The Tualatin River Basin in Washington County, Oregon, is a complex area with highly developed agricultural, forestry, industrial, commercial, and residential activities. Population has grown in the past thirty years from fifty to over 270 thousand. Accompanying this population growth have been the associated increases in transportation, construction, and recreational...
Previous research in South Fork Hinkle Creek suggested that coastal cutthroat trout exhibit an aggregated spatial pattern across multiple spatial scales. To evaluate the persistence of the observed abundance patterns and identify factors that affect those patterns, half-duplex passive integrated transponders (PIT-tags) were implanted in 320 coastal cutthroat trout (>...
Recent studies of headwater streams have demonstrated their importance to overall watershed biodiversity, nutrient cycling, and energy flux. However, little attention has been paid to long-term effects of forest harvest on macroinvertebrate communities in headwater streams. This study investigated headwater stream macroinvertebrate communities in the H.J. Andrews Experimental Forest, Oregon,...
Riparian areas are eco-tones where aquatically- and terrestrially-derived insect biomass is exchanged between habitats, presenting consumers with new sources of energy, and resulting in a reciprocal subsidy. The relative contribution of energy exchange and the
resulting impacts on vertebrate riparian consumers, such as fish or birds, remains poorly understood. We...
A method based on fatty acid (FA) analysis is used to profile microbial community structure (MCS). Various extraction protocols are available, which alter the types of FAs extracted from soils. The more time consuming but widely used protocol extracts only FAs from phospholipids (PLFA). This technique is desirable because PLFAs...
Wildlife managers are on the front lines of the effort to conserve wildlife and
are required to do so cost-effectively. This dissertation consists of three manuscripts
that integrate economics and ecology to inform cost-effective wildlife management.
The first and second manuscripts focus on identifying cost-effective wildlife
management plans. The third...
The objectives of this thesis were to examine the links between soil microbial community composition and function using the nitrogen (N) cycle as a model for these interactions and to assess the impact of environmental factors such as microclimate, vegetation type, and nutrient availability on microbial diversity and N transformations...
The number of women diagnosed with diabetes, including gestational diabetes, will continue to increase in the face of epidemic rates of obesity. The concurrent rise in obesity and diabetes makes it important to determine the risk factors for gestational diabetes mellitus (GDM) and the nature and extent of care offered...
Orchard floor management (OFM) practices can improve soil function and alter
the soil biological community. Soil function is dependent on soil forming materials and
on management practices but little is known about how OFM affect orchard soil quality,
fertilizer N uptake, or tree growth and production.
Research plots were located...
The Amphipoda have been divided into the suborders Gammaridea,
Caprellidea, Cyamidea, Hyperiidea and Ingolfiellidea
(Schram 1986, Crustacea. Oxford University Press, New
York). However, Myers and Lowry (2003) regard the caprellids,
or skeleton shrimps, and the cyamids, or whale lice, as
families Caprellidae and Cyamidae. These distinctive groups
are covered in...