Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 68

Full-Text Articles in Entire DC Network

Wildland Fire Deficit And Surplus In The Western United States, 1984-2012, Sean A. Parks, Carol Miller, Marc-Andrè Parisien, Lisa M. Holsinger, Solomon Z. Dobrowski, John Abatzoglou Dec 2015

Wildland Fire Deficit And Surplus In The Western United States, 1984-2012, Sean A. Parks, Carol Miller, Marc-Andrè Parisien, Lisa M. Holsinger, Solomon Z. Dobrowski, John Abatzoglou

Forest Management Faculty Publications

Wildland fire is an important disturbance agent in the western US and globally. However, the natural role of fire has been disrupted in many regions due to the influence of human activities, which have the potential to either exclude or promote fire, resulting in a "fire deficit" or "fire surplus," respectively. In this study, we developed a model of expected area burned for the western US as a function of climate from 1984 to 2012. We then quantified departures from expected area burned to identify geographic regions with fire deficit or surplus. We developed our model of area burned as …


Spatial Aspects Of Tree Mortality Strongly Differ Between Young And Old-Growth Forests, Andrew J. Larson, James A. Lutz, Daniel C. Donato, James A. Freund, Mark E. Swanson, Janneke Hillrislambers, Douglas G. Sprugel, Jerry F. Franklin Nov 2015

Spatial Aspects Of Tree Mortality Strongly Differ Between Young And Old-Growth Forests, Andrew J. Larson, James A. Lutz, Daniel C. Donato, James A. Freund, Mark E. Swanson, Janneke Hillrislambers, Douglas G. Sprugel, Jerry F. Franklin

Forest Management Faculty Publications

Rates and spatial patterns of tree mortality are predicted to change during forest structural development. In young forests, mortality should be primarily density dependent due to competition for light, leading to an increasingly spatially uniform pattern of surviving trees. In contrast, mortality in old-growth forests should be primarily caused by contagious and spatially auto-correlated agents (e.g., insects, wind), causing spatial aggregation of surviving trees to increase through time. We tested these predictions by contrasting a three-decade record of tree mortality from replicated mapped permanent plots located in young (<60-year-old) and old-growth (>300-year-old) Abies amabilis forests. Trees in young forests died at a …


Suitable Days For Plant Growth Disappear Under Projected Climate Change: Potential Human And Biotic Vulnerability, Camilo Mora, Iain R. Caldwell, Jamie M. Caldwell, Micah R. Fisher, Brandon M. Genco, Steven W. Running Jun 2015

Suitable Days For Plant Growth Disappear Under Projected Climate Change: Potential Human And Biotic Vulnerability, Camilo Mora, Iain R. Caldwell, Jamie M. Caldwell, Micah R. Fisher, Brandon M. Genco, Steven W. Running

Ecosystem and Conservation Sciences Faculty Publications

Ongoing climate change can alter conditions for plant growth, in turn affecting ecological and social systems. While there have been considerable advances in understanding the physical aspects of climate change, comprehensive analyses integrating climate, biological, and social sciences are less common. Here we use climate projections under alternative mitigation scenarios to show how changes in environmental variables that limit plant growth could impact ecosystems and people. We show that although the global mean number of days above freezing will increase by up to 7% by 2100 under “business as usual” (representative concentration pathway [RCP] 8.5), suitable growing days will actually …


Quantifying Environmental Limiting Factors On Tree Cover Using Geospatial Data, Johnathan A. Greenberg, Maria J. Santos, Solomon Z. Dobrowski, Vern C. Vanderbilt, Susan L. Ustin Feb 2015

Quantifying Environmental Limiting Factors On Tree Cover Using Geospatial Data, Johnathan A. Greenberg, Maria J. Santos, Solomon Z. Dobrowski, Vern C. Vanderbilt, Susan L. Ustin

Forest Management Faculty Publications

Environmental limiting factors (ELFs) are the thresholds that determine the maximum or minimum biological response for a given suite of environmental conditions. We asked the following questions: 1) Can we detect ELFs on percent tree cover across the eastern slopes of the Lake Tahoe Basin, NV? 2) How are the ELFs distributed spatially? 3) To what extent are unmeasured environmental factors limiting tree cover? ELFs are difficult to quantify as they require significant sample sizes. We addressed this by using geospatial data over a relatively large spatial extent, where the wall-to-wall sampling ensures the inclusion of rare data points which …


2014 Future Earth Young Scientists Conference On Integrated Science And Knowledge Co-Production For Ecosystems And Human Well-Being, Ivy Shiue, Leah Samberg, Benard Kulohoma, Diana Dogaru, Carina Wyborn, Perrine Hamel, Peper Sogaard Jorgensen, Paul Lussier, Bharath Sundaram, Michelle Lim, Antonio Tironi Nov 2014

2014 Future Earth Young Scientists Conference On Integrated Science And Knowledge Co-Production For Ecosystems And Human Well-Being, Ivy Shiue, Leah Samberg, Benard Kulohoma, Diana Dogaru, Carina Wyborn, Perrine Hamel, Peper Sogaard Jorgensen, Paul Lussier, Bharath Sundaram, Michelle Lim, Antonio Tironi

Forest Management Faculty Publications

Effective integration in science and knowledge co-production is a challenge that crosses research boundaries, climate regions, languages and cultures. Early career scientists are crucial in the identification of, and engagement with, obstacles and opportunities in the development of innovative solutions to complex and interconnected problems. On 25-31 May 2014, International Council for Science and International Social Science Council, in collaboration with the International Network of Next-Generation Ecologists and Institute for New Economic Thinking: Young Scholars Initiative, assembled a group of early career researchers with diverse backgrounds and research perspectives to reflect on and debate relevant issues around ecosystems and human …


Changing Forest Structure Across The Landscape Of The Sierra Nevada, Ca, Usa, Since The 1930s, Christopher R. Dolanc, Hugh D. Safford, James H. Thorne, Solomon Z. Dobrowski Aug 2014

Changing Forest Structure Across The Landscape Of The Sierra Nevada, Ca, Usa, Since The 1930s, Christopher R. Dolanc, Hugh D. Safford, James H. Thorne, Solomon Z. Dobrowski

Forest Management Faculty Publications

Understanding the dynamics of forest structure aids inference regarding future forests and their distributions around the world. Over the last few decades, several papers have addressed changing forest structure in the Sierra Nevada, CA, USA, but these studies were limited in scope. We carried out a broad comparison of forest density and composition in the 1930s versus the 2000s for the west slope of the central and northern Sierra Nevada, using the two most extensive data sets available. Forests in this region have endured a long, complex history of human disturbance, and are now experiencing climatic shifts. We subdivided the …


Meanings And Robustness: Propositions For Enhancing Benefit Sharing In Social-Ecological Systems, Ernita Van Wyk, Charles Breen, Wayne A. Freimund Aug 2014

Meanings And Robustness: Propositions For Enhancing Benefit Sharing In Social-Ecological Systems, Ernita Van Wyk, Charles Breen, Wayne A. Freimund

Society and Conservation Faculty Publications

Given increased pressure on natural resources to deliver benefits, complex trade-offs and the regulation of behaviours in relation to benefits is of key concern. Behaviours that signify resistance to the rules according to which benefits are allocated prompt us to consider causal links and feedbacks between benefits, perceptions of benefits, meanings attached to the benefits, and the regulatory instruments that mediate the distribution of benefits. An understanding of how meanings influence the perception of benefits exposes the complexity inherent in how people perceive and allocate value to natural resource benefits. Meanings are personal, sometimes overlapping, context dependent and variable across …


Spatially Nonrandom Tree Mortality And Ingrowth Maintain Equilibrium Pattern In An Old-Growth Pseudotsuga–Tsuga Forest, James A. Lutz, Andrew J. Larson, Tucker J. Furniss, Daniel C. Donato, James A. Freund, Mark E. Swanson, Kenneth J. Bible, Jiquan Chen, Jerry F. Franklin Aug 2014

Spatially Nonrandom Tree Mortality And Ingrowth Maintain Equilibrium Pattern In An Old-Growth Pseudotsuga–Tsuga Forest, James A. Lutz, Andrew J. Larson, Tucker J. Furniss, Daniel C. Donato, James A. Freund, Mark E. Swanson, Kenneth J. Bible, Jiquan Chen, Jerry F. Franklin

Forest Management Faculty Publications

Mortality processes in old-growth forests are generally assumed to be driven by gap-scale disturbance, with only a limited role ascribed to density-dependent mortality, but these assumptions are rarely tested with data sets incorporating repeated measurements. Using a 12-ha spatially explicit plot censused 13 years apart in an approximately 500-year-old Pseudotsuga–Tsuga forest, we demonstrate significant density-dependent mortality and spatially aggregated tree recruitment. However, the combined effect of these strongly nonrandom demographic processes was to maintain tree patterns in a state of dynamic equilibrium. Density-dependent mortality was most pronounced for the dominant latesuccessional species, Tsuga heterophylla. The long-lived, early-seral Pseudotsuga menziesii …


Can Fire Atlas Data Improve Species Distribution Model Projections?, Shawn M. Crimmins, Solomon Z. Dobrowski, Alison R. Mynsberge, Hugh D. Safford Jul 2014

Can Fire Atlas Data Improve Species Distribution Model Projections?, Shawn M. Crimmins, Solomon Z. Dobrowski, Alison R. Mynsberge, Hugh D. Safford

Forest Management Faculty Publications

Correlative species distribution models (SDMs) are widely used in studies of climate change impacts, yet are often criticized for failing to incorporate disturbance processes that can influence species distributions. Here we use two temporally independent data sets of vascular plant distributions, climate data, and fire atlas data to examine the influence of disturbance history on SDM projection accuracy through time in the mountain ranges of California, USA. We used hierarchical partitioning to examine the influence of fire occurrence on the distribution of 144 vascular plant species and built a suite of SDMs to examine how the inclusion of fire-related predictors …


Fire Activity And Severity In The Western Us Vary Along Proxy Gradients Representing Fuel Amount And Fuel Moisture, Sean A. Parks, Marc-Andrè Parisien, Carol Miller, Solomon Z. Dobrowski Jun 2014

Fire Activity And Severity In The Western Us Vary Along Proxy Gradients Representing Fuel Amount And Fuel Moisture, Sean A. Parks, Marc-Andrè Parisien, Carol Miller, Solomon Z. Dobrowski

Forest Management Faculty Publications

Numerous theoretical and empirical studies have shown that wildfire activity (e.g., area burned) at regional to global scales may be limited at the extremes of environmental gradients such as productivity or moisture. Fire activity, however, represents only one component of the fire regime, and no studies to date have characterized fire severity along such gradients. Given the importance of fire severity in dictating ecological response to fire, this is a considerable knowledge gap. For the western US, we quantify relationships between climate and the fire regime by empirically describing both fire activity and severity along two climatic water balance gradients, …


Tourism And Protected Areas: A Growing Nexus Of Challenge And Opportunity, Stephen F. Mccool, Anna Spenceley Jun 2014

Tourism And Protected Areas: A Growing Nexus Of Challenge And Opportunity, Stephen F. Mccool, Anna Spenceley

Society and Conservation Faculty Publications

Three significant trends are converging with the result of increasing the importance of understanding and managing the nexus of tourism and protected areas. Firstly, international travel and tourism continues to grow significantly, resulting in more people wanting to visit, learn and appreciate their natural and cultural heritage. Secondly, international conservation efforts are increasingly dependent on protected areas serving as the cornerstone of slowing (ideally stopping) the loss of biological diversity. Thirdly, demands from society on protected areas are not only increasing, they are diversifying as well. Increased demand is, in part, the result of a growing human population that competes …


Local Spatial Structure Of Forest Biomass And Its Consequences For Remote Sensing Of Carbon Stocks, M. Rejou-Mechain, H. C. Muller-Landau, M. Detto, S. C. Thomas, T. Le Toan, S. S. Saatchi, J. S. Barreto-Silvia, N. A. Bourg, S. Bunyavejchewin, N. Butt, W. Y. Brockelman, M. Cao, D. Cardenas, J.-M. Chiang, G. B. Chuyong, K. Clay, R. Condit, H. S. Dattaraja, S. J. Davies, A. Duque, S. Esufali, C. Ewango, R.H.S. Fernando, C. D. Fletcher, I.A.U.N. Gunatilleke, Z. Hao, K. E. Harms, T. B. Hart, B. Herault, R. W. Howe, S. P. Hubbell, D. J. Johnson, D. Kenfack, A. J. Larson, L. Lin, Y. Lin, J. A. Lutz, J.-R. Makana, Y. Malhi, T. R. Marthews, R. W. Mcewan, S. M. Mcmahon, W. J. Mcshea, R. Muscarella, A. Nathalang, N.S.M. Noor, C. J. Nytch, A. A. Oliveira, R. P. Phillips, N. Pongpattananurak, R. Punchi-Manage, R. Salim, J. Schurman, R. Sukumar, H. S. Suresh, U. Suwanvecho, D. W. Thomas, J. Thompson, M. Uriarte, R. Valencia, A. Vicentini, A. T. Wolf, S. Yap, Z. Yuan, C. E. Zartman, J. K. Zimmerman, J. Chave Apr 2014

Local Spatial Structure Of Forest Biomass And Its Consequences For Remote Sensing Of Carbon Stocks, M. Rejou-Mechain, H. C. Muller-Landau, M. Detto, S. C. Thomas, T. Le Toan, S. S. Saatchi, J. S. Barreto-Silvia, N. A. Bourg, S. Bunyavejchewin, N. Butt, W. Y. Brockelman, M. Cao, D. Cardenas, J.-M. Chiang, G. B. Chuyong, K. Clay, R. Condit, H. S. Dattaraja, S. J. Davies, A. Duque, S. Esufali, C. Ewango, R.H.S. Fernando, C. D. Fletcher, I.A.U.N. Gunatilleke, Z. Hao, K. E. Harms, T. B. Hart, B. Herault, R. W. Howe, S. P. Hubbell, D. J. Johnson, D. Kenfack, A. J. Larson, L. Lin, Y. Lin, J. A. Lutz, J.-R. Makana, Y. Malhi, T. R. Marthews, R. W. Mcewan, S. M. Mcmahon, W. J. Mcshea, R. Muscarella, A. Nathalang, N.S.M. Noor, C. J. Nytch, A. A. Oliveira, R. P. Phillips, N. Pongpattananurak, R. Punchi-Manage, R. Salim, J. Schurman, R. Sukumar, H. S. Suresh, U. Suwanvecho, D. W. Thomas, J. Thompson, M. Uriarte, R. Valencia, A. Vicentini, A. T. Wolf, S. Yap, Z. Yuan, C. E. Zartman, J. K. Zimmerman, J. Chave

Forest Management Faculty Publications

Advances in forest carbon mapping have the potential to greatly reduce uncertainties in the global carbon budget and to facilitate effective emissions mitigation strategies such as REDD+. Though broad scale mapping is based primarily on remote sensing data, the accuracy of resulting forest carbon stock estimates depends critically on the quality of field measurements and calibration procedures. The mismatch in spatial scales between field inventory plots and larger pixels of current and planned remote sensing products for forest biomass mapping is of particular concern, as it has the potential to introduce errors, especially if forest biomass shows strong local spatial …


Consequences Of A Refuge For The Predator-Prey Dynamics Of A Wolf-Elk System In Banff National Park, Alberta, Canada, Joshua F. Goldberg, Mark Hebblewhite, Jonathan M. Bardsley Mar 2014

Consequences Of A Refuge For The Predator-Prey Dynamics Of A Wolf-Elk System In Banff National Park, Alberta, Canada, Joshua F. Goldberg, Mark Hebblewhite, Jonathan M. Bardsley

Wildlife Biology Faculty Publications

Refugia can affect predator-prey dynamics via movements between refuge and non-refuge areas. We examine the influence of a refuge on population dynamics in a large mammal predator-prey system. Wolves (Canis lupus) have recolonized much of their former range in North America, and as a result, ungulate prey have exploited refugia to reduce predation risk with unknown impacts on wolf-prey dynamics. We examined the influence of a refuge on elk (Cervus elaphus) and wolf population dynamics in Banff National Park. Elk occupy the Banff townsite with little predation, whereas elk in the adjoining Bow Valley experience higher wolf predation. The Banff …


Assessing Nutrient Limitation In Complex Forested Ecosystems : Alternatives To Large-Scale Fertilization Experiments, Benjamin W. Sullivan, Silvia Alvarez-Clare, Sarah C. Castle, Stephen Porder, Sasha C. Reed, Laura Schreeg, Cory C. Cleveland, Alan R. Townsend Mar 2014

Assessing Nutrient Limitation In Complex Forested Ecosystems : Alternatives To Large-Scale Fertilization Experiments, Benjamin W. Sullivan, Silvia Alvarez-Clare, Sarah C. Castle, Stephen Porder, Sasha C. Reed, Laura Schreeg, Cory C. Cleveland, Alan R. Townsend

Ecosystem and Conservation Sciences Faculty Publications

Quantifying nutrient limitation of primary productivity is a fundamental task of terrestrial ecosystem ecology, but in a high carbon dioxide environment it is even more critical that we understand potential nutrient constraints on plant growth. Ecologists often manipulate nutrients with fertilizer to assess nutrient limitation, yet for a variety of reasons, nutrient fertilization experiments are either impractical or incapable of resolving ecosystem responses to some global changes. The challenges of conducting large, in situ fertilization experiments are magnified in forests, especially the high-diversity forests common throughout the lowland tropics. A number of methods, including fertilization experiments, could be seen as …


Structure And Composition Of Old-Growth And Unmanaged Second-Growth Riparian Forests At Redwood National Park, Usa, Christopher R. Keyes, Emily K. Teraoka Feb 2014

Structure And Composition Of Old-Growth And Unmanaged Second-Growth Riparian Forests At Redwood National Park, Usa, Christopher R. Keyes, Emily K. Teraoka

Forest Management Faculty Publications

Restoration of second-growth riparian stands has become an important issue for managers of redwood (Sequoia sempervirens [D. Don] Endl.) forest reserves. Identifying differences between old-growth and second-growth forest vegetation is a necessary step in evaluating restoration needs and targets. The objective of this study was to characterize and contrast vegetation structure and composition in old-growth and unmanaged second-growth riparian forests in adjacent, geomorphologically similar watersheds at Redwood National Park. In the old-growth, redwood was the dominant overstory species in terms of stem density, basal area, and importance values. Second-growth was dominated by red alder (Alnus rubra Bong.), …


Examining Historical And Current Mixed-Severity Fire Regimes In Ponderosa Pine And Mixed-Conifer Forests Of Western North America, Dennis C. Odion, Chad T. Hanson, Andre Arsenault, William L. Baker, Dominick A. Dellasala, Richard L. Hutto, Walt Klenner, Max A. Moritz, Rosemary L. Sherriff, Thomas T. Veblen, Mark A. Williams Feb 2014

Examining Historical And Current Mixed-Severity Fire Regimes In Ponderosa Pine And Mixed-Conifer Forests Of Western North America, Dennis C. Odion, Chad T. Hanson, Andre Arsenault, William L. Baker, Dominick A. Dellasala, Richard L. Hutto, Walt Klenner, Max A. Moritz, Rosemary L. Sherriff, Thomas T. Veblen, Mark A. Williams

Biological Sciences Faculty Publications

There is widespread concern that fire exclusion has led to an unprecedented threat of uncharacteristically severe fires in ponderosa pine (Pinus ponderosa Dougl. ex. Laws) and mixed-conifer forests of western North America. These extensive montane forests are considered to be adapted to a low/moderate-severity fire regime that maintained stands of relatively old trees. However, there is increasing recognition from landscape-scale assessments that, prior to any significant effects of fire exclusion, fires and forest structure were more variable in these forests. Biota in these forests are also dependent on the resources made available by higher-severity fire. A better understanding of …


Invasive Plant Erodes Local Song Diversity In A Migratory Passerine, Yvette K. Ortega, Aubree Benson, Erick Greene Feb 2014

Invasive Plant Erodes Local Song Diversity In A Migratory Passerine, Yvette K. Ortega, Aubree Benson, Erick Greene

Biological Sciences Faculty Publications

Exotic plant invasions threaten ecosystems globally, but we still know little about the specific consequences for animals. Invasive plants can alter the quality of breeding habitat for songbirds, thereby impacting important demographic traits such as dispersal, philopatry, and age structure. These demographic effects may in turn alter song-learning conditions to affect song structure and diversity. We studied Chipping Sparrows (Spizella passerina) breeding in six savannas that were either dominated by native vegetation or invaded by spotted knapweed (Centaurea stoebe), an exotic forb known to diminish food resources and reproductive success. Here, we report that the prevalence of older birds was …


Agricultural Conversion Without External Water And Nutrient Inputs Reduces Terrestrial Vegetation Productivity, William Kolby Smith, Cory C. Cleveland, Sasha C. Reed, Steven W. Running Jan 2014

Agricultural Conversion Without External Water And Nutrient Inputs Reduces Terrestrial Vegetation Productivity, William Kolby Smith, Cory C. Cleveland, Sasha C. Reed, Steven W. Running

Ecosystem and Conservation Sciences Faculty Publications

Driven by global population and standard of living increases, humanity co-opts a growing share of the planet's natural resources resulting in many well-known environmental trade-offs. In this study, we explored the impact of agriculture on a resource fundamental to life on Earth: terrestrial vegetation growth (net primary production; NPP). We demonstrate that agricultural conversion has reduced terrestrial NPP by ~7.0%. Increases in NPP due to agricultural conversion were observed only in areas receiving external inputs (i.e., irrigation and/or fertilization). NPP reductions were found for ~88% of agricultural lands, with the largest reductions observed in areas formerly occupied by tropical forests …


Management For Mountain Pine Beetle Outbreak Suppression: Does Relevant Science Support Current Policy?, Diana Six, Eric Biber, Elisabeth Long Jan 2014

Management For Mountain Pine Beetle Outbreak Suppression: Does Relevant Science Support Current Policy?, Diana Six, Eric Biber, Elisabeth Long

Ecosystem and Conservation Sciences Faculty Publications

While the use of timber harvests is generally accepted as an effective approach to controlling bark beetles during outbreaks, in reality there has been a dearth of monitoring to assess outcomes, and failures are often not reported. Additionally, few studies have focused on how these treatments affect forest structure and function over the long term, or our forests’ ability to adapt to climate change. Despite this, there is a widespread belief in the policy arena that timber harvesting is an effective and necessary tool to address beetle infestations. That belief has led to numerous proposals for, and enactment of, significant …


Understanding Relationships Among Abundance, Extirpation, And Climate At Ecoregional Scales, Erik A. Beever, Solomon Z. Dobrowski, J. Long, A. R. Mynsberge, N. B. Piekielek Jul 2013

Understanding Relationships Among Abundance, Extirpation, And Climate At Ecoregional Scales, Erik A. Beever, Solomon Z. Dobrowski, J. Long, A. R. Mynsberge, N. B. Piekielek

Forest Management Faculty Publications

Recent research on mountain-dwelling species has illustrated changes in species' distributional patterns in response to climate change. Abundance of a species will likely provide an earlier warning indicator of change than will occupancy, yet relationships between abundance and climatic factors have received less attention. We tested whether predictors of counts of American pikas (Ochotona princeps) during surveys from the Great Basin region in 1994-1999 and 2003-2008 differed between the two periods. Additionally, we tested whether various modeled aspects of ecohydrology better predicted relative density than did average annual precipitation, and whether risk of site-wide extirpation predicted subsequent population counts of …


Nitrogen Cycling Responses To Mountain Pine Beetle Disturbance In A High Elevation Whitebark Pine Ecosystem, Megan P. Keville, Sasha C. Reed, Cory C. Cleveland Jun 2013

Nitrogen Cycling Responses To Mountain Pine Beetle Disturbance In A High Elevation Whitebark Pine Ecosystem, Megan P. Keville, Sasha C. Reed, Cory C. Cleveland

Ecosystem and Conservation Sciences Faculty Publications

Ecological disturbances can significantly affect biogeochemical cycles in terrestrial ecosystems, but the biogeochemical consequences of the extensive mountain pine beetle outbreak in high elevation whitebark pine (WbP) (Pinus albicaulis) ecosystems of western North America have not been previously investigated. Mountain pine beetle attack has driven widespread WbP mortality, which could drive shifts in both the pools and fluxes of nitrogen (N) within these ecosystems. Because N availability can limit forest regrowth, understanding how beetle-induced mortality affects N cycling in WbP stands may be critical to understanding the trajectory of ecosystem recovery. Thus, we measured above- and belowground N …


A Comparison Of Producer Gas, Biochar, And Activated Carbon From Two Distributed Scale Thermochemical Conversion Systems Used To Process Forest Biomass, Nathaniel Anderson, J. Greg Jones, Deborah Page-Dumroese, Daniel Mccollum, Stephen Baker, Daniel Loeffler, Woodam Chung Jan 2013

A Comparison Of Producer Gas, Biochar, And Activated Carbon From Two Distributed Scale Thermochemical Conversion Systems Used To Process Forest Biomass, Nathaniel Anderson, J. Greg Jones, Deborah Page-Dumroese, Daniel Mccollum, Stephen Baker, Daniel Loeffler, Woodam Chung

Forest Management Faculty Publications

Thermochemical biomass conversion systems have the potential to produce heat, power, fuels and other products from forest biomass at distributed scales that meet the needs of some forest industry facilities. However, many of these systems have not been deployed in this sector and the products they produce from forest biomass have not been adequately described or characterized with regards to chemical properties, possible uses, and markets. This paper characterizes the producer gas, biochar, and activated carbon of a 700 kg h−1 prototype gasification system and a 225 kg h−1 pyrolysis system used to process coniferous sawmill and forest …


Decision Making In Forest Road Planning Considering Both Skidding And Road Costs: A Case Study In The Hyrcanian Forest In Iran, M. Jourgholami, E. Abdi, Woodam Chung Jan 2013

Decision Making In Forest Road Planning Considering Both Skidding And Road Costs: A Case Study In The Hyrcanian Forest In Iran, M. Jourgholami, E. Abdi, Woodam Chung

Forest Management Faculty Publications

Hyrcanian forest is the only forest designated for commercial timber production in Iran. Ground-based skidding is the most common extraction system used in the forest, though large parts of the forest are still inaccessible due to the low road density (1-2 m ha-1). To facilitate timber harvesting in the forest, it has been proposed to increase the road density up to 20 m ha-1. The aim of this study was to incorporate the estimated skidding costs through a time study into an existing transportation planning tool, NETWORK 2000, to help decision making on forest road building. …


Latent Resilience In Ponderosa Pine Forest: Effects Of Resumed Frequent Fire, Andrew J. Larson, R. Travis Belote, C. Alina Cansler, Sean A. Parks, Matthew S. Dietz Jan 2013

Latent Resilience In Ponderosa Pine Forest: Effects Of Resumed Frequent Fire, Andrew J. Larson, R. Travis Belote, C. Alina Cansler, Sean A. Parks, Matthew S. Dietz

Forest Management Faculty Publications

Ecological systems often exhibit resilient states that are maintained through negative feedbacks. In ponderosa pine forests, fire historically represented the negative feedback mechanism that maintained ecosystem resilience; fire exclusion reduced that resilience, predisposing the transition to an alternative ecosystem state upon reintroduction of fire. We evaluated the effects of reintroduced frequent wildfire in unlogged, fire-excluded, ponderosa pine forest in the Bob Marshall Wilderness, Montana, USA. Initial reintroduction of fire in 2003 reduced tree density and consumed surface fuels, but also stimulated establishment of a dense cohort of lodgepole pine, maintaining a trajectory toward an alternative state. Resumption of a frequent …


A True Partnership, Paul Alaback Aug 2012

A True Partnership, Paul Alaback

Forest Management Faculty Publications

No abstract provided.


Ecological Importance Of Large-Diameter Trees In A Temperate Mixed-Conifer Forest, James A. Lutz, Andrew J. Larson, Mark E. Swanson, James A. Freund May 2012

Ecological Importance Of Large-Diameter Trees In A Temperate Mixed-Conifer Forest, James A. Lutz, Andrew J. Larson, Mark E. Swanson, James A. Freund

Forest Management Faculty Publications

Large-diameter trees dominate the structure, dynamics and function of many temperate and tropical forests. Although both scaling theory and competition theory make predictions about the relative composition and spatial patterns of large diameter trees compared to smaller diameter trees, these predictions are rarely tested. We established a 25.6 ha permanent plot within which we tagged and mapped all trees greater than or equal to 1 cm dbh, all snags greater than or equal to 10 cm dbh, and all shrub patches greater than or equal to 2 m2. We sampled downed woody debris, litter, and duff with line …


Biomass And Burning Characteristics Of Sugar Pine Cones, Anton T. Gabrielson, Andrew J. Larson, James A. Lutz, James J. Reardon Jan 2012

Biomass And Burning Characteristics Of Sugar Pine Cones, Anton T. Gabrielson, Andrew J. Larson, James A. Lutz, James J. Reardon

Forest Management Faculty Publications

We investigated the physical and burning characteristics of sugar pine (Pinus lambertiana Douglas) cones and their contribution to woody surface fuel loadings. Field sampling was conducted at the Yosemite Forest Dynamics Plot (YFDP), a 25.6 ha mapped study plot in Yosemite National Park, California, USA. We developed a classification system to describe sugar pine cones of different sizes and decay conditions, and examined differences among cone classes in biomass, bulk density, flame length, burning time, consumption, and relative contribution to surface fuel loads. Sugar pine cones comprised 601 kg ha-1 of surface fuels. Mature cones comprised 54% of …


Early-Stage Thinning For The Restoration Of Young Redwood--Douglas-Fir Forests In Northern Coastal California, Usa, Jesse F. Plummer, Christopher R. Keyes, J. Morgan Varner Jan 2012

Early-Stage Thinning For The Restoration Of Young Redwood--Douglas-Fir Forests In Northern Coastal California, Usa, Jesse F. Plummer, Christopher R. Keyes, J. Morgan Varner

Forest Management Faculty Publications

Among forested parks and reserves of the Pacific Coast of the United States, the restoration of late-successional conditions to second-growth stands is a management priority. Some traditional silvicultural treatments may help achieve this objective. We evaluated early-stage thinning as a restoration treatment to facilitate the growth and development of young (33- to 45-year old), homogeneous, and second-growth stands of coast redwood (Sequoia sempervirens) and Douglas-fir (Pseudotsuga menziesii). Targeting both stand-level responses and dominant (focal) tree responses for analysis, we compared structural attributes of adjacent thinned and unthinned stands, 12–17 years after thinning. Thinned stands displayed enhanced metrics of tree vigor, …


User's Guide To Snap For Arcgis : Arcgis Interface For Scheduling And Network Analysis Program, Woodam Chung, Dennis Dykstra, Fred Bower, Stephen O'Brien, Richard M. Abt, John Sessions Jan 2012

User's Guide To Snap For Arcgis : Arcgis Interface For Scheduling And Network Analysis Program, Woodam Chung, Dennis Dykstra, Fred Bower, Stephen O'Brien, Richard M. Abt, John Sessions

Forest Management Faculty Publications

This document introduces a computer software named SNAP for ArcGIS®, which has been developed to streamline scheduling and transportation planning for timber harvest areas. Using modern optimization techniques, it can be used to spatially schedule timber harvest with consideration of harvesting costs, multiple products, alternative destinations, and transportation systems. SNAP for ArcGIS attempts either to maximize a net present value or minimize discounted costs of harvesting and transportation over the planning horizon while meeting given harvest volume and acreage constraints. SNAP for ArcGIS works in the ArcGIS environment and provides an easy-to-use analytical tool for sophisticated spatial planning of timber …


Deriving Fuel Mass By Size Class In Douglas-Fir (Pseudotsuga Menziesii) Using Terrestrial Laser Scanning, Carl Seielstad, Crystal Stonesifer, Eric Rowell, Lloyd Queen Aug 2011

Deriving Fuel Mass By Size Class In Douglas-Fir (Pseudotsuga Menziesii) Using Terrestrial Laser Scanning, Carl Seielstad, Crystal Stonesifer, Eric Rowell, Lloyd Queen

Forest Management Faculty Publications

Requirements for describing coniferous forests are changing in response to wildfire concerns, bio-energy needs, and climate change interests. At the same time, technology advancements are transforming how forest properties can be measured. Terrestrial Laser Scanning (TLS) is yielding promising results for measuring tree biomass parameters that, historically, have required costly destructive sampling and resulted in small sample sizes. Here we investigate whether TLS intensity data can be used to distinguish foliage and small branches (less than or equal to 0.635 cm diameter; coincident with the one-hour timelag fuel size class) from larger branchwood (>0.635 cm) in Douglas-fir (Pseudotsuga …