood quality and forest inventory.

Effect of Armillaria root disease on quality and value of green Douglas-fir lumber

2010 ◽  
Vol 86 (2) ◽  
pp. 263-266 ◽  
Author(s):  
M G Cruickshank
Keyword(s):  
Tree Species ◽  
Wood Quality ◽  
Douglas Fir ◽  
Root Disease ◽  
Tree Level ◽  
Stem Taper ◽  
Negative Effect ◽  
Key Words Disease ◽  
Armillaria Root Disease ◽  
The Impact

For a few tree species, scattered accounts of impact caused by root disease exist in the literature mainly at the tree level. No product quality impacts have ever been measured or properly costed. To provide some information on value impacts, green rough-sawn Douglas-fir lumber was cut from trees with and without Armillaria root disease. This produced 80 boards from six trees in two planted stands. Fewer boards came from living diseased trees compared to healthy trees of similar diameter (1.3 m) at both sites, suggesting that disease may affect stem taper or form. Lumber from diseased trees was affected most often by warp and for healthy trees by knots, but warp affected value the most. Disease appears to have at best no effect, and at worst, a negative effect on lumber value but is not likely to increase value. This is the first report of the impact of a root disease on lumber quality and value, but further work would be required to properly assess this. Key words: disease, Armillaria root disease, conifer, Douglas-fir, wood quality, lumber warping, lumber value, lumber grading

scholarly journals An exploration of ringbarking to reduce the severity of Armillaria root disease in logged areas in British Columbia

2015 ◽  
Vol 45 (12) ◽  
pp. 1803-1805 ◽  
Author(s):  
Bill Chapman ◽  
Bruce Schellenberg
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Tree Mortality ◽  
Timber Harvesting ◽  
Douglas Fir ◽  
Root Disease ◽  
The World ◽  
Armillaria Root Disease ◽  
Severity Of The Disease

Ringbarking is a girdling technique that is used prior to timber harvesting to reduce losses to Armillaria root disease in some parts of the world. The technique had not previously been evaluated in British Columbia, Canada. Small plots of primarily Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees that were ringbarked prior to timber harvesting had approximately 50% lower levels of Armillaria root disease caused tree mortality in young trees after 15 years than plots of trees that were not ringbarked. Ringbarking did not reduce Armillaria root disease in this trial as much as has been reported in other research. This could be attributable to the centre of the small plots being within 5–10 m of live and dead Armillaria-infected trees in the surrounding forest. The treatment did reduce the severity of the disease by both statistically and biologically significant amounts and, therefore, warrants further investigation as a possible treatment where timber harvesting is conducted in Armillaria root disease affected stands.

The relationship between gross crown dimensions and sapwood area at crown base in Douglas-fir

1989 ◽  
Vol 19 (5) ◽  
pp. 557-565 ◽  
Author(s):  
Douglas A. Maguire ◽  
David W. Hann
Keyword(s):  
Leaf Area ◽  
Surface Area ◽  
Strong Relationship ◽  
Douglas Fir ◽  
Total Leaf Area ◽  
Sapwood Area ◽  
Crown Length ◽  
Total Leaf ◽  
Conic Surface ◽  
Crown Dimensions

Crown dimensions and sapwood area near crown base were measured on 189 Douglas-fir trees in southwestern Oregon. Sapwood areas were interpolated or extrapolated to crown base with a sapwood taper function. Various transformations of crown length and crown radius (as well as crown base stem diameter as a surrogate for crown diameter) were assessed for their ability to predict crown base sapwood area. Regression analyses indicated that no single untransformed variable was a good predictor of sapwood area at crown base, but that combinations representing conic surface area performed quite well. Given the consistently strong relationship between total leaf area and sapwood area at crown base, conic surface area should accurately reflect total leaf area and relative photosynthetic potential of the tree. Gross crown dimensions and crown base sapwood area prove complementary in a forest modeling context, owing to the structural appeal of the former and the physiological appeal of the latter.

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