Forest Sciences Commons^™

Modeling Environmental Factors Related To Drought-Induced Tree Mortality Based On Lidar And Hyperspectral Imagery, Lauren Nicole Sharwood

Dissertations and Theses

Climate change is projected to bring more frequent and prolonged droughts, causing widespread forest die-off. Identifying tree mortality over large spatial extents in response to the most recent California drought will help forest managers and conservationists understand where there may be a greater likelihood of future die-offs. In order to find more at-risk areas, this study evaluated how interacting site-specific topographic, climate, substrate, and stand characteristics mediated tree mortality in the Central Sierra Nevada during the 2012-2016 drought. The author used lidar and hyperspectral imagery provided by the National Ecological Observatory Network to identify individual dead trees using the Random …

Variability In Historical Fire Patterns Of A Moist Mixed-Conifer Forest In The Northern Blue Mountains Of Oregon, Laura Marie Platt

Dissertations and Theses

High variability in historical fire patterns characteristic to mixed-severity fire regimes is expected to have contributed to a structurally heterogeneous landscape throughout much of the forested ecosystems of the western United States. After more than a hundred years of fire exclusion in the region, many forests have shifted to a more homogeneous structure, which raises concern regarding these forests' ability to sustain expected increases in fire activity with a warming climate. The shift is not uniform across the west, however, and differences in historical disturbance patterns and changes due to land management are not well characterized in forests across a …

Tree Canopy Cover And Potential In Portland, Or: A Spatial Analysis Of The Urban Forest And Capacity For Growth, Jeff Ramsey

Dissertations and Theses

Urban forests have positive impacts on human and ecosystem health, reduce stress on aging stormwater infrastructure, increase property values, and reduce energy consumption. The scale of these benefits ranges from the hyper-local to the global. While the benefits of urban forests can extend well beyond the boundaries of cities, they often do not reach all residents of the city equally. Urban forest policies do not adequately address environmental equity or employ planting strategies with knowledge of the social and political factors that determine the spatial variations of tree canopy extent in cities. Chapter I analyzes the determinants of current canopy …

Understory Diversity And Succession On Coarse Woody Debris In A Coastal, Old-Growth Forest, Oregon, Shannon Lee Mcdonald

Dissertations and Theses

This research examines the relationship between understory plant diversity and logs in a Pacific Northwest (PNW) Sitka spruce (Picea sitchensis)-western hemlock (Tsuga heterophylla) old-growth, coastal forest. These forests are renowned for their high forest productivity, frequent wind storms, and slow log decomposition rates that produce unmatched accumulations of coarse woody debris (CWD) yet few studies have examined the relationship between CWD and understory vegetation ecology. My research addressed this topic by comparing understory plant census data between paired fallen log and forest floor sites (n=20 pairs). My objectives were to: 1) determine the influence of substrate type on community composition …

Forest Landscape Change Detection In The Meseta PuréPecha, MichoacáN, MéXico, John Malcolm Chase

Dissertations and Theses

Social, political, economic, and environmental factors converge in developing countries to stimulate high rates of deforestation. Forest conversion reduces biodiversity, contributes to carbon loading of the atmosphere, alters the global water balance, and degrades the quality of life for rural people. Mexico is the fifth most biologically diverse country in the world and temperate and tropical forests in Mexico are rapidly disappearing with environmental and cultural repercussions for people and ecosystems.

Social, political, economic, and environmental factors converge in developing countries to stimulate high rates of deforestation. Forest conversion reduces biodiversity, contributes to carbon loading of the atmosphere, alters the …

The Effect Of Declining Timber Supplies And Productivity Increases In The Forest Products Industries Upon Employment In Douglas County, Oregon, Patrick L. Burden

Dissertations and Theses

This thesis examines some of the factors that will have significant impact upon employment in Douglas County, Oregon to the year 2000.

The major question this research attempts to answer is: Given a continuation of current policies and programs, what will future employment levels in the forest product industries and total employment levels in all industries in Douglas County be to the year 2000.