Partial cutting lodgepole pine stands to reduce losses to the mountain pine beetle

1987 ◽  
Vol 17 (10) ◽  
pp. 1234-1239 ◽  
Author(s):  
Mark D. McGregor ◽  
Gene D. Amman ◽  
Richard F. Schmitz ◽  
Robert D. Oakes

Partial cutting prescriptions were applied in the fall of 1978 through the early winter of 1980 to lodgepole pine stands (Pinuscontorta Douglas var. latifolia Engelmann) threatened by mountain pine beetle (Dendroctonusponderosae Hopkins) in the Kootenai and Lolo National Forests in western Montana, U.S.A. Partial cutting prescriptions consisted of removing from separate stands all trees 17.8, 25,4, and 30.5 cm and larger diameter at breast height (dbh), and prescriptions leaving 18.4, 23.0, and 27.6 m2 basal area per hectare. In thinned stands, the first 5 years' results following cutting showed greatly reduced tree losses to mountain pine beetle when compared with untreated stands (P < 0.01) on both forests. There were no significant differences in tree losses among partial cut treatments (P > 0.05). Post treatment mortality of lodgepole pine 12.7 cm and larger dbh to mountain pine beetle averaged 4.0 to 38.6% on the Kootenai and 6.0 to 17.1% on the Lolo in treated stands, compared with averages of 93.8 and 73.1% in untreated stands. Partial cutting appears to be useful for reducing lodgepole losses to mountain pine beetle.

1988 ◽  
Vol 18 (6) ◽  
pp. 688-695 ◽  
Author(s):  
Gene D. Amman ◽  
Mark D. McGregor ◽  
Richard F. Schmitz ◽  
Robert D. Oakes

Thinning stands of lodgepole pine (Pinuscontorta Douglas var. latifolia Engelmann) is thought to increase vigor and thereby reduce susceptibility to mountain pine beetle (Dendroctonusponderosae Hopkins). Partial cut stands of lodgepole in the Kootenai and Lolo National forests, Montana, U.S.A., provided opportunity (i) to determine growth response of 76- to 102-year-old lodgepole pines following thinning and (ii) to test the hypothesis that vigor of residual trees infested and uninfested by beetles does not differ. Lodgepole pine stands receiving different partial cutting prescriptions were sampled. Characteristics measured for trees within the sample were diameter at breast height, grams of stem wood per square metre of foliage, periodic growth ratio, and leaf area. Trees in most treatments showed decreased growth the 1st year following thinning. The 1st year was followed by increased growth during the next 4 years. Of the tree characteristics measured, only dbh was significantly different on both forests between live trees and trees killed by the mountain pine beetle; the latter were larger (P < 0.001). The low amount of mountain pine beetle infestation in all stands in the presence of poor growth response and vigor of residual trees suggests that factors other than tree vigor will regulate mountain pine beetle infestations in recently thinned lodgepole pine stands. We hypothesize change in stand microclimate is the principal factor.


Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 536 ◽  
Author(s):  
Kristen Pelz ◽  
Charles Rhoades ◽  
Robert Hubbard ◽  
Frederick Smith

The severity of lodgepole pine mortality from mountain pine beetle outbreaks varies with host tree diameter, density, and other structural characteristics, influencing subcanopy conditions and tree regeneration. We measured density and leader growth of shade-intolerant lodgepole pine, shade-tolerant Engelmann spruce, and very shade-tolerant subalpine fir regeneration beneath stands that experienced moderate and high overstory lodgepole pine mortality (average 40% and 85% of total basal area) a decade earlier. Lodgepole comprised >90% of the overstory basal area and mature spruce and fir were present in both mortality levels, though live basal area and disturbance history differed. Post-beetle outbreak recruitment was high in both mortality levels, but there were more lodgepole in high than moderate mortality plots (1140 stems ha−1 vs. 60 stems ha−1) and more subalpine fir in moderate than high mortality plots (4690 stems ha−1 vs. 2870 stems ha−1). Pine advance regeneration, established prior to outbreak, was more dense in high mortality than moderate mortality sites (930 stems ha−1 vs. 310 stems ha−1), but the trend was generally the opposite for the other conifers. Lodgepole recruitment increased and subalpine fir decreased with greater forest floor light availability. All species grew faster in high mortality areas than their counterparts in moderate mortality areas. However, in high mortality areas pine grew faster than the more shade tolerant species, and in moderate mortality areas spruce and fir grew faster than pine. These species-specific responses to the degree of overstory mortality will influence future stand composition and rate of forest recovery after mountain pine beetle outbreaks.


2020 ◽  
Vol 472 ◽  
pp. 118257
Author(s):  
Jennifer G. Klutsch ◽  
Gail Classens ◽  
Caroline Whitehouse ◽  
James F. Cahill ◽  
Nadir Erbilgin

1989 ◽  
Vol 19 (1) ◽  
pp. 65-68 ◽  
Author(s):  
B. S. Lindgren ◽  
J. H. Borden ◽  
G. H. Cushon ◽  
L. J. Chong ◽  
C. J. Higgins

The effect of the aggregation-inhibiting pheromone verbenone on mountain pine beetle attacks in lodgepole pine stands was assessed by affixing verbenone release devices on trees on a 10 × 10 m grid. In one experiment, aggregation to trees baited with an attractive combination of trans-verbenol, exo-brevicomin, and myrcene was reduced in verbenone-treated blocks compared with control blocks (attractive baits only). The mean number of trees with mass attacks (≥31.3 attacks/m2), mean percentage of available trees mass attacked, and mean total number of trees infested were reduced by 74.3, 66.7, and 58.5%, respectively. The ratio of 1987 attacks to 1986 attacks was reduced from 14.0 to 2.6. In a second experiment, using no attractive baits, verbenone caused similar but nonsignificant reductions. The mean number of trees with mass attacks, mean percentage of available trees mass attacked, and mean total number of trees infested were reduced by 75.2, 53.5, and 62.1%, respectively. The 1987 to 1986 attack ratio was reduced from 13.2 in control blocks to 0.2 in the verbenone-treated blocks, and the percentage of trees that were infested but not mass attacked was significantly increased, from 45.7% in the control blocks to 63.2% in the verbenone-treated blocks. We conclude that verbenone shows promise as a management tool for controlling the mountain pine beetle.


2021 ◽  
Vol 97 (01) ◽  
pp. 65-77
Author(s):  
W. Richard Dempster ◽  
Sharon Meredith

Changes in the structure and dynamics of lodgepole pine stands following the 2006 outbreak of mountain pine beetle in western Alberta were investigated by monitoring attacked permanent sample plots over the following decade and projecting future stand development with locally validated growth models. Results suggest that a wide range in growth and yield of attacked stands is likely, with projected impacts varying from minor and inconsequential modifications to full stand replacement. Severely disturbed stands are unlikely to naturally regenerate to pine. The degree to which timber production is naturally restored in such stands will depend to a large extent on the amount and composition of non-pine advance growth and regeneration. Variation in attack severity and tree species composition will, in the absence of clearcutting following disturbance, result in increased diversity in stand and forest structure. Recommendations are made for scheduling salvage and restoration operations to ameliorate losses in timber supply.


Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 552 ◽  
Author(s):  
Howard Williams ◽  
Sharon Hood ◽  
Christopher Keyes ◽  
Joel Egan ◽  
José Negrón

Mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB) is an aggressive bark beetle that attacks numerous Pinus spp. and causes extensive mortality in lodgepole pine (Pinus contorta Douglas ex Loudon; LPP) forests in the western United States and Canada. We used pre-outbreak LPP attributes, cumulative MPB attack severity, and areal extent of mortality data to identify subwatershed-scale forest attributes associated with severe MPB-caused tree mortality that occurred across the Northern Rockies, USA from 1999–2014. We upscaled stand-level data to the subwatershed scale to allow identification of large LPP areas vulnerable to MPB. The highest mortality occurred in subwatersheds where LPP mean basal area was greater than 11.5 m2 ha−1 and LPP quadratic mean diameter was greater than or equal to 18 cm. A coarse assessment of federally-owned LPP-dominated forestland in the analysis area indicated about 42% could potentially be silviculturally treated. Silvicultural management may be a suitable option for many LPP forests, and our hazard model can be used to identify subwatersheds with LPP attributes associated with high susceptibility to MPB across landscape spatial scales. Identifying highly susceptible subwatersheds can help prioritize general areas for potential treatments, especially where spatially extensive areas of contiguous, highly susceptible LPP occur.


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