Physical Sciences and Mathematics Commons^™

Data From: Climate Change-Driven Cumulative Mountain Pine Beetle-Caused Whitebark Pine Mortality In The Greater Yellowstone Ecosystem, William W. Macfarlane

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In 2018-2019 the Landscape Assessment System (LAS), an aerial survey method was used to assess mountain pine beetle (Dendroctonus ponderosae; MPB) - caused mortality of whitebark pine (Pinus albicaulis) across the Greater Yellowstone Ecosystem (59000 km2; GYE). This consisted of 11,942 km of flightlines, along which 4,434 geo-tagged, oblique aerial photos were captured and processed. A mortality rating of none to severe (0 to 4 nt attack or 5.0 5.4 old attack) was assigned to each photo based on the amount of red (recent attack) and gray (old attack) trees visible. The method produced a photo inventory of 74 percent …

Quantification Of Hydrologic Response To Forest Disturbance In Western U.S. Watersheds, Sara A. Goeking

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forested watersheds produce more than half of the water supply in the United States. Forests affect how precipitation is partitioned into available water versus evapotranspiration. This dissertation investigated how water yield and snowpack responded to forest disturbance following recent disturbances in western U.S. forests during the period 2000-2019.

Chapter 2 systematically reviewed 78 recent studies that examined how water yield or snowpack changed after forest disturbances. Water yield and snowpack often increased after disturbance, but decreased in some circumstances. Decreased water yield was most likely to occur following disturbances that did not remove the entire forest canopy. It was also …

Low Offspring Survival In Mountain Pine Beetle Infesting The Resistant Great Basin Bristlecone Pine Supports The Preference-Performance Hypothesis, Erika L. Eidson, Karen E. Mock, Barbara J. Bentz

Wildland Resources Faculty Publications

The preference-performance hypothesis states that ovipositing phytophagous insects will select host plants that are well-suited for their offspring and avoid host plants that do not support offspring performance (survival, development and fitness). The mountain pine beetle (Dendroctonus ponderosae), a native insect herbivore in western North America, can successfully attack and reproduce in most species of Pinus throughout its native range. However, mountain pine beetles avoid attacking Great Basin bristlecone pine (Pinus longaeva), despite recent climate-driven increases in mountain pine beetle populations at the high elevations where Great Basin bristlecone pine grows. Low preference for a potential …

The Influence Of Aspen Chemistry And The Nutritional Context On Aspen Herbivory, Kristen Y. Heroy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consumption of aspen by herbivores is one major force causing aspen decline in North America. In this Dissertation, I aimed to determine why herbivores prefer browsing on certain aspen stands over others, and why they prefer consuming aspen that contains chemical defenses over understory forages like grasses, forbs, and shrubs. I explored the influence of nutrients and chemical defenses within aspen on aspen intake and preference by lambs in pen experiments. I also explored drivers of aspen preference on the landscape by looking at relationships between aspen herbivory, indicators of aspen health, amount of nutrients available in the understory, and …

Effect Of Foliage And Root Carbon Quantity, Quality, And Fluxes On Soil Organic Carbon Stabilization In Montane Aspen And Conifer Stands In Utah, Antra Boča

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil organic carbon (SOC) positively affects many soil properties (e.g., fertility and water holding capacity), and the amount of carbon (C) in soil exceeds the amount in the atmosphere by about three times. Forest soils store as much C as is found in trees. Tree species differ in their effect on SOC pools. Quaking aspen forests in the Western US often store more stable SOC in the mineral soil than nearby conifers. During the last decades a decline in aspen cover, often followed by conifer encroachment, has been documented. A shift from aspen to conifer overstories may negatively affect the …

Reducing Reliance On Supplemental Winter Feeding In Elk (Cervus Canadensis): An Applied Management Experiment At Deseret Land And Livestock Ranch, Utah, Dax L. Mangus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife managers have fed elk in North America for nearly 100 years. Giving winter feed to elk can compensate for a shortage of natural winter range and may boost elk populations while also helping prevent commingling with livestock and depredation of winter feed intended for livestock. In contrast to these benefits of supplemental feeding, there are economic and environmental costs associated with feeding, and elk herds that winter on feeding grounds have a higher risk of contracting and transmitting disease. Brucellosis is of primary concern now, and Chronic Wasting Disease may be in the future. Many see the discontinuation of …

Great Salt Lake Watershed: Its Role In Maintaining The Wetlands Of The Great Salt Lake, Danny C. White Jr.

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The following bioregional planning study is a direct result of the 2009- 2010 studio project initiated by the United States Fish and Wildlife Service (FWS). The FWS contacted the study team and asked them to determine how the future growth and development of the Bear River Watershed would impact the Bear River Migratory Bird Refuge (BRMBR). The study looked at all of the physical and biophysical systems within the Bear River Watershed to identify the issues that had an effect on the BRMBR.

It became apparent from the original project that the future of the BRMBR and other Great Salt …

Invertebrate Community Changes Along Coqui Invasion Fronts In Hawaii, Ryan T. Choi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Puerto Rican coqui frog, Eleutherodactylus coqui, was introduced to Hawaii in the late 1980s via the commercial horticulture trade. Previous research has shown that coquis can change invertebrate communities, but these studies were conducted at small scales using controlled, manipulative experiments. The objective of this research was to determine whether coqui invasions change invertebrate communities at the landscape scale across the island of Hawaii. At each invasion front, we measured environmental variability on either side of the front and removed sites that were too variable across the front to ensure that the impacts we measured were the result …

Spatiotemporal Modeling Of Threats To Big Sagebrush Ecological Sites In Northern Utah, Alexander J. Hernandez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study tested the performance of classification, regression, and ordination techniques to evaluate the spatiotemporal dynamics of threats to big sagebrush ecological sites. The research was focused on invasion by annual exotic grasses and encroachment by woodlands.

We sought to identify those areas that have had a persistent coverage of cheatgrass (Bromus tectorum) in big sagebrush ecological sites. We took advantage of the contrast in greenness between multi-temporal (within one year) remotely sensed vegetation indices captured in the spring and summer to find a distinct phenological signature that allowed mapping cheatgrass. We utilized support vector machines (SVM) to classify three …

Fuel Loads, Fire Severity, And Tree Mortality In Florida Keys Pine Forests, Jay Sah, Mike S. Ross, Danielle Ogarcak, Jim R. Snyder

North American Forest Ecology Workshop

In fire dependent forested ecosystems, fire managers are greatly interested in predicting the consequences of their management-oriented prescribed burnings on post-fire tree mortality. While fire intensity is believed to be a strong predictor of tree mortality, fire behavior itself largely depends on fuel characteristics, including both their structure and spatial distribution. We examined the type and distribution of fuels, their effects on fire behavior, and the effects of fire on tree mortality in slash pine forests in the Florida Keys. We conducted a burning experiment in six blocks, and burned eleven plots, three in winter and eight in summer, over …

Overstory Dynamics In An Uncut Pine-Hardwood Stand: Lessons From Seventy Years Of Passive Management, Don Bragg, Michael G. Shelton

North American Forest Ecology Workshop

Long-term demonstration projects on experimental forests can be adapted from their original goals to provide insights into contemporary research questions. For instance, a 32.4-hectare cutover parcel on the Crossett Experimental Forest, the eventual Reynolds Research Natural Area (RRNA), was reserved in 1936 to act as a control for more intensively managed study areas. Over the last 70+ years, the RRNA has been allow to develop under 'natural' conditions that include no harvesting or other human interventions-with the notable exception of fire control. From 1937 until the most recent measurement in 2007, overall stand basal increased from about 20 to 36 …

What Drives Decomposition Rates Of Coarse Woody Debris (Cwd)?, Steffen Herrmann, Jurgen Bauhus

North American Forest Ecology Workshop

Currently increasing efforts are made to manage CWD as a habitat component and a carbon store in forest ecosystems. For this a basic understanding of patterns and rates of dead wood decomposition in different forests is crucial. The decomposition rate of CWD is mainly dependent on climatic (wood temperature, wood moisture) and substrate specific (tree species, decay stage, diameter) variables. Here, we analysed the influence of these factors using a combined approach. 1) We assessed the decay rate of Fagus sylvatica, Picea abies and Pinus sylvestris in three diameter classes (10-20 cm, 20-40 cm, >40 cm) along a climatic/altitudinal gradient …

Seed Release In Lodgepole Pine Forests After Mountain Pine Beetle Outbreak, Francios Teste, Vic J. Lieffers, Simon M. Landhausser

North American Forest Ecology Workshop

Serotinous lodgepole pine (Pinus contorta var. latifolia) usually regenerates after fire or harvesting provided conditions that are warm enough to open the cones. There are concerns that large-scale stand mortality due to mountain pine beetle (MPB) outbreak could greatly reduce natural regeneration of lodgepole pine because the closed cones are held in place in the tree canopy without any seed release. We selected 15 stands (five gray-attacked, five red-attacked, and five green) in the Sub-Boreal Spruce biogeoclimatic zone of British Columbia to determine loss of canopy seed via breakage of twig-bearing cones and cone opening (i.e., loss of serotiny) throughout …

Potential Effects Of Climate Change On Mixed Severity Fire Regimes, Jessica Halofsky, Dave L. Peterson

North American Forest Ecology Workshop

The frequency, severity, and extent of wildfire are strongly related to climate, and increasing temperatures with climate change will likely lead to changes in fire regimes in many types of ecosystems. Increased spring and summer temperatures with climate change will result in relatively early snowmelt, lower summer soil and fuel moisture, and longer fire seasons in the West. These conditions will lead to increased fire frequency and extent. Higher temperatures may also interact with vegetation and fuel characteristics to increase fire intensity and severity. Mixed severity fire regimes may be uniquely influenced by these climate-induced changes in the frequency, extent, …

Assessment Of Prescribed Burning Effects In Paludified Black Spruce Forests In Ontario’S Clay Belt Region, Sebastien Renard, Sylvie Gauthier, Nicole Fenton, Yves Bergeron, David Pare

North American Forest Ecology Workshop

Paludification, the accumulation of poorly decomposed organic matter principally originating from Sphagnum, transforms black spruce forests to forested peatlands in the prolonged absence of fire. High-severity wildfires reverse this process by burning the organic matter layer and thus restart forest succession; in contrast low severity wildfires remove only the tree layer and do not reduce paludification. On the Ontario Clay Belt, a physiogeographic region prone to paludification due to its cold climate and poor drainage, current forest harvest practices (Careful Logging Around Advanced Growth; CLAAG) mimic low severity fires by removing trees but lacking forest floor and soil disturbances caused …

An Integrated Study Investigating Masticated Fuel Treatments In The Rocky Mountains, Robert Keane, Helen Y. Smith

North American Forest Ecology Workshop

Many coniferous forests in the western US once supported frequent, low intensity fires, but due to a century of fire exclusion and other factors, severe wildfires have now become common. With the goal of lowering fire intensities and severities, one possible fuel treatment that is currently gaining favor in with many land managers is mastication which breaks, shreds, or grinds canopy (seedlings, saplings and pole trees) and surface fuel (fine and coarse woody material) into smaller sizes and deposits the treated fuel on the ground. However, very little is known concerning the effects of this treatment on the resulting fire …

A Post-Fire Index For Describing Mixed Severity Outcomes After Wildfire, Theresa Jain, Russel T. Graham, David S. Pilliod, Leigh Lentile

North American Forest Ecology Workshop

Kimmins (1997) argues that “words” and their correct usage are important and that the “careless use of language often causes confusion and misunderstanding and is a factor in many conflicts.” The public often lacks the technical knowledge to understand and interpret the use of inconsistent terminology and each discipline within resource science and management has developed their own definitions and application of specific terms. The fire community is no different. The only consistent component in the fire literature is the interchangeable use of the terms fire intensity, fire severity, and burn severity. Moreover, within each of these definitions, the terms …

Mechanical Mastication Showed Fewer Negative Above-And Belowground Impacts Than Slash Pile Burning, Suzanne Neal, Carolyn H. Sieg, Catherine A. Gehring, Matthew A. Bowker

North American Forest Ecology Workshop

Management designed to reduce wildfire risk must consider both above- and belowground factors in order to promote native plant growth and reduce soil erosion. This goal is challenging because current methods, such as tree thinning and burning the resulting slash, can create soil disturbances that favor exotic plants. We compared mechanical mastication to slash pile burning (both 6-months and 2.5-years post treatment) and untreated controls in pinyon-juniper (Pinus edulis-Juniperus osteosperma) woodland and measured soil properties, arbuscular mycorrhizal fungi (AMF) and understory plant composition. Our results showed slash pile burns had severely degraded soil properties, low plant and AMF abundance and …

The Influence Of Mastication On Soils And Fuels In Moist And Dry Forests Of The Northern Rocky Mountains, Theresa Jain, Russel T. Graham

North American Forest Ecology Workshop

We evaluated the applicability of mastication as a fuel treatment alternative within Northern Rocky Mountain moist and dry forests to treat post-harvest activity slash (moist forest) and standing trees (dry forest). On the moist forest site, we compared four different slash treatments, mastication, machine grapple piling, lop and scatter, and a control within a wildland urban interface setting to determine the effects of these treatments on soil nutrition, forest floor depth, and woody debris distributions. We randomly assigned the slash treatments and controls to 12 one-acre plots. Nitrogen, soil carbon, and magnesium concentrations within the soil components were not significantly …

Aspen Mortality In The Intermountain West: What Forest Inventory And Analysis Plots Tell Us, Fred Baker, John D. Shaw

North American Forest Ecology Workshop

Reports of a long-term decline in area dominated by aspen forests, coupled with increased mortality attributed to long term drought, have lead to concerns of increased mortality in aspen forests. We examined data collected by USDA Forest Service Inventory and Analysis (FIA) to quantify aspen mortality. Most aspen stands in the Intermountain West are older than 80 years, a recommended rotation age for the best sites. Plot mortality rate was not related to site index or stand age. Many stands, however, have stem density greater than one would expect for self-thinning stands. At a given latitude, aspen plots with mortality …

Ecosystem Recovery Following A Mountain Pine Beetle Outbreak In Northern British Columbia: A Case Of Shifting Values, Craig Delong, Bennita Kaytor, Bruce J. Rogers

North American Forest Ecology Workshop

The massive Mountain Pine Beetle (MPB) outbreak in northern British Columbia created a unique opportunity to examine ecosystem change over time in response to this disturbance. Prior to this outbreak, the dominant disturbance agents were wildfire and harvesting. A key question is how timber and habitat value will change over time in response to this disturbance and how this might be impacted by extensive clearcut salvage harvest. We have established 48 permanent sample plots in MPB impacted stands. Changes in stand structure, vegetation and functional wildlife habitat along with tree mortality and growth are being monitored. There has been almost …

Surface Fuel Loadings In Mulching Treatments In Colorado Coniferous Forests, Mike Battaglia, Chuck Rhoades, Monique E. Rocca, Michael G. Ryan

North American Forest Ecology Workshop

Recent large-scale, severe wildfires in the western United States have prompted extensive fuel treatment programs to reduce potential wildfire size and severity. Often, unmerchantable material is mechanically masticated because removing the material is cost-prohibitive. Mastication treatments involve shredding, chopping, or chipping small trees and/or shrubs into small chunks and leaving the material on site. While it is obvious that mechanical treatments will increase surface fuel loads, few studies have addressed how treatments alter fuel particle size and quantity. We examined how mastication treatments alter the distribution of woody material size by comparing paired masticated and untreated sites in lodgepole pine …

Regeneration Dynamics In Mountain Pine Beetle-Disturbed Forests: Lessons From The Current And The 1978-82 Flathead Epidemics, Dave Coates

North American Forest Ecology Workshop

There are two dominant mechanisms for development of a new tree layer and subsequent canopy recruitment after major canopy mortality events. First, regeneration may develop from a pulse of new post-disturbance recruitment. Alternatively, regeneration can be from the existing seedling bank that survived the canopy mortality event. The timing and extent of post-disturbance recruitment from seed and the relative importance of the existing seedling bank is poorly understood in MPB-disturbed forests. The recruitment of post-MPB seedlings is a function of seed-source availability, seedbed substrate, overstory structure, and time since MPB attack. In the northern interior, post-MPB recruitment was sparse in …

Patterns Of Structural Response To Simulated Partial Harvesting Of Boreal Mixedwood Stands, Mark Vanderwel, John P. Caspersen, Jay R. Malcolm

North American Forest Ecology Workshop

Partial harvesting has been proposed as an approach for maintaining late-successional structure within managed boreal mixedwood stands. Although little long-term data is available to evaluate its effects in this stand type, recent advances in individual tree-based stand modeling provide an opportunity to simulate post-harvest stand development following different retention harvests. Using the stand dynamics model SORTIE-ND, we examined 40-year patterns of structural change in response to different intensities (30%, 50%, and 70% removal) and spatial patterns (uniform, small patch, large patch) of harvesting in aspen-dominated mixedwood stands. We assessed structural dynamics through a suite of variables representing the distribution of …

Stand Density In South Florida Tropical Forests: Implications For The Function And Management Of Everglades Tree Islands, M. Ross, P. L. Ruiz, J. P. Sah, L. Lopez, N. Colbert

North American Forest Ecology Workshop

Within the continental US, the broadleaved forests of south Florida are exceptional in the abundance and diversity of tree species of tropical origin. Dry tropical forests are regionally most extensive in the upper Florida Keys, but are also represented on the mainland as fragments on limestone rocklands, and as “tree islands” embedded in the Everglades marsh. The exposed Everglades tree islands have a history of human use reaching back thousands of years, and are subject to frequent disturbance from tropical storms and hurricanes. They are sensitive to the hydrology of the surrounding marsh, which can lead to gradual changes in …

Long-Term Effects Of Alternative Group Selection Harvesting Designs On Stand Production, C. Halpin, C. G. Lorimer, J. J. Hanson, B. Palik

North American Forest Ecology Workshop

Interest in group selection harvesting has increased in recent years because of limitations associated with both clearcutting and single-tree selection. Field data have suggested that group selection openings can have higher production rates than single-tree gaps, but whether this translates into higher production rates at the stand level is not clear. We used CANOPY, a crown-based northern hardwoods model calibrated with data from uneven-aged and even-aged stands, to simulate sustainable harvest volumes of a number of different group selection approaches over 300 years, and also compared results with those from single-tree selection and clearcutting. When a combination of single-tree and …

Canopy Cover Prediction From Stand Density Attributes: Stocking, Crown Width, And Overlap Functions, Andrew Gray, Anne Mcintosh, Steve Garman

North American Forest Ecology Workshop

The goals for a wide range of forest management objectives are often stated in terms of the amount and layering of canopy cover. However, measuring canopy cover is labor intensive and different techniques provide widely different estimates. Several approaches have been developed to predict cover from common tree or stand-level density attributes, with varying results. This study used line-intercept measured tree cover from 1,424 Forest Inventory and Analysis (FIA) plots across Oregon to build predictive models from estimates of tree stocking, crown width, and other stand attributes (mean diameter, stand height, SDI, etc.). A variety of adjustments were applied to …

Influence Of Coarse Woody Material (Cwm) On Soil Microarthropods In Black Spruce-Feather Moss Forests Of Western Quebec, Enrique Doblas-Miranda, Timothy T. Work

North American Forest Ecology Workshop

Increasing demands for biofuels have opened the possibility for an overall decrease in the amount of residual coarse woody material (CWM) in forests. While CWM is known to be an important resource for saproxylic species that reside within downed logs, the relative importance of CWM for organisms residing beneath, in the soil is poorly understood. In this context, CWM likely modifies conditions as well as nutrient levels for soil communities that lie beneath. The relative importance of CWM for underlying soil communities may be accentuated in the black-spruce clay-belt region of Western Québec where soil nutrients are extremely limited by …

Effects Of Regeneration Practices On The Growth In Loblolly Pine Plantations From The Perspective Of Hierarchy Theory, Thomas Dean, D.Andrew Scott, Gorden Holley

North American Forest Ecology Workshop

The long-term effects of high-production harvesting and subsequent site-preparation practices are typically evaluated from a limiting resource perspective. Machines used in the harvesting compact the soil reducing aeration and uptake of water and nutrients. Moving the entire tree from the site removes organic matter and parts of the forest floor. Models translate these effects into direct consequences on tree growth and ultimately productivity. Trees response often conflicts with model predictions in many cases. Hierarchy theory does not require organisms to behave deterministically to account for behavior, but it does require a different approach. Our proposed talk will present an application …

Forest Ecosystem Dynamics In A Non-Linear World, Sybille Haeussler

North American Forest Ecology Workshop

Forest ecosystems across North America are under increasing stress from the accelerating pace of global change which involves simultaneous changes in resource availability (temperature, moisture, nutrients), disturbance regimes (fire, insects, diseases, extreme weather, logging, urbanization) and (3) species distributions (invasive organisms, threatened species). Interactions among the agents of global change can generate emergent or unexpected ecosystem behaviour. Complex systems science provides a strong theoretical foundation for understanding these factor interactions and provides many new mathematical and simulation modeling tools that can generate complex, non-linear behaviour and provide improved understanding of ecosystem response to global change. I present an updated version …