Terrestrial and Aquatic Ecology Commons^™

Increased Harbor Porpoise Mortality In The Pacific Northwest, Usa: Understanding When Higher Levels May Be Normal, Jessica L. Higgins, Stephen A. Raverty, Stephanie A. Norman, John Calambokidis, Joseph K. Gaydos, Deborah A. Duffield, Dyanna M. Lambourn, James M. Rice, Brad Hanson, Kristin Wilkinson, Steven J. Jeffries, Brent Norberg, Lynne Barre

Biology Faculty Publications and Presentations

In 2006, a marked increase in harbor porpoise Phocoena phocoena strandings were reported in the Pacific Northwest of the USA, resulting in the declaration of an unusual mortality event (UME) for Washington and Oregon to facilitate investigation into potential causes. The UME was in place during all of 2006 and 2007, and a total of 114 porpoises stranded during this period. Responders examined 95 porpoises; of these, detailed necropsies were conducted on 75 animals. Here we review the findings related to this event and how these compared to the years immediately before and after the UME. Relatively equal numbers among …

Urban Stream Burial Increases Watershed-Scale Nitrate Export, Jake J. Beaulieu, Heather E. Golden, Christopher D. Knightes, Paul M. Mayer, Sujay S. Kaushal, Michael J. Pennino, Clay P. Arango, David A. Balz, Colleen M. Elonen, Ken M. Fritz, Brian H. Hill

All Faculty Scholarship for the College of the Sciences

Nitrogen (N) uptake in streams is an important ecosystem service that reduces nutrient loading to downstream ecosystems. Here we synthesize studies that investigated the effects of urban stream burial on N-uptake in two metropolitan areas and use simulation modeling to scale our measurements to the broader watershed scale. We report that nitrate travels on average 18 times farther downstream in buried than in open streams before being removed from the water column, indicating that burial substantially reduces N uptake in streams. Simulation modeling suggests that as burial expands throughout a river network, N uptake rates increase in the remaining open …

The Pioneer Of Santa Rosa Island, Andrea Martinez, Michael Perez, Kathryn Mceachern, Sarah Chaney, Ken Niessen

STAR Program Research Presentations

Santa Rosa Island which is part of the Channel Islands in California has a ranching history that goes as far back as the year 1843. While rich in history, the island is no longer “rich” in native plant populations due to the sheep, cattle and other livestock that once occupied the island. As a result of these grazers that the ranchers livelihood depended on, a great disturbance in the native plant population took place. It is up to plants such as Baccharis pilularis, commonly known as Coyote brush, to assist these endangered and threatened plants to once again flourish …

Interdisciplinary Modeling For Water-Related Issues Graduate Course, Laurel Saito, Alexander Fernald, Timothy Link

All ECSTATIC Materials

The science and management of aquatic ecosystems is inherently interdisciplinary, with issues associated with hydrology, atmospheric science, water quality, geochemistry, sociology, economics, environmental science, and ecology. Addressing water resources issues in any one discipline invariably involves effects that concern other disciplines, and attempts to address one issue often have consequences that exacerbate existing issues or concerns, or create new ones (Jørgensen et al. 1992; Lackey et al. 1975; Straskraba 1994) due to the strongly interactive nature of key processes (Christensen et al. 1996). Thus, research and management of aquatic ecosystems must be interdisciplinary to be most effective, but such truly …

Alliaria Petiolata (M.Bieb.) Cavara & Grande [Brassicaceae], An Invasive Herb In The Southern Ozark Plateaus: A Comparison Of Species Composition And Richness, Soil Properties, And Earthworm Composition And Biomass In Invaded Versus Non-Invaded Sites, Jennifer D. Ogle

Graduate Theses and Dissertations

Invasive species are widely recognized as organisms that severely alter ecosystem processes in the habitats to which they are introduced. Alliaria petiolata is one of the most important invasive plants in forests of the northern United States. This study examined the geographic distribution of the plant in the southern Ozarks, as well as the effect that it may be having on natural processes within forests of the region by comparing plant species richness, plant cover, and soil properties in invaded and non-invaded plots. It was found that A. petiolata is not significantly altering species richness, cover, or soil properties in …

The Functional And Distributional Ecology Of Mycetozoans Under Changing Edaphic And Climatic Dynamics, Geoffrey Lloyd Zahn

Graduate Theses and Dissertations

Investigations into the distribution and ecosystem functions of fruiting amoebae revealed that local-scale environmental conditions can largely explain broad biogeographical patterns in species assemblage, the way in which amoeboid predators shape bacterial communities and how this top-down influence may affect global biogeochemical processes in a changing climate. The distribution and assemblage of protosteloid amoebae on the islands of New Zealand and Hawaii did not yield any expected patterns of island biogeography, and conformed to other global regions studied. The strongest predictor of species richness in a given region was sampling effort and these species do not appear to have any …

Carbon Storage Potential Of Windbreaks On Agricultural Lands Of The Continental United States, William Ballesteros Possu

School of Natural Resources: Dissertations, Theses, and Student Research

Agricultural production systems face major challenges under climate change scenarios in terms of expected negative impacts on productivity and persistence of the crops. Greenhouse gases from agriculture continue to rise although not as fast as from other fossil fuel-based human activities. Windbreaks perform several ecosystems functions that improve the local and regional capacity of crop systems to increase yields and offer environmental services by minimizing the negative effects of extreme weather events. Windbreaks also represent an important means of mitigating greenhouse gas emissions. This is predominantly accomplished by the windbreak trees storing carbon (C) in their above and belowground woody …

Introducing Green Manures In An Organic Soybean–Winter Wheat–Corn Rotation: Effects On Crop Yields, Soil Nitrate, And Weeds, Katja Koehler-Cole

School of Natural Resources: Dissertations, Theses, and Student Research

In organic soybean– winter wheat – corn rotations, animal manure is a common choice to maintain high yields, but leguminous crops grown as green manures after wheat harvest and incorporated into the soil before corn planting, can be an alternative when animal manure is not accessible. Forage legumes with high dry matter (DM) production and high biological N fixation have been shown to meet corn N demand. However, in Eastern Nebraska, lack of precipitation can reduce green manure growth and N fixation, leading to an insufficient N supply for corn, but corn growth can also be impacted by green manure …

Serpentine Ecosystem Responses To Varying Water Availability And Prescribed Fire In The U.S. Mid-Atlantic Region, Jessica Schedlbauer

Biology Faculty Publications

No abstract provided.

Population Structure Of Central Stoneroller (Campostoma Anomalum) On The Ozark Plateau In Arkansas And Missouri, Mallory Jane Jeffers

Graduate Theses and Dissertations

Stream fishes on the Ozark Plateau have been influenced both by historic events (i.e. vicariance versus dispersal) and ecological forces (i.e. flow regime). To examine the role of these processes, genetic structure of Central Stoneroller (Campostoma anomalum), an ecologically important omnivorous minnow with a broad distribution and elevated abundance, was evaluated across populations in the White River drainage of the Ozark Plateau in Arkansas and Missouri. Fin clips of five to eight individuals were taken at each of 20 sites (N=138 individuals; average=6.9), selected so as to represent two different flow regimes: intermittently flashy (N=10 sites; N=73 individuals; average=7.3/ site) …

Monochamus Titillator Oviposition And Intraspecific Competition In Shortleaf Pine Bolts, Ryan Patrick Rastok

Graduate Theses and Dissertations

Monochamus titillator (Coleoptera: Cerambycidae) feed on trees in the family Pinaceae as adults and larvae. Adults feed on healthy twigs and branches and oviposit on stressed, dead, or dying trees. Prior to oviposition, females construct pits on the bark surface using their mandibles. The number of eggs laid beneath bark, where oviposition pits have been constructed, varies greatly. Developmental time and adult body size also vary greatly. I investigated oviposition and intraspecific competition with the goal of determining the degree to which various insect densities and oviposition times impact the following: 1) oviposition pit construction; 2) egg deposition; 3) emergence, …

A Fatty Acid Based Bayesian Approach For Inferring Diet In Aquatic Consumers, Aaron W. E. Galloway, Michael T. Brett, Gordon W. Holtgrieve, Eric J. Ward, Ashley P. Ballantyne, Carolyn W. Burns, Martin J. Kainz, Doerthe C. Muller-Navarra, Jonas Persson, Joseph L. Ravet, Ursula Strandberg, Sami J. Taipale, Gunnel Alhgren

Ecosystem and Conservation Sciences Faculty Publications

We modified the stable isotope mixing model MixSIR to infer primary producer contributions to consumer diets based on their fatty acid composition. To parameterize the algorithm, we generated a ‘consumer-resource library’ of FA signatures of Daphnia fed different algal diets, using 34 feeding trials representing diverse phytoplankton lineages. This library corresponds to the resource or producer file in classic Bayesian mixing models such as MixSIR or SIAR. Because this library is based on the FA profiles of zooplankton consuming known diets, and not the FA profiles of algae directly, trophic modification of consumer lipids is directly accounted for. To test …

Fuels And Fires Influence Vegetation Via Above- And Belowground Pathways In A High-Diversity Plant Community, Paul R. Gagnon, Heather A. Passmore, Matthew Slocum, Jonathan A. Myers, Kyle E. Harms, William J. Platt, C.E. Timothy Paine

Biology Faculty Research

1. Fire strongly influences plant populations and communities around the world, making it an important agent of plant evolution. Fire influences vegetation through multiple pathways, both above- and belowground. Few studies have yet attempted to tie these pathways together in a mechanistic way through soil heating even though the importance of soil heating for plants in fire-prone ecosystems is increasingly recognized.
2. Here we combine an experimental approach with structural equation modelling (SEM) to simultaneously examine multiple pathways through which fire might influence herbaceous vegetation. In a high-diversity longleaf pine groundcover community in Louisiana, USA, we manipulated fine-fuel biomass and monitored the …

Investigations Of Larval Pacific Lamprey Entosphenus Tridentatus Osmotic Stress Tolerance And Occurrence In A Tidally-Influenced Estuarine Stream, Gregory Shell Silver

Dissertations and Theses

Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range and reductions in Pacific lamprey abundance have been observed in Western North America, and may be indicators of range-wide declines. In the face of declining populations, the U.S. Fish and Wildlife Service has partnered with tribal, state, federal, and local entities to implement a regional Pacific lamprey conservation agreement aimed at reducing threats to Pacific lamprey and improving their habitats and population status. Research needs identified in the conservation agreement include assessing …

Tolerance Of The Invasive New Zealand Mud Snail To Various Decontamination Procedures, Christopher N. Acy

Lawrence University Honors Projects

In an attempt to stop the spread of invasive species, state governments have established decontamination procedures for use on contaminated equipment. However, different species can tolerate various procedures depending on their morphology and physiology. The New Zealand mud snail (Potamopyrgus antipodarum) is invasive to the United States and may alter the food web of streams due to the snail’s high reproductive ability, causing potential problems for native trout populations and local economies. We collected mud snails from the recently invaded Black Earth Creek, WI and tested their tolerance to decontamination protocols being considered by the Wisconsin Department of …

Diel Vertical Migration Of An Invasive Calanoid Copepod, Eurytemora Affinis, In Little Sturgeon Bay, Wisconsin, Alexandra N. Poli

Lawrence University Honors Projects

Eurytemora affinis, a calanoid copepod, is known to be a versatile, prolific invader of freshwater ecosystems across the globe. It has recently been documented in the Laurentian Great Lakes, including in Little Sturgeon Bay, an embayment of Lake Michigan. One survival mechanism that could make E. affinis a successful invader is diel vertical migration (DVM), a behavior in which animals move to different lakes depths at different times of day in order to avoid predation. Much is known about DVM of E. affinis, but primarily from studies in marine and brackish systems. Our goal was to investigate how …

An Analysis Of Juvenile Chinook Salmon Outmigration Speed And Survival In Response To Habitat Features: Sacramento River From Knights Landing To Sacramento, California, Natalie N. Mcnair

Master's Theses

Outmigration is an important life stage for Chinook salmon (Oncorhynchus tshawytscha) survival in the Sacramento River, and yet our understanding of their behavior and needs during this time is limited. To gain a better understanding of their survival and movement rates during outmigration, late fall run Chinook salmon smolts were tracked using acoustic telemetry techniques. Habitat features were measured and quantified throughout the study area to evaluate how Chinook salmon respond to key levee features including shade, instream woody material, and aquatic vegetation. The overall average movement speed through the entire study area was 0.77 m/s with an …

The Characterization Of A Vital Wisconsin Waterway: A Biological Assessment Of The Lower Fox River From 2006-2014, Emily L. Kiehnau

Lawrence University Honors Projects

The Lower Fox River has historically been used as a navigational crossroads, a waste disposal system, and source of hydroelectric power. Over the years, heavy use of the river has negatively affected water quality and the overall health of the system. Unhealthy rivers cannot function properly. Biological assessment based on animal surveys are often used to determine river health. I used data from the Lawrence University and Fox River Navigational System Authority invasive species-monitoring project to explore how the distribution of animals in the Fox River has changed over time and across locations. Monitoring surveys have taken place between June …

Microsatellite Analysis Of Population Structure In The Santa Ana Speckled Dace (Rhinicthys Osculus), Stacey A. Nerkowski

Electronic Theses, Projects, and Dissertations

Rhinichthys osculus, the Speckled Dace, is one of the most ubiquitous fish in western North America. Within the Southern California region, the local taxon is known as the Santa Ana Speckled Dace. The purpose of this study was to characterize and identify polymorphic microsatellite markers for R. osculus in which twenty-three were identified through Illumina pair-end sequencing. Seven of these loci were then used to examine the patterns of genetic variation and population structure that occurred within and among the watersheds in the Southern California. The study also examined the regional relationships among Southern California, Central California and Owen’s …

Reproductive Ecology And Hatchling Behavior Of Olive Ridley Sea Turtles In Honduras, Noemi Duran Royo

Loma Linda University Electronic Theses, Dissertations & Projects

In this dissertation, I investigated the reproductive ecology and hatchling behavior of the olive ridley (Lepidochelys olivacea) sea turtle population nesting in Pacific Honduras. I begin by reviewing olive ridley reproduction, human use of this species, and past and present conservation on nesting beaches. I also propose a conservation strategy to improve nesting beach conservation programs in developing countries. In the first of four empirical studies, I used microsatellite markers to assess multiple paternity levels of the Honduran population, and found evidence for multiple paternity in 75% of the nests examined. This rate, higher than expected for a population of …