Ecology and Evolutionary Biology Commons^™

Novel Tools For Community Based Assessment And Monitoring Of Forest Phenology Response To Environmental Variability And Change In The Tropics, Jennifer Christine Ramos-Chavez

Open Access Theses & Dissertations

Tropical ecosystems provide a variety of services and resources for global well-being. However, landscapes within this biome are undergoing rapid changes mostly due to anthropogenic activities. These systems are further impacted by current, extreme fluctuations in climate, including climate change and El Niño Southern Oscillation (ENSO). With predicted future increase in strength and occurrence of these climate oscillations, these landscapes and their plant communities will be impacted and changed. There is a gap in research and knowledge among tropical Indonesian landscapes in regards to the effects of global climate change at the community level. Therefore, there is an urgent need …

Disentangling Resource Acquisition From Interspecific Behavioral Aggression To Understand The Ecological Dominance Of A Common, Widespread Temperate Forest Ant, Robert Warren

Biology Faculty Datasets

No abstract provided.

Conservation Grazing With Native Irish Cattle In High Nature Value Environments, Kilian Kelly

Theses

Marrying conservation objectives with farming practices is a challenging necessity in the current era of anthropogenically-driven biodiversity loss. Upland habitats created by traditional farming are havens for wildlife but face multiple threats, including overgrazing and abandonment. Extensive cattle farming in the uplands has been mooted as a useful conservation measure, but Irish evidence supporting this approach is lacking. This thesis examines home range, habitat preferences and activity budgets for Dexter cattle in an extensive upland setting in southwest Ireland. It investigates the effects of the grazing regime on EU-protected habitats and ground beetles. Free-ranging cattle grazed the site over three …

Ecologically Distinct Populations Of Hawaiian Petrel (Pterodroma Sandwichensis): Quantitative Isotopic Analysis To Explore The Uniqueness Of Foraging Habits In Kauai And Hawaii Populations, Drew Casey

Williams Honors College, Honors Research Projects

Many topics from conservation biology, evolutionary biology, and ecology will be applied to help answer the question many conservation biologists ask: is this population both genetically and ecologically distinct enough to warrant an independent conservation approach? If the answer is yes, then more resources can be distributed to conserving that population. If the answer is no, more resources can be devoted to other conservation goals, such as conserving one of the other three breeding populations of Hawaiian petrel or generally trying to maximize the overall population size of the species and possibly saving the endangered Hawaiian petrel. This will be …

The Cardiovascular Response To Acute Hypoxic Conditions In Danio Rerio, Bryce Fetterman

Williams Honors College, Honors Research Projects

There are many fish that can withstand hypoxia levels. One in particular is the zebrafish (Danio rerio). The zebrafish is a small-sized, Cyprinid teleost fish, and has been used in a laboratory setting for many reasons. A few reasons being that they are widely available, easy to care for, and the cost for these fish are very low. There are various reasons why these fish are used as a model. One main reason is because their cardiovascular system is one of the first developing organs. This allows for better resolution when studying the cardiovascular system. The purpose of …

High-Throughput Two-Stage Dereplication Of Cave Bacteria To Discover Novel Antibiotic Compounds, Alexander Archey

Williams Honors College, Honors Research Projects

Since their discovery over a century ago, antibiotics have been a staple of combating infectious diseases. However, bacteria develop resistance to antibiotics through a variety of mechanisms. Efforts to identify new antibiotics often fail by discovering already-known antibiotics, or failing to synthesize new antibiotics that are safe for clinical use. The aim of this research was to dereplicate bacteria- to screen for antibiotic production in- normally isolated in cave ecosystems. Using two new technologies, the Antibiotic Resistance Platform (ARP) and a data acquisition and bioinformatics technique (IDBac), my dereplicating method allowed high throughput of bacterial screening for antibiotics. In this …

Spatiotemporal Variability Of Rockfish Recruitment On California's North Coast In Relation To Habitat Availability, Carolyn Belak

Cal Poly Humboldt theses and projects

Characterizing primary drivers of temporal and spatial variability in recruitment is imperative to understanding the role of pre- and post-settlement processes influencing marine population dynamics. On benthic reefs, the quality and quantity of suitable settlement habitat can alter post-settlement density-dependent mortality rates and increase chances of survival. The north coast of California has experienced highly unusual oceanographic conditions in recent years, leading to severe loss of highly productive kelp forests and potentially deleterious ecosystem consequences. In the present thesis, I aimed to determine the effects of canopy-forming bull kelp (Nereocystis) and alternative complex habitats on the recruitment of …

Multivariate Habitat-Based Predictive Modeling Of Three Demersal Rockfish Species In Central California, Georgia R. Martel

Cal Poly Humboldt theses and projects

Accurate, spatially explicit models of rockfish abundance are critical in implementing ecosystem-based management strategies and designating essential fish habitats and marine protected areas. Multibeam bathymetry methods and visual, non-extractive submersible transect surveys were combined to collect environmental variables and fish abundance data at three distinct sites within the study region. Zero-adjusted models were developed using habitat classification analyses of high-resolution (5 m) digital elevation models. Model accuracies were assessed by using a reserved subset of the original datasets. To demonstrate that a model’s predictive power was linked to its spatial origins, Mean Absolute Error and coefficient of determination values were …

A Tale Of Two Cervids: Habitat Selection And Spatial Ecology Of Roosevelt And Tule Elk In California, Adam S. Mohr

Cal Poly Humboldt theses and projects

California’s Roosevelt (Cervus canadensis rooseveltii) and tule elk (C. c. nannodes) populations have experienced a remarkable recovery after over-hunting and habitat loss nearly extirpated them from the state. Greater clarity of Roosevelt and tule elk habitat selection patterns would help managers continue to effectively support the recovery of these two iconic subspecies. As the manner in which elk populations balance their competing resource needs is unique to each population (Skovlin et al. 2002), I have examined Roosevelt and tule elk habitat selection patterns in separate analyses and present these results in independent chapters. In both cases, …

Phylogenetic And Population Genetic Analysis Of The Humboldt's Flying Squirrel Using High-Throughput Sequencing Data, Stella Chi Yuan

Cal Poly Humboldt theses and projects

The intraspecific genetic variation and diversity within the Humboldt’s flying squirrel (Glaucomys oregonensis) has not yet been characterized despite its elevation to full species in 2017. The San Bernardino flying squirrel (G. o. californicus) is thought to be the southernmost population of G. oregonensis and is restricted to the San Bernardino and San Jacinto Mountains in California, but recent surveys indicate they have been extirpated from the latter locality. In order to provide baseline genetic data across the geographic range of G. oregonensis, I had the following objectives: 1) investigate the intraspecific molecular variation in …

Estimates Of Calf Survival And Factors Influencing Roosevelt Elk Mortality In Northwestern California, Erin Nigon

Cal Poly Humboldt theses and projects

Survival of juvenile ungulates is known to be highly variable, yet it is fundamental to understanding the dynamics and trends of wildlife populations. Factors influencing calf survival are poorly understood in northwestern California where Roosevelt elk (Cervus canadensis roosevelti) are known to exist. The objectives of this study were 1) to estimate summer and annual survival rates and determine recruitment rates for Roosevelt elk calves in the area, 2) to evaluate differences in calf survival by examining the effects of individual and population level covariates on summer and annual calf survival, 3) to identify factors influencing the timing …

Impacts Of Flow Releases On Invertebrate Drift And Juvenile Chinook Salmon (Oncorhynchus Tshawytscha) Diet On The Trinity River Below Lewiston Dam, Thomas R. Starkey-Owens

Cal Poly Humboldt theses and projects

Benthic macroinvertebrate (BMI) drift, species composition and abundance are specific to local hydrologic and habitat conditions, which can restrict or enhance availability to salmonids as a food resource. Currently, a knowledge gap exists on the Trinity River (northern California) in how flow releases from Lewiston Dam potentially impact BMI drift and feeding opportunities for juvenile salmonids. Samples of BMIs from drift, benthos, and diets of juvenile Chinook salmon (Oncorhynchus tshawytscha) were collected from two sites in the upper Trinity River February-April 2018, during stable flow conditions (~8 ) and two increased flow conditions peaking at ~50 . Chironomidae …

Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong

Cal Poly Humboldt theses and projects

Distinct populations of steelhead in the wild are in decline. The propagation of steelhead in hatcheries has been used to boost population numbers for recreational fisheries and for use in conservation. However, hatchery breeding practices of steelhead can result in changes in genetic structure. I investigated the genetic structure of winter-run steelhead (Oncorhynchus mykiss) returning to the Mad River, California, where a hatchery has been used enhance production for recreational fisheries since 1971. Genetic variability in Mad River steelhead was evaluated using 96 single nucleotide polymorphisms (SNPs) among 4203 individuals, including the Mad River and nearby locations, and …

Comparing Environmental Dna And Traditional Monitoring Approaches To Assess The Abundance Of Outmigrating Coho Salmon (Oncorhynchus Kisutch) In California Coastal Streams, Emerson Alan Kanawi

Cal Poly Humboldt theses and projects

Environmental DNA (eDNA) has the potential to dramatically increase the information available to managers regarding species distribution and abundance. Collection of reliable survey information on fish abundance is essential to monitor population trends and restoration efforts for endangered and threatened species. In Northern California, coho salmon are a federally listed species and a focus of ongoing monitoring programs and restoration projects. I examined the feasibility of using eDNA to supplement, or replace, traditional outmigrating juvenile coho salmon monitoring approaches currently used at two existing coho salmon life-cycle monitoring stations. Over the spring of 2018 and spring of 2019, I collected …

The Effects Of Woody Vegetation Encroachment And Removal Within A Coastal Fen, Joseph Saler

Cal Poly Humboldt theses and projects

Early successional wetland habitat is being lost in temperate regions worldwide as a result of changes in disturbance regimes that allow for the establishment and dominance of woody species. In particular, this phenomenon is pronounced in fens, which harbor high numbers of rare herbaceous species that require early successional habitat. I investigated the relationship between woody vegetation encroachment and herbaceous species diversity within a Northern California coastal fen that has been undergoing encroachment by woody vegetation for ca. 80 years by recording species richness and cover data from 338 permanent plots throughout the fen. I also investigated the effect of …

The Effects Of Low-Level Pharmaceuticals On Stream Biofilm Structure And Function Across A Land-Use Gradient In Streams Of The Huron River Watershed, Elizabeth Mae Stover

Master's Theses and Doctoral Dissertations

Pharmaceuticals and personal care products (PPCPs) are a contaminant class of worldwide concern. Their environmental omnipresence indicates they may be a potential source of global change, and ecosystem-scale impacts at non-lethal levels have not been fully explored. We used stream biofilms to assess ecosystem responses to PPCPs. Biofilms were cultivated in streams draining areas of different land use and then exposed to triclosan, diphenhydramine, and sulfamethoxazole-trimethoprim treatments. We found evidence that low levels of these PPCPs affected some, but not all, aspects of biofilm processes and bacterial community composition. Bacterial carbon uptake was reduced (p = 0.06) and we found …

Dietary Antioxidants Attenuate The Endocrine Stress Response During Long-Duration Flight Of A Migratory Bird, Stefania Casagrande, Kristen J. Demoranville, Lisa Trost, Barbara J. Pierce, Amadeusz Bryła, Maciej Dzialo, Edyta T. Sadowska, Ulf Bauchinger, Scott R. Mcwilliams

Biology Faculty Publications

Glucocorticoids (GCs) are metabolic hormones that promote catabolic processes, which release stored energy and support high metabolic demands such as during prolonged flights of migrating birds. Dietary antioxidants (e.g. anthocyanins) support metabolism by quenching excess reactive oxygen species produced during aerobic metabolism and also by activating specific metabolic pathways. For example, similar to GCs’ function, anthocyanins promote the release of stored energy, although the extent of complementarity between GCs and dietary antioxidants is not well known. If anthocyanins complement GCs functions, birds consuming anthocyanin-rich food can be expected to limit the secretion of GCs when coping with a metabolically challenging …

Stimulated Growth Response To Sand Burial Of A Coastal Shrub, D. Nicole Keller

Theses and Dissertations

Drivers of vegetation zonation on barrier islands are complex and interconnected. Sand burial is a strong driver in dynamic coastal systems, especially in the foredune community. However, it is not well understood how burial impacts the interdunal swales communities and it is especially difficult to separate the effects of burial from salinity. Climate change is altering the frequency of overwash events as well as expanding the range of the native shrub, Morella cerifera, on the Virginia barrier islands. To accurately forecast island response to climate change it is important to understand how the shrub responds to sand burial. Juvenile …

Changes In Prey Mortality: The Efects Of Multiple Predators And Temperature On California Mussels, Wesley Hull

Cal Poly Humboldt theses and projects

Organisms serve as prey to a variety of predators within natural systems, detecting threats through physical and chemical means. While predator feeding behavior is also affected by the presence of other predators, it is unclear whether differing modes of detection have similar effects on predator feeding behavior. In rocky intertidal zones in northern California, the California mussel (Mytilus californianus) is a competitively dominant foundation species consumed by a variety of predators. I quantified the individual and combined effects of ochre star (Pisaster ochraceus) and rock crab (Romaleon antennarium) predation on mussels by implementing mussel …

Genotypic Diversity And Host-Specificity Of Frankia Bacteria Associated With Sympatric Populations Of Alnus Rubra And Alnus Rhombifolia In Oregon, Mehmet Ali Balkan, Nathan U. Stewart, Emily S. Kauffman, Emily R. Wolfe, Daniel J. Ballhorn

Biology Faculty Publications and Presentations

Biological nitrogen fixation is one of the most critical processes contributing to ecosystem productivity and stability on a global scale. In temperate climates of the northern hemisphere, plant-root associated bacteria of the genus Frankia are the major nitrogen fixers in forest environments. Trees belonging to the genus Alnus are the most widespread hosts of Frankia in the Pacific Northwest, and a myriad of biotic and abiotic factors can influence the robustness of this symbiosis. Host identity and bacterial strain are important features that can impact Alnus-Frankia association, but little is known about the interplay of intrageneric hosts that co-occur in …

Bee Diversity Of Three Appalachian Shale Barren Sites, Olivia C. Latham

Theses and Dissertations

Insect pollination is vital to ecosystem function. However, climate change, habitat loss, pesticides, and a variety of other anthropogenic sources are contributing to a decline in pollinator diversity. Fragile small ecosystems with a high composition of specialized plant species that rely on specific pollinators such as Appalachian shale barrens, are especially at risk of losing biodiversity. This study combines the use of active sweep net sampling of endemic shale barren forbs and passive trap methods over the course of a bloom season (April-August) in three barren sites to identify bee community populations and visitation relationships between pollinator species and endemic …

Developing An Odonate-Based Index For Monitoring Freshwater Ecosystems In Rwanda: Towards Linking Policy To Practice Through Integrated And Adaptive Management, Erasme Uyizeye

Antioch University Dissertations & Theses

Worldwide, the decline of biodiversity in freshwater ecosystems is occurring at an alarming rate, due to anthropogenic threats, which directly impact humans in a variety of ways. Freshwater ecosystems occupy an integral part of political, socio-economic and ecological spheres. Integrated Watershed Management (IWM) and Adaptive Management (AM) conceptual frameworks provide an underpinning holistic platform from which to evaluate the performance of policies and actions on the ground in relation to freshwater ecosystem management. I investigate the extent to which environmental policies and practices embrace IWM and AM frameworks in Rwanda. Furthermore, this dissertation develops an odonate-based ecological monitoring tool, referred …

Taxa Specific Responses To Flooding Shape Patterns Of Abundance In A River Rock Pool Metacommunity, Charles R. Stunkle

Theses and Dissertations

Connectivity and habitat area are important landscape characteristics that drive patterns of abundance and diversity across scales. However, responses to connectivity and patch size are dependent on species traits. Riverine landscapes are highly dynamic both spatially and temporally with hydrologic connectivity being a major driver of abundance and diversity. Here we modeled densities of the Virginia river snail and skimmer dragonfly nymphys, two taxa with differences in their dispersal abilities and life histories, as a function of flooding, patch area, and season in over 300 riverine rock pools. We found key differences in how each taxon responded to these predictors …

Evidence Of Local Adaptation To Climate In An Invasive Ectotherm: A Study On The Eurasian Gypsy Moth (Lymantria Dispar) In North America, Phillip M. Gibbs

Theses and Dissertations

Invasive species exist in nearly every ecosystem both terrestrial and aquatic. Improving our understanding of the mechanisms that shape the ability of these organisms to physiologically cope with their surroundings will be crucial to preparing for future impacts of climate change. The Gypsy Moth (Lymantria dispar) has been expanding its range across North America over the last 100+ years since its arrival in Medford, Massachusetts. This study quantifies upper thermal limits (UTL) across 8 different populations of L. dispar in North America and seeks to determine if signals of local adaptation to climate across a latitudinal gradient may …

Conospermum Undulatum: Insights Into Population Genetics And Pollination Ecology Of A Threatened Species, Nicola Delnevo

Theses: Doctorates and Masters

Fragmentation of natural vegetation is currently one of the largest threats to biodiversity. Within the southwest Australia global biodiversity hotspot, the Swan Coastal Plain was historically cleared for agriculture and forestry and is now experiencing extensive land clearing for urbanisation. The wavy-leaved smokebush Conospermum undulatum is a rare species endemic to the Swan Coastal Plain, and its future persistence is threatened by urban expansion.

Throughout this research, I investigated the pollination ecology of this species and found a specific association between C. undulatum and native bees for pollination. I also demonstrated that C. undulatum has evolved pollen with resistance to …

Current Dog Breeding Practices Impacts On Health And Preservation Of Purebred Dogs, Bridget E. Baker

Honors Theses and Capstones

No abstract provided.

Compassionate Conservation And Elephant Personhood, Arian D. Wallach, Sujeewa Jasinghe, Sudarshani Fernando, Jessica Bell Rizzolo

Animal Sentience

Baker and Winkler (2020) advocate a rehabilitation program that would end the oppression of elephants — not by severing human-elephant relations, but by enabling human-bonded elephants to live a full life. We consider this program within a compassionate conservation framework, which recognises all sentient beings as persons. From this vantage point, we gaze further into the future to ask what direction just human-elephant relations could take: What could emerge from a human-elephant relation once elephants are no longer enslaved and requiring rescue? We envisage a future — beyond captivity and rewilding — of elephant sovereignty.

Future Of Thailand's Captive Elephants, Antoinette Van De Water, Michelle Henley, Lucy Bates, Rob Slotow

Animal Sentience

Removal from natural habitat and commodification as private property compromise elephants’ broader societal value. Although we support Baker & Winkler’s (2020) plea for a new community-based rewilding conservation model focused on mahout culture, we recommend an expanded co-management approach to complement and enhance the regional elephant conservation strategy with additional local community stakeholders and the potential to extend across international borders into suitable elephant habitat. Holistic co-management approaches improve human wellbeing and social cohesion, as well as elephant wellbeing, thereby better securing long-term survival of Asian elephants, environmental justice, and overall sustainability.

The Effects Of Boring Sponge Infestation On Condition, Growth, And Sex Change In Crepidula Fornicata, Nicole L. Kleinas

College of Graduate Studies: Theses & Dissertations

The Atlantic slipper limpet, Crepidula fornicata, is a sequential hermaphrodite whose size at sex-change is plastic with respect to social and population cues. As an organism allocates energy between growth, reproduction and maintenance, an increased cost of one process may affect another. In this paper, I evaluate whether the presence of an epibiotic sponge (Cliona celata) affects the growth, condition and sex-change of C. fornicata individuals. Population surveys demonstrate a variable effect of Cliona presence on C. fornicata condition. The results of a twelve-week in situ experiment demonstrated a decrease in growth when C. celata was present. …

One Welfare, The Role Of Health Professionals, And Climate Change, Anne Fawcett

Animal Sentience

Wiebers & Feigin argue that the COVID-19 crisis is a call for humanity to rethink our relationships with animals and the environment. This One Welfare approach has implications for the role of health care professionals and demands that we address climate change.