Forest managers of public lands in western Oregon and Washington have become increasingly interested in creating additional conifer cohorts in young, even-aged, second-growth Douglas-fir stands. The purpose of our research was to assess the establishment, survival, and growth of naturally-regenerated and underplanted conifers 10-13 years after overstory thinning and understory...
Previous research examining the influences of post-fire salvage logging on abundances of birds has focused primarily on the response of cavity-nesting species. There is limited research in regard to the impact of salvage logging on a broader range of bird species. In addition, little is known about how different intensities...
Bale Mountains National Park (BMNP) is currently considered the most important conservation area in Ethiopia. BMNP was established over forty years ago to protect Ethiopian endemic fauna and to preserve an array of habitat types including Afroalpine, Afromontane, and the second largest natural humid forest (Harenna forest) left in Ethiopia....
Two case studies of 5 ecosystems were used to examine the nitrogen fixation rate of red alder (Alnus rubra Bong.), varnishleaf (Ceanothus velutinus var. laevigatus (Hook.) T. & G.), deerbrush (C. i ntegerrimus H. & A.), and snowbrush (C. velutinus var. velutinus Dougl. Ex Hook). The first case study assayed...
Intensive forest management (IFM, dense conifer plantings and herbicide applications) may alter the characteristics of early seral plant communities that function as major habitat resources for a host of wildlife species, including cervid herbivores such as Cervus elaphus and Odocoileus hemionus. Such large herbivores can also substantially affect plant community...
Investigations of the Pleistocene peopling of the New World require archaeologists to establish an understanding of the paleoenvironmental conditions that would have affected early foraging peoples. Other studies have focused on the timing and route of migration and the peopling of the Americas. This project contributes to the body of...
This collection of three manuscripts serves to improve methods for collecting, interpreting, and utilizing autocorrelated data from headwater stream networks. Each stream network is comprised of linear segments. These segments lie within a unique branching structure that connects the segments via flowing water, and the connectivity provided by water varies...
Tree species directly and indirectly affect soil nutrient cycles. I sought to characterize soils and foliage associated with four common canopy tree species (Douglas-fir, western hemlock, western redcedar, and bigleaf maple) in mixed-species old-growth forests of the Oregon Coast Range and to determine whether and how soils differ among the...
Native America tribes and community members throughout Oregon have asserted a strong opposition to the fossil fuel industry’s attempt to expand railways, build pipelines, and construct refineries, holding facilities, and export terminals. Despite the limited presence of fossil fuel infrastructure in the state, however, the industry is actively pursuing permits...
Small pelagic fishes (SPF), such as anchovies and sardines, are ecologically important due to their large abundance and intermediate trophic position that links plankton production to upper trophic levels. They are also economically important, supporting large fisheries that contribute to one fourth of the world fish landings. Reproductive success in...
Ungulates comprise some of the most well researched and intensely managed wildlife populations on earth. As such, they are recognized as ideal study subjects for developing and modifying management tools or theories (Danell et al. 1994, Shipley 2010). An introduced moose (Alces alces gigas) population on the Copper River Delta...
Large areas of non-coniferous communities in southwestern Oregon are thinned to reduce fire hazard and accomplish ecosystem restoration, under the assumption that current fuel loads are unnaturally high. Although Oregon white oak (Quercus garryana) woodlands are a characteristic landscape component in this region, little is known about their current or...
I studied presence, relative abundance, and resource selection of bats in managed Douglas-fir (Pseudotsuga menziesii) forests in western Oregon from May through September, 1999–2001. Species richness was not related to elevation, density of snags, or length of edge or perennial streams in sampled landscapes. I captured bats more frequently in...
We conducted capture and acoustic surveys for bats in six areas along a latitudinal gradient in Southeast Alaska from mid-May to September in 2005 and we continued surveys on Prince of Wales Island from mid-May to September in 2006. We determined the level of effort required to catch each species...
Vegetation provides food for many insects, and many insects serve as food for bats. We investigated the linkages among these three trophic levels in riparian areas throughout the Oregon Coast Range by examining the influence of vegetation cover, composition, and structure on the activity of nocturnal insects and bats, the...
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E. Macro-moths captured in conifer- and deciduous-dominated stream reaches..... 212
F
The diverse lichen flora of the Pacific Northwest is being impacted by
population growth and by forest management practices. Accumulating information
about our lichen flora will improve our conservation strategies. This dissertation first
collects information to improve our understanding of how lichen communities vary
among forests of differing structure, and...
Mixed-severity fire occurrence is increasingly recognized in Pseudotsuga forests of the Pacific Northwest, but questions remain about how tree mortality varies, and forest structure is altered, across the disturbance gradient observed in these fires. Therefore, we sampled live and dead biological legacies at 45 one ha plots, with four 0.10...
Fundamental objectives in the field of conservation biology involve understanding the processes that influence small and declining populations and applying that knowledge to develop appropriate monitoring strategies and targeted management and conservation actions. Critical first steps in determining the relative role of factors that drive population declines involves estimation of...
The genus Phytophthora contains some of the most destructive pathogens of forest trees, including the most destructive pathogen of alder in recent times, Phytophthora alni. Alder trees were reported to be suffering from canopy dieback in riparian ecosystems in western Oregon, which prompted a survey of alder health and monitoring...
Prairie-oak ecosystems in the Willamette Valley, Oregon have experienced habitat loss and degradation; most of these ecosystems are fragmented into smaller patches. Prairie-oak butterfly species, in the Willamette Valley, have decreased dramatically due to loss or degradation of habitat. More research is needed on sustaining the populations of butterflies in...