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

Forest Sciences Commons

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

PDF

Portland State University

2011

Discipline
Keyword
Publication
Publication Type

Articles 1 - 6 of 6

Full-Text Articles in Forest Sciences

The Influence Of Land Use And Climate Change On Forest Biomass And Composition In Massachusetts, Usa, Jonathan R. Thompson, David R. Foster, Robert M. Scheller, David Kittridge Oct 2011

The Influence Of Land Use And Climate Change On Forest Biomass And Composition In Massachusetts, Usa, Jonathan R. Thompson, David R. Foster, Robert M. Scheller, David Kittridge

Environmental Science and Management Faculty Publications and Presentations

Land use and climate change have complex and interacting effects on naturally dynamic forest landscapes. To anticipate and adapt to these changes, it is necessary to understand their individual and aggregate impacts on forest growth and composition. We conducted a simulation experiment to evaluate regional forest change in Massachusetts, USA over the next 50 years (2010–2060). Our objective was to estimate, assuming a linear continuation of recent trends, the relative and interactive influence of continued growth and succession, climate change, forest conversion to developed uses, and timber harvest on live aboveground biomass (AGB) and tree species composition. We examined 20 …


Effectiveness Of Forest Management Strategies To Mitigate Effects Of Global Change In South-Central Siberia, Eric J. Gustafson, Anatoly Z. Shvidenko, Robert M. Scheller Jul 2011

Effectiveness Of Forest Management Strategies To Mitigate Effects Of Global Change In South-Central Siberia, Eric J. Gustafson, Anatoly Z. Shvidenko, Robert M. Scheller

Environmental Science and Management Faculty Publications and Presentations

We investigated questions about the ability of broad silvicultural strategies to achieve multiple objectives (reduce disturbance losses, maintain the abundance of preferred species, mitigate fragmentation and loss of age-class diversity, and sequester aboveground carbon) under future climate conditions in Siberia. We conducted a factorial experiment using the LANDIS-II landscape disturbance and succession model. Treatments included varying the size and amount of areas cut and the cutting method (selective or clearcut). Simultaneously, the model simulated natural disturbances (fire, wind, insect out-breaks) and forest succession under projected future climate conditions as predicted by an ensemble of global circulation models. The cutting method …


Lakeview, Oregon: The Little Town That Collaboration Saved, Laura Singer, Emily Rome, Liubov Doerr, Mari Saint Pierre, Dick Townsend, Alexander Freed, Daniel Mcduffee, Greg Nugent, Gretchen Olsen, Kirk Rea, Melissa Long, Ross D. Lamberth, Shelley D. Searle Jul 2011

Lakeview, Oregon: The Little Town That Collaboration Saved, Laura Singer, Emily Rome, Liubov Doerr, Mari Saint Pierre, Dick Townsend, Alexander Freed, Daniel Mcduffee, Greg Nugent, Gretchen Olsen, Kirk Rea, Melissa Long, Ross D. Lamberth, Shelley D. Searle

National Policy Consensus Center Publications and Reports

The assessment team was made up of a diverse group - eight undergraduate PSU students, two graduate teaching assistants and one instructor - representing all ages, interests and fields of study. However, one thing everyone had in common was an interest in learning about collaboration and how it might be used to improve the state of Oregon, the nation and even the world. To that end, everyone participating in the Capstone course hoped to enhance their “Skills for Being an Effective Collaborator.” As this is the first time this course has been offered, we hope our success in meeting its …


Structuring Expert Input For A Knowledge-Based Approach To Watershed Condition Assessment For The Northwest Forest Plan, Usa, Sean N. Gordon, Kirsten Gallo Jan 2011

Structuring Expert Input For A Knowledge-Based Approach To Watershed Condition Assessment For The Northwest Forest Plan, Usa, Sean N. Gordon, Kirsten Gallo

Institute for Sustainable Solutions Publications and Presentations

Assessments of watershed condition for aquatic and riparian species often have to rely on expert opinion because of the complexity of establishing statistical relationships among the many factors involved. Such expert-based assessments can be difficult to document and apply consistently over time and space. We describe and reflect on the process of developing a computer-based decision support application from expert judgments for assessing aquatic and riparian conditions over the 100,000 km2 managed by the US federal government under the Northwest Forest Plan. The decision support system helped structure and document the assessment process and provided consistency and transparency to the …


Propagule Pressure And Disturbance Drive The Spread Of An Invasive Grass, Brachypodium Sylvaticum, Laura Alayna Vician Taylor Jan 2011

Propagule Pressure And Disturbance Drive The Spread Of An Invasive Grass, Brachypodium Sylvaticum, Laura Alayna Vician Taylor

Dissertations and Theses

The invasibility, or susceptibility of an ecosystem to biological invasion is influenced by changes in biotic and abiotic resistance often due to shifts in disturbance regime. The magnitude of invasive propagule pressure interacts with an ecosystem's invasibility to determine the extent of a biological invasion. I examined how propagule pressure, forest community structure and disturbance interact to influence the invasibility of temperate Pacific Northwest forests by the newly-invasive grass, Brachypodium sylvaticum. My goal was to identify which of these factors is most instrumental in enabling the shift from establishment to population growth in B. sylvaticum at the edge of …


Interception In Open-Grown Douglas-Fir (Pseudotsuga Menziesii) Urban Canopy, Mitchell Bixby Jan 2011

Interception In Open-Grown Douglas-Fir (Pseudotsuga Menziesii) Urban Canopy, Mitchell Bixby

Dissertations and Theses

I hypothesized that Douglas-fir trees (Pseudotsuga menziesii) standing apart from other trees ('open-grown') will intercept more rainfall than Douglas-fir trees standing near other trees ('closed-canopy'). Open-grown trees differ structurally and are more common in urban settings, yet have been infrequently studied. Existing literature, based primarily on closed-canopy trees, suggests Douglas-fir trees in Pacific Northwest forests intercept approximately 25% of rainfall annually. Because open-grown trees have more vertical leaf area than individual trees in closed-canopy forests, I expected to find higher interception by open-grown trees.

I collected throughfall under four open-grown Douglas-firs using six static collectors ('buckets') per tree, …