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Full-Text Articles in Physical Sciences and Mathematics

Can Pastoral Linkages To Livestock Markets Be Sustained In Southern Ethiopia?, D. Layne Coppock, Getachew Gebru, Solomon Desta, Seyoum Tezera, Zewdu Edea Dec 2009

Can Pastoral Linkages To Livestock Markets Be Sustained In Southern Ethiopia?, D. Layne Coppock, Getachew Gebru, Solomon Desta, Seyoum Tezera, Zewdu Edea

Environment and Society Faculty Publications

The PARIMA project has facilitated collective action, empowerment of women, and increased involvement in livestock marketing among pastoralists on the Borana Plateau since 2001. Fifty-nine collective-action groups formed by PARIMA and her partners have been recently merged into market-oriented cooperatives, consistent with government policy. We used focus groups and participatory appraisals to assess the extent that market linkages have been sustained since previously reported in 2006. The markets have been growing, but are volatile. Members report they need access to early warning and livestock market-information systems, as well as more capital, to promote trade. Export firms have imposed added conditions …


Costs Of Implementing Collective Action And Capacity Building Among Pastoralists In Southern Ethiopia, D. Layne Coppock, Seyoum Tezera, Solomon Desta Dec 2009

Costs Of Implementing Collective Action And Capacity Building Among Pastoralists In Southern Ethiopia, D. Layne Coppock, Seyoum Tezera, Solomon Desta

Environment and Society Faculty Publications

Since 2000, the PARIMA project has implemented risk-management activities among semi-settled pastoralists in southern Ethiopia. The goal has been to improve human welfare via collective action and capacity building. Outcomes include progress in income generation, asset conservation, and livelihood diversification. Fifty-nine collective-action groups were created. Dominated by women, they included over 2,000 founding members and groups have recently merged to form 37 cooperatives, consistent with government policy. Creating sustainable impacts via collective action and capacity building requires many inputs. Taking raw, illiterate volunteers and transforming them into sustainable groups took up to three years, on average. Costs of implementing this …


Eleven Years Of Parima Activities In North-Central Kenya: Impacts On Egerton University And Neighboring Communities, D. Layne Coppock, Abdillahi Aboud, Mark Mutinda, Stellamaris Muthoka Dec 2009

Eleven Years Of Parima Activities In North-Central Kenya: Impacts On Egerton University And Neighboring Communities, D. Layne Coppock, Abdillahi Aboud, Mark Mutinda, Stellamaris Muthoka

Environment and Society Faculty Publications

The PARIMA project was created to improve the well-being of pastoralists and agro-pastoralists in northern Kenya and southern Ethiopia via risk-management research, training, and outreach. The project began to collaborate with Egerton University’s Department of Natural Resources in 1998 and many joint activities were undertaken over the next 11 years. Among them were regional household research on pastoral risks and their management, a training program for Egerton teaching staff to obtain post-graduate degrees, facilitation of Egerton faculty and staff to attend professional meetings, and provision of computer hardware and software that led to the creation of a GIS teaching and …


Simple Cooling Method Improves The Quality Of Marketed Camel Milk In Northern Kenya, D. Layne Coppock, A. O. Adongo, F. Wayua, I. J. Sagalla, H. K. Walaga, C. Amboga Dec 2009

Simple Cooling Method Improves The Quality Of Marketed Camel Milk In Northern Kenya, D. Layne Coppock, A. O. Adongo, F. Wayua, I. J. Sagalla, H. K. Walaga, C. Amboga

Environment and Society Faculty Publications

Milk marketing is important for many pastoralists to generate income, especially poor households with little else to sell. Milk is accumulated at pastoral settlements and transported to local markets on foot, by pack animals, or in vehicles. Despite challenges of heat and long-distance travel, pastoralists or traders do not attempt to cool marketed milk and possibly reduce risk of spoilage. Milk spoilage is an important problem that limits urban consumer demand. Our research objective was to determine effects of water-soaked hemp (burlap), wrapped around plastic jerry cans, on reducing milk temperature and enhancing quality of marketed camel milk, a key …


Alternative Sampling And Analysis Methods For Digital Soil Mapping In Southwestern Utah, Colby W. Brungard Dec 2009

Alternative Sampling And Analysis Methods For Digital Soil Mapping In Southwestern Utah, Colby W. Brungard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Digital soil mapping (DSM) relies on quantitative relationships between easily measured environmental covariates and field and laboratory data. We applied innovative sampling and inference techniques to predict the distribution of soil properties, soil attributes, taxonomic classes, and dominant vegetation across a 30,000-ha complex Great Basin landscape in southwestern Utah. This arid rangeland was characterized by rugged topography, diverse vegetation, and intricate geology. Environmental covariates calculated from digital elevation models (DEM) and spectral satellite data were used to represent factors controlling soil development and distribution. We investigated optimal sample size and sampled the environmental covariates using conditioned Latin Hypercube Sampling (cLHS). …


Hydro-Economic Models: Concepts, Design, Applications, And Future Prospects, Julien Harou, Manuel Pulido-Velazquez, David E. Rosenberg, Josue Medellin-Azuara, Jay Lund, Richard Howitt Sep 2009

Hydro-Economic Models: Concepts, Design, Applications, And Future Prospects, Julien Harou, Manuel Pulido-Velazquez, David E. Rosenberg, Josue Medellin-Azuara, Jay Lund, Richard Howitt

Civil and Environmental Engineering Faculty Publications

Future water management will shift from building new water supply systems to better operating existing ones. The variation of water values in time and space will increasingly motivate efforts to address water scarcity and reduce water conflicts. Hydro-economic models represent spatially distributed water resource systems, infrastructure, management options and economic values in an integrated manner. In these tools water allocations and management are either driven by the economic value of water or economically evaluated to provide policy insights and reveal opportunities for better management. A central concept is that water demands are not fixed requirements but rather functions where quantities …


East Canyon Reservoir Water Intake Structure Final Environmental Assessment And Finding Of No Significant Impact, United States Department Of The Interior, Bureau Of Reclamation Sep 2009

East Canyon Reservoir Water Intake Structure Final Environmental Assessment And Finding Of No Significant Impact, United States Department Of The Interior, Bureau Of Reclamation

Environmental Assessments (UT)

The purpose of the proposed action is to authorize SWDC to build and operate facilities to deliver water to the Park City/Snyderville Basin area (Figure 1.2). The need for the proposed action is a growing demand for water in the Park City/Snyderville Basin area due to population growth and increased development of recreation facilities and vacation homes.


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 …


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 …


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 …


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 …


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 …


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, …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …