Mountain Pine Beetle Infestation Research Articles

Designer Niches Promote Seedling Survival in Forest Restoration: A 7-Year Study of Whitebark Pine (Pinus albicaulis) Seedlings in Waterton Lakes National Park

Designer niches in which environmental variables are controlled are useful in forest restoration to enhance survival of planted tree seedlings. Here, we evaluate particular manipulated habitats, on site variables, and pre-seedling conditions hypothesized to improve the survival rate of whitebark pine (Pinus albicaulis) seedlings out-planted in Waterton Lakes National Park. The tree species is in peril due to blister rust and mountain pine beetle infestations in its range; and is a restoration priority in Waterton Lakes because populations in the park are highly infected with blister rust (up to 90%). At Summit Lake, 21 plots were set up and half of each was terra-torched; 1000 seedlings were planted in clusters of three, under four conditions: on burned areas in burned beargrass mats, in burned areas where beargrass mats were not present, in unburned areas where beargrass was present, and in unburned areas without beargrass. This study reports data for the seventh year after planting, and overall, survival was 53% for individual seedlings and at least one seedling survived in 60.8% of clusters. Planting in burned areas increased cluster survival (by 34.3%, p ˂ 0.0001) and planting near microsites increased cluster survival (by 19.3%, p ˂ 0.0001); the type of microsite did not make a difference. Planting in beargrass mats decreased survival, but not significantly (8.9%, p = 0.11) and this was true for burns, not unburned areas. Inoculation with native ectomycorrhizal fungi did not enhance survival most likely because controls on lightly terra-torched and unburned areas had access to local native fungi. This is the first study to report statistics on the planting of seedlings in clusters; the results need to be compared with studies where seedlings are planted individually.

Single-generation effects on terpenoid defenses in lodgepole pine populations following mountain pine beetle infestation.

The recent mountain pine beetle outbreak in western Canada provides an opportunity to study the selection and heritability of tree defenses. We examined terpenoid-based defenses of seedling lodgepole pines which were offspring of mature trees subjected to high levels of mountain pine beetle selective pressure. Seedlings were grown from one of three types of cones: old cones on live trees; young cones on live trees; and cones on trees killed by beetles. Offspring thus represented crosses of non-surviving (NS) x surviving (S), S x S, and NS x NS parents, respectively. Methyl jasmonate was used to induce a defensive reaction in the seedlings. Seed source had a significant effect on levels of ten different terpenes, but not on total terpene concentrations. When the seedlings were grouped by location and treatment type, the seedlings of different cone types could be almost entirely distinguished by terpene profiles.

Insects emerging from novel species of host trees attacked by mountain pine beetle, Dendroctonus ponderosae Hopkins, 1902 (Coleoptera: Curculionidae: Scolytinae), in the University of Idaho Arboretum

A naturally-occurring infestation of mountain pine beetle, Dendroctonus ponderosae Hopkins, 1902 (Coleoptera: Curculionidae: Scolytinae), in the Shattuck Arboretum on the campus of the University of Idaho, Moscow, was found to be attacking non-native conifers. The arboretum had experienced a prior infestation in similar tree species in the late 1960s (Furniss & Schenk 1969). Infested trees were harvested, and an approximately 0.3-m section of each tree was cut from a height of 10 m on the bole and maintained under laboratory conditions. All insects that emerged from the bolts were collected and identified. In the current infestation, trees successfully attacked by mountain pine beetle included jack pine (Pinus banksiana Lamb.), Austrian pine (P. nigra L.), red pine (P. resinosa Sol. Ex Alton), pitch pine (P. rigida Mill.), eastern white pine (P. strobus L.), Scots pine (P. sylvestris L.), Norway spruce (Picea abies H. Karst.) and white spruce (P. glauca (Moench) Voss). A total of 777 mountain pine beetle were captured as they emerged from the bolts, and emergence densities of the beetle were similar across tree species. Insects from three orders, 15 families and 27 species emerged from the bolts. Species richness of the emerged insect assemblages were similar across tree species. Shortleaf pine had the largest number of emerged species of insects captured, followed by white spruce and eastern white pine.

The Mountain Pine Beetle: A Study of Tourism Businesses’ Perceptions of the Risk of Ecological Disturbances

Recent increases in forest insect activities pose a potential risk to the ecosystem and often have social and economic consequences. In areas dependent on outdoor recreation and tourism, businesses such as parks, accommodations, restaurants, and attractions are central stakeholders in forest management, and it is important for policy makers to craft more effective policies that incorporate business needs. Management agencies understand the need to adapt the standard management strategies to focus on prevention, early detection, and prompt response. Yet, heterogeneity among stakeholders in terms of values, ideologies, capacity, and vested interests, make it difficult to get broad participation in management practices. The present study examines the attitudes and perceptions of tourism and outdoor recreation businesses regarding the mountain pine beetle (MPB, MPB Dendroctonus ponderosae) infestation in the Black Hills Forest, South Dakota, U.S. Despite significant efforts to stymie the infestation, the beetle has changed the forest ecosystem by killing pine trees. The dead trees have not only changed the aesthetic landscape but also have presented a safety hazard and financially impacted local businesses. The Health Belief Model served as a theoretical framework for this study. Data were generated from 417 businesses, such as accommodations, restaurants, convention and visitors bureaus (CVBs), and attractions, using a targeted online survey. While in general, owners and managers of tourism businesses in the Black Hills felt that the MBP had affected their business operations, the study found substantial variation in the range and degree of perceived impacts and potential risks. The use of the Health Belief Model facilitated the understanding of variations in support and participation in combating MPB activities among tourism businesses, with those having greater knowledge of MPB, higher perceived severity, higher self-efficacy, and higher perceived benefits being more likely to engage in the recommended ecological management activities. The level of perception was also influenced by the location of the business with relation to recent MPB outbreaks. The study highlights that in order to increase participation in combating the pine beetle outbreak, policy makers must develop programs that not only improve awareness but also increase stakeholder self-efficacy and the perceived benefits of participation. Management strategies should also be adaptable to a more local context in order to accommodate differences in risk perceptions related to an ecological disturbance. Subscribe to JPRA

Assessing the Impact of a Mountain Pine Beetle Infestation on Stand Structure of Lodgepole Pine Forests in Colorado Using the Forest Inventory and Analysis Annual Forest Inventory

Assessing the Impact of a Mountain Pine Beetle Infestation on Stand Structure of Lodgepole Pine Forests in Colorado Using the Forest Inventory and Analysis Annual Forest Inventory

Innovative wildfire mitigation by municipal governments: Two case studies in Western Canada

Wildfires are an environmental hazard event experienced by communities around the world. Recent wildfires in Canada clearly show that wildfires can have significant and long-lasting effects on the communities that are impacted, which highlights the importance of mitigation. At the community level, municipal governments can play an important role in wildfire mitigation. Partners in Protection, a non-governmental organization in Canada, developed the FireSmart program and manual in 1999 which recommends how homeowners and municipal governments can reduce their wildfire risks. Some municipal governments have been innovative by not only adopting FireSmart recommendations, but by also developing and implementing their own additional measures to reduce wildfire risks.The purpose of this study was to explore how and why two municipal governments in western Canada, Logan Lake and Kamloops in the province of British Columbia, developed and implemented innovative wildfire mitigation measures. Semi-structured interviews were conducted with 21 individuals involved in municipal wildfire mitigation plans and activities in the two municipalities. These two municipal governments were able to overcome funding and public opposition barriers. We found that post-wildfire window of opportunity, mountain pine beetle infestation, public and government support, issue champions, access to resources, and collaboration, helped these two municipal governments to develop and implement their innovative wildfire mitigation measures.

Carbon isotopic composition of forest soil respiration in the decade following bark beetle and stem girdling disturbances in the Rocky Mountains.

Bark beetle outbreaks are widespread in western North American forests, reducing primary productivity and transpiration, leading to forest mortality across large areas and altering ecosystem carbon cycling. Here the carbon isotope composition (δ(13) C) of soil respiration (δJ ) was monitored in the decade after disturbance for forests affected naturally by mountain pine beetle infestation and artificially by stem girdling. The seasonal mean δJ changed along both chronosequences. We found (a) enrichment of δJ relative to controls (<1 ‰) in near-surface soils in the first 2 years after disturbance; (b) depletion (1‰ or no change) during years 3-7; and (c) a second period of enrichment (1-2‰) in years 8-10. Results were consistent with isotopic patterns associated with the gradual death and decomposition of rhizosphere organisms, fine roots, conifer needles and woody roots and debris over the course of a decade after mortality. Finally, δJ was progressively more (13) C-depleted deeper in the soil than near the surface, while the bulk soil followed the well-established pattern of (13) C-enrichment at depth. Overall, differences in δJ between mortality classes (<1‰) and soil depths (<3‰) were smaller than variability within a class or depth over a season (up to 6‰).

Erratum to: Local Perceptions of MPB Infestation, Forest Management, and Connection to National Forests in Colorado and Wyoming

The Mountain Pine Beetle (MPB) infestation in Colorado and Wyoming impacts federal and state forest managers, the recreation and tourism industry, ecosystem services, and the general sustainability of livelihoods in proximity to forested areas. Using qualitative analyses, this paper investigates whether a linkage exists between individuals’ value orientations and their attitudes toward forest management in relation to MPB infestations. Data were obtained in 2011 from three open-ended questions in a mail survey of residents in Colorado and Wyoming. Our qualitative analysis revealed four value orientation types: 1) biocentric, 2) anthropocentric, 3) spiritual/therapeutic, and 4) pluralist. Additionally, respondents were generally supportive of forest management practices and the majority had a “do what you need to save the forest” attitude. A linkage between value orientations toward the national forest and management practices was identified. Research and management implications are discussed.

The economic impact of the mountain pine beetle infestation in British Columbia: provincial estimates from a CGE analysis

The mountain pine beetle (MPB) epidemic in British Columbia (BC) peaked in 2004 and 2005, and by 2012,.53 per cent of the merchantable pine had been attacked. The annual kill has declined steadily since 2005 and is projected to continue to do so. However, given the significant amount of beetle killed wood, the timber supply is expected to fall dramatically in the coming decades. This study estimates the future provincial economic impacts of the MPB infestation in a dynamic computable general equilibrium (CGE) model, by examining the effects of the reduction in timber supply from BC forests over the 2009–2054 period. Results suggest that there will be a cumulative present value loss of $57.37 billion (or 1.34 per cent) in GDP and a $90 billion decline in welfare (compensating variation) from 2009 to 2054 in BC. These estimates emphasize the significance of negative economic impacts that may be in store for the economy in this, and potentially other provinces, and can be used to help policy-makers better understand the net benefits of adaptation options geared towards reducing the spread of such pests.

A trade flow analysis of the global softwood log market: implications of Russian log export tax reduction and New Zealand log production restriction

This study employs a recursive dynamic spatial partial equilibrium model to investigate the trade flow trends in the global softwood log market. A baseline forecast from 2012 to 2021 is first projected and then compared with three alternative scenarios: (1) Russia reduces its ad valorem softwood log export tax to 8 per cent to comply with its World Trade Organization accession agreements; (2) New Zealand experiences no expansion at all of its plantation forest log production due to social and environmental considerations (i.e. increased Maori ownership of forest land and the implementation of emissions trading schemes); and (3) a combination of the proposed policies in Russia and New Zealand mentioned above. The results of the baseline projection demonstrate that softwood log prices will increase in every region globally and that China will continue to be the world’s largest softwood log importer. However, softwood log exports from Russia, the US and Canada are expected to drop significantly as a result of current Russian export restrictions, the recovery of the US housing market and mountain pine beetle infestations in western Canada. A comparison of the simulated scenarios with the baseline projection reveals that reducing the Russian softwood log export tax will have a greater impact on softwood log prices and total world trade than restricting log production in New Zealand due to the comparatively large log production capacity in Russia. In any scenario, significant trade flow changes (i.e. trade-offs) in response to the proposed policy changes are observed in China and the major export regions. The results of this study offer insights for forest managers and policy makers to examine the global impacts of potential changes in trade policies and supply constraints in these two important softwood log supply regions in addition to highlighting China’s role in the world softwood log market.

Does soil respiration decline following bark beetle induced forest mortality? Evidence from a lodgepole pine forest

Lodgepole pine (Pinus contorta var. latifolia) forests across western North America have been undergoing a major mortality event owing to a mountain pine beetle (Dendroctonus ponderosae) infestation. We studied biotic and abiotic drivers of growing season soil respiration in four mature stands experiencing different levels of mortality between 2008 and 2012 in southeastern Wyoming, USA. Bark beetle infestation significantly altered forest structure during the 5-year study period. Live basal area (LBA) declined and mortality ranged from near zero to more than 80% in stands with the lowest and highest mortality, respectively. LBA explained 66% of the spatial variation in peak growing season soil respiration, which ranged from 1.4±0.1μmolm−2s−1 in stands with lowest LBA to 3.1±0.2μmolm−2s−1 with highest LBA. However, within stands, soil respiration did not change over the five-year study period, likely because pre-infestation LBA governed ecosystem-level differences. During peak growing season, soil respiration was significantly correlated with fine root biomass and mid-day photosynthetic photon flux density, providing strong evidence that autotrophic respiration dominated the forest soil respiration flux. Each factor predicted from 35% to 55% of seasonal soil respiration variability with the highest correlation coefficients in stands with the lowest mortality. However, we did not observe significant changes in the peak growing season soil respiration over time within stands undergoing beetle infestation, suggesting that remaining soil respiration activity in dead stands may be attributed to heterotrophic activity and surviving vegetation. Ecosystem modeling often does not adequately represent complex changes in stand structure following beetle infestation, but these dynamic processes should be included to better predict disturbance effects on carbon (C) cycling.

Apparent foraging success reflects habitat quality in an irruptive species, the Black-backed Woodpecker

ABSTRACT Dramatic fluctuations in food resources are a key feature of many habitats, and many species have evolved a movement strategy to exploit food resources that are unpredictable in space and time. The availability of food resources may be a particularly strong determinant of habitat quality for irruptive bird species. We studied the apparent foraging success of Black-backed Woodpeckers (Picoides arcticus), an irruptive species that responds opportunistically to pulsed food resources in burned forests and mountain pine beetle (MPB) infestations. Prior investigations revealed that the highest population growth rates of Black-backed Woodpeckers occurred in habitat created by summer wildfire, with intermediate population growth rates in MPB infestations, and the lowest population growth rates in habitats created by prescribed fire in fall. We tested whether apparent foraging success was associated with known habitat quality in order to assess the potential for food availability to regulate population gr...

Assessing Functional Role and Community Dynamics of Whitebark Pine at Alpine Treeline, Grand Teton National Park

Whitebark pine (Pinus albicaulis) is a keystone and foundation tree species in high elevation ecosystems of the Rocky Mountains. At alpine treelines along the eastern Rocky Mountain Front and in the Greater Yellowstone Ecosystem, whitebark pine often initiates tree islands through facilitation, thereby shaping vegetation pattern. This role will likely diminish if whitebark pine succumbs to white pine blister rust infection, climate change stress, and mountain pine beetle infestations. Here, we established baseline measurements of whitebark pine’s importance and blister infection rates at two alpine treelines in Grand Teton National Park. Our specific objectives were to: 1) examine the potential relationship between whitebark pine establishment and krummholz tree island formation at the upper alpine treeline ecotone in GTNP; 2) characterize blister rust infection rate and intensity at two treeline study areas and in whitebark pine growing both solitarily and within tree islands; and 3) characterize the biophysical environments a) where whitebark pine is/is not a majority tree island initiator, and b) with varying blister rust infection rates in treeline whitebark pine. In July 2015, we field-sampled treeline composition and blister rust infection in all krummholz whitebark pine in a total of 40 study plots. Preliminary results reveal: 1) that whitebark pine is a substantial component of treeline ecosystems, but is not a significant majority tree island initiator, and 2) blister rust infection levels for both study areas combined is 15.65%. Blister rust and mountain pine beetle interactions were not evident at the two study areas. This work provides important baseline measurements for understanding how community structure and composition may be altered given infestation by pathogens and pests in GTNP, especially in light of changing climate regimes.

Soil Nitrogen Five Years after Bark Beetle Infestation in Lodgepole Pine Forests

The unprecedented scale of recent mountain pine beetle (Dendroctonus ponderosae, MPB) infestation in lodgepole pine (Pinus contorta ex Loudon var. latifolia Engelm. ex S. Watson) forests of western North America may significantly impact the role of forest soils as important sinks for global C and N. The aim of this study was to explain soil and litter N responses in stands experiencing total mortality during the first 5 yr of MPB outbreak. Four-year monitoring (2009–2012) of needlefall deposition, soil water-filled pore space (WFPS), NH₄, NO₃, potentially mineralizable N (PMN), dissolved organic N (DON), N₂O, and CH₄ was established in Medicine Bow National Forest in stands of different infestation histories (infested in 2007, 2008, and uninfested). Results suggest that total stand mortality demonstrated strong temporal dynamics. First-year soil responses included increases in PMN and were followed by WFPS and NH₄ increases in the second year, NO₃ increase in the third year, and DON increase in in the fourth year of the infestation. Litter NH₄ increased within 1 yr, but litter PMN, NO₃, and DON increased 3 yr after the infestation, suggesting enhanced litter decomposability. Soil N₂O and CH₄ fluxes also started to increase 4 yr after the infestation. These changes were indicative of ongoing disequilibrium for the period of at least 5 yr after MPB infestation. The magnitude of N mineralization and N₂O and CH₄ fluxes may continue to increase beyond the initial 5 yr of monitoring because litter-derived labile N will probably contribute to the second pulse of N mineralization.

The competitiveness of Canadian softwood lumber: a disaggregated trade-flow analysis

A recursive dynamic spatial equilibrium model is used to examine the global competitiveness of Canadian softwood lumber. To address the restrictive assumption of softwood lumber homogeneity, this study disaggregates softwood lumber into two product groups: (i) higher grade lumber that includes appearance, select structural-grade lumber, and Japanese J-grade lumber; and (ii) lower grade lumber that includes the United States dimension lumber that is commonly used in construction and utility- and economy-grade lumber. Factors that may affect global softwood lumber markets are simulated in the model to project global softwood lumber trade flows from 2012 to 2021. The results indicate that the reduced lumber supply in western Canada caused by the mountain pine beetle (Dendroctonus ponderosae Hopkins) infestation combined with demand increases in several regions of the world will contribute to a global increase in softwood lumber prices. Our results suggest that the global price increase will be greater for lower grade softwood lumber than for higher grade lumber. The United States and China will continue to be the top two markets for lower grade Canadian softwood lumber. Although Canadian exports of lower grade softwood lumber to the United States are expected to increase marginally over time in response to the recovery of American housing starts, softwood lumber exports to China are expected to drop significantly, and it is forecasted that exports from the Russian Federation will fill that void. These findings provide strong market signals for both forest managers and the forest-products industry to assess supply chain profitability and adjust production planning accordingly.

Correction: The Role of Wildfire, Prescribed Fire, and Mountain Pine Beetle Infestations on the Population Dynamics of Black-Backed Woodpeckers in the Black Hills, South Dakota

Correction: The Role of Wildfire, Prescribed Fire, and Mountain Pine Beetle Infestations on the Population Dynamics of Black-Backed Woodpeckers in the Black Hills, South Dakota

Metal fate and partitioning in soils under bark beetle-killed trees

Recent mountain pine beetle infestation in the Rocky Mountains of North America has killed an unprecedented acreage of pine forest, creating an opportunity to observe an active re-equilibration in response to widespread land cover perturbation. This work investigates metal mobility in beetle-impacted forests using parallel rainwater and acid leaches to estimate solid–liquid partitioning coefficients and a complete sequential extraction procedure to determine how metals are fractionated in soils under trees experiencing different phases of mortality. Geochemical model simulations analyzed in consideration with experimental data provide additional insight into the mechanisms controlling metal complexation. Metal and base-cation mobility consistently increased in soils under beetle-attacked trees relative to soil under healthy trees. Mobility increases were more pronounced on south facing slopes and more strongly correlated to pH under attacked trees than under healthy trees. Similarly, soil moisture was significantly higher under dead trees, related to the loss of transpiration and interception. Zinc and cadmium content increased in soils under dead trees relative to living trees. Cadmium increases occurred predominantly in the exchangeable fraction, indicating increased mobilization potential. Relative increases of zinc were greatest in the organic fraction, the only fraction where increases in copper were observed. Model results reveal that increased organic complexation, not changes in pH or base cation concentrations, can explain the observed differences in metal partitioning for zinc, nickel, cadmium, and copper. Predicted concentrations would be unlikely to impair human health or plant growth at these sites; however, higher exchangeable metals under beetle-killed trees relative to healthy trees suggest a possible decline in riverine ecosystem health and water quality in areas already approaching criteria limits and drinking water standards. Impairment of water quality in important headwater streams from the increased potential for metal mobilization and storage will continue to change as beetle-killed trees decompose and forests begin to recover.

MPB Critical Forest Inventory

The Mountain Pine Beetle epidemic in Alberta has been substantial, with several forest products companies facing a potential decrease in fibre supply as a result. Accurate forest inventory is integral in developing management strategies that effectively address the infestation. Within this context, forest inventory must provide enough species composition detail to allow the design of appropriate harvesting activities. The project evaluated the use of softcopy photo-interpretation and a semi-automated inventory approach to create a forest inventory with a higher level of detail, and looked to advance these methodologies to explore whether metrics such as tree height and volume could also be included. The project also aimed to demonstrate the benefits that such an inventory could provide in growth and yield analysis and within the general framework of integrated land management. Results indicate that the more detailed inventory is useful in addressing forest management challenges associated with the Mountain Pine Beetle infestation and in improving growth and yield analysis, resulting in an overall enhancement to strategic and operational planning. The inventory can also be used for integrated land management, allowing for species composition to be spatially identified within the stand and the identification of other features including anthropogenic disturbance and microsites.

Cultural Practices for Prevention and Mitigation of Mountain Pine Beetle Infestations

In recent years, the mountain pine beetle, Dendroctonus ponderosae Hopkins, has impacted >8.9 million hectares of forests in the western United States. During endemic populations, trees weakened by other agents are often colonized by D. ponderosae but may be difficult to detect due to their scarcity. Once populations reach incipient levels, tree defenses are often insufficient in deterring mass attacks, and populations rapidly increase causing substantial levels of tree mortality under certain circumstances. There are two general approaches for reducing the negative impacts of D. ponderosae on forests. Direct control involves short-term tactics designed to address current infestations by manipulating beetle populations and includes the use of fire, insecticides, semiochemicals, sanitation harvests, or combinations of these treatments. Indirect control is preventive and designed to reduce the probability and severity of future infestations by manipulating stand, forest and/or landscape conditions by reducing the number of susceptible host trees through thinning, prescribed burning, and/or alterations of age classes and species composition. We review tree, stand, and landscape factors associated with D. ponderosae infestations and analyze the effectiveness of treatments for preventing and mitigating undesirable levels of tree mortality. We describe the current state of our knowledge and identify gaps for making informed management decisions.

The role of wildfire, prescribed fire, and mountain pine beetle infestations on the population dynamics of black-backed woodpeckers in the black hills, South Dakota.

Wildfire and mountain pine beetle infestations are naturally occurring disturbances in western North American forests. Black-backed woodpeckers (Picoides arcticus) are emblematic of the role these disturbances play in creating wildlife habitat, since they are strongly associated with recently-killed forests. However, management practices aimed at reducing the economic impact of natural disturbances can result in habitat loss for this species. Although black-backed woodpeckers occupy habitats created by wildfire, prescribed fire, and mountain pine beetle infestations, the relative value of these habitats remains unknown. We studied habitat-specific adult and juvenile survival probabilities and reproductive rates between April 2008 and August 2012 in the Black Hills, South Dakota. We estimated habitat-specific adult and juvenile survival probability with Bayesian multi-state models and habitat-specific reproductive success with Bayesian nest survival models. We calculated asymptotic population growth rates from estimated demographic rates with matrix projection models. Adult and juvenile survival and nest success were highest in habitat created by summer wildfire, intermediate in MPB infestations, and lowest in habitat created by fall prescribed fire. Mean posterior distributions of population growth rates indicated growing populations in habitat created by summer wildfire and declining populations in fall prescribed fire and mountain pine beetle infestations. Our finding that population growth rates were positive only in habitat created by summer wildfire underscores the need to maintain early post-wildfire habitat across the landscape. The lower growth rates in fall prescribed fire and MPB infestations may be attributed to differences in predator communities and food resources relative to summer wildfire.