Age- and size-related response of lodgepole pine to inoculation with Europhium clavigerum

1973 ◽  
Vol 51 (6) ◽  
pp. 1155-1160 ◽  
Author(s):  
D. M. Shrimpton

In 1970, 280 lodgepole pines between 8 and 140 years old, in the east Kootenay region of British Columbia, were inoculated with Europhium clavigerum. The resinous response of the tree to this inoculation was used as a measure of potential resistance to bark beetle attack. Trees between 31 and 50 years old had the greatest frequency of potentially resistant individuals. The following year, 250 trees between 10 and 120 years old were inoculated on June 11, July 5, and July 23, with similar results. The youngest (10–30) and oldest (91–120) trees had a greater decrease in frequency of resistant individuals, as the summer progressed, than the intermediate age classes. Trees rated as potentially resistant from all three inoculations had faster growth rates and thicker phloem than those rated nonresistant.

1987 ◽  
Vol 65 (1) ◽  
pp. 95-102 ◽  
Author(s):  
H. S. Whitney ◽  
R. J. Bandoni ◽  
F. Oberwinkler

A new basidiomycete, Entomocorticium dendroctoni Whitn., Band. & Oberw., gen. et sp. nov., is described and illustrated. This cryptic fungus intermingles with blue stain fungi and produces abundant essentially sessile basidiospores in the galleries and pupal chambers of the mountain pine bark beetle (Dendroctonus ponderosae Hopkins Coleoptera: Scolytidae) in lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.). The insect apparently disseminates the fungus. Experimentally, young partially insectary reared adult beetles fed E. dendroctoni produced 19% more eggs than beetles fed the blue stain fungi.


2005 ◽  
Vol 35 (7) ◽  
pp. 1527-1539 ◽  
Author(s):  
J M Kranabetter ◽  
J Friesen ◽  
S Gamiet ◽  
P Kroeger

Commercial forest rotations are usually shorter than natural disturbance return intervals, which could affect the distribution of ectomycorrhizal fungal (EMF) species dependent on late-seral stands. We examined this potential reduction in species richness by comparing ectomycorrhizal mushroom communities across four age-classes (pole stage, young, mature, and old growth) of western hemlock (Tsuga heterophylla (Raf.) Sarg.) – lodgepole pine (Pinus contorta Dougl. ex Loud.) stands on submesic sites in northwestern British Columbia. Almost 130 species of ectomycorrhizal mushrooms were identified over the 12 sites during the 3-year study period. EMF richness was lowest in pole stands and almost twice as high in the older age-classes. Species composition and abundance were related to stand age, with relatively large differences in communities between the ages of 20 and 120 and relatively smaller differences between 120 and 225 years. Twelve species, including the economically important pine mushroom (Tricholoma magnivelare (Peck) Redhead), were late-seral stand dependent, fruiting in forests that are at least older than 85 years. This distribution of ectomycorrhizal mushrooms across stand ages suggests EMF succession is primarily an accumulation of species and is likely affected by differences in dispersal by ectomycorrhizal fungi, soil properties (increased soil acidity and reduced nitrogen availability), and the rate of stand development. The evidence for EMF species limited to late-seral stands supports the maintenance of some mature forests within these landscapes to conserve EMF richness.


2010 ◽  
Vol 142 (6) ◽  
pp. 557-573 ◽  
Author(s):  
Erin L. Clark ◽  
Allan L. Carroll ◽  
Dezene P.W. Huber

AbstractThe mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), is a destructive insect pest in western Nearctic conifer forests. Currently, British Columbia, Canada, is experiencing the largest recorded outbreak of this insect, including areas that historically have had low climatic suitability for it. We analyzed 26 constitutive resin terpenes in phloem samples from British Columbia lodgepole pine (Pinus contorta) populations to test for differential resistance to mountain pine beetle attack, based upon the likelihood of previous exposure to mountain pine beetle. We assessed sampled trees for number of mountain pine beetle attacks, number of pupal chambers, and tree survival the following spring. Significant differences were found when levels of certain terpenes in lodgepole pine populations that had likely experienced substantial mountain pine beetle infestations in the past were compared with those in populations that likely had not experienced large outbreaks of mountain pine beetle. Although we expected southern pine populations to contain more total terpenes than northern populations, owing to higher historical exposure to the beetle, the converse was found. Northern populations generally had higher levels of constitutive terpenes and beetle attack than southern populations. Because several terpenes are kairomones to the mountain pine beetle and also serve as precursors for the synthesis of pheromones, the lower levels of terpenes expressed by lodgepole pines from the historical range of the mountain pine beetle may render them less chemically perceptible to foraging beetles.


1964 ◽  
Vol 42 (2) ◽  
pp. 145-158 ◽  
Author(s):  
A. C. Molnar ◽  
B. Sivak

A rust fungus, discovered infecting ponderosa pine (Pinus ponderosa Laws.) at Telkwa, B.C. in 1960 and reported to be the European pine twist rust, Melampsora pinitorqua Rostr., is shown to be the native rust M. albertensis Arth., which was previously thought to have Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) as its only coniferous host. Four other pines are shown to be susceptible to the rust: lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.), jack pine (P. banksiana Lamb.), red pine (P. resinosa Ait.), and Scots pine (P. sylvestris L.).Melampsora occidentalis Jacks. was shown to be able to infect ponderosa and lodgepole pines as well as its previously known host, Douglas fir.Only current year's germinants or current year's shoots of very young pines appeared susceptible to these rusts.These are the first records of a species of Uredinales infecting two coniferous genera and it is suggested that other examples may be found by closer observation of younger age classes of hosts.The rust is not considered a special hazard to pine in British Columbia at the present time.


2015 ◽  
Vol 105 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Kennedy Boateng ◽  
Kathy J. Lewis

We studied spore dispersal by Dothistroma septosporum, causal agent of a serious outbreak of red band needle blight in lodgepole pine plantations in northwest British Columbia. Spore abundance was assessed at different distances and heights from inoculum sources and microclimatic factors were recorded during two consecutive years. Conidia were observed on spore traps from June to September during periods of rainfall. It was rare to detect spores more than 2 m away from inoculum sources. The timing and number of conidia dispersed were strongly tied to the climatic variables, particularly rainfall and leaf wetness. Should the trend toward increased spring and summer precipitation in the study area continue, the results suggest that disease spread and intensification will also increase. Increasing the planting distances between lodgepole pine trees through mixed species plantations and overall reduction in use of lodgepole pine for regeneration in wet areas are the best strategies to reduce the spread of the disease and enhance future productivity of plantations in the study area.


2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Teresa A. Newsome ◽  
Jean L. Heineman ◽  
Amanda F. Linnell Nemec

Critical height ratios for predicting competition between trembling aspen and lodgepole pine were identified in six juvenile stands in three south-central British Columbia ecosystems. We used a series of regression analyses predicting pine stem diameter from the density of neighbouring aspen in successively shorter relative height classes to identify the aspen-pine height ratio that maximizedR2. Critical height ratios varied widely among sites when stands were 8–12 years old but, by age 14–19, had converged at 1.25–1.5. MaximumR2values at age 14–19 ranged from 13.4% to 69.8%, demonstrating that the importance of aspen competition varied widely across a relatively small geographic range. Logistic regression also indicated that the risk of poor pine vigour in the presence of aspen varied between sites. Generally, the degree of competition, risk to pine vigour, and size of individual aspen contributing to the models declined along a gradient of decreasing ecosystem productivity.


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