The effects of host genotype, growth rate, and needle age on the distribution of a mutualistic, endophytic fungus in Douglas-fir plantations

1988 ◽  
Vol 18 (5) ◽  
pp. 601-605 ◽  
Author(s):  
Dennis Todd
Keyword(s):  
Growth Rate ◽  
Endophytic Fungus ◽  
Detailed Examination ◽  
Douglas Fir ◽  
Host Genotype ◽  
Needle Age ◽  
Insecticidal Toxins

Two young plantations of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were examined for the presence of a symptomless endophytic fungus, Meriaparkeri Sherwood-Pike (Hemiphacideaceae). This fungus occurred in the needles of nearly every tree examined, with infection frequencies increasing with the age of the needle. Previous reports have asserted that M. parkeri is a mutualist that produces insecticidal toxins. The maternal parentage of the trees and age of the needles were highly significant predictors of infection frequencies. A detailed examination of two families of trees revealed that infection frequencies differed between sites and were positively correlated with the height of the host. Mutualism and microhabitat effects are discussed.

Effects of thinning and urea fertilization on the distribution of area increment along the boles of Douglas-fir at Shawnigan Lake, British Columbia

1984 ◽  
Vol 14 (6) ◽  
pp. 879-884 ◽  
Author(s):  
A. J. Thomson ◽  
H. J. Barclay
Keyword(s):  
Growth Rate ◽  
Radial Growth ◽  
Temporal Trend ◽  
Douglas Fir ◽  
Regression Methods ◽  
Average Area ◽  
Breast Height ◽  
Urea Fertilization ◽  
Measurement Period ◽  
Growth Distribution

The effects of fertilization and thinning of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) on the distribution of area increment along the bole were assessed using radial growth measurements 6 and 9 years after treatment. Within treatments, the average area increment per tree was linearly related to diameter at breast height, and this relationship was used to evaluate the effects of treatment on growth rate. Fertilization had the greatest effect on average area increment, and for a particular fertilization regime, thinning increased the response. Thinning modified the distribution of growth over the bole of all trees and increased butt flare, especially in smaller trees. The effect declined from the 4- to 6-year measurement period to the 7-to 9-year measurement period. Fertilization had no consistent effect on growth distribution. The regression methods used in this study provided a more sensitive measure of form changes than previous methods, were independent of size distribution, and facilitated extrapolations and evaluation of temporal trend.

Co-incident variations in growth rate and heartwood extractive concentration in Douglas-fir

2003 ◽  
Vol 186 (1-3) ◽  
pp. 257-260 ◽  
Author(s):  
Adam M. Taylor ◽  
Barbara L. Gartner ◽  
Jeffrey J. Morrell
Keyword(s):  
Growth Rate ◽  
Douglas Fir

Five-year growth responses of Douglas-fir, western hemlock, and western redcedar seedlings to manipulated levels of overstory and understory competition

2006 ◽  
Vol 36 (10) ◽  
pp. 2439-2453 ◽  
Author(s):  
Timothy B Harrington
Keyword(s):  
Growth Rate ◽  
Nitrogen Content ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Volume Index ◽  
Stem Volume ◽  
Western Redcedar ◽  
Foliar Nitrogen ◽  
Relative Growth ◽  
Vegetation Control

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western redcedar (Thuja plicata Donn ex D. Don) seedlings were planted in March 2001 within three clearcut-harvested, shelterwood, or thinned stands of mature Douglas-fir near Olympia, Washington. From 2002 to 2005, areas of vegetation control of 0, 4.5, or 9 m2 were maintained with herbicides around a total 162 seedlings per species. Photosynthetically active radiation (PAR) was 34%, 62%, and 100% of full sunlight in thinned stands, shelterwoods, and clearcuts, respectively. Effects of overstory level and vegetation control on seedling growth and resource availability generally were additive. Seedling stem volume index in clearcuts averaged four to eight times that observed in thinned stands, and with vegetation control, it averaged two to four times that observed without it. In thinned stands, relative growth rate of seedling stem volume index had a positive linear relationship with PAR (R2 = 0.38). Foliar nitrogen content of Douglas-fir explained 71% of the variation in relative growth rate. Factors explaining the most variation in foliar nitrogen content differed between thinned stands (PAR, R2 = 0.34) and clearcuts or shelterwoods (midday water potential, R2 = 0.63), suggesting that light and root competition, respectively, were the primary growth-limiting factors for these overstory levels.

scholarly journals Incidence and Impact of Swiss Needle Cast in Forest Plantations of Douglas-fir in Coastal Oregon

Plant Disease ◽  
2000 ◽  
Vol 84 (7) ◽  
pp. 773-778 ◽  
Author(s):  
E. M. Hansen ◽  
J. K. Stone ◽  
B. R. Capitano ◽  
P. Rosso ◽  
W. Sutton ◽  
...  
Keyword(s):  
Severe Disease ◽  
Tree Height ◽  
Aerial Survey ◽  
Douglas Fir ◽  
Permanent Plots ◽  
Forest Plantations ◽  
Needle Age ◽  
Needle Cast ◽  
Needle Retention ◽  
Swiss Needle Cast

An epidemic of Swiss needle cast, caused by the ascomycete Phaeocryptopus gaeumannii, is causing defoliation and growth reductions in Douglas-fir forest plantations along the Oregon Coast. The area of symptomatic plantations has been monitored annually since 1996 by aerial survey; in spring 1999, 119,500 ha were affected. Pathogen and symptom development have also been monitored on nine permanent plots in stands of differing disease severity. Infection levels and symptom severity are greatest in low elevation plantations close to the coast. In areas of severe disease, trees retain only current year needles. Defoliation is proportional to the number of stomata occluded by pseudothecia of the fungus, with needles being shed when about 50% of stomata are occupied, regardless of needle age. Fungus sporulation and premature needle abscission are greatest on the upper branches of trees. Annual application of fungicides increases needle retention significantly. Tree height and diameter growth and total tree volume are reduced by disease, and tree volume is significantly correlated with needle retention on our plot trees. The epidemic continues to be most severe in Douglas-fir plantations established on sites where Sitka spruce and western hemlock or red alder predominated in earlier times.

Effects of thinning on water stress and growth in Douglas-fir

1988 ◽  
Vol 18 (1) ◽  
pp. 100-105 ◽  
Author(s):  
Gilbert Aussenac ◽  
André Granier
Keyword(s):  
Growth Rate ◽  
Water Stress ◽  
Water Balance ◽  
Soil Water ◽  
Tree Growth ◽  
Rapid Evolution ◽  
Douglas Fir ◽  
Water Reserve ◽  
Growth Increase ◽  
Northeastern France

The effects of a systematic thinning (alternate row) on water stress and growth in a 19-year-old Douglas-fir plantation (Pseudotsugamenziesii var. menziesii Franco) was studied during 5 years in northeastern France. Thinning has an important effect on water balance. The increase of the soil water reserve led to a lower duration and level of water stress in the thinned plot, especially during the first 3 years after thinning. This study revealed a rapid evolution of the water balance, since the evapotranspiration ratio of the two plots (control and thinned) had increased from 0.83 during the 1st year to 1.03 during the 5th year after thinning. Together with microclimate influences, thinning increased tree growth substantially (more than 100%); this growth increase resulted from a higher growth rate and longer growth periods (from 26 to 49 days).

Wood Structure and Growth Ring Width of Vital and Non-Vital Douglas Fir (Pseudotsuga Menziesii) from a Single Stand in the Netherlands

IAWA Journal ◽  
1986 ◽  
Vol 7 (4) ◽  
pp. 309-318 ◽  
Author(s):  
Ingrid de Kort
Keyword(s):  
Growth Rate ◽  
Growth Ring ◽  
Ring Width ◽  
Douglas Fir ◽  
Wood Structure ◽  
Growth Reduction ◽  
External Appearance ◽  
Dead Trees ◽  
Growth Ring Width ◽  
C 50

A comparison was made of diameter growth and wood structure in 26 trees of Douglas fir of different vitality cJasses in a decJining, c. 50- years old stand in De Peel (southeastern Netherlands). Ring width patterns agree cJosely but not perfectly with vitality cJasses as estimated by external appearance of the crown. The 'diseased' vitality cJasses all show growth reductions over the last 20 to 30 years. In the most diseased cJass no wood had been formed at all at the stern base over the last 4 to 10 years. The onset of growth reduction may be connected with the effect of air pollution in the last 40 to 50 years. The most striking result was the inverse relationship between growth rate in the first 10 to 15 years of growth, and growth rate in the last decades: all trees which are healthy at present showed slow radial growth when young, and all diseased to dead trees exhibited fast growth in their youth.

scholarly journals Variation in specific needle area of old-growth Douglas-fir in relation to needle age, within-crown position and epicormic shoot production

2002 ◽  
Vol 22 (1) ◽  
pp. 31-40 ◽  
Author(s):  
H. Ishii ◽  
E. D. Ford ◽  
M. E. Boscolo ◽  
A. C. Manriquez ◽  
M. E. Wilson ◽  
...  
Keyword(s):  
Douglas Fir ◽  
Old Growth ◽  
Needle Age ◽  
Crown Position ◽  
Shoot Production ◽  
Epicormic Shoot

Comparison of selected Douglas-fir seed sources for cambial and leader growth patterns in four western Oregon environments

1977 ◽  
Vol 7 (1) ◽  
pp. 154-164 ◽  
Author(s):  
William H. Emmingham
Keyword(s):  
Growth Rate ◽  
British Columbia ◽  
Growth Pattern ◽  
Douglas Fir ◽  
Growth Patterns ◽  
Seasonal Growth ◽  
Growth Duration ◽  
Cambial Growth ◽  
Seed Sources ◽  
Definite Pattern

The leader and cambial growth of sapling Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) from both inland and coastal varieties followed a definite pattern in four western Oregon environments. Generally, buds became active first and cambial growth became active soon after. Leader growth stopped in August, long before cambial growth, which continued into October. Phenology, total seasonal growth, and growth pattern for trees from coastal sources from Vancouver Island, B.C., to southern Oregon were more similar than for trees from inland sources from British Columbia to Idaho and Arizona. Most of the differences among populations in one season's growth were related to growth rate rather than growth duration.

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