Terrestrial and Aquatic Ecology Commons^™

Assessment Of Microbial Carbon Processing And Its Implications To The Carbon Budget Of Lake Superior, Lindsey Michelle Koren

Theses and Dissertations

Over the past few decades, there has been increased research focus on carbon cycling within aquatic systems, especially with the changing global climate. Inland waters play a major role in the global carbon cycle, but the fundamental features remain poorly understood, particularly the large lakes of the world. Our experimental approach assessing the carbon budget of Lake Superior, the largest freshwater lake by area, provides spatial and temporal variability that has been previously overlooked but may be critical to our understanding on the biogeochemical processes controlling the lake. Multiple stations were chosen across the lake, both nearshore and offshore, to …

Why Cod Don't Like To Sunbathe: Quantity And Quality In The Animal Kingdom, Christoph Jung

Animal Sentience

The difference between a cod and a lizard is not just a quantitative one. The recognition of qualitative differences between species does not imply a moral ranking. Our species’ special abilities to shape the earth mean we have a special responsibility for ensuring a liveable future for all organisms, human and non-human.

Protecting Patients Who Lack A Voice, Rainer Spiegel

Animal Sentience

Neither human young today nor future human generations nor non-human species have a voice in protecting the biosphere. Treves et al. propose courts and trustees for defending their interests. I describe an analogy with attempts to represent the interests of children and comatose patients in medicine.

Tree Squirrels And Fishers In Northern California: The Effects Of Masting Hardwoods On Stand Use, Andria M. Townsend

Cal Poly Humboldt theses and projects

In western North America, tree squirrels such as western gray (Sciurus griseus) and Douglas squirrels (Tamiasciurus douglasii) are potentially important prey for fishers (Pekania pennanti). Western gray squirrels in particular may be highly ranked due to their large body size. Masting trees including black oak (Quercus kelloggii) and tanoak (Notholithocarpus densiflorus) produce an important food source for tree squirrels; therefore, forest stands containing these trees may be useful to foraging fishers. I hypothesized that; 1) the abundance of western gray and Douglas squirrels in a stand is influenced by the …

Freshwater And Marine Survival Of Coho Salmon (Oncorhynchus Kisutch) As A Function Of Juvenile Life History, Grace Katherine Ghrist

Cal Poly Humboldt theses and projects

Juvenile Coho Salmon (Oncorhynchus kisutch) in coastal California streams exhibit various life history strategies during their freshwater development. One strategy of interest to managers and conservationists is the early migrant. Juvenile early migrants emigrate from natal habitat into lower parts of the watershed or estuary during their first fall or winter, where they rear before migration to the ocean. By contrast, the more prevalent spring migrant resides in natal reaches over the winter and migrates directly to the ocean the following spring. Salmon monitoring programs generally estimate juvenile production and demographic rates using only spring migrants, and these …

Shade Trees Preserve Avian Insectivore Biodiversity On Coffee Farms In A Warming Climate, Sarah L. Schooler

Cal Poly Humboldt theses and projects

Coffee is an important export in many developing countries, with a global annual trade value of $100 billion. Climate change is projected to drastically reduce the area where coffee is able to be grown. Shade trees may mitigate the effects of climate change through temperature regulation for coffee growth, temperature regulation for pest control, and increase in pest-eating bird diversity. The impact of shade on bird diversity and microclimate on coffee farms has been studied extensively in the Neotropics, but there is a dearth of research in the Paleotropics. I examined the local effects of shade on bird presence and …

Using Environmental Dna And Occupancy Modeling To Estimate Rangewide Metapopulation Dynamics Of The Endangered Tidewater Goby Eucyclogobius Spp., Chad M. Martel

Cal Poly Humboldt theses and projects

Conservation of species is most effective when metapopulation dynamics are well understood and incorporated into management plans, allowing managers to target conservation efforts where they will be most effective. The development of environmental DNA (eDNA) methods provides an efficient and highly sensitive approach to generate presence and absence data needed to elucidate metapopulation dynamics. Combining sample detection histories from eDNA surveys with occupancy models that account for non-detection can offer unbiased estimates of rangewide metapopulation dynamics. However, traditional occupancy models do not allow direct evaluation of the drivers of site occupancy, extinction, and colonization. Herein, I utilize a novel dynamic …

Life History Of The Coastal Tailed Frog (Ascaphus Truei) Across An Elevational Gradient, Adrian Daniel Macedo

Cal Poly Humboldt theses and projects

The life history of a species is described in terms of its growth, longevity, and reproduction. Unsurprisingly, life history traits are known to vary in many taxa across environmental gradients. In the case of amphibians, species at high elevations and latitudes tend to have shorter breeding seasons, shorter activity periods, longer larval periods, reach sexual maturity at older ages, and produce fewer and larger clutches per year.

The Coastal Tailed Frog (Ascaphus truei) is an ideal species for the study of geographic variation in life history because it ranges across most of the Pacific Northwest from northern California …

Relationship Between Habitat And Barn Owl Prey Delivery Rate And Composition In A Napa Valley Vineyard Agroecosystem, Dane A. R. St. George

Cal Poly Humboldt theses and projects

The provision of habitat for natural enemies of agricultural pests is common in integrated pest management approaches globally but has rarely been examined for vertebrate predators controlling vertebrate pests. To mitigate the economic and environmental costs of treating for rodent pests, winegrape producers in Napa Valley, California, have installed nest boxes to attract barn owls (Tyto alba) to their properties, but their effectiveness to control rodent pests in vineyards has not been thoroughly tested. A rigorous estimate of the number of rodents barn owls remove from the landscape is a necessary first step, and this study aimed to …

Characterizing Water Quality And Hydrologic Properties Of Urban Streams In Central Virginia, Rikki Lucas

Theses and Dissertations

The objective of this study was to characterize water quality and hydrologic properties of urban streams in the Richmond metropolitan area. Water quality data were analyzed for six urban sites and two non-urban sites. Geomorphological surveys and conservative tracer studies were performed at four urban sites and one non-urban site to describe intra- and inter- site variability in transient storage, channel geomorphology, and related hydrologic parameters. Urban sites showed elevated concentrations of nitrogen and more variable TSS concentrations relative to reference sites. Urban channels were deeply incised with unstable banks and low sinuosity. Little Westham Creek exhibited the greatest transient …

Nutrient Uptake Among Urban And Non-Urban Streams Within The Piedmont Physiographic Province Of Virginia, Joseph T. Famularo

Theses and Dissertations

To assess how urbanization impacts stream nutrient uptake, a series of instantaneous (i.e. slug) nutrient additions were conducted in 3 urban and 3 non-urban streams during open and closed canopy conditions. Single additions of N, P, and combined additions of N and P were performed at each site. These data were used to test the hypothesis that high N:P concentrations in urban streams would result in P-limited conditions, and to assess differences in nutrient uptake kinetics (i.e., the relationship between uptake and concentration) between urban and non-urban streams. The results show that there were no consistent differences in N vs. …

Exploration Of Sonic Hedgehog Gene Expression In Fathead Minnows (Pimephales Promelas), Brooke Renee Greiner

Undergraduate Honors Theses

Pollutants, as a result of wastewater treatments, have been shown to have negative impacts on aquatic ecosystems. To better understand the possible consequences caused by effluents on ecosystems, it is important to examine ecotoxicology data. One of the most commonly used species for water quality testing is the fathead minnow, Pimephales promelas. Ecotoxicology can then be taken one step further to understand the effects of pollutants on a molecular level. Previous research had identified effluents as causes for abnormal minnow fin morphology. In order to collect additional data on development, tanks with fathead minnows were placed at the Charleston …

Influence Of Climate Change And Prescribed Fire On Habitat Suitability And Abundance Of The High-Elevation Endemic Cow Knob Salamander (Plethodon Punctatus), Carl David Jacobsen

Graduate Theses, Dissertations, and Problem Reports

Amphibians are facing global declines due to climate change, loss and degradation of habitat, invasive species, and disease. The Appalachian region of the eastern USA is a global biodiversity hotspot for salamanders, which are considered keystone species that influence nutrient dynamics in terrestrial and aquatic food webs. There are high rates of salamander endemism in the Appalachian region, with many species restricted to isolated, high elevation areas. The Cow Knob Salamander (Plethodon punctatus) is one such species. It is only found at elevations >675 m (most populations are above 900 m) on Shenandoah Mountain, North Mountain, and Nathaniel …

Undescribed Oomycete Pathogens On Zostera Marina And Z. Japonica In The Puget Sound, Theresa Proctor

Summer Research

A diverse range of marine organisms relies on seagrass as a foundational species. However, seagrass populations are declining at an alarming rate and recent analysis of seagrass root microbiomes indicates that oomycetes (fungi-like protists that are notorious terrestrial plant pathogens) infect up to 99% of seagrasses worldwide. Shockingly, very little is known about marine oomycetes and their ecological roles. The Elliott lab has isolated and cultured six oomycete species from eelgrass (Zostera marina) root samples: Phytophthora gemini, aHalophytophthoraspecies discovered by WSU, and four undescribed oomycete species. During the summer of 2018, I generated temperature and salinity growth curves and isolated …

The Effects Of Temperature On Maternal Investment Of Ovary Tissue In The Fish Species Danio Rerio, Noah R. Dillon, Alyce Demarais

Summer Research

The impact of climate change is predicted to increase water temperatures by 2 °C on average globally within the next century. As ectotherms, fish metabolism is directly connected to ambient water temperature. With a shift in metabolism due to temperature change, physiological processes like maternal investment may be affected. This study is an ecological and developmental investigation of the impacts of shifting environmental temperature conditions on the reproductive traits of the fish species Danio rerio. This study investigated Danio rerio under different temperatures to measure maternal investment. Female Danio rerio were exposed to temperature treatments 20-30 °C. Ovary tissue …

Where Birds Chill: An Assessment Of The Habitat Preferences Of Birds Overwintering In Hudson Valley Forests, Elizabeth Claire Axley

Senior Projects Spring 2019

Many avian species overwinter in eastern North America; however, studies on bird populations are rarely undertaken during this critical survival time, and little is known as to their habitat preferences and foraging behavior. In this observational study, we performed a survey of birds overwintering in the Hudson Valley’s temperate, primarily-deciduous forests, assessing avian populations’ habitat preferences through the vegetative structural variables surrounding overwintering birds as they forage. Our results suggest that high canopy cover is critically important to predicting overwintering bird occupancy on a microhabitat scale. Moreover, overwintering birds preferentially occupy forest plots not dominated by sugar maples, in spite …

Autumn Roost Selection By Male Hoary Bats (Lasiurus Cinereus) In Northern California, Danielle (Skye) Salganek

Cal Poly Humboldt theses and projects

The hoary bat, Lasiurus cinereus, is a solitary bat that roosts in the foliage of trees throughout the western hemisphere. Roosts are subject to the ambient temperature of their surroundings, thus hoary bats undergo long-distance migrations between summer and winter ranges to avoid freezing temperatures. Habitat selection has been studied during the summer for maternal female hoary bats, but not during migration and winter. Autumn migration coincides with the hoary bat mating period and it has been proposed that male and female bats may rendezvous on migration paths. Individuals may select roosts in stopover locations that enhance fitness by providing …

Response Of Headwater Amphibians To Long-Term Logging Impacts And Assessing Potential For Restoration In Redwood National And State Parks, Alyssa Marquez

Cal Poly Humboldt theses and projects

The timescale of community response to disturbance varies drastically, and slow-recovering ecosystems such as coastal redwood forests may take hundreds of years to return to old-growth conditions post-logging. Few studies have quantified long-term (>50 years) impacts of disturbance on ecosystems, specifically aquatic ecosystems. This study provides evidence of the persistence of historical logging impacts 50 years post-logging through the comparison of headwater amphibian populations (occupancy and abundance) and stream characteristics using a control-treatment study with a logged watershed, Streelow Creek, as the treatment and a pristine old-growth watershed, Godwood Creek, as the control. The immediately adjacent old-growth watershed acts …

Ectomycorrhizal Fungal Community Assembly On Seedlings Of A Neotropical Monodominant Tree, Carolyn Delevich

Cal Poly Humboldt theses and projects

Formation of ectomycorrhizae may facilitate early seedling survival of ectomycorrhizal tree species due to enhanced nutrient acquisition. This could be especially important in heavily shaded understories of tropical monodominant forests where host plant photosynthetic capacity is limited. Little information is available on ectomycorrhizal (ECM) fungal colonization or community development of monodominant seedling cohorts, which have high survival rates. Following a 2016 mast seeding event, we sequentially measured percent colonization and species composition of ECM fungi on live and recently dead seedlings of the tropical monodominant tree Dicymbe corymbosa. We also compared seedling ECM fungi to those of nearby adult …

Assessment And Recovery Of Stream Restoration Efforts On Fish Communities, Jessica Marie Rohr

Masters Theses

Aquatic systems are subjected to disturbances of various types, including natural and anthropogenic, or can deteriorate due to accumulating unfavorable conditions, including receding banks, decreasing riparian vegetation, and disrupted flow patterns. An analysis was done on a variety of streams in central Illinois that experienced one or multiple anthropogenic disturbances without remediation to determine the natural recovery dynamics of each system. A separate analysis was performed on a multi-site restored stream with a complex restoration project with a variety of restoration methods. This data were collected over at periods of time spanning from 5-15 years, including time prior to disturbance/restoration …