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1
Addison, Audrey L. "Beetles, Fungi and Trees: A Story for the Ages? Modeling and Projecting the Multipartite Symbiosis Between the Mountain Pine Beetle, Dendroctonus ponderosae, and Its Fungal Symbionts, Grosmannia clavigera and Ophiostoma montium." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/2302.
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As data collection and modeling improve, ecologists increasingly discover that interspecies dynamics greatly affect the success of individual species. Models accounting for the dynamics of multiple species are becoming more important. In this work, we explore the relationship between mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins) and two mutualistic fungi, Grosmannia clavigera and Ophiostoma montium. These species are involved in a multipartite symbiosis, critical to the survival of MPB, in which each species benefits. Extensive phenological modeling has been done to determine how temperature affects the timing of life events and cold-weather mortality of MPB. The fungi have also been closely studied to determine how they interact with MPB and how they differ in terms of virulence, response to temperature, and nutritional benefits to developing beetles. Overall, researchers consider G. clavigera to be the superior mutualist. Beetles developing near G. clavigera are larger, produce more brood, and have higher survival rates. Regarding temperature preferences, G. clavigera is considered “cool-loving,” growing at cooler temperatures than O. montium. These findings lead researchers to wonder 1) why has G. clavigera not displaced iv O. montium from the mutualism (if it is the superior mutualist) and 2) what will happen to the MPB-fungus mutualism in the face of a warming climate. In this work we present two models connecting fungal growth in a tree to predictions of MPB emergence: a stochastic, individual-based model and a deterministic, tree-based model. We begin by exploring whether variability in temperature can act as a stabilizing mechanism and find that temperature variability due to MPB periodically transitioning between different thermal environments is the most likely explanation for the continued presence of both fungi in the mutualism. Using the second model, we parameterize and validate the model using attack and emergence observations of MPB and the fungi they are carrying. In the process, we test several submodels to learn more about specific MPB-fungi interactions. Finally, utilizing information from previous fungal growth experiments, we test and parameterize several growth rate curves using Bayesian techniques to determine whether the inclusion of prior knowledge can lead to more realistic fits.
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Oneil, Elaine E. "Developing stand density thresholds to address mountain pine beetle susceptibility in eastern Washington forests /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/5536.
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Mosher, Brittany Ann. "Avian community response to a mountain pine beetle epidemic." Thesis, Montana State University, 2011. http://etd.lib.montana.edu/etd/2011/mosher/MosherB1211.pdf.
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Recent epidemics of mountain pine beetles (Dendroctonus ponderosae) will fundamentally alter forests of the Intermountain West, impacting management decisions related to fire, logging, and wildlife conservation. We evaluated effects of a recent mountain pine beetle epidemic on site occupancy dynamics of 49 avian and one mammal species in forests dominated by ponderosa pine (Pinus ponderosa) on the Helena National Forest, Montana. Point count data were collected during the avian breeding seasons (May-July) of 2003-06 (pre-epidemic) and again during 2009-10 (during epidemic). We used a Bayesian hierarchical model that accounts for detection probability to obtain occupancy estimates for rare species as well as common ones. We used one model to investigate changes occupancy for all species with respect to the timing of the beetle outbreak and then used a second model to determine whether the relationships seen were associated to changes in snag density. Results show that 30% of species exhibited strong short-term associations between occupancy probability and the occurrence of the beetle epidemic and 12% of species exhibited strong short-term associations between occupancy probability and snag density. Predictions were partially met, as we saw short-term increases in occupancy probability for beetle-foraging species, decreases for some foliage-gleaning canopy insectivores, and intermediate amounts of change for many ground and shrub insectivores. While short-term ecological changes caused by a mountain pine beetle outbreak were associated with changes in occupancy rates for individual species, the overall species richness of native avifauna was unaffected. Though further study over a longer period of time will be necessary to understand the complete dynamics of this disturbance, our results suggest that well-planned salvage operations after beetle outbreaks could also maintain suitable habitat for successfully breeding avian species.
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Strohm, Shaun. "Dispersal of Mountain Pine Beetle and impacts of management." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44798.
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In this thesis, we use a reaction-diffusion equation with chemotaxis to model the interaction between Mountain Pine Beetle (MPB, Dendroctonius ponderosae), Mountain Pine Beetle pheromones, and susceptible trees. The goal is to understand how the movement and attack of MPB is affected by management activities.
We investigate the spatial pattern formation of attack clusters in a system for Mountain Pine Beetle. Mathematical analysis is utilized to discover the spacing between beetle attacks on the susceptible landscape. The model predictions are verified by analyzing aerial detection survey data of Mountain Pine Beetle attack from the Sawtooth National Recreation Area. We find that the distance between Mountain Pine Beetle attack clusters predicted by our model and observed in the Sawtooth National Recreation Area are the same. These results clarify the spatial mechanisms controlling the transition from incipient to epidemic populations and may eventually lead to control measures which protect forests from MPB outbreaks.
Our next avenue of investigation is using an experimental study and theoretical work to help understand the effects of habitat fragmentation on the movement of the MPB. The experimental study consists of trap catch data for MPB in different domains of fragmented habitat. We simulate the experimental system using our mathematical model, testing different hypothesis on initial position of MPB emergence and diffusion speed. Our study provides support for the hypothesis that MPB may move faster in harvested landscapes, and that MPB emerge uniformly over the landscape.
Finally, we use a multi-year spatially explicit model to test the effectiveness of the management strategies of baiting and tree-removal and prescribed burning. We find that baiting and tree-removal is successful at reducing MPB density and forest impact, as long as MPB emergence densities are not too small. We predict that tree removal without baiting can be more successful than combined baiting and tree removal if the searched area has a large density of MPB. Finally, analysis of our model indicates that prescribed burning can be more effective than clearcutting given certain assumptions about the reproductive output and attractiveness of burned trees.
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Gross, Donovan. "Mountain Pine Beetle Fecundity and Offspring Size Differ Among Lodgepole Pine and Whitebark Pine Hosts." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/34.
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Whitebark pine (Pinus albicaulis Engelmann) is a treeline species in the central Rocky Mountains. Its occupation of high elevations previously protected whitebark pine from long-term mountain pine beetle outbreaks. The mountain pine beetle, however, is currently reaching outbreaks of record magnitude in high-elevation whitebark pine. We used a factorial laboratory experiment to compare mountain pine beetle (Dendroctonus ponderosae Hopkins) life history characteristics between a typical host, lodgepole pine (Pinus contorta Engelmann), and whitebark pine. We tested the effects of natal host and brood host on beetle fecundity, offspring size, and brood sex-ratio. We reared mountain pine beetles from whitebark pine and from lodgepole pine, and infested half of them into their natal host and half into the other host. Fecundity was greater overall in lodgepole pine brood hosts. Among lodgepole brood hosts, beetles from whitebark pine had greater fecundity. Fecundity was also significantly related to phloem thickness, which was greater in lodgepole pine. Offspring were larger from whitebark brood hosts than from lodgepole, regardless of their parents’ natal host. Finally, sex-ratio was closer to 1:1 in lodgepole than in whitebark brood hosts. We conclude that host species affects life history of mountain pine beetle with consequences for individual beetle fitness.
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Dean, Diana K. "Host utilization by the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae), in mixed stands of limber pine, Pinus flexilis James, and lodgepole pine, Pinus contorta latifolia Engelmann." Laramie, Wyo. : University of Wyoming, 2007. http://proquest.umi.com/pqdweb?did=1404342031&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Runesson, Ulf Torarind. "Considerations for early remote detection of mountain pine beetle in green-foliaged lodgepole pine." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/31483.
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A general review of the mountain pine beetle (Dendroctonus ponderosae Hopkins) - lodgepole pine (Pinus contorta Dougl.) complex, including previous broad-band remote sensing studies aimed at early detection, is provided. The main emphasis of this thesis is on the utility of waveform analysis, based on in-situ spectroscopy, to successfully differentiate between tree canopies experiencing various degrees of stress. Damage to the tree canopies was both beetle-induced and artificial. In support of the spectroscopy, foliar analysis was performed. In addition, for comparative purposes, large-scale color-infrared photographs were both visually interpreted and measured for dye layer densities. Further, airborne digital broad-band data for the same study site were also acquired and analyzed.
Despite significant differences in pigmentation levels and moisture status, the analysis showed poor detection success with both the densitometry and visual interpretation of the color-infrared photographs. This is in sharp contrast with previous studies and is concluded to be attributed to the natural variation from year to year and from site to site. The analysis of the digital airborne data resulted in equally poor differentiation between healthy and damaged tree canopies.
The main objective of utilizing waveform analysis to take advantage of anticipated pigmentation reductions in stressed trees yielded very positive results. There were significant blue-shifts in the red-edge positions of currently attacked tree
canopies. The data suggest that in a situation where conventional detection means such as those based on photo sensitivity fail, a suitable red-edge threshold can be determined from attacked trees and used to successfully differentiate healthy from currently attacked lodgepole pines.Forestry, Faculty of
Graduate
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Pureswaran, Deepa S. "Dynamics of pheromone production and communication in the mountain pine beetle, Dendroctonus ponderosae Hopkins and the pine engraver, Ips pini (Say) (Coleoptera: Scolytidae)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ51452.pdf.
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Braun, David M. "Host colonization behavior of the mountain pine beetle (Dendroctonus ponderosae Hopkins) in thinned and unthinned stands of second-growth ponderosa pine (Pinus ponderosa Laws.) /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/5482.
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Moreira-Munoz, Simon. "Timber supply and economic impact of mountain pine beetle salvage strategies." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/697.
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To address the scale mountain pine beetle (MPB) outbreak in British Columbia, salvage has become fully integrated with timber supply strategies. The objective of this thesis is to assess the economic impact of different salvage strategies depending on different attack levels, decay rates, and stakeholder discount rates. The study area is located in N.E. British Columbia where the MPB has not yet reached its peak and where susceptible to attack stands account for 40% of the area. Salvage strategies were modelled with a timber supply model (Woodstock) which uses a linear programming type II optimization approach. Performance of the model was assessed over a range of indicators such as NPV, profit, salvage proportion, species composition, inventory levels, and non-recoverable volume. Sensitivity analyses were conducted on harvest flow, discount rate, and ending inventory. The model was very sensitive to the intensity of attack and less sensitive to the decay level. The high level of attack resulted in large volume losses, mostly as un-salvaged inventory.
Although allowable annual cut (AAC) uplifts have an economic benefit, they do not necessarily maximize the salvage of pine. Non-pine species are an important component of the salvage and these species are also essential for the future timber supply. If the objective is to ensure quality and quantity of the future forest, policies have to complement AAC uplifts by strongly encouraging the salvage of mainly pine-leading stands and management options that minimize the “by-catch” of non-pine species and minimize destruction of advanced regeneration during salvage. However, this has an opportunity cost for the private industry where the objective is to maximize profit. If the salvage strategy focuses on decreasing the impact on cash flows, achieving desirable ending inventory levels, avoiding salvage of stands after shelf-life, and reducing impact on non-attack species, then the current harvest level will likely lead to a mid-term timber supply fall-down. Using the fibre for bioenergy production is an alternative if managing for bioenergy can be integrated into harvest operations. However, unlike mill residues, the bioenergy supply has to fully account for harvest and transportation costs of dead wood to the mill.
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Berheide, Daniel W. "Factors influencing public support for managing the mountain pine beetle epidemic." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42279.
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The mountain pine beetle (MPB) epidemic is the largest recorded outbreak in British Columbia’s history currently covering almost 10 percent of British Columbia’s 9.2 million hectares of forest. The problems it poses are not merely ecological but also social and economic. An evaluation of the public’s perceptions of mountain pine beetle management alternatives provides decision-makers with information needed to reduce conflicts, identify communication priorities, and make balanced decisions concerning the use and recovery of affected areas. A survey was administered to 312 respondents, half in Prince George, a more forest-dependent community, and half in Kelowna, a less forest-dependent one. While this research found considerable public support for increased harvesting, it did not vary by location even though the residents of Prince George, the more forest-dependent community, were more concerned about the economic impact of the MPB than the residents of Kelowna. Concern for the economic impact of the MPB was not associated with support for harvesting. In contrast, the residents of Prince George reported greater knowledge, which was associated with support for harvesting. Finally, holding an ecological modernization viewpoint was not associated with location but it was associated with support for harvesting. Although respondents in the two study areas were concerned with the economic impact of the mountain pine beetle, the driver for supporting increased harvesting appeared to be a belief that human intervention can solve environmental problems. This research demonstrates the value of an examination of the social determinants of public support for strategies for managing natural disturbances in the policy making process.
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Eager, Thomas James. "Investigation of Host Selection by Mountain Pine Beetle (Dendroctonus Ponderosae) Hopk. in Lodgepole Pine (Pinus Contorta) Dougl." DigitalCommons@USU, 1986. https://digitalcommons.usu.edu/etd/7300.
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Lodgepole pines Pinus contorta (Douglas) were treated by girdling to assess the response by an endemic population of mountain pine beetle Dendroctonus ponderosae (Hopkins) (Coleoptera: Scolytidae). Capture in 'sticky traps' indicated that the beetles were attracted while in flight towards the wounded trees. A significant difference in the landing rates of bark beetles between the treated and untreated trees indicated that the beetles were able to distinguish wounded from non-wounded trees while still in flight. Pressure chamber readings demonstrated that water stress developed in the girded trees when compared to the non-girdled trees.
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Anhold, John Albert. "Lodgepole Pine Susceptibility Rating of Mountain Pine Beetle Through the Use of a Density Management Diagram." DigitalCommons@USU, 1986. https://digitalcommons.usu.edu/etd/7263.
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Ninety-four unmanaged lodgepole pine stands were examined to evaluate the relationship between stand density and susceptibility to mountain pine beetle attack. Sample included stands from a broad geographical range in the western United States.
Beetle population trends were not significantly related to variation in stand density as measured by stand density index (SDI). The percentage of trees killed per acre by the mountain pine beetle in stands with greater than eighty percent lodgepole pine did vary significantly with changes in SDI. From these data three SDI zones were identified: 1) stands with SDI's of less than 125 showed low potential for attack, 2) stands between 125 and 250 SDI showed much greater levels of tree mortality, gradually decreasing toward the 250 SDI, 3) tree mortality decreased in stands as density increased beyond the 250 SDI value.
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Bockino, Nancy Karin. "Interactions of white pine blister rust, host species, and mountain pine beetle in whitebark pine ecosystems in the Greater Yellowstone." Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1594498141&sid=3&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Marston, Bryce Kendrick. "Influence of the Mountain Pine Beetle disturbance on large wood dynamics and channel morphology in mountain streams." Diss., Kansas State University, 2017. http://hdl.handle.net/2097/35499.
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Doctor of PhilosophyDepartment of Geography
Charles W. Martin
Disturbance regimes are important determinants of both terrestrial and aquatic ecosystem structure and function. Disturbances may linger in the landscape and lag temporally, influencing stream ecosystem form and function for decades, if not centuries. The recent enhanced Mountain Pine Beetle (MPB) infestation in pine forests of the Rocky Mountain region has resulted in extensive tree mortality, producing the potential for significant increases in carbon supply to stream channels. To better understand MPB impacts on in-stream large wood (LW), a census was conducted in 30 headwater streams within the Medicine Bow National Forest in south-central Wyoming, across the temporal spectrum from early- to late-stage MPB-infestation. A subset of those streams exhibiting mean conditions at each level of infestation was surveyed to determine any significant differences in channel morphology or aquatic ecosystem function. Results indicate that wood loads related to the MPB-infestation significantly increase with time since initial infestation. However, even in late-stage infestation streams, many of the fallen MPB-killed trees are bridging across the channels and have yet to break and ramp down sufficiently enough to enter between the channel margins. Wood loads will continue to increase as more trees fall and bridging pieces decompose, break and then enter the channel. Measurable increases in the amount of LW with time since initial beetle infestation have both positive and negative effects on channel form and function. Although forest MPB-infestation has peaked in the study area, streams are still early on a curve of rapidly increasing wood loads that are beginning to affect streams and have the potential to dramatically increase the carbon base of regional stream ecosystems.
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Duthie, Marnie A. "Evaluation of a neem-based insecticide for control of the mountain pine beetle." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq24124.pdf.
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McManis, Anne Elise. "Phenology of a Southern Population of Mountain Pine Beetle (Dendroctonus ponderosae)." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7006.
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Mountain pine beetle (Dendroctonus ponderosae, Hopkins) is a major disturbance agent in pine ecosystems of western North America. Adaptation to local climates has resulted in primarily univoltine (one generation per year) generation timing across a thermally diverse latitudinal gradient. We hypothesized that this pattern in total development time is shaped by selection for slower developmental rates, altered developmental thresholds, or oviposition rates in southern populations inhabiting warmer climates. To investigate traits responsible for latitudinal differences we measured lifestage-specific development of southern mountain pine beetle eggs, larvae and pupae across a range of temperatures. We also describe and model oviposition of southern US MPB. Using a novel technique that included frequent X-ray imaging, oviposition rate and fecundity were estimated separately and shown to both be significant and independent sources of variation. When compared with previously collected data for a northern MPB population, total oviposition time predicted for southern MPB at a constant 20°C was slightly longer than that of northern MPB, but the delay was too small to account for significant differences between the populations in total development time.
Developmental rate curves for eggs, larvae, and pupae were fit using maximum posterior likelihood estimation with a Bayesian prior to improve fit stability. When compared to previously published data for a northern population (Régnière et al. 2012), observed developmental rates of the southern and northern populations were similar across all studied lifestages at 20 and 25°C, although southern individuals were generally faster at temperature extremes (10 and 27°C). These findings were inconsistent with our hypothesis that southern individuals would have consistently slower rates. Optimal development of southern individuals occurred at higher temperatures, with higher development thresholds, as compared with northern individuals. Our results suggest that evolved traits in the remaining unstudied lifestage, teneral (i.e., pre-emergent) adult, likely influence latitudinal differences in mountain pine beetle generation time.
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Yurk, Brian P. "Modeling the Evolution of Insect Phenology with Particular Reference to Mountain Pine Beetle." DigitalCommons@USU, 2009. https://digitalcommons.usu.edu/etd/385.
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Climate change is likely to disrupt the timing of developmental events (phenology) in insect populations in which development time is largely determined by temperature. Shifting phenology puts insects at risk of being exposed to seasonal weather extremes during sensitive life stages and losing synchrony with biotic resources. Additionally, warming may result in loss of developmental synchronization within a population, making it difficult to find mates or mount mass attacks against well-defended resources at low population densities. It is unknown whether genetic evolution of development time can occur rapidly enough to moderate these effects. The work presented here is largely motivated by the need to understand how mountain pine beetle (MPB) populations will respond to climate change. MPB is an important forest pest from both an economic and ecological perspective, because MPB outbreaks often result in massive timber loss. Recent MPB range expansion and increased outbreak frequency have been linked to warming temperatures. We present a novel approach to modeling the evolution of phenology by allowing the parameters of a phenology model to evolve in response to selection on emergence time and density. We also develop a temperature-dependent phenology model for MPB that accounts for multiple types of developmental variation: variation that persists throughout a life stage, random variation, and variation due to the MPB oviposition mechanism. This model is parameterized using MPB development time data from constant temperature laboratory experiments. We use Laplace's method to approximate steady distributions of the evolution model under stable temperatures. Here the mean phenotype allows for parents and offspring to be oviposited at exactly the same time of year in consecutive generations. These results are verified numerically for both MPB and a two-stage model insect. The evolution model is also applied to investigate the evolution of phenology for MPB and the two-stage model insect under warming temperatures. The model predicts that local populations can only adapt to climate change if development time can adapt so that individuals can complete exactly one generation per year and if the rate of temperature change is moderate.
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Bleiker, Katherine Patricia. "Multi-partner mutualisms interactions among the mountain pine beetle and two ophiostomatoid fungal associates /." CONNECT TO THIS TITLE ONLINE, 2007. http://etd.lib.umt.edu/theses/available/etd-05202008-120358/.
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Grummon, Christine. "Examining the role of collaborative governance in fostering adaptive capacity: A case study from northwest Colorado." Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20516.
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Over the past two decades, the mountain pine beetle (MPB) has killed millions of acres of forest across western North America. In addition to extensive environmental disturbance, the MPB epidemic has deeply impacted human systems, including motivating the formation of novel environmental governance arrangements. In Colorado, the Colorado Bark Beetle Cooperative (CBBC) formed as a collaboration between federal, state, and local stakeholders to address the epidemic. This study used a combination of GIS analysis and qualitative document analysis to understand how the CBBC has been able to respond adaptively to changes in the landscape pattern of MPB damage. I found that the CBBC was able to respond adaptively to changes in the MPB outbreak through shifting their organizational direction and activities. However, the adaptive capacity of the group was constrained by logistical factors, the declining importance of MPB at a national level, and the ways in which the group framed the MPB problem.
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Heavilin, Justin. "The Red Top Model: A Landscape-Scale Integrodifference Equation Model of the Mountain Pine Beetle-Lodgepole Pine Forest Interaction." DigitalCommons@USU, 2007. https://digitalcommons.usu.edu/etd/7137.
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Under normative conditions the mountain pine beetle (Dendroctonus ponderosae Hopkins) has played a regulating role in healthy lodgepole pine (Pinus contorta) forests. However, recently eruptive outbreaks that result from large pine beetle populations have destroyed vast tracts of valuable forest. The outbreaks in North America have received a great deal of attention from both the timber industry and government agencies as well as biologists and ecologists.
In this dissertation we develop a landscape-scaled integrodifference equation model describing the mountain pine beetle and its effect on a lodgepole pine forest. The model is built upon a stage-structured model of a healthy lodgepole pine forest with the addition of beetle pressure in the form of an infected tree class. These infected trees are produced by successful beetle attack, modelled by response functions. Different response functions reflect different probabilities for various densities. This feature of the model allows us to test hypotheses regarding density-dependent beetle attacks.
To capture the spatial aspect of beetle dispersal from infected trees we employ dispersal kernels. These provide a probabilistic model for finding given beetle densities at some distance from infected trees. Just as varied response functions model different attack dynamics, the choice of kernel can model different dispersal behavior. The modular nature of the Red Top Model yields multiple model candidates. These models allow discrimination between broad possibilities at the land scape scale: whether or not beetles are subject to a threshold effect at the lands cape scale and whether or not host selection is random or directed. We fit the model using estimating functions to two distinct types of data: aerial damage survey data and remote sensing imagery. Having constructed multiple models, we introduce a novel model selection methodology for spatial models based on facial recognition technology.
Because the regions and years of aerial damage survey and remote sensing data in the Sawtooth National Recreation Area overlap, we can compare the results from data sets to address the question of whether remote sensing data actually provides insight to the system that coarser scale but less expensive and more readily available aerial damage survey data does not.
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Bentz, Barbara Joan. "Management decision-making tools for mountain pine beetle (Dendroctonus ponderosae) (Coleoptera: Scolytidae) populations in lodgepole pine (Pinus contorta) stands." Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-07282008-135558/.
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Toone, Chelsea. "Influence of Mountain Pine Beetle on Fuels, Foliar Fuel Moisture Content, and Litter and Volatile Terpenes in Whitebark Pine." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/2049.
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Mountain pine beetle (Dendroctonus ponderosae Hopkins) has caused extensive tree mortality in whitebark pine (Pinus albicaulis Engelm) forests. Previous studies conducted in various conifer forests have shown that fine surface fuels are significantly altered during a bark beetle outbreak. Bark beetle activity in conifer stands has also been shown to alter foliar fuel moisture content and chemistry over the course of the bark beetle rotation.The objective of this study was to evaluate changes to fine surface fuels, foliar fuel moisture and chemistry and litter chemistry in and under whitebark pine trees infested by mountain pine beetle. Fuels were measured beneath green (healthy) trees compared to red (two years since initial MPB attack with 50% or greater needles remaining) and gray (greater than two years since attack with between 15% and 45% needles remaining) trees. Foliar moisture content was measured in four mountain pine beetle crown condition classes: green-uninfested, green-infested (current year’s attack), yellow (last year’s attack), and red. Total terpene content was analyzed in whitebark pine needle litter and volatile terpenes were collected and analyzed from green, green-infested, yellow, and red trees.Significant differences were found in litter depths under green, red, and graytrees. Duff depths were significantly less beneath green trees than red and gray trees. One hour and ten hour fuels were more influenced by diameter and crown size than beetle crown condition classes. Foliar fuel moisture content dramatically decreased from green-infested to the red beetle crown condition class. No differences were detected in shrub and forb biomass between green, red, and gray trees. Green-infested trees had significantly lower foliar fuel moisture than green trees and by late in the season showed fuel moisture levels similar to red trees which had the lowest fuel moisture content. Litter beneath red trees contained large amounts of terpenes, including compounds known to increase foliage flammability that remain in the litter throughout the fire season. Total terpene content emitted from red foliage is greater than green-infested or yellow foliage.
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Plattner, Alex. "Pathogenicity and taxonomy of fungi associated with the mountain pine beetle in British Columbia." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/345.
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The mountain pine beetle is associated with a diverse array of fungi. Grosmannia clavigera is the most pathogenic of these fungi. A comparison was made between two methods that have been used to assess fungal pathogenicity. Results were similar for older trees inoculated with G. clavigera using either the alternating flap technique or cork borer method. Using the cork borer method, younger lodgepole pine trees were inoculated with five different isolates of G. clavigera. After a 48 week incubation period, isolates ATCC 18086, B5 and H55 had induced stronger pathogenic indicators compared to isolates KW 1407 and B20. After a 7 week incubation period, only isolate ATCC 18086 had induced stronger pathogenic indicators. Usually, this isolate grew faster at lower temperatures and in a low oxygen environment. Isolate KW 1407 consistently produced milder pathogenic indicators during both incubation periods. Among the non-pathogenic fungal associates of the mountain pine beetle, Ceratocystiopsis minuta may be considered the most important because it is the type species for the genus Ceratocystiopsis. The history of this genus is complicated because no physical specimen exists for C. minuta. The phylogeny of the genus Ceratocystiopsis was evaluated. Many isolates of C. minuta were assessed as potential epitypes. Several isolates of C. minuta from previous work were shown to be misidentified. C. minuta isolate CBS 116796 is recommended for future genetic work within the genus Ceratocystiopsis. For morphological work, using measurements from the literature is recommended since CBS 116796 did not produce fruiting bodies.
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Bleiker, Katherine Patricia. "MULTI-PARTNER MUTUALISMS: INTERACTIONS AMONG THE MOUNTAIN PINE BEETLE AND TWO OPHIOSTOMATOID FUNGAL ASSOCIATES." The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-05202008-120358/.
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I investigated interactions between the mountain pine beetle (Dendroctonus ponderosae) and its two main ophiostomatoid fungal associates,Grosmannia clavigera and Ophiostoma montium, as well as interactions between the two fungi. The main research questions were: What drives bark beetle fungal interactions? What is the nature of the interaction between the two species of fungi? I tested the hypothesis that the fungi provide nutritional benefits to the bark beetles. Evidence suggests a nutritional role of fungi in the diet of bark beetles because beetles emerging from attacked trees carrying G. clavigera were larger than beetles carrying O. montium, which in turn were larger than beetles without either fungus. Larval choice feeding experiments indicate that the two fungi may actually provide complimentary benefits. To address the second question, I tested for competition between the two fungi on artificial media. Growth of each species slowed when it encountered media occupied by the other species, indicating competition; however, both species eventually invaded media occupied by the other species. Although G. clavigera colonized unoccupied media the fastest, O. montium was more effective in colonizing media occupied by G. clavigera when their relative growth rates were considered. In another study, the relative abundances of the two fungi were sampled in beetle-attacked trees in the field over the one year life cycle of the insect. I found no evidence of interference competition, but exploitation competition was prevalent after a year when the fungi co-occurred in the phloem. Finally, I examined whether the two fungi are differentially transported in the mycangia and on the exoskeleton of the beetle using scanning electron microscopy and isolating fungi from the mycangia and elytra. I found no evidence of differential transport of G. clavigera or O. montium in the mycangia and on the exoskeleton from isolation data. There was also no evidence that one fungus was more likely to be transported on the exoskeleton than the other species using electron microscopy. The fungi appear to exist in the mycangium in an altered, yeast or yeast-like state rather than as conidia.
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Farfán, Lina. "Comparative population genetic analysis of fungal associates of the mountain pine beetle (Dendroctonus ponderosae)." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46766.
Full textAbstract:
The mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, has destroyed over 18 million ha of pine forest in Canada since 1999, the largest insect epidemic in recorded history. Fungal symbionts in the Ophiostomales (Ascomycetes) play an important role in the outbreak by reducing the tree defense response following beetle colonization, making its environment more conducive to the insect development. A better understanding of the population genetics attributes of the fungal associates could be important to elucidate their role and to explain epidemic patterns. We investigated the genetic structure of one of those fungal associates, Leptographium longiclavatum, sampled from 28 locations in western North America using 11 microsatellite markers developed from the genome of its closest relative, Grosmannia clavigera, another fungal symbiont of the MPB. We found that L. longiclavatum has a distinctive genetic population structure, and by using Bayesian clustering inference, we discovered the presence of three clusters that are concordant with geographic origin of the samples. In addition, we observed an apparent North-South pattern of genetic diversity consistent with the chronology of the epidemic. Structure output showed one cluster comprised of individuals from Northern Alberta where the beetle-fungus complex has been recently established, and a second cluster composed of individuals originating along the Rocky Mountains, and a third cluster was from populations in BC. High haplotypic diversity was found throughout the range sampled, a surprising result given that sexual fruiting structures have never been observed for this fungus. Consistent with recent introduction history, the least differentiated populations were located in northern BC and Alberta. We observed a strong correlation in the genetic diversity pattern observed in L. longiclavatum, G. clavigera and D. ponderosae, as shown by a significant correlation in the genetic distance matrices amongst L. longiclavatum, G. clavigera, and D. ponderosae. This correlation and the similar north-south population structure of these interacting organisms suggest a joint population history consistent with the dependence of fungal dispersal on their bark beetle vector. These results can help clarify the roles and close relationships between the beetles and their fungal associates.
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Duncan, Jacob P. "A Spatiotemporal Mountain Pine Beetle Outbreak Model Predicting Severity, Cycle Period, and Invasion Speed." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4729.
Full textAbstract:
The mountain pine beetle (MPB, Dendroctonus ponderosae), a tree-killing bark beetle, has historically been part of the normal disturbance regime in lodgepole pine (Pinus contorta) forests. In recent years, warm winters and summers have allowed MPB populations to achieve synchronous emergence and successful attacks, resulting in widespread population outbreaks and resultant tree mortality across western North America. We develop an age-structured forest demographic model that incorporates temperature-dependent MPB infestations: the Susceptible-Infested-Juvenile (SIJ) model. Stability of fixed points is analyzed as a function of population growth rates, and indicates the existence of periodic outbreaks that intensify as growth rates increase. We devise analytical methods to predict outbreak severity and duration as well as outbreak return time.
To assess the vulnerability of natural resources to climate change, we develop a thermally-driven mechanistic model to predict MPB population growth rates using a distributional model of beetle phenology in conjunction with criteria for successful tree colonization. The model uses projected daily minimum and maximum temperatures for the years 2025 to 2085 generated by three separate global climate models. Growth rates are calculated each year for an area defined by latitude range 42° N to 49° N and longitude range 108° W to 117° W on a Cartesian grid of approximately 4km resolution. Using these growth rates, we analyze how the optimal thermal window for beetle development is changing with respect to elevation as a result of climate change induced warming. We also use our combined model to evaluate if thermal regimes exist that would promote life cycle bivoltinism and discuss how yearly growth rates would change as a result.
Outbreaks of MPB are largely driven by host tree stand demographics and spatial effects of beetle dispersal. We augment the SIJ model to account for the spatial effects of MPB dispersal throughout a forest landscape by coupling it with a Gaussian redistribution kernel. The new model generates a train of sustained solitary waves of infestation that move through a forest with constant speed. We convert the resulting integrodifference equation into a partial differential equation and search for travelling wave solutions. The resulting differential equation provides predictions of the shape of an outbreak wave profile and of peak infestation as functions of wave speed, which can be calculated analytically. These results culminate in the derivation of an explicit formula for predicting the severity of an outbreak based on the net reproductive rate of MPB and host searching efficiency.
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Sharma, Rajeev. "Using multispectral and hyperspectral satellite data for early detection of mountain pine beetle damage." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31064.
Full textAbstract:
Mountain pine beetle [MPB] [Dendroctonous ponderosae Hopk.) is the most serious pest of
mature lodgepole pine (Pinus contorta) in western North America. Three key research issues
important in developing satellite-based methods for early MPB damage detection and mapping are
examined in this thesis. Relevant questions relating to these issues are: i) is it possible to provide
information on MPB-attacked stands using satellite imagery at an earlier date than conventional
methods; ii) is spectral variability in mature lodgepole pine stands significant enough to warrant
consideration in MPB attack detection at a landscape level; and iii) are satellite-based hyperspectral
bands useful in forest tree species discrimination and early detection of MPB-attacked stands. The
first two questions were investigated using multispectral Landsat-7 ETM+ data; the third question was
investigated using EO-1 Hyperion hyperspectral data.
Using a multi-step deductive approach, MPB-attacked stands were identified with an
accuracy of 69% using the Landsat imagery, approximately four months earlier than would be
possible with conventional surveys. Significant spectral variability was found in mature stands of
lodgepole pine, Douglas-fir (Pseudotsuga menziesii) and spruce (Picea spp.) at the landscape level.
Among the three variables examined (stand age, site index and site ecology), site ecology (BEC
subzone/variants) had the largest influence on the spectral signatures of the three species. Douglas-fir,
lodgepole pine and spruce could be identified with an identification accuracy of 81.8%, 82.1% and
78.9%, respectively, using a subset of nine narrow bands from the Hyperion sensor, mainly
distributed in the 1500-1800 nm spectral region. Corresponding accuracies using Landsat data were
66.1%, 74.3% and 67.6%. Another set of nine spectral bands, optimized to identify MPB attack and
distributed mainly in the 900-1100 nm spectral region, resulted in identification accuracies of 81.7%
and 80.2% for MPB-attacked (mainly green-attack) and unattacked stands, respectively.
The results of this thesis demonstrate that early detection of MPB-attacked stands is possible
using multispectral and hyperspectral data at a scale and resolution to be of practical use to the forest
managers. Some of the results from this study have already been used operationally for planning the
harvest of MPB-killed trees.Forestry, Faculty of
Graduate
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Brown, Mathew. "The carbon, water and energy balances of two lodgepole pine stands recovering from mountain pine beetle attack in British Columbia." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/33787.
Full textAbstract:
Over the past decade British Columbia (BC) has experienced the largest mountain pine beetle (MPB) outbreak on record. This study used the eddy covariance (EC) technique to examine the impact of the MPB outbreak on the net ecosystem production (NEP) and evapotranspiration (E) of two lodgepole pine stands in the central interior of BC from 2007 to 2010. MPB-06, an 85-year-old stand, and MPB-03, a 110-year-old stand, were first attacked by the beetle in 2006 and 2003, respectively. EC measurements were also made in two harvested stands, one in 2005 and one in 1997 (CC-05 and CC-97, respectively) during the 2007 growing season.
Annual NEP increased from -81 to 64 g carbon (C) m-² from 2007 to 2010 at MPB-06 due to an increase in gross ecosystem photosynthesis (Pg). At MPB-03, annual NEP also varied with Pg, ranging from -57 g C m-² in 2007 to 6 g C m-² in 2009. Annual ecosystem respiration (Re) did not vary greatly over the four years at both sites. At MPB-03, Pg was reduced by drought in 2009 and 2010. The increase in Pg at both sites was due to an increase in the photosynthetic capacity of the surviving trees and vegetation, as shown by foliar net-assimilation measurements. Light response analysis indicated that daytime Re values derived using nighttime NEP data were likely realistic estimates of the actual respiratory fluxes. NEP measurements at CC-97 and CC-05, showed that these stands are likely to remain C sources for as many as 10 years following harvesting. There was little interannual variation in E at both sites as the surviving trees and vegetation compensated for reductions in E due to the death of the overstory. Root-zone drainage was much greater at MPB-03 than at MPB-06, due to larger P at MPB-03. Growing season water deficit showed both stands to be water limited in spite of the high proportion of dead pine trees. Results from this study showed the importance of the remaining healthy trees and vegetation in the recovery of these stands from MPB attack.
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Sattler, Derek Felix. "A hybrid model to estimate natural recruitment and growth in stands following mountain pine beetle disturbance." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/3819.
Full textAbstract:
A method of linking SORTIE-ND and PrognosisBC was developed for the purpose of predicting natural regeneration and forecasting future stand conditions in mountain pine beetle (Dendroctonus ponderosae Hopkins - MPB) attacked stands in the Interior Douglas-fir (IDF) and Sub-Boreal Spruce (SBS) biogeoclimatic ecosystem zones of central and southeastern British Columbia. PrognosisBC, a spatially-implicit growth model, lacked a submodel suitable for predicting natural regeneration in unsalvaged MPB-disturbed stands. To fill this gap, estimates of regeneration (trees <7.5 cm diameter at breast height - DBH) were supplied to PrognosisBC using the light-mediated forest dynamics model SORTIE-ND and the linked model was used to forecast future stand conditions. In order to improve results, a density-dependent system of crown allometry equations to predict crown depth and crown radius was developed and then added to SORTIE-ND. The equations used stand-level measures of stems ha-¹, basal area (m² ha-¹), and the basal area of trees taller than the target tree to explicitly account of the effects of crowding on the crown axes. Additionally, crown radius and crown depth were used as dependent regressors. The equations were fit using a nonlinear three-stage least squares estimator and generally provided good estimates of crown depth and crown radius for lodgepole pine (Pinus contorta var. latifolia), hybrid spruce (Picea engelmannii x glauca (Moench) Voss), Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and trembling aspen (Populus tremuloides Michx.).
Tests of the hybrid model with the improved system of crown allometry equations were performed using reconstructed plot data collected from natural stands disturbed by MPB 25-years ago. The hybrid model provided good estimates (small mean bias and low root mean square error) for the basal area of advance regeneration (2 < DBH < 7.5 cm) for lodgepole pine (Pinus contorta var. latifolia). The best estimates were achieved when trees <7.5 cm DBH were transferred from SORTIE-ND to PrognosisBC 15-years after MPB-disturbance. For trees <2 m in height, poor estimates of stems ha-¹ where obtained. Despite the shortcomings with respect to trees <2 m tall, the results suggest that linking SORTIE-ND and PrognosisBC is an effective method of building a hybrid model capable of being used in MPB-disturbed forests. However, full parameterization of the SORTIE-ND model is likely needed to obtain accurate estimates for all sizes of natural regeneration.
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Schen-Langenheim, Greta Katherine. "Evaluation of Semiochemical Strategies for the Protection of Whitebark Pine Stands Against Mountain Pine Beetle Attack Within the Greater Yellowstone Ecosystem." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/572.
Full textAbstract:
High-dose verbenone, verbenone plus nonhost volatiles (NHVs), and both semiochemicals in combination with aggregant-baited funnel traps were tested for stand- level protection against mountain pine beetle attack for two consecutive years (2004-2005) at three seral high elevation whitebark pine sites in the Greater Yellowstone Ecosystem. In 2004, two 0.25-hectare treatments comprised of 25 high-dose verbenone pouches or verbenone pouches combined with single baited funnel traps were tested in a push-pull strategy. In 2005, 25 high-dose verbenone and 25 NHV pouches, or verbenone and NHV in combination with baited funnel trap clusters were tested. In both years, treatments were compared to 0.25-hectare control plots with no semiochemicals or funnel traps. The proportion of trees attacked by mountain pine beetle in treated plots was significantly reduced, when compared to control plots, at only one site treated with verbenone in 2004, and at only one site in 2005. High-dose verbenone alone, verbenone and NHVs, and both semiochemicals combined with baited funnel traps in a push-pull strategy did not consistently reduce the proportion of mountain pine beetle attacked trees relative to control plots. No covariates tested, including stand density, beetle population size, or tree size were consistently significant in explaining proportion of trees attacked.
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Gillanders, Steve Neil. "Multitemporal remote sensing of landscape pattern dynamics resulting from mountain pine beetle infestation and timber harvest." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/15220.
Full textAbstract:
Occurring over multiple years and impacting an area over 13 million hectares to date, the
current epidemic of mountain pine beetle (Dendroctonus ponderosae Hopkins) in British
Columbia lends itself to the use of remote sensing technologies for monitoring purposes.
Change detection procedures based upon spectral values are common; however,
monitoring changes in landscape pattern presents opportunities for the generation of
unique and ecologically important information. Furthermore, while the use of two images may provide the means to identify change, the use of more than two images affords the ability for long-term monitoring and characterization of processes such as change rates and dynamics. The initial component of this study consists of a literature review undertaken to investigate and summarize methods and applications of landscape pattern analysis using three or more image dates. This information was in turn used to make recommendations for the application of landscape pattern analysis of a time-series of remotely-sensed data
to a case study involving mountain pine beetle infestation and timber harvesting.
Following the review, we focused on the detection and monitoring of lodgepole pine
stands in order to quantify the progression of forest fragmentation and loss of
connectivity as a result of mountain pine beetle infestation and timber harvest. This was accomplished using a key set of landscape pattern indices applied to six Landsat satellite images spanning 1993 to 2006. Through our analysis we found that the impacts of the mountain pine beetle on forest spatial pattern consist of an increase in the number of forest patches, shape complexity, and patch isolation, and a decrease in forest patch size
and interspersion. In addition, we determined that in a spatial context, mountain pine beetle infestation plays a significantly greater role in forest fragmentation and loss of connectivity than timber harvest. However, we also discuss the limitations of these findings due to the differences between natural and anthropogenic disturbances and the
inability of Landsat data to detect patch-level dynamics. This research demonstrates the unique information available from satellite image time-series combined with landscape pattern analysis to better understand the combined effects of insect infestation and forest harvesting.
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Korol, Jerome John. "A simulation of predation by non-game birds on the mountain pine beetle (Dendroctonus ponderosae Hopkins)." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25882.
Full textAbstract:
Available information on bird-lodgepole pine, bird-mountain pine beetle, and mountain pine beetle-lodgepole pine interactions was reviewed. A computer model was constructed for the purpose of simulating variations in these interactions. Three lodgepole pine stand structures and three sets of bird responses to changes in beetle density were simulated. It was determined that birds may be able to suppress beetle population growth and reduce maximum beetle density under 'typical' stand conditions, but could only prevent an epidemic when unrealistically high bird densities were assumed. Increasing base-line bird densities to levels which were realistically obtainable had effects similar to those obtained when predator efficiency was increased. No amount of avian predation could prevent a massive epidemic from occurring when stand conditions were such that beetle productivity was optimized. A mountain pine beetle epidemic, as well as bird functional and numerical responses, did not occur when a stand structure representing a preventive thinning was simulated. Preventive silvicultural methods such as thinning or reduction of rotation age, combined with practices such as retention of wildlife trees on clearcut sites in order to increase non-game bird densities, could help prevent endemic beetle populations from reaching epidemic levels.Forestry, Faculty of
Graduate
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Eidson, Erika L. "Great Basin Bristlecone Pine Resistance to Mountain Pine Beetle: An Evaluation of Dendroctonus ponderosae Host Selection Behavior and Reproductive Success in Pinus longaeva." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6324.
Full textAbstract:
Over the last two decades, mountain pine beetle (Dendroctonus ponderosae) populations reached epidemic levels across much of western North America, including high elevations where cool temperatures previously limited beetle persistence. Many high-elevation pine species are susceptible hosts and experienced high levels of mortality in recent outbreaks, but co-occurring Great Basin bristlecone pine (Pinus longaeva), the longest-living non-clonal organism, were not attacked. I assessed Great Basin bristlecone pine resistance to mountain pine beetle by evaluating mountain pine beetle host selection behavior and reproductive success in this species.
To evaluate mountain pine beetle host selection preference for Great Basin bristlecone pine, I used no-choice 48-hour attack box experiments that confined pioneering female beetles onto pairs of living Great Basin bristlecone and limber pine (P. flexilis), a susceptible host tree species. To investigate the effect of induced tree defenses on host selection behavior, I repeated the tests on paired sections of Great Basin bristlecone and limber pines that had been recently cut, thereby removing their capacity for induced defensive reactions to an attack. Mountain pine beetles avoided Great Basin bristlecone pine relative to limber pine, suggesting that Great Basin bristlecone pine has a high level of resistance to mountain pine beetle due at least in part to stimuli that repel pioneering females from initiating attacks, even when induced defenses are compromised.
To investigate mountain pine beetle reproductive success in Great Basin bristlecone pine, I compared the mating success, fecundity, and brood production of mountain pine beetle parents placed in cut Great Basin bristlecone pine bolts with that of mountain pine beetles placed in cut bolts of limber pine and lodgepole pine (P. contorta), two susceptible species. Initial reproductive development was similar in all three tree species, but nearly all brood in Great Basin bristlecone pine died before emerging. The extensive offspring mortality observed in Great Basin bristlecone pine may be a key evolutionary driver behind mountain pine beetle aversion to the species. These findings suggest that Great Basin bristlecone pine is a highly resistant species with low vulnerability to climate-driven increases in mountain pine beetle outbreaks at high elevations.
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Khadempour, Lily. "Changes in fungal associate abundance over mountain pine beetle lifecycle using target-specific primers and quantitative PCR." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/38068.
Full textAbstract:
The mountain pine beetle (MPB) is a native bark beetle of western North America that attacks pine tree species, in particular, lodgepole pine. It is closely associated several ophiostomatoid fungi, with which it has a mutually beneficial relationship.
This thesis is comprised of two sections. The first objective was to develop target-specific PCR primers that could identify the major fungal species associated with MPB: the pathogenic Grosmannia clavigera and Leptographium longiclavatum, the less pathogenic Ophiostoma montium, and an un-described Ceratocystiopsis species (Cop. sp.1). Growing, isolating and extracting DNA from fungi vectored by MPB can be time and labour intensive, and these associates can be difficult to differentiate morphologically. I designed three rDNA primer sets that specifically amplify short rDNA amplicons from O. montium, Cop. sp.1. and the pine Leptographium clade (i.e. G. clavigera and L. longiclavatum). I also designed two primer sets, from another gene, that can differentiate G. clavigera and L. longiclavatum. The primers reliably identify their targets from DNA obtained from pure fungal cultures, pulverized beetles, beetle galleries, and tree phloem inoculated with G. clavigera.
The second objective was to use these target-specific primers in conjunction with qPCR to compare the relative abundance of MPB fungal associates during the beetle life cycle. To determine the changes in relative abundance of the fungal species, MPB galleries were sampled at four phases in the beetle life cycle: eggs, larvae, pupae and teneral adults. Multivariate analysis of covariance indicated that changes in the relative abundance of the fungi over the lifecycle of the MPB were statistically significant. Univariate analysis of covariance showed a statistically significant difference in the abundance of Cop. sp.1 through the lifecycle, and pair- wise analysis showed that the difference occurs after the larval phase. The staining fungi O. montium and the Leptographium species did not change significantly through the MPB lifecycle.
The work described in this thesis contributes to our understanding of the interactions between the MPB and its fungal associates and provides a tool for further studies that require rapid detection, identification and quantification of MPB fungal associates.
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Cohen, Jed Jacob. "The Effect of Mountain Pine Beetle Induced Tree Mortality on Home Values in the Colorado Front Range." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23170.
Full textAbstract:
Throughout the past decade American pine forests have experienced an epidemic of Mountain Pine Beetle (MPB) induced tree mortality. This thesis estimates the losses to home values caused by deteriorating forest quality in the Front Range Counties of Larimer and Boulder Colorado. We employ a repeat sales model that allows for region specific price indices, and non-linear age-related depreciation in home values. We use the time-invariant existence of pine forest near a home to overcome shortcomings in the measurement of MPB damage. We infer from temporal changes in the marginal "effect of pine trees near a home the approximate MPB "effect . We label this strategy the translating commodity approach. Using this strategy we are able to show that diminished forest quality causes forests to become a dis-amenity that negatively affects nearby home values. The total loss in 2011 home values due to their proximity to dying forest is estimated to be $137 million for all the homes in our sample. Such substantial losses may justify a forest management policy shift in order to better mitigate the risk of future MPB outbreaks.Master of Science
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Garza, Mario Nicholas. "Biophysical and Climate Analysis of the Mountain Pine Beetle (Dendroctonus ponderosae) Infestations in the Crown of the Continent, 1962 to 2014." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/75134.
Full textAbstract:
Mountain pine beetles (Dendroctonus ponderosae) are native insects that have decimated millions of hectares of mature pine (Pinaceae) forests in western North America. The purpose of this study is to investigate biophysical and climatic correlates of Mountain Pine Beetle (MPB) insect outbreaks in the Crown of the Continent Ecosystem (CCE) from 1962 to 2014 using Aerial Detection Survey (ADS) and climate data. Specific objectives were: 1) to develop statistical models to determine how selected biophysical correlates (slope, aspect, elevation, and latitude) and 2) to understand how local and global climate variables relate to the extent of the MPB infestations in the CCE, and 3) to contextualize the results of the models with historical climate data. Overall, the major findings of this study are: 1) despite its limitations, the ADS data seems suitable for analysis of beetle damage with respect to climate and topographic factors, on a regional scale, 2) there appears to be a link between local biophysical factors and winter precipitation and TPA within the CCE, and 3) a combination of a negative-phase PDO and La Niña is important in forecasting a decline in MPB spread, during a given year. This study is the first, to our knowledge, to explore spatio-temporal patterns of MPB outbreaks using biophysical factors, and both local and global climate variables, over a fifty-year timespan in the CCE. In the future, additional geospatial analyses may enable a landscape assessment of factors contributing to variability of MPB infestation and damage as this insect continues to spread.Master of Science
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Stone, William E. "The Impact of a Mountain Pine Beetle Epidemic on Wildlife Habitat and Communities in Post-Epidemic Stands of a Lodgepole Pine Forest in Northern Utah." DigitalCommons@USU, 1995. https://digitalcommons.usu.edu/etd/799.
Full textAbstract:
Natural disturbance events influence the patterns and processes in many forest ecosystems. Ecosystem management of coniferous forests in western North America requires the recognition of the importance that natural disturbance regimes have in achieving sustainable resource production and maintaining biological diversity . Mountain pine beetle epidemics have played an historic role in the succession and structure of lodgepole pine forests in this region. Their effects on wildlife habitat and communities are undocumented, but are presumed to be substantial. I sought to quantify these effects in forty 1-ha stands of monotypic, even-aged, mature lodgepole pine forest in northern Utah approximately 3-8 years following an extensive epidemic. I selected 5 stands that were unaffected by the epidemic and 35 that had tree mortalities ranging from 14 to 95 %. Mean understory biomass in 50 1-m2 plots demonstrated an exponential increase from 4g m-2 in unaffected stands, 40 g m-2 in stands with moderate (51-75% dead) tree mortalities, and up to 110 g m-2 in severely (76-100 % dead) affected stands. Plant species diversity and heterogeneity were highest in stands with moderate tree mortality. Horizontal visual obscurity (from 0- 2.5 m high) was highest in stands with> 40% tree mortality. Canopy cover and volume decreased linearly and curvilinearly, respectively, with increasing tree mortality. Foliage height diversity was higher in stands with moderate tree mortality than in stands with high, low, or no mortality. Abundance and diversity of avian species were highest in stands with moderate tree mortality. Small and medium-sized mammal species were more abundant and diverse in stands with moderate and severe tree mortality than in stands with no or low (26-50 % dead) tree mortality, but the pattern is less clear than for avian species. Fecal pellet groups of large ungulates increased linearly with increasing tree mortality, but the pattern of occurrence of snowshoe hare fecal pellets to increasing tree mortality was less clear. Insect abundance and species diversity increased linearly with tree mortality. Canonical correspondence analysis of insect, avian, and mammalian communities revealed that understory vegetation biomass, diversity, and heterogeneity, as well as foliage height diversity, were the habitat factors that consistently explained the distribution of these species in stands affected by beetle-caused tree mortality.
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Mathys, Amanda. "Impact of partial harvesting on the net ecosystem production of a mixed conifer forest following mountain pine beetle attack." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43113.
Full textAbstract:
The recent mountain pine beetle (MPB) outbreak has had a major impact on the carbon (C) cycling of lodgepole pine forests in British Columbia. Mitigation efforts to control the insect outbreak have led to increased harvesting rates in the province. This study determines whether partial harvesting as an alternative forest management response to clearcutting can increase the net ecosystem production (NEP) of a mixed conifer forest (MPB-09) in Interior BC. Using the eddy-covariance (EC) technique, the C dynamics of the 70-year old stand were studied over the two years after partial harvest following MPB attack and also compared to an adjacent clearcut (MPB-09C) over the growing season.
The annual NEP at MPB-09 increased from -107 g C m⁻² in 2010 to -57g C m⁻² in 2011. The increase of NEP was because the associated increase in annual gross ecosystem photosynthesis (GEP) from 812 g C m⁻² in 2010 to 954 g C m⁻² in 2011 exceeded the increase in annual respiration (Re) from 920 g C m⁻² to 1011 g C m⁻² in the two years of study. During the growing season of 2010, NEP at MPB-09C was -132 g C m⁻² indicating high C losses in the clearcut. MPB-09 was a C sink during the growing season of both years, increasing from 9 g C m⁻² in 2010 to 47 g C m⁻² in 2011. The increase of NEP in the partially harvested forest suggests stand recovery following harvest, which corresponds to a 25% increase in the maximum assimilation rate in the second year. This study shows that retaining the healthy residual forest can greatly enhance the C sequestration of MPB-attacked stands and has important implications for forest management.
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Davis, Ryan Stephen. "Ponderosa Pine Mortality and Bark Beetle-Host Dynamics Following Prescribed and Wildland Fires in the Northern Rocky Mountains, USA." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/44.
Full textAbstract:
Ponderosa pine delayed mortality, and bark beetle attacks and emergence were monitored on 459 trees for 3 years following one prescribed fire in Idaho and one wildland fire in Montana. Resin flow volume (ml) was measured on 145 fire-injured ponderosa pine 2 and 3 years post-fire. Logistic regression was used to construct two predictive ponderosa pine mortality models, and two predictive bark beetle-attack models. Post-fire delayed tree mortality was greater with the presence of primary bark beetles independent of diameter at breast height (DBH) (cm), and was greater in smaller diameter trees most likely due to direct effects of fire-caused injuries; mortality was lower in trees with less percent bud kill (PBK). The frequency of bark beetle attack was greater in trees with less percent bud kill and greater bole char height proportion (CHIP). Attack frequency was also greater on trees with higher percent bud kill and greater diameter at breast height. Classification tables for all predictive models were presented for application in post-fire management development. Multivariate ANOVA analyses were used to describe the effects of morphological and fire-injury variables on ponderosa pine resin production, and bark beetle attack preference and emergence. Resin production (ml) was significantly greater on burned than unburned trees. Resin flow increased significantly between June and July 1 year following fire and from June to August 2 years following fire. Resin flow was lower on the north bole aspect than the south and west aspects of unburned trees. Resin flow of burned trees significantly increased through the summer and was greatest in trees with high pre-fire live crown length (m) (LCL). Resin flow of unburned trees differed significantly by year, month, bole aspect, and live crown length. Resin increased by month and live crown length, decreased from 2005 to 2006, and was less on the northern bole aspect than all other aspects. Bark beetles preferred to attack fire-injured trees, especially within bole-scorched areas. No significant differences in bark beetle emergence were found between fire-injured and non fire-injured trees. On burned sites, beetle emergence was greatest from larger diameter trees with less severe fire injury. Western pine beetle (Dendroctonus brevicomis LeConte) had the greatest emergence from fire-injured ponderosa pine, and Ips pini (Say) had significantly greater emergence from non fire-injured ponderosa pine.
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Emmel, Carmen. "Vertical distribution of carbon dioxide, water vapour, momentum and energy exchange within and above a forest stand affected by the mountain pine beetle." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46254.
Full textAbstract:
The mountain pine beetle (MPB) has killed vast areas of pine forest in British Columbia, Canada converting forests from carbon sinks to sources. Different management options for these forests exist ranging from no treatment to complete removal of the infested forest (clearcut). The MPB attack and the following management alter the microclimate and carbon balance of affected stands. An intensive field campaign was conducted in the summer of 2010 in an affected forest without treatment in the interior of British Columbia. Eddy covariance, radiation, temperature, humidity and carbon dioxide (CO???) measurements were made at seven heights on a tower within and above the canopy. This dissertation assessed the impact of the MPB attack and the structure of the disturbed canopy on the contribution of various vegetation layers (ground, secondary structure, overstory) to exchanges of CO???, water vapour (H???O), momentum and sensible heat. Previous research has shown that forests without treatment can return to being carbon sinks faster than clearcut sites. It was hypothesized that the rich secondary structure (mostly immature trees that survived the beetle attack) was responsible for this fast recovery. The current dissertation showed that canopy layers in this sparse and open-canopy stand were aerodynamically well coupled with the atmosphere above and allowed 60 % of photosynthetically active radiation to reach the ground. Given these favorable light conditions, the secondary structure was indeed responsible for a large proportion of the CO??? uptake; however, the understory (< 1 m high) contributed at least equally to the CO??? uptake. A dissimilarity in the vertical distribution of sources and sinks of CO???, H???O and sensible heat was found. The dissimilarity between CO??? and H???O was caused by the differences in water use efficiency of the different vegetation layers. Gradient-diffusion theory (K-theory) applicability was examined in order to guide modeling of stand microclimates and growth conditions. Momentum flux (shear stress) could be adequately determined using K-theory and an adjusted length scale. In the case of the other scalars, the use of K-theory was found to be problematic due to counter-gradient fluxes, the inability to resolve gradients and fluxes and/or source scales.
42
King, Leonora Adele. "The impacts of wildfire and Mountain Pine Beetle disturbance on wood budgets, stability and related sediment storage in low-sediment supply streams of the Okanagan Basin." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/39752.
Full textAbstract:
This thesis presents the Large Woody Debris (LWD) budgets and related sediment dynamics of
12 headwater streams in the Okanagan Basin of British Columbia. The study streams include 3
wildfire (from the recent Okanagan Mountain Park Fire in 2003) sites and 3 control sites in the
Interior Douglas-fir (IDF) biogeoclimatic zone, and 3 recent Mountain Pine Beetle (MPB)
infestation sites and 3 control sites in the Montane Spruce (MS) zone. The wood budget
components were quantified based on repeated annual wood surveys, and represent the first
wood budgets produced in the literature. Wildfire was found to significantly increase annual
wood recruitment by more than an order of magnitude over undisturbed or control streams.
MPB had not significantly increased LWD recruitment, but is expected to increase over the
coming decades. Both of the riparian disturbances had shifted the size distribution of recruits to
larger wood sizes. Our analysis confirms that the matrix of relative wood size presented by
Hassan et al. (2005) is a good predictor of wood stability and export. Wood stability was in turn
a primary determinant of wood function and the role of wood in sediment storage.
Wood in the study streams stored between 0% and 90% of the sediment in the channels.
Sediment stores increased with increasing functional wood loading. This highlights an important
role of LWD in sediment storage in spite of large variations. However, in contrast to literature
on the role of LWD in supply-rich streams, LWD in our supply-limited streams was found to
have no statistical relationship to sediment diversity and was found to be less effective at causing
sediment fining. We suggest that LWD-related sediment storage sites in supply-limited streams
replace rather than supplement alluvial storage sites as they would in sediment-supply rich
streams, and thus do not increase sediment diversity. Furthermore, LWD is a less important roughness element in these step-pool systems compared to pool-riffle systems, and is thus not
effective at causing sediment fining under step-pool conditions.
43
Schwab, Olaf Sebastian. "An agent-based forest sector modeling approach to analyzing the economic effects of natural disturbances." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2921.
Full textAbstract:
This dissertation describes the development of CAMBIUM, an agent-based forest sector model for large-scale strategic analysis. This model is designed as a decision support tool for assessing the effect that changes in forest product demand and resource inventories can have on the structure and economic viability of the forest sector. CAMBIUM complements existing forest sector models by modeling aggregate product supply as an emergent property of individual companies’ production decisions and stand-level ecological processes. Modeling the forest products sector as a group of interacting autonomous agents makes it possible to introduce production capacity dynamics and the potential for mill insolvencies as factors in modeling the effects of market and forest inventory based disturbances.
This thesis contains four main manuscripts. In the first manuscript I develop and test a dispersal algorithm that projects aggregated forest inventory information onto a lattice grid. This method can be used to generate ecologically and statistically consistent datasets where high-quality spatial inventory data is otherwise unavailable.
The second manuscript utilizes this dataset in developing a provincial-level resource dynamics model for assessing the timber supply effects of introducing weevil-resistant spruce. This model employs a stand-level approach to simulating weevil infestation and associated merchantable volume losses. Provincial-level impacts are determined by simulating harvest activities over a 350 year time horizon.
In the third manuscript I shift the focus to interactions between forest companies. I analyze the effects of strategic decisions on sector structure by developing CAMBIUM as an agent-based model of competition and industry structure evolution. The forest sector is modeled as a group of autonomous, interacting agents that evolve and compete within the limitations posed by resource inventories and product demand.
In the final manuscript I calibrate CAMBIUM to current conditions in the British Columbia forest sector. Industry agents compete for roundwood inputs, as well as for profits in finished product markets for pulp, panel products, and lumber. To test the relevance and utility of this model, CAMBIUM is used to quantify the cumulative impacts of a market downturn for forest products and mountain pine beetle induced timber supply fluctuations on the structure of the forest sector.
44
Ewanick, Shannon Melinda. "Bioconversion of mountain pine beetle-killed lodgepole pine to ethanol." Thesis, 2006. http://hdl.handle.net/2429/17981.
Full textAbstract:
Global warming is widely acknowledged as being caused by an increase in the production of greenhouse gases, largely CO₂, generated from the burning of fossil fuels such as gasoline. By offsetting a portion of gasoline usage with alternative fuels, such as ethanol, CO₂ emissions could be reduced. Bioethanol can be produced from many types of biomass, including softwoods. For maximal ethanol yield from softwoods, the most effective bioconversion process is considered by many to be SO₂-catalysed steam explosion followed by separate or simultaneous hydrolysis and fermentation. This method has been shown to be effective on both spruce and Radiata pine, although past research at UBC on Douglas-fir showed that additional delignification was necessary in order to obtain satisfactory sugar recovery and hydrolytic conversion. Another promising softwood species for bioconversion in British Columbia is lodgepole pine, which has been severely affected by the mountain pine beetle and its associated fungus and is consequently widely available and relatively inexpensive. Prior to investigating the bioconversion of lodgepole pine, the UBC steam explosion process was evaluated and was found to be comparable to that used at Lund University in Sweden. Following this, optimization of pretreatment conditions of beetle-killed lodgepole pine for maximal ethanol yield revealed that the highest ethanol yield after SSF, 77% of theoretical, was derived from substrates pretreated at 200°C, 5 min, 4% SO₂. When these and other conditions were applied to healthy, and mixed (50/50 healthy/beetle-killed) wood, the beetle-killed substrate provided higher sugar recovery after pretreatment, higher hydrolytic conversion, and higher overall ethanol yield after SSF. This was likely a result of two factors. The first, reduced uptake of SO₂ during the impregnation step effectively reduced the pretreatment severity and increased sugar recovery and fermentability. Secondly, increased fines may have improved the enzymatic digestibility of the substrate. The work in this thesis established the technical feasibility of producing ethanol from lodgepole pine in a two-step process consisting of SO₂-catalyzed steam explosion followed by SSF of the combined liquid and solid fractions. In addition, the short residence time required for SSF as well as the reduced cost of the raw material suggest that the process could be economically attractive as well.Forestry, Faculty of
Graduate
45
Lee, Sangwon. "Fungi associated with the mountain pine beetle, Dendroctonus ponderosae." Thesis, 2006. http://hdl.handle.net/2429/18218.
Full textAbstract:
The mountain pine beetle (MPB; Dendroctonus ponderosae) and its fungal associates have infested large areas of lodgepole pine (Pinus contorta var. latifolia) forests in British Columbia. In order to understand how the fungi affect the beetle epidemics and tree defenses [i.e. tree defences], in this work we identified the fungal species associated with the MPB, characterized their pathogenicity, and investigated the genetic structure of a fungal species, one of the major pathogens. Identifying ophiostomatoid fungi by a classical morphology approach is often inconclusive. For accurate identification, molecular approaches were developed for Ophiostoma montium and Ophiostoma clavigerum. O. montium could be differentiated from a synonymous species, O. ips, using a single polymerase chain reaction of either the β-tubulin gene or ribosomal DNA. Similarly, restriction fragment length polymorphism analysis of the β-tubulin gene using the enzyme Hin fI could distinguish O. clavigerum from other morphologically related ophiostomatoid fungi. Using molecular and morphological approaches, we characterized the diversity of MPB fungal associates. Fungi were isolated from beetles, beetle galleries and sapwood of infested lodgepole pines in six epidemic sites across British Columbia. A total of 1042 fungi that belong to nine species were recognized. Unexpectedly, an O. minutum-like species was frequently isolated from the beetle. Unknown Leptographium and Entomocorticium species were also isolated in addition to the known MPB associates O. clavigerum and O. montium. The unknown Leptographium species was reported as Leptographium longiclavatum sp.nov. The pathogenicity of L. longiclavatum to mature lodgepole pines was estimated and compared to the pathogenicity of O. clavigerum, an MPB associate that is known to kill mature pines when inoculated at high density. For this test, foliage colour, phloem lesions, occlusions, and sapwood moisture content of inoculated trees were examined. The data showed that L. longiclavatum was a pathogen, although it seemed slightly less virulent than O. clavigerum. The genetic diversity of 170 O. clavigerum isolates from five sites in Canada and two sites in the USA was characterized using amplified fragment length polymorphism (AFLP). While the genetic diversity was low, and the geographic and genetic distances were not significantly correlated, we identified two genetically distinct groups in the population.Forestry, Faculty of
Graduate
46
Harrison, Daniel. "Effects of intensive fertilization on soil nutrient cycling in lodgepole pine and interior spruce forests in the Central Interior of British Columbia." Thesis, 2011. http://hdl.handle.net/1828/3615.
Full textAbstract:
The growth and productivity of British Columbia’s interior forests is largely
limited by soil nutrient availability. Fertilization has been shown to be an effective
silvicultural tool for increasing the development of immature stands throughout the
region. This has lead to increased interest in long-term, repeated fertilization as a means
of addressing timber-supply shortfalls as a result of the current mountain pine beetle
(Dendroctonus ponderosae) outbreak. However, there is little information related to the
impacts of repeated fertilization on the cycling of nutrients in many of these stands. This
study makes use of a long-term (13-15 year) fertilization experiment in two lodgepole
pine (Pinus contorta Dougl. var. latifolia Engelm) and two interior spruce (Picea glauca
[Moench] Voss and Picea engelmannii Parry) forests in the central interior of British
Columbia subject to two levels (periodic and annual) of nitrogen(N)-based fertilization.
The primary goal of the project was to examine the effects of different fertilizer regimes
on aspects of soil chemistry. Specifically, this project was concerned with the impacts of
repeated fertilization on: 1) soil carbon (C) and N cycling, and 2) soil base cation (e.g.,
Ca, Mg & K) availability. Soil and foliar nutrient regimes were quantified throughout the
2008 and 2009 growing seasons using ion-exchange membrane (IEM) plant root
simulator (PRS) probes and traditional soil and foliar analyses. Fertilization increased N
cycling at all sites, with generally elevated soil and foliar N and significant soil-foliar N
relationships in several cases. Nitrate (NO3
-) increased in the fertilized plots in several
cases; however, there was minimal evidence of NO3
- leaching. Greater than 90% of
fertilizer-N inputs were retained onsite, suggesting these forests are not N-saturated. Soil,
tree and total ecosystem C generally increased in response to fertilization, with the spruce
sites exhibiting greater C accrual per unit of fertilizer N than the pine sites. Further,
significant linear relationships between soil C and N were evident at all sites. At sites
with poorly buffered soils (pH < 4), fertilizer treatments generally led to increased soil
acidification and decreases in soil and foliar Ca. Decreases in soil Ca may have been due
to significant increases in sulfate leaching; whereas foliar Ca decreases appear to be
related to compromised uptake systems, potentially from increased soil aluminum.
Buffering capacities, rather than forest type, appear to be the best predictor of soil and
foliar Ca responses to fertilization. Despite significant changes in soil chemistry at all
four sites, it does not appear that current fertilization rates are detrimentally affecting tree
growth.Graduate
47
Zhao, Yong. "Development of Bio-based Phenol Formaldehyde Resol Resins Using Mountain Pine Beetle Infested Lodgepole Pine Barks." Thesis, 2013. http://hdl.handle.net/1807/36080.
Full textAbstract:
Phenol formaldehyde (PF) resol resins have long been used widely as wood adhesives due to their excellent bonding performance, water resistance and durability. With the growing concern for fossil fuel depletion and climate change, there is a strong interest in exploring renewable biomass materials as substitutes for petroleum-based feedstock. Bark, rich in phenolic compounds, has demonstrated potential to partially substitute phenol in synthesizing bio-based PF resins.
In this study, acid-catalyzed phenol liquefaction and alkaline extraction were used to convert mountain pine beetle (MPB; Dendroctonus ponderosae) infested lodgepole pine (Pinus contorta) barks to phenol substitutes, liquefied bark and bark extractives. Two types of bio-based phenol formaldehyde (PF) resol resins, namely liquefied bark-PF resin and bark extractive-PF resins, were then synthesized and characterized.
It was found that acid-catalyzed phenol liquefaction and alkaline extraction were effective conversion methods to obtain phenol substitute with the maximum yield of 85% and 68%, respectively. The bio-based PF resol resins had higher molecular weights, higher polydispersity indices, shorter gel times, and faster curing rates than the lab synthesized control PF resin without the bark components. Based on the lap-shear tests, the bio-based PF resol resins exhibited comparable wet and dry bonding strength to lab PF resin and commercial PF resin. The post-curing thermal stability of the bio-based PF resins was similar to the lab control PF resin.
The liquid-state 13C nuclear magnetic resonance (NMR) study revealed significant influences on the resin structures by the inclusion of the bark components. Methylene ether bridges, which were absent in the lab PF resin, were found in the bio-based PF resins. The bark components favored the formation of para-ortho methylene linkages in the bio-based bark extractive-PF resins. The liquefied bark-PF resin showed a higher ratio of para-para/ortho-para methylene link (-CH2-), a higher unsubstituted/substituted hydrogen (-H/-CH2OH) ratio and a higher methylol/methylene (-CH2OH/-CH2-) ratio than the bark extractive-PF resin. Both tannin components of bark alkaline extractives and phenolated barks contributed to the acceleration of the curing rate of the bio-based resins.
This research demonstrated the promise of the bio-based PF resins containing either bark alkaline extractives or liquefied barks as environmentally friendly alternatives to PF adhesives derived solely from fossil fuel based phenol and proposed a novel higher value-added application of the largely available barks from the mountain pine beetle-infested lodgepole pine trees.
48
Francis, Alexandra. "Evaluating habitat use of female moose in response to large scale salvage logging practices in British Columbia, Canada." Thesis, 2020. http://hdl.handle.net/1828/12093.
Full textAbstract:
Global biodiversity is in decline as a result of unprecedented human alterations to the
earth’s land cover. Understanding the ecological mechanisms of these large-scale changes in biodiversity is imperative in furthering our knowledge on the effects these alterations may have on animal behaviour and consequently on populations, allowing researchers and managers to effectively conserve species. During the last decade, there have been reports of moose populations both increasing and decreasing in North America due to a variety of factors (e.g., climate change, habitat disturbance, disease, etc.). Within British Columbia, wildlife managers have reported moose population declines of up to 50 – 70%, while other areas have remained stable. These changes have coincided, spatially and temporally, with the largest recorded mountain pine beetle (Dendroctonus ponderosae) outbreak. The outbreak resulted in extensive logging and road building in attempts to recover economic value from the beetle killed trees, resulting in drastic changes to the landscape. Understanding the effects that a highly disturbed landscape has on a species is critical for effective management and conservation.
To investigate this, I examined the seasonal response of female moose to landscape
change caused by the Mountain Pine Beetle outbreak and attendant salvage logging
infrastructure in the Interior of British Columbia on the Bonaparte Plateau. First, I used a cluster analysis framework to develop biologically relevant seasons for female moose using individual movement and habitat use. I then used this temporal framework to develop seasonal home ranges for each individual moose. Second, I modeled the seasonal habitat selection of female moose to examine how moose respond to salvage logging infrastructure (i.e., dense road network and extensive cutblocks) using resource selection functions in an information-theoretic framework. We tested whether predation risk, forage availability or the cumulative effects of salvage logging best predicted moose space-use.
Moose movement data clustered into five biologically relevant seasons, which were consistent with our biological and ecological knowledge of moose in the study area; however, these seasons and the size of the range differed from other seasons defined using alternative methods in the region. Across all seasons, the cumulative effects of forage availability and risk best predicted female moose distribution. In the calving and fall seasons, the top risk model best predicted moose habitat selection while the top forage availability model better explained moose habitat selection in spring, summer, and winter. Our results identified the importance of defining biological seasons using empirical data and how these seasons can differ from arbitrarily defined seasons, as well as the implications these can have in subsequent analysis and management. Additionally, we found that moose are seasonally trading the benefits of foraging for predation risk in these highly disturbed landscapes, using some aspects of salvage logging. My results bring perspective on how moose are using a highly disturbed landscape at the seasonal scale and a nuanced approach to landscape management.Graduate
49
Dordel, Julia. "Influences of mountain pine beetle (Dendroctonus ponderosea), fire, and ungulate browsing on forest stand structure in the southern Canadian Rocky Mountains." Thesis, 2005. http://hdl.handle.net/2429/16434.
Full textAbstract:
Forests in the montane and lower subalpine ecoregions of the southern Canadian
Rocky Mountains may have been more open and structurally diverse at the beginning of
the 20th century than today. Today, mature Pinus contorta var. latifolia Dougl.
(lodgepole pine) causing mountain pine beetle (MPB, Dendroctonus ponderosae)
infestations, infrequent high severity fires, and herbivory appear to have increased in
Banff and Kootenay National Parks. Based on a review of the literature it was
hypothesised that
1. MPB infestations increase forest stand structural diversity;
2. Browsing intensity decreases with increasing amounts of coarse woody debris;
and
3. Disturbances such as MPB infestation and low severity fire lead to decreased
MPB stand susceptibility.
Stand structure parameters were investigated in mesic montane and lower subalpine
stands 15, 25, and 65 years after MPB outbreaks. Parameters measured were tree
density, diameter, height class, species, and age distributions as well as coarse woody
debris mass. Also, influences of fire frequency, time since fire and fire severity on the
current stand structure were analysed. A MPB susceptibility index was calculated for
stands with different MPB and fire disturbance histories. The Shannon-Wiener index
indicated higher stand structural diversity on plots 15 years but not 25 and 65 years
after MPB infestations. Influences of fire on stand structure were limited to increasing
tree density with increasing time since the stand initiation fire, and higher proportions of
understory vegetation at lower fire severities. Also, there was an indication that high
amounts of coarse woody debris resulted in reduced browsing intensity. Finally, the
MPB susceptibility index was significantly lower on stands with previous MPB
infestations. The MPB susceptibility index also tended to be lower with increasing
number of fires. Consequently, none of the above hypothesis could be rejected. Low
intensity fires and a reduction of herbivory might be crucial to promote other early
successional species such as Populus tremuloides (trembling aspen). Management
strategies allowing for MPB and fire disturbances would benefit the ecosystems in the
study area.Forestry, Faculty of
Graduate
50
Sharma, Rajeev. "Detection of mountain pine beetle infestations using Landsat TM Tasseled Cap transformations." Thesis, 2001. http://hdl.handle.net/2429/11449.
Full textAbstract:
This study investigated the identification of probable mountain pine beetle (Dendroctonus ponderosae
Hopk.) attacked sites using Tasseled Cap transformations namely, brightness, greenness and wetness,
derived from Landsat-7 digital data in parts of Vanderhoof Forest District, in Prince George Forest
Region, British Columbia. Lodgepole pine (Pinus contorta Dougl.) constitutes about 80 percent of
the total forest vegetation in the study area. About 85 percent of lodgepole pine stands are greater
than 60 years of age, and hence susceptible to mountain pine beetle attack. Landsat-7 ETM digital
data (Bands'!, 2,3,4,5&7), acquired on August 2, 1999 and September 12, 1999, were the primary
remote sensing data source for the study. In addition, TRIM map sheets (1:20,000) derived road and
river vectors, and 1:20,000 forest cover maps and a beetle infestation coverage maps of the area
(prepared based on aerial sketch mapping and ground probes) were collateral data sources.
Methodology consisted of: i) pre-processing of satellite data (atmospheric and geometric corrections),
ii) computation of Tasseled Cap coefficients for the Landsat-7 data, since these were not available, iii)
identification of mountain pine beetle attacked stands, and iv) accuracy assessment of attacked stands.
Some of the major observations based on results obtained were: i) Tasseled Cap indices for
infestations of more than 30 attacked trees / site (< 0.09 ha in size) were found to vary in a relatively
narrow range; however for infestation sites with less than 30 tree / site the Tasseled Cap indices had
random and large dispersions; ii) values of Tasseled Cap indices for September were found to be
lower than those for August for all the cover types; iii) differences between mean brightness, greenness,
and wetness of healthy and attacked stands were statistically significant for August; iv) the identification
accuracy for attacked lodgepole pine stands were 38.82 and 26.17 percent for August and September,
respectively; v) a linear relationship was observed between the number of attacked trees at a site and
identification accuracy for the August data but not for September data; vi) the poor identification accuracy
was mainly due to the sub-pixel size of infestations.