scholarly journals Comparison of silvicultural regimes of lodgepole pine (Pinus contorta) in Sweden 5 years after precommercial thinning

Silva Fennica ◽  
2013 ◽  
Vol 47 (3) ◽  
Author(s):  
Kristina Ahnlund Ulvcrona ◽  
Lars Karlsson ◽  
Ingegerd Backlund ◽  
Urban Bergsten
2005 ◽  
Vol 35 (6) ◽  
pp. 1314-1318 ◽  
Author(s):  
Peter V Blenis ◽  
Wuhan Li

Infection of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) by western gall rust has been shown to decrease with tree height and age, but the effects of those two factors have not been separated. Five replicate artificial inoculations were done on a total of 327 trees of different ages in two height classes. Temperature and percentage of spore germination at the height of inoculation, shoot development (stem elongation at the time of inoculation as a proportion of final shoot elongation), main stem leader length at the time of inoculation, tree height, and tree age were measured. Modeled percentages of infected trees and the number of galls per 10 cm of shoot length decreased by 85% and 88%, respectively, as tree age increased between 2 and 10 years, indicating the undesirability of early, aggressive precommercial thinning of lodgepole pine stands in areas where western gall rust is common. By controlling and (or) statistically accounting for inoculum, microclimate, and phenological factors, it was possible to demonstrate that changes in susceptibility with tree age are sufficient to account for the reduction in infection with tree height.


2006 ◽  
Vol 36 (1) ◽  
pp. 48-61 ◽  
Author(s):  
P M.F Lindgren ◽  
D B Ransome ◽  
D S Sullivan ◽  
T P Sullivan

We investigated plant community responses (abundance, species diversity, and structural diversity) to a range of precommercial thinning densities in young lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands 12 to 14 years after thinning, with both unthinned and old-growth stands for comparison. Abundance of understory plants, especially herbs, appeared to increase dramatically in the thinned stands. The moss layer was significantly more abundant in old-growth stands than in the young pine stands. Of a total of 108 species sampled, only three were introduced species, all of which occurred more frequently in the low-density stands than in any of the other stands. Thinning treatments appeared to increase the abundance of late-seral species. Our results suggest that by disrupting canopy closure, thinning decreased the dominance of tall trees and increased the abundance of herbs, shrubs, and trees in the understory height classes. As a result, thinning to low densities significantly increased the structural richness of the tree layer and caused an increase in total structural diversity, which, although only marginally significant (p = 0.06), was likely biologically important. Our results suggest that thinning will enhance the abundance, species diversity, and structural diversity of the plant community 12 to 14 years postthinning.


2000 ◽  
Vol 76 (5) ◽  
pp. 753-757 ◽  
Author(s):  
Peter V. Blenis

To evaluate the threat of armillaria root disease in precommercially thinned lodgepole pine (Pinus contorta var. latifolia), a total of 66 15 × 15-m plots were established in dense lodgepole pine regeneration, 18 to 21 years after harvest, on three infested sites near Hinton, Alberta. Three treatments (2.5-m spacing, 1.5-m spacing and an unspaced control) were randomly applied to plots having similar densities and levels of mortality. After 11 years there was no significant difference among the treatments in cumulative percent mortality. Based on observed levels of mortality, it would appear that spacing need not be avoided in infested stands, although it likely would be prudent to space more closely than 2.5 m in younger stands and in parts of stands having more than 5–10% mortality. Key words: precommercial thinning, spacing, armillaria root disease, Armillaria ostoyae


2011 ◽  
Vol 41 (12) ◽  
pp. 2403-2412 ◽  
Author(s):  
Daniel M. Kashian ◽  
Rebecca M. Jackson ◽  
Heather D. Lyons

Extensive outbreaks of the mountain pine beetle ( Dendroctonus ponderosae Hopkins) will alter the structure of many stands that will likely be attacked again before experiencing a stand-replacing fire. We examined a stand of lodgepole pine ( Pinus contorta var. latifolia Engelm. ex S. Watson) in Grand Teton National Park currently experiencing a moderate-level outbreak and previously attacked by mountain pine beetle in the 1960s. Consistent with published studies, tree diameter was the main predictor of beetle attack on a given tree, large trees were preferentially attacked, and tree vigor, age, and cone production were unimportant variables for beetle attack at epidemic levels. Small trees killed in the stand were killed based mainly on their proximity to large trees and were likely spatially aggregated with large trees as a result of the previous outbreak. We concluded that the driving factors of beetle attack and their spatial patterns are consistent across outbreak severities but that stand structure altered by the previous outbreak had implications for the current outbreaks in the same location. This study should catalyze additional research that examines how beetle-altered stand structure affects future outbreaks — an important priority for predicting their impacts under climate change scenarios that project increases in outbreak frequency and extent.


2009 ◽  
Vol 15 (3) ◽  
pp. 535-548 ◽  
Author(s):  
E. A. H. SMITHWICK ◽  
M. G. RYAN ◽  
D. M. KASHIAN ◽  
W. H. ROMME ◽  
D. B. TINKER ◽  
...  

1986 ◽  
Vol 64 (10) ◽  
pp. 2368-2371 ◽  
Author(s):  
Keith N. Egger ◽  
J. W. Paden

Forty isolates of postfire ascomycetes (Pezizales) were tested for in vitro pathogenicity on seeds and germinants of lodgepole pine, Pinus contorta Dougl. Two known pathogens, Caloscypha fulgens (Pers.) Boud. and Botrytis cinerea Pers., were included as a check of the method. Caloscypha fulgens was the only fungus that caused serious declines in seed germination, although several species of postfire Pezizales were capable of preemergence seed infection. Rhizina undulata Fr. and Pyropyxis rubra (Peck) Egger were strongly pathogenic on germinants. Pyropyxis rubra was not previously known to be pathogenic. Many isolates were weakly pathogenic on germinants under the conditions tested.


2014 ◽  
Vol 64 ◽  
pp. 161-170 ◽  
Author(s):  
Zaki-ul-Zaman Asam ◽  
Mika Nieminen ◽  
Connie O’Driscoll ◽  
Mark O’Connor ◽  
Sakari Sarkkola ◽  
...  

1989 ◽  
Vol 121 (6) ◽  
pp. 521-523 ◽  
Author(s):  
A.J. Stock ◽  
R.A. Gorley

The mountain pine beetle, Dendroctonus ponderosae Hopk., causes extensive mortality of lodgepole pine, Pinus contorta var. latifolia Engelm., throughout western North America (Van Sickle 1982). The Prince Rupert Forest Region, in the northwest of British Columbia, initiated an aggressive beetle management program in 1981. Logging of infested stands, and winter felling and burning of individual infested trees are the most common direct control techniques.The “Bristol Lake” infestation developed in the Bulkley Forest District, approximately 55 km northwest of Smithers, B.C., on a steep rocky ridge within the valley of Harold Price Creek. The area contained large volumes of mature lodgepole pine, and control of the infestation was therefore considered critical to the local beetle management plan, but the size (50 ha) and rough topography of the infested area precluded normal direct control measures.


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