Occurrence of juvabione-related compounds in grand fir and Pacific silver fir infested by balsam woolly aphid

1974 ◽  
Vol 52 (3) ◽  
pp. 585-587 ◽  
Author(s):  
George S. Puritch ◽  
W. W. Nijholt

Two juvabione-related compounds, (+)-todomatuic acid and dehydrotodomatuic acid, were found in conjunction with certain balsam woolly aphid infested Abies grandis (Dougl.) Lindl. and Abies amabilis (Dougl.) Forbes but not with noninfested trees.The localized occurrence and variable distribution of these compounds within the wood of infested trees is discussed.

1959 ◽  
Vol 91 (4) ◽  
pp. 208-212 ◽  
Author(s):  
A. Tunnock ◽  
J. A. Rudinsky

The balsam woolly aphid, Adelges piceae (Ratz.) (Adelgidae, Homoptera), originally introduced from Europe, was reported on grand fir, Abies grandis (Doug.) Lindl., in the Willamette Valley by Keen (5) around 1930. Serious outbreaks of this insect were first recorded on subalpine fir, A. lasiocarpa (Hook.) Nutt., in Oregon and Pacific silver fir, A. amabilis (Doug].) Forb., in Washington in 1954 ( 3 ) . At present about 600,000 acres of subalpine and Pacific silver firs are heavily infested in the Pacific Northwest.


1965 ◽  
Vol 43 (6) ◽  
pp. 631-639 ◽  
Author(s):  
R. A. Shoemaker

Study of the type of Dimerosporium balsamicola (Peck) Ell. & Ev. (≡ Meliola balsamicola Peck) revealed that this species is a melioline hyperparasite. The fungus is transferred to Dimerium, redescribed, illustrated, and distinguished from Phacocryptopus nudus (Peck) Petrak, Asterina sp., and from Epipolaeum abietis (Dearness) n. comb. (≡ Dimerosporium abietis Dearness), which also occur on Abies in North America. In all, four species of Epipolaeum that occur on conifer needles are treated: Epipolaeum abietis on Abies grandis (Dougl.) Lindl. and Abies amabilis (Dougl.) Forb. in western North America, on Abies alba Mill. in France, and on Keteleeria davidiana Beiss. in Formosa; Epipolaeum tsugae (Dearness) n. comb. on Tsuga canadensis (L.) Carr. in eastern North America, and on Tsuga heterophylla (Raf.) Sarg. and Tsuga mertensiana (Bong.) Carr. in western North America; Epipolaeum pseudotsugae (V. M. Miller & Bonar) n. comb. on Pseudotsuga taxifolia (Poir.) Britton from western North America; Epipolaeum terrieri (Petrak in Terrier) n. comb. on Abies alba in Switzerland.


2014 ◽  
Vol 44 (10) ◽  
pp. 1145-1155 ◽  
Author(s):  
Adrian Weber ◽  
J.P. (Hamish) Kimmins ◽  
Benjamin Gilbert ◽  
Yueh-Hsin Lo ◽  
Juan A. Blanco

Sustainable forest practices are often designed to mimic natural disturbance and successional processes, yet succession is poorly understood in many ecosystems. On northeastern Vancouver Island, the “disturbance hypothesis” is a widely assumed succession model asserting that shade-tolerant western redcedar (Thuja plicata Donn ex D. Don) and the ericaceous shrub salal (Gaultheria shallon Pursh) invade and colonize highly productive western hemlock (Tsuga heterophylla (Raf.) Sarg.) – Pacific silver fir (Abies amabilis Douglas ex J. Forbes) stands (HA) on zonal sites in the absence of stand-replacing wind disturbance. This leads to the development of low-productivity, low-density, uneven-aged, open-crowned redcedar–hemlock–salal stands (CH). In conflict with this model, old, apparently stable HA stands lacking redcedar can be found on such sites as well. We sought evidence for the predicted transition to CH stands by examining stand composition, crown closure, tree size class frequency distributions, salal cover, and redcedar establishment on young HA (∼90 years old), old HA (>160 years), and CH (>160 years) stands. When adjacent to a redcedar stand, young HA stands had fewer redcedar seedlings but more redcedar adult trees than old HA stands. However, redcedar abundance did not differ between young and old HA stands at distances further than 10 m from adjacent redcedar stands. This could indicate that redcedar recruits into HA stands at stand establishment and that redcedar seedling establishment is low under the thick canopy of young HA stands. The chronosequence data also suggest that both old HA and CH stands are self-replacing stand types in these forests, contrary to the disturbance hypothesis. We develop a new, multipathway model for this ecosystem that is based on the chronosequence data and life-history traits of the focal tree species and suggest that disturbance plays a role opposite to the equilibrium model.


1968 ◽  
Vol 100 (4) ◽  
pp. 412-420 ◽  
Author(s):  
M. D. Atkins ◽  
T. A. D. Woods

AbstractSurvival of the balsam woolly aphid on Abies grandis logs was observed to evaluate the danger of spreading the pest while moving logs. Active stages of the aphid survived submergence in sea water for 7 days and periodic sprinkling with sea water for 3 weeks. Dormant stages survived submergence up to 28 days. Active aphids survived on logs in the forest as long as 5 months. Crawlers frequently re-established on logs and completed a second generation there. Dormant neosistentes on autumn-felled trees persisted over winter and resumed development in the spring. Recommendations for moving infested logs through uninfested areas are made.


2016 ◽  
Vol 46 (3) ◽  
pp. 427-436 ◽  
Author(s):  
Gary Kerr ◽  
Victoria Stokes ◽  
Andrew Peace ◽  
Alan Fletcher ◽  
Sam Samuel ◽  
...  

Pacific silver fir (Abies amabilis Douglas ex J. Forbes) was first introduced to Britain in 1830 but has not been widely planted and occupies a minute part of the forest estate. The results of six experiments established in the uplands of Britain examining material from 30 collection sites in 14 seed zones clearly demonstrate that its potential has not been recognised. The trials were assessed after 28 years and show that Pacific silver fir has the potential to be as productive as other common species options. There was little variation in performance between the 14 seed zones, and future seed collections could be carried out within a wide geographical range, including mainland British Columbia and Vancouver Island and the Olympic Mountains and western Cascades of Washington. The silvicultural characteristics of the species mean that it could be used more widely to diversify forests in Britain both as a plantation species and in the wider use of continuous cover management. More work is justified to determine its susceptibility to Annosum root rot (Heterobasidion annosum (Fr.) Bref), confirm its productivity on sites with rainfall below 800 mm·a–1 and (or) with a high peat content, and provide more detail on its wood properties.


1998 ◽  
Vol 28 (6) ◽  
pp. 808-819 ◽  
Author(s):  
N Buchmann ◽  
T M Hinckley ◽  
J R Ehleringer

Carbon isotope ratios ( delta 13C) of canopy air and carbon isotope discrimination at the ecosystem level were studied in three montane Pacific silver fir (Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes) stands, an old-growth and two younger stands. Spatial and temporal variations of canopy CO2 concentrations ([CO2]) and their delta 13C were strongly related to stand structure. Within the old-growth stand, both daytime canopy [CO2] and canopy delta 13C stayed close to those of the troposphere, either indicating low overall photosynthetic rates or high turbulent mixing. Pronounced periods of photosynthetic drawdown below baseline [CO2] accompanied by more enriched canopy delta 13C were observed for the two younger and denser stands. Canopy [CO2] profiles seemed closely related to changes in soil conditions. Soil respiration rates were positively related to soil temperature, but negatively to soil moisture. delta 13C of soil-respired CO2 stayed relatively constant at -24.55 ± 0.20%oduring the growing season. Significant relationships existed between canopy delta 13C and 1/[CO2] in all three stands. Using the intercepts of these regressions, we calculated an average delta 13C for ecosystem respiration of -26.4 ± 0.1%o. Ecosystem carbon isotope discrimination ( DELTA e), an integrating measure for carbon exchange between the troposphere and the entire ecosystem, stayed relatively constant through time. DELTA e showed no significant stand structure effect (leaf area index, density) and averaged 18.9%o for the old-growth and 19.2 ± 0.2%ofor the two younger stands.


1998 ◽  
Vol 28 (8) ◽  
pp. 1146-1163 ◽  
Author(s):  
John N Owens ◽  
Sheila J Morris

The reproductive development from pollination until seed maturity for Pacific silver fir (amabilis fir; Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes) was studied at two sites in British Columbia. Ten trees growing at varying elevations at each site were flagged and two or more cones were collected from each tree every 1 or 2 weeks. Following size measurements, cones were dissected and 20 ovules from each cone were sampled, fixed, embedded in paraffin, sectioned, and stained for anatomical study. Ovule, megagametophyte, and embryo size was measured and stage of ovule or seed and embryo was determined. At both sites the phenology and details of development were similar. The major causes of cone loss were frost at pollination and insect damage following pollination. The seed potential per cone was 359-408, but the filled seeds per cone based on cutting tests and X-raying was only 18-22%. The major causes of seed loss were insect damage (32-39%) during ovule and seed development and failure of ovules to be pollinated (26-31%). Although the amount of insect damage was similar at both sites, damage at Site 1 was primarily caused by Megastigmus sp. larvae in the seeds whereas at Site 2, damage was to seeds, scales, and the cone axis and due to Earomyia abietum larvae. Megagametophyte and embryo development is described and the time and causes of the seed loss are related to development. Anomalous types of development are described and possible causes discussed.


1995 ◽  
Vol 15 (11) ◽  
pp. 727-738 ◽  
Author(s):  
L. Kulchetscki ◽  
I. S. Harry ◽  
E. C. Yeung ◽  
T. A. Thorpe

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