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- Autotomy (1)
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Articles 1 - 7 of 7
Full-Text Articles in Life Sciences
Hydrologic And Nutrient Fluxes In A Small Watershed With Changing Agricultural Practices, Bridger Cohan
Hydrologic And Nutrient Fluxes In A Small Watershed With Changing Agricultural Practices, Bridger Cohan
WWU Graduate School Collection
Many watersheds are subject to nonpoint-source inputs of nutrients from human activities, contributing to eutrophication of surface waters. The magnitude of these inputs is in turn dependent on the types of land use within a watershed, and on the specific land management strategies employed. Exact nutrient contributions resulting from particular management actions are difficult to identify, but field studies of nutrient fluxes through a waterway over time can shed light on the net impact of trends in land use and management. I investigated nutrient fluxes through upper Kamm Creek in northwest Washington State, to determine if historical changes in land …
Long-Term Propagule Pressure Overwhelms Early Community Determination Of Invader Success In A Serpentine Grassland, Amanda N. Carr
Long-Term Propagule Pressure Overwhelms Early Community Determination Of Invader Success In A Serpentine Grassland, Amanda N. Carr
WWU Graduate School Collection
The role of plant diversity in reducing invasions has generated decades of debate. Diverse communities might be more resistant to invasion because the communities contain resident species that are functionally similar to the invader (limiting similarity/sampling effect), or the residents use the range of available resources more effectively (complementarity) than single species. However, the resistance of diverse communities to invasion appears to decline with increasing spatial and temporal scale, in a phenomenon called the “invasion paradox.” I addressed two groups of hypotheses related to this paradox, broadly that: (1) functional diversity and functional identity resist invasion initially, via complementarity or …
Evaluation Of The Stream Function Assessment Methodology (Sfam) In Watersheds Of The Puget Sound Lowlands, Michelle Bahnick
Evaluation Of The Stream Function Assessment Methodology (Sfam) In Watersheds Of The Puget Sound Lowlands, Michelle Bahnick
WWU Graduate School Collection
Effective stream management requires identification of anthropogenic degradation effects on stream functioning. However, few stream assessment protocols aim to evaluate stream functions (i.e., ecosystem processes), integrate multiple disciplines, and combine stream reach assessment with landscape-level context. To address these shortcomings, several agencies in Oregon collaborated to develop the Stream Function Assessment Methodology (SFAM). However, SFAM has yet to be tested against established protocols and some SFAM metrics have no equivalent data sources outside of Oregon. I conducted SFAM (2015 draft version) on 36 stream reaches in Water Resource Inventory Area 8 in Washington State. I compared SFAM scores to commensurate …
Characterizing Potential Bacterial Pathogens Of Pisaster Ochraceus Sea Stars With Wasting Disease, Chelsea Hutchinson
Characterizing Potential Bacterial Pathogens Of Pisaster Ochraceus Sea Stars With Wasting Disease, Chelsea Hutchinson
WWU Graduate School Collection
In 2013 sea star wasting disease (SSWD) caused an epizootic in over 20 species of asteroids along the west coast of North America. To see if SSWD was still affecting wild populations, we surveyed populations of the sea star, Pisaster ochraceus, in Birch Bay, WA. Our surveys indicated that advanced symptoms (lesion formation) increased 73% from July to September in 2017. To understand the role of bacteria in SSWD, we isolated bacteria with tissue-degrading potential from epidermal tissues of P. ochraceus animals in Birch Bay, WA. Next, we identified these isolates via 16S rRNA gene sequencing. Our results indicated …
Site Occupancy Analysis Of The Sagebrush Lizard (Sceloporus Graciosus) In The Disappearing Desert-Scrub Of The Columbia Basin, Ryan R. (Ryan Robert) Drake
Site Occupancy Analysis Of The Sagebrush Lizard (Sceloporus Graciosus) In The Disappearing Desert-Scrub Of The Columbia Basin, Ryan R. (Ryan Robert) Drake
WWU Graduate School Collection
The shrub-steppe landscape of the Columbia Basin has been the target of agricultural and urban development, and the resulting fragmentation and degradation has led to the disappearance of unique arid mesohabitats. In central Washington, the sandy lowland habitats resembling desert-scrub, which under natural conditions are characterized by a shrub-and-sand mosaic, have become increasingly degraded by humans directly (e.g., flooding, agriculture) or indirectly (e.g. cheatgrass introduction). These habitats have unique community assemblages with species adapted to the sandy substrates and unobstructed matrix between shrubs. While much conservation literature focuses on the loss of shrubsteppe habitat, there has been little research on …
Cross-Sectional Scat Sampling Reveals Intrapopulation Feeding Diversity In A Marine Predator, Madelyn Voelker
Cross-Sectional Scat Sampling Reveals Intrapopulation Feeding Diversity In A Marine Predator, Madelyn Voelker
WWU Graduate School Collection
Harbor seals (Phoca vitulina) have substantial impacts on species of concern. To understand and predict the impact that harbor seals have in their communities, we need to describe their level of individual specialization because it can affect food web dynamics, responses to changes in prey availability, and the accuracy of predictive models. I estimated intrapopulation feeding diversity, a proxy for individual specialization, of P. vitulina in the Salish Sea relative to sex, time, and location using repeated cross-sectional sampling of scat. Based on 1,083 scat samples collected from five haul-out sites over the course of four, non-sequential years, …
Wasted And Castrated: Two Diseases Affecting The Ochre Star, Pisaster Ochraceus, In North America, Zoë Zilz
Wasted And Castrated: Two Diseases Affecting The Ochre Star, Pisaster Ochraceus, In North America, Zoë Zilz
WWU Graduate School Collection
Understanding the diseases that plague marine organisms is essential to the management and conservation of coastal ecosystems, especially in the face of a possible sixth mass extinction. An increase in mass-mortality events, often caused by epizootics, is modifying intertidal ecosystems. When predators that have disproportionately large trophic impacts on their community and maintain community structure (i.e., keystone predators) suffer from widespread population declines it destabilizes population dynamics ecosystem-wide, and can have long-term or sometimes permanent effects. This thesis is comprised of two studies that examined two maladies affecting a keystone predator, the ochre star Pisaster ochraceus, in Eastern Pacific …