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Utah State University

2009

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Articles 31 - 60 of 208

Full-Text Articles in Physical Sciences and Mathematics

Residential Water Demand Under Alternative Rate Structures: Simulation Approach, David E. Rosenberg Aug 2009

Residential Water Demand Under Alternative Rate Structures: Simulation Approach, David E. Rosenberg

Civil and Environmental Engineering Faculty Publications

Econometricians have long studied the effect of price on residential water demand and the impact on water use of the rate (tariff) structure in which price signals are embedded. This paper applies an existing deductive model of residential water use for the intermittent supply system in Amman, Jordan and simulates demand responses across a cross section of households over many uniform, increasing block, and linear price (quadratic charge) rate structures at historically low and significantly higher prices. Results show inelastic piped water demand responses for all rate structures at historically low prices similar to findings from a prior econometric study …

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Analysis And Modeling Of Ducted And Evanescent Gravity Waves Observed In The Hawaiian Airglow, D. B. Simkhada, J. B. Snively, Michael J. Taylor, S. J. Franke Aug 2009

Analysis And Modeling Of Ducted And Evanescent Gravity Waves Observed In The Hawaiian Airglow, D. B. Simkhada, J. B. Snively, Michael J. Taylor, S. J. Franke

All Physics Faculty Publications

Short-period gravity waves of especially-small horizontal scale have been observed in the Maui, Hawaii airglow. Typical small-scale gravity wave events have been investigated, and intrinsic wave propagation characteristics have been calculated from simultaneous meteor radar wind measurements. Here we report specific cases where wave structure is significantly determined by the local wind structure, and where wave characteristics are consistent with ducted or evanescent waves throughout the mesopause region. Two of the documented events, exhibiting similar airglow signatures but dramatically different propagation conditions, are selected for simple numerical modeling case studies. First, a Doppler-ducted wave trapped within relatively weak wind flow …

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Testing And Application Of Surrogate Surfaces For Understanding Potential Gaseous Oxidized Mercury Dry Deposition, Seth N. Lyman, Mae Sexauer Gustin, Eric M. Prestbo, Phillip I. Kilner, Eric Edgerton, Ben Hartsell Jul 2009

Testing And Application Of Surrogate Surfaces For Understanding Potential Gaseous Oxidized Mercury Dry Deposition, Seth N. Lyman, Mae Sexauer Gustin, Eric M. Prestbo, Phillip I. Kilner, Eric Edgerton, Ben Hartsell

USU Uintah Basin Faculty Publications

Currently there is no standard method for measurement of atmospheric mercury dry deposition. While all operationally defined forms of atmospheric mercury (elemental, oxidized, and particulate) can be dry deposited, oxidized forms are of concern due to high deposition velocities, water solubility, and reactivity. This paper describes the development of a surrogate surface for characterizing potential dry deposition of gaseous oxidized mercury (GOM). Laboratory tests showed that the surface collected HgCl2, HgBr2, and HgO with equal efficiency, and deposition was not significantly influenced by temperature, humidity, or ozone concentrations. Deposition of mercury to surfaces in field deployments was correlated with GOM …

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The Effect Of Negative Energy Shells On Schwarzschild Spacetime And Their Penrose Diagrams, Jeffrey Hazboun, Tevian Dray Jul 2009

The Effect Of Negative Energy Shells On Schwarzschild Spacetime And Their Penrose Diagrams, Jeffrey Hazboun, Tevian Dray

Presentations

No abstract provided.

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The Effect Of Negative-Energy Shells On The Schwarzschild Black Hole, Jeffrey Hazboun, Tevian Dray Jul 2009

The Effect Of Negative-Energy Shells On The Schwarzschild Black Hole, Jeffrey Hazboun, Tevian Dray

Faculty publications

We construct Penrose diagrams for Schwarzschild spacetimes joined by massless shells of matter, in the process correcting minor flaws in the similar diagrams drawn by Dray and ’t Hooft (Commun Math Phys 99:613–625, 1985), and confirming their result that such shells generate a horizon shift. We then consider shells with negative energy density, showing that the horizon shift in this case allows for travel between the heretofore causally separated exterior regions of the Schwarzschild geometry. These drawing techniques are then used to investigate the properties of successive shells, joining multiple Schwarzschild regions. Again, the presence of negative-energy shells leads to …

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Theory Of Planned Behavior Model Fit Using Atod Prevention Program Data, Ying Jin Jul 2009

Theory Of Planned Behavior Model Fit Using Atod Prevention Program Data, Ying Jin

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

This report is to test the Theory of Planned Behavior (TpB) model fit using the data collected from the ATOD Prevention Program conducted by the Operation Snowball Program from year 2004 to 2007 in Naperville, Illinois. Measurement Model and Structural Equation Modeling are used as principal modeling methods to test internal consistency of assigned measures for each construct and the dependency between constructs respectively. The results show that the ATOD Prevention Program data does not fit the TpB model perfectly. Extra paths should be added to the original theoretical model in order to obtain a satisfactory model fit.

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Fuel Loads, Fire Severity, And Tree Mortality In Florida Keys Pine Forests, Jay Sah, Mike S. Ross, Danielle Ogarcak, Jim R. Snyder Jun 2009

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 …

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Overstory Dynamics In An Uncut Pine-Hardwood Stand: Lessons From Seventy Years Of Passive Management, Don Bragg, Michael G. Shelton Jun 2009

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 …

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What Drives Decomposition Rates Of Coarse Woody Debris (Cwd)?, Steffen Herrmann, Jurgen Bauhus Jun 2009

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 …

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Seed Release In Lodgepole Pine Forests After Mountain Pine Beetle Outbreak, Francios Teste, Vic J. Lieffers, Simon M. Landhausser Jun 2009

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 …

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Potential Effects Of Climate Change On Mixed Severity Fire Regimes, Jessica Halofsky, Dave L. Peterson Jun 2009

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, …

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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 Jun 2009

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 …

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An Integrated Study Investigating Masticated Fuel Treatments In The Rocky Mountains, Robert Keane, Helen Y. Smith Jun 2009

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 …

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A Post-Fire Index For Describing Mixed Severity Outcomes After Wildfire, Theresa Jain, Russel T. Graham, David S. Pilliod, Leigh Lentile Jun 2009

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 …

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Mechanical Mastication Showed Fewer Negative Above-And Belowground Impacts Than Slash Pile Burning, Suzanne Neal, Carolyn H. Sieg, Catherine A. Gehring, Matthew A. Bowker Jun 2009

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 …

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The Influence Of Mastication On Soils And Fuels In Moist And Dry Forests Of The Northern Rocky Mountains, Theresa Jain, Russel T. Graham Jun 2009

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 …

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Aspen Mortality In The Intermountain West: What Forest Inventory And Analysis Plots Tell Us, Fred Baker, John D. Shaw Jun 2009

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 …

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Ecosystem Recovery Following A Mountain Pine Beetle Outbreak In Northern British Columbia: A Case Of Shifting Values, Craig Delong, Bennita Kaytor, Bruce J. Rogers Jun 2009

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 …

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Surface Fuel Loadings In Mulching Treatments In Colorado Coniferous Forests, Mike Battaglia, Chuck Rhoades, Monique E. Rocca, Michael G. Ryan Jun 2009

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 …

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Regeneration Dynamics In Mountain Pine Beetle-Disturbed Forests: Lessons From The Current And The 1978-82 Flathead Epidemics, Dave Coates Jun 2009

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 …

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Patterns Of Structural Response To Simulated Partial Harvesting Of Boreal Mixedwood Stands, Mark Vanderwel, John P. Caspersen, Jay R. Malcolm Jun 2009

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 …

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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 Jun 2009

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 …

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Long-Term Effects Of Alternative Group Selection Harvesting Designs On Stand Production, C. Halpin, C. G. Lorimer, J. J. Hanson, B. Palik Jun 2009

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 …

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Canopy Cover Prediction From Stand Density Attributes: Stocking, Crown Width, And Overlap Functions, Andrew Gray, Anne Mcintosh, Steve Garman Jun 2009

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 …

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Influence Of Coarse Woody Material (Cwm) On Soil Microarthropods In Black Spruce-Feather Moss Forests Of Western Quebec, Enrique Doblas-Miranda, Timothy T. Work Jun 2009

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 …

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Effects Of Regeneration Practices On The Growth In Loblolly Pine Plantations From The Perspective Of Hierarchy Theory, Thomas Dean, D.Andrew Scott, Gorden Holley Jun 2009

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 …

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Forest Ecosystem Dynamics In A Non-Linear World, Sybille Haeussler Jun 2009

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 …

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Seven-Year Results Of Testing Paper Mill Residual Sludge As A Soil Ameliorant Of Iron Mine Tailings, M. Bridgen Jun 2009

Seven-Year Results Of Testing Paper Mill Residual Sludge As A Soil Ameliorant Of Iron Mine Tailings, M. Bridgen

North American Forest Ecology Workshop

Paper mill residual solids, extracted from a settling pond in Newton Falls, NY, were tested for their efficacy as a site ameliorant. The test site was a twenty-five-year-old sand tailings, created by a former iron mining operation. Sludge was applied in trenches, as either 20% or 40% solids. Black locust, hybrid poplar, and willow seedlings were planted over the site to establish near forest-like vegetation. Seven years after establishment, overall survival is about 80%. The entrenched sludge provided increased soil moisture retention, deeper root development, increased nutrient availability and retention, and larger leaf sizes. Sludge applications resulted in greater above-ground …

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Aspen Ecology In The United States: Recent Advances And Future Needs, Paul C. Rogers Jun 2009

Aspen Ecology In The United States: Recent Advances And Future Needs, Paul C. Rogers

North American Forest Ecology Workshop

This presentation (along with a similar Canadian perspective) will offer a context for subsequent papers in the Advances in North American Aspen Ecology session. Collectively, we hope to outline major areas of research in North America, especially as they relate to perceived management needs. There is a long and rich history of ecological research in aspen systems of the United States. Probably the most striking long-term change, from a managerial perspective, has been a shift toward biological benefits of aspen as opposed to past avoidance, or even active denudation, of these systems in favor of more commercial species. This talk …

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How Best Should We Manage Hybrid Poplar Plantations? Interactions Of Site Preparation, Vegetation Control And Fertilization, Simon Bilodeau-Gauthier, David Pare, Christian Messier Jun 2009

How Best Should We Manage Hybrid Poplar Plantations? Interactions Of Site Preparation, Vegetation Control And Fertilization, Simon Bilodeau-Gauthier, David Pare, Christian Messier

North American Forest Ecology Workshop

The silviculture of hybrid poplars is a promising solution to reduce the pressure on natural forests while maintaining the wood supply to industries. However, hybrid poplars are sensitive to competing vegetation and to inadequate soil conditions and fertility. Possible management tools include mechanical site preparation (MSP), vegetation control, and fertilization. We present here the results after five years of growth for eight formerly forested sites (40 hectares total) on Podzols in the province of Quebec, Canada. The experimental design combines four MSP treatments (harrowing, scarifying, mounding, and no preparation) with four frequencies of plant competition control by brushing (from never …

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