scholarly journals Characteristics of forest legacies following two mountain pine beetle outbreaks in British Columbia, Canada

2015 ◽  
Vol 45 (10) ◽  
pp. 1387-1396 ◽  
Author(s):  
René I. Alfaro ◽  
Lara van Akker ◽  
Brad Hawkes
Keyword(s):  
British Columbia ◽  
North America ◽  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Management Actions ◽  
Mountain Pine ◽  
Pine Beetle

The mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera, Curculionidae), a native insect of North America, periodically reaches population sizes that cause serious economic impact to the forest industry in western North America. The most recent outbreak in British Columbia (BC), Canada, which began in the late 1990s, is only now (2015) abating, after causing unprecedented tree mortality in lodgepole pine (Pinus contorta Douglas ex. Loudon) forests. In this paper, we make use of permanent research plots to report on the condition of lodgepole pine forests in the Chilcotin Plateau of central BC, which underwent two fully documented mountain pine beetle outbreaks. In this region, the first outbreak started in the late 1970s and lasted until the mid-1980s; the second outbreak began in the early 2000s and ended in 2010. We measured the impacts of these outbreaks in terms of tree mortality and describe the characteristics of the legacies that remain following these outbreaks, including survivors in various canopy layers and levels of existing and new regeneration. We provide evidence in support of the existence of postdisturbance legacies that classify into five distinct stand structure types. Abundant regeneration and surviving intermediate canopy layers in most stands indicate that management actions to restock pine stands in this area will not likely be necessary. The information provided by this study is important for estimating future forest development and timber supply and for forest planning and management.

Forest structure altered by mountain pine beetle outbreaks affects subsequent attack in a Wyoming lodgepole pine forest, USA

2011 ◽  
Vol 41 (12) ◽  
pp. 2403-2412 ◽  
Author(s):  
Daniel M. Kashian ◽  
Rebecca M. Jackson ◽  
Heather D. Lyons
Keyword(s):  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Climate Change Scenarios ◽  
Cone Production ◽  
Mountain Pine ◽  
Large Trees ◽  
Pine Beetle ◽  
The 1960S

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.

Entomocorticium dendroctoni gen. et sp. nov. (Basidiomycotina), a possible nutritional symbiote of the mountain pine beetle in lodgepole pine in British Columbia

1987 ◽  
Vol 65 (1) ◽  
pp. 95-102 ◽  
Author(s):  
H. S. Whitney ◽  
R. J. Bandoni ◽  
F. Oberwinkler
Keyword(s):  
British Columbia ◽  
Bark Beetle ◽  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Pine Bark ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Blue Stain Fungi ◽  
Blue Stain

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.

scholarly journals Subwatershed-Level Lodgepole Pine Attributes Associated with a Mountain Pine Beetle Outbreak

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 552 ◽  
Author(s):  
Howard Williams ◽  
Sharon Hood ◽  
Christopher Keyes ◽  
Joel Egan ◽  
José Negrón
Keyword(s):  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
Lodgepole Pine ◽  
Spatial Scales ◽  
Basal Area ◽  
Mortality Data ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Pinus Spp

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.

Susceptibility of lodgepole pine stands to the mountain pine beetle: testing of a rating system

2000 ◽  
Vol 30 (1) ◽  
pp. 44-49 ◽  
Author(s):  
T L Shore ◽  
L Safranyik ◽  
J P Lemieux
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Prediction Interval ◽  
Lodgepole Pine ◽  
Basal Area ◽  
Data Set ◽  
Mountain Pine ◽  
Forest Region ◽  
Pine Beetle

A system for rating the susceptibility of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) stands to the mountain pine beetle (Dendroctonus ponderosae Hopkins) was field tested in 38 stands in the Cariboo forest region of British Columbia in a retrospective study. A linear relationship was defined between the percentage of basal area killed by the mountain pine beetle and the susceptibility indices for the sample stands. The system was further tested using an independent data set of 41 stands from across southern British Columbia. Forty of the 41 stands fell within the 95% prediction interval of the original model data for stand susceptibility. This study provides validation for a susceptibility rating model described in 1992. The regression model and associated confidence interval also provide a useful tool for landscape level loss predictions due to the mountain pine beetle.

Changes in stand structure in uneven-aged lodgepole pine stands impacted by mountain pine beetle epidemics and fires in central British Columbia

2010 ◽  
Vol 86 (1) ◽  
pp. 87-99 ◽  
Author(s):  
Jodi N. Axelson ◽  
René I. Alfaro ◽  
Brad C. Hawkes
Keyword(s):  
British Columbia ◽  
Mountain Pine Beetle ◽  
Stand Structure ◽  
Fire Regime ◽  
Lodgepole Pine ◽  
Measurement Data ◽  
Douglas Fir ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Pine Stands

We examined the development of lodgepole pine (Pinus contorta Dougl.) in uneven-aged stands in the Interior Douglasfir (IDF) biogeoclimatic zone of central of British Columbia (B.C.), which are currently undergoing a massive outbreak of the mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB). Using historical ecological approaches, dendrochronology, and stand measurement data, we determined the roles MPB and fire disturbances have played in the ecological processes of lodgepole pine in an Interior Douglas-fir zone. We found that multiple mixed-severity fires created patchy uneven-aged stands dominated by lodgepole pine. Since fire suppression in the 20th century, multiple MPB disturbances have maintained the structural complexity of the stands and favoured regeneration of lodgepole pine in the understory despite the absence of fire, resulting in self-perpetuating multi-age lodgepole pine stands. Analysis of the stand structures remaining after multiple MPB outbreaks showed that, even with high overstory mortality, the sample stands contained several MPB-initiated cohorts, consisting of younger and smaller-diameter lodgepole pine. These surviving lodgepole pine layers, which are less susceptible to beetle, will provide important ecological legacies, and could play an important role in the mid-term timber supply chain. We concluded that, in the absence of fire, the MPB plays a more frequent role in directing stand dynamics and structure in uneven-aged lodgepole pine stands resulting in selfperpetuating complex stands in the central interior. We compared and contrasted these findings with those obtained in “even-aged” lodgepole pine stands, also in the Interior Douglas-fir zone in the southern interior, which were investigated in an earlier study. Key words: lodgepole pine, mountain pine beetle, dendroecology, complex stands, mixed-severity fire regime

scholarly journals Effects of Stand Structure, Browsing, and Biophysical Conditions on Regeneration Following Mountain Pine Beetle in Mixed Lodgepole Pine and Aspen Forests of the Southern Rockies

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 525
Author(s):  
Kristen Pelz ◽  
Frederick Smith
Keyword(s):  
Populus Tremuloides ◽  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Basal Area ◽  
Animal Damage ◽  
Mountain Pine ◽  
Pine Regeneration ◽  
Pine Beetle

Aspen (Populus tremuloides) and lodgepole pine (Pinus contorta var. latifolia) co-occur in the southern Rocky Mountains (USA), where mountain pine beetle (MPB, Dendroctonus ponderosae) has caused extensive lodgepole pine mortality since the late 1990s. Both species excel in post-disturbance high-light environments, but lodgepole pine has generally been thought to establish poorly on undisturbed seedbeds, and aspen suckering may be inhibited by intact aspen overstory. We ask whether lodgepole pine and aspen will regenerate in sufficient quantities to revegetate these forests. We visited a random sample of aspen and lodgepole pine stands across the affected landscape in northern Colorado and southern Wyoming to measure regeneration and overstory mortality. Lodgepole pine regeneration is occurring in 85% of stands, and most stands have >550 stems ha−1. The median aspen sucker density was 6175 stems ha−1. Surprisingly, neither lodgepole pine nor aspen regeneration density was related to overstory mortality level. Animal damage is currently affecting aspen in these forests. Over 50% of stands had damage to 60% or more of their suckers, but 30% of stands had <20% of their stems damaged. Browsed stems were significantly shorter for their ages and were shorter than the 2.5-m height threshold for possible elk browsing. However, the results suggest that sufficient quantities of down lodgepole pine may protect aspen from damage and allow aspen to successfully recruit to the overstory. Multiple regression analysis showed that down lodgepole pine basal area, followed by browsing pressure, were the most important predictors of sucker height and the proportion of suckers browsed. Although 15% of stands had no lodgepole pine regeneration, aspen and lodgepole pine forests are generally regenerating despite animal browsing on aspen. This study is the first to present a regional perspective on regeneration in MPB-affected lodgepole pine and aspen forests, and overall, intervention does not seem necessary to ensure a mix of both species in the future.

Wildfire’s resistance to control in mountain pine beetle-attacked lodgepole pine forests

2013 ◽  
Vol 89 (06) ◽  
pp. 783-794 ◽  
Author(s):  
Wesley G. Page ◽  
Martin E. Alexander ◽  
Michael J. Jenkins
Keyword(s):  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
Lodgepole Pine ◽  
Wildland Fire ◽  
Fire Suppression ◽  
Pine Forests ◽  
Fire Behaviour ◽  
Mountain Pine ◽  
Pine Beetle

Concerns about the impacts of mountain pine beetle (Dendroctonus ponderosae Hopkins)-caused tree mortality on wildfire potential in lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) forests have to date largely focused on the potential for extreme fire behaviour, including the development and spread of crown fires. Given that the wildland fire environment in which fire managers and firefighters work is composed of many interacting physical and human factors, viewing crown fire behaviour as the only or even the most important outcome of the tree mortality associated with a mountain pine beetle outbreak is questionable. Proper assessment of wildfire potential entails a broader approach, which requires expanding the concept of wildfire resistance to control to include an analysis of all relevant factors and their interactions. In this paper we describe a holistic concept of analyzing the impacts of mountain pine beetle-caused tree mortality on wildfire potential in lodgepole pine forests on the basis of fire behaviour characteristics, fire suppression operations, and firefighter safety considerations within the framework of three recognizable stages of the approximate time since the initiation of an outbreak (i.e., “red” ∼1 to 5 years, “gray” ∼5 to 15 years, and post-epidemic ∼15+ years).

Differences in the constitutive terpene profile of lodgepole pine across a geographical range in British Columbia, and correlation with historical attack by mountain pine beetle

2010 ◽  
Vol 142 (6) ◽  
pp. 557-573 ◽  
Author(s):  
Erin L. Clark ◽  
Allan L. Carroll ◽  
Dezene P.W. Huber
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Insect Pest ◽  
Differential Resistance ◽  
Mountain Pine ◽  
Tree Survival ◽  
Pine Beetle ◽  
Lodgepole Pines

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.

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