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Lichens Of Ultramafic Rocks: A Multidisciplinary Approach To Understanding The Ecology Of An Understudied Organism In A Well-Studied System, Michael Mulroy

Master's Theses

Lichens are among the most prominent and successful life forms of metal-rich habitats, including ultramafic rocks and soils; however, research on lichens of ultramafic habitats is limited, especially on the North American continent. A review of the published literature on lichens of ultramafic substrates in North America yielded a total of 437 lichen species reported from ultramafic rocks and soils. Lichen assemblages of ultramafic substrates vary in composition and are dominated by acidophytic (low pH preferring) taxa with a minor, but consistent, basiphytic (high pH preferring) component. Species lists from ultramafic habitats in different geographic regions varied widely, suggesting that …

Ectotherm Thermoregulation At Fine Scales: Novel Methods Reveal A Link Between The Spatial Distribution Of Temperature And Habitat Quality, Ian Axsom

Master's Theses

Investigating ecological questions at the scale of individual organisms is necessary to understand and predict the biological consequences of environmental conditions. For small organisms this can be challenging because we need tools with the appropriate accuracy and resolution to record and quantify their ecological interactions. Unfortunately, many of our existing tools are only appropriate for medium to large organisms or those that are wide ranging, inhibiting our ability to investigate the ecology of small organisms at fine scales.

In Chapter 1, I tested a novel workflow for recording animal movements at very fine spatial and temporal scales. The workflow combined …

A Floristic Study Of The Cal Poly Swanton Pacific Ranch And A New Combination In Sanicula Crassicaulis (Apiaceae), Sanicula Crassicaulis Var. Nudicaulis, Reed J. Kenny

Master's Theses

Globally we are experiencing a biodiversity crisis and potentially a sixth mass extinction event. Plant specimens are one of the best, most concrete records of biodiversity that we can create. Despite this, the rate of plant collecting has declined steeply since World War II. Now more than ever, plant collections are vital, both for the purpose of quantifying the plant biodiversity in an area and for discovering previously unrecognized diversity.

In Chapter 1, we conducted a floristic survey of the Cal Poly Swanton Pacific Ranch. The Swanton Pacific Ranch (SPR) is located north of the small town of Davenport California, …

Influence Of Soil Water Content And Soil Amendments On Trace Metal Release And Seedling Growth In Serpentine Soil, Viraj Gunarathne, Nishanta Rajakaruna, Udaya Gunarathne, Jayanta Kumar Biswas, Zach A. Raposo, Meththika Vithanage

Biological Sciences

This study was conducted to evaluate the synergistic effects of organic amendments and soil water status on trace metal release from serpentine soil.

Comparative Thermal Ecology Of Coastal And Inland Pacific Rattlesnakes (Crotalus Oreganus), Hayley Layne Crowell

Master's Theses

Global biodiversity is declining as a direct result of anthropogenic climate change. Ectothermic species have become focal organisms for studying the ecological effects of altered climates due to the clear relationship between environmental temperatures and ectotherms’ basic physiological functions. Historically, examinations of these effects have focused heavily on heliothermic lizards, and most others have tended to focus on single populations or sympatric species within a single community. Addressing the longterm energetic implications of environmental temperature variation will provide valuable insight into the cascading physiological effects that certain populations or species may experience as a result of altered climates.

In this …

Cold Acclimation Response Of Non-Native Italian Wall Lizard (Podarcis Siculus) Populations From New York And California, Daniel Haro

Master's Theses

Understanding how organisms respond to climatic variability and novel conditions is becoming an increasingly important task for ecologists. For ectotherms in the northern hemisphere, the response to cold is of special interest, considering that poleward range expansion events and increasing variability of temperatures during winter are already being observed as consequences of a warming planet. Though direction of change in physiological variables in response to cold is well studied in ectotherms, the extent to which traits can change and the rate at which they can change is not.

We compared the extent and rate of change in cold tolerance (CT …

Ultramafic Geoecology Of South And Southeast Asia, M.L. Galey, A. Van Der Ent, M.C.M. Iqbal, N. Rajakaruna

Biological Sciences

Globally, ultramafic outcrops are renowned for hosting foras with high levels of endemism, including plants with specialised adaptations such as nickel or manganese hyperaccumulation. Soils derived from ultramafic regoliths are generally nutrient-deficient, have major cation imbalances, and have concomitant high concentrations of potentially phytotoxic trace elements, especially nickel. The South and Southeast Asian region has the largest surface occurrences of ultramafic regoliths in the world, but the geoecology of these outcrops is still poorly studied despite severe conservation threats. Due to the paucity of systematic plant collections in many areas and the lack of georeferenced herbarium records and databased information, …

The Alpine Vascular Plants Of Baxter State Park, Maine, Usa, Abigail J. Urban, Glen H. Mittelhauser, Matthew Dickinson, N. Rajakaruna

Biological Sciences

We conducted 12 days of field surveys on five mountains over 1100 m in elevation (Katahdin, North Brother, South Brother, Mount Coe, and The Owl) in Baxter State Park (BSP), Maine during the summers of 2013–14. In addition, we examined historic manuscripts, unpublished data, and herbarium records for plant records from the five mountains. Katahdin, the largest and tallest of the five mountains, has a rich history of botanical exploration and we documented 1559 herbarium vouchers that were collected from the mountain, primarily before the mid-1900s. Combining all data sources, we documented 38 families, 87 genera, and 131 taxa of …

Circadian And Circatidal Rhythms Of Protein Abundance In The Intertidal Mussel Mytilus Californianus, Cory Elowe

Master's Theses

The intertidal zone is a dynamic environment that fluctuates with the 12.4-h tidal and 24-h light/dark cycle to predictably alter food availability, temperature, air exposure, wave action, oxygen partial pressure, and osmotic conditions. Intertidal sessile bivalves exhibit behavioral or physiological changes to minimize the persistent challenges of fluctuating environmental conditions, such as adjusting gaping behavior and heart rate. At the cellular level, transcriptomic studies on mussels’ baseline circadian and circatidal rhythms have determined that the circadian rhythm is the dominant transcriptional rhythm. However, as proteins reflect the basic molecular phenotype of an organism and their abundance may differ greatly from …

A Comparative Study Of The Flora And Soils Of Great Duck And Little Duck Islands, Maine, Usa, Luka Negoita, Matthew Dickinson, Glen H. Mittlehauser, N. Rajakaruna

Biological Sciences

Strong environmental gradients and varied land-use practices have generated a mosaic of habitats harboring distinct plant communities on islands on the coast of Maine. Botanical studies of Maine’s islands, however, are generally limited in number and scope. Baseline studies of Maine’s islands are necessary for assessing vegetation dynamics and changes in habitat conditions in relation to environmental impacts imposed by climate change, rising sea levels, invasive species, pests and pathogens, introduced herbivores, and human disturbance. We conducted a survey of the vascular plants and soils of forest, field, and ocean-side communities of Great Duck and Little Duck Islands, ME. These …

Global Research On Ultramafic (Serpentine) Ecosystems (8th International Conference On Serpentine Ecology In Sabah, Malaysia): A Summary And Synthesis, Antony Van Der Ent, Nishanta Rajakaruna, Robert Boyd, Guillaume Echevarria, Rimi Repin, Dick Williams

Biological Sciences

Since 1991, researchers from approximately 45 nations have participated in eight International Conferences on Serpentine Ecology (ICSE). The Conferences are coordinated by the International Serpentine Ecology Society (ISES), a formal research society whose members study geological, pedological, biological and applied aspects of ultramafic (serpentine) ecosystems worldwide. These conferences have provided an international forum to discuss and synthesise multidisciplinary research, and have provided opportunities for scientists in distinct fields and from different regions of the world to conduct collaborative and interdisciplinary research. The 8th ICSE was hosted by Sabah Parks in Malaysia, on the island of Borneo, and attracted the largest …

Growth And Nickel Uptake By Serpentine And Non-Serpentine Populations Of Fimbristylis Ovata (Cyperaceae) From Sri Lanka, P. K. D. Chathuranga, S. K. A. T. Dharmasena, Nishanta Rajakaruna, M.C.M. Iqbal

Biological Sciences

Compared with serpentine floras of Southeast Asia, the serpentine vegetation of Sri Lanka is impoverished in regard to serpentine endemics and nickel hyperaccumulators. All species so far documented from the serpentine outcrops of Sri Lanka also have non-serpentine populations; it is unclear whether the serpentine populations are physiologically distinct and deserve ecotypic recognition. We conducted a preliminary study to examine whether serpentine and non-serpentine populations of Fimbristylis ovata represent locally adapted ecotypes by investigating their growth and potential for nickel uptake and tolerance under greenhouse conditions. Although both populations of F. ovata showed a similar growth pattern in serpentine soil …

Photosynthetic Thermal Tolerance And Recovery To Short Duration Temperature Stress In Desert And Montane Plants: A Comparative Study, David William Gallagher

Master's Theses

• Climate change models predict an increase in frequency and amplitude of extreme weather events, including heat waves. To better predict how the composition and distribution of plant assemblages might respond to these changes in temperature, it is important to understand how species currently respond to these extremes. Photosynthetic thermal tolerance (T₂₅)and photosynthetic recovery (RT₂₅) were quantified in 27 species. We also studied the relationships between T₂₅, RT₂₅ and leaf mass per area (LMA). Leaf temperature was also monitored in the field.
• Leaves used in this study were collected from two distinct …

The Role Of Elevation And Soil Chemistry In The Distribution And Ion Accumulation Of Floral Morphs Of Streptanthus Polygaloides Gray (Brassicaceae), A Californian Nickel Hyperaccumulator, Nathaniel S. Pope, Michael Fong, Robert S. Boyd, Nishanta Rajakaruna

Biological Sciences

Background: The flora of serpentine/ultramafic soils provides an excellent model system for the study of natural selection in plant populations. Streptanthus polygaloides is a nickel hyperaccumulator that is endemic to serpentine soils in the Sierra Nevada of California, and has four floral morphs (yellow, purple, yellow-to-purple and undulate).

Aims: We investigate three hypotheses: (1) the purple morph occurs in colder, wetter climates than the yellow morph; (2) tissue–soil ionic relationships differ among morphs; and (3) morphs occur on soils with differing elemental concentrations.

Methods: We queried herbarium records to investigate patterns of occurrence among the yellow and purple floral morphs, …

Seasonal Food Habits Of Burrowing Owls (Athene Cunicularia) In Human-Altered Landscapes, Carie Marie Wingert

Master's Theses

In 2004, I initiated a year-long study to investigate the food habits of burrowing owls (Athene cunicularia). Burrowing owls have been found in a variety of human-altered landscapes; however, little is known about burrowing owl food habits in urban landscapes. Burrowing owl food habits during the non-breeding season are also largely undocumented, despite increasing concern over the survival of overwintering burrowing owls. Differences in prey consumption between reproductive and non-reproductive owls during the breeding season have not yet been examined. I collected pellets over a 12 month period at four study sites affected by different levels of human …

Vitamin D Sub-Set Analysis From The Flash Study, Megan Bishop, Laura Hall, Ann Mcdermott, Aydin Nazmi

Master's Theses

Vitamin D is important to the health of college students. The objective of our study was to measure sun exposure, skin pigmentation, vitamin D intake, and serum 25-hydroxyvitamin D (25[OH]D) in a subset of participants from The Following the Longitudinal Aspects of Student Health (FLASH) Study to determine the best predictors of 25(OH)D status. Participants were college-aged freshman who had their blood drawn in spring (Visit 1) and fall 2010 (Visit 2) at California Polytechnic State University (Cal Poly), San Luis Obispo, CA. (35.3°N). Vitamin D intake was measured using a 28-day food frequency recall questionnaire (specific to vitamin D …

Experimentally Altered Navigational Demands Induce Changes In The Cortical Forebrain Of Free-Ranging Northern Pacific Rattlesnakes (Crotalus O. Oreganus), Matthew L. Holding, Julius A. Frazier, Emily N. Taylor, Christine R. Strand

Biological Sciences

The hippocampus of birds and mammals plays a crucial role in spatial memory and navigation. The hippocampus exhibits plasticity in adulthood in response to diverse environmental factors associated with spatial demands placed on an animal. The medial and dorsal cortices of the telencephalon of squamate reptiles have been implicated as functional homologues to the hippocampus. This study sought to experimentally manipulate the navigational demands placed on free-ranging northern Pacific rattlesnakes (Crotalus o. oreganus) to provide direct evidence of the relationship between spatial demands and neuroplasticity in the cortical telencephalon of the squamate brain. Adult male rattlesnakes were radio-tracked for 2 …

Temperature Thresholds And Degree-Day Model For Marmara Gulosa (Lepidoptera: Gracillariidae), M. J. O'Neal, David H. Headrick, Gregory H. Montez, E.E. Grafton-Cardwell

Horticulture and Crop Science

The developmental thresholds for Marmara gulosa Guillen & Davis (Lepidoptera: Gracillariidae) were investigated in the laboratory by using 17, 21, 25, 29, and 33°C. The lowest mortality occurred in cohorts exposed to 25 and 29°C. Other temperatures caused >10% mortality primarily in egg and Þrst and second instar sap-feeding larvae. Linear regression analysis approximated the lower developmental threshold at 12.2°C. High mortality and slow developmental rate at 33°C indicate the upper developmental threshold is near this temperature. The degree-day (DD) model indicated that a generation requires an accumulation of 322 DD for development from egg to adult emergence. Average daily …

Addressing Biased Occurrence Data In Predicting Potential Sierra Nevada Red Fox Habitat For Survey Prioritization, Casey Cleve, John D. Perrine, Barbara Holzman, Ellen Hines

Biological Sciences

The Sierra Nevada red fox Vulpes vulpes necator is listed as a threatened species under the California Endangered Species Act. It originally occurred throughout California’s Cascade and Sierra Nevada mountain regions. Its current distribution is unknown but should be determined in order to guide management actions. We used occurrence data from the only known population, in the Lassen Peak region of northern California, combined with climatic and remotely sensed variables, to predict the species’ potential distribution throughout its historic range. These model predictions can guide future surveys to locate additional fox populations. Moreover, they allow us to compare the relative …

Combining Conventional Tests And Terminal Restriction Fragment Analysis To Evaluate Microbial Quality Of Raw Milk, Haibin Guo

Master's Theses

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Abstract

Combining Conventional Tests and Terminal Restriction Fragment Analysis to Evaluate Microbial Quality of Raw Milk

Haibin Guo

The dairy industry is an important part in the domestic economy in the U.S. and the quality of dairy products hinges on raw milk quality. Microorganisms play a critical role in raw milk quality and they are currently tested and monitored by conventional microbiological tests. …

The Proteomic Response Of Sea Squirts (Genus Ciona Congeners) To Heat Stress: Evidence For Differential Thermal Sensitivities, Loredana Serafini

Master's Theses

The sea squirts Ciona intestinalis and C. savignyi have disparate distribution patterns, which may result from differences in their thermal tolerance limits. Because C. intestinalis, an almost cosmopolitan species, has a more widespread distribution, it is thought that it is better adapted to endure a wide range of temperatures. In order to compare the heat stress response between these two congeners, we studied global changes in protein expression, using a proteomics approach. To characterize the response to extreme heat stress, animals of both species were exposed to temperatures of 22°C, 25°C, and 28°C for 6 h, and then were …

Sierra Nevada Red Fox (Vulpes Vulpes Necator): A Conservation Assessment, John D. Perrine, Lori A. Campbell, Gregory A. Green

Biological Sciences

One goal of the Sierra Nevada Forest Plan Amendment (SNFPA) 2001 and 2004 Records of Decision was to protect and recover native Sierra Nevada red fox (Vulpes vulpes necator) populations in the Sierra Nevada (USDA Forest Service 2001 p. 14). To accomplish this goal, the ROD commits the U.S. Department of Agriculture (USDA) Forest Service to completing a conservation assessment for the Sierra Nevada red fox in cooperation with other federal, state, and local agencies, as well as Tribal governments. This conservation assessment synthesizes the best available scientific information and thought concerning habitat relationships, population status and trends, historical and …

Purple Martin, Progne Subis, In San Luis Obispo County Riparian Habitat: Presence, Persistence, Nesting, Brooding And Reproductive Success, Shannon Eileen Murphy

Biological Sciences

The State of California, as of 2002, identified the Purple Martin as a bird species of Special Concern (Airola et al., 2003). These migrants were historically found in a unique habitat in Central California; nesting in natural cavities of Western Sycamores within Riparian Habitats. I am proposing that Purple Martins still successfully nest and brood young in this unique habitat in San Luis Obispo County. The primary study site is in Atascadero where Highway 41 meets San Gabriel Road and San Gabriel Road crosses Atascadero creek. The secondary site is Highway 58 in Santa Margarita where the highway crosses the …

Advances In Serpentine Geoecology: A Retrospective, Nishanta Rajakaruna, Robert S. Boyd

Biological Sciences

(In absence of a text abstract the first paragraph of the paper is provided.)

Serpentine habitats have long provided model settings for geoecological research (reviewed in Alexander et al. 2007, Brady et al. 2005, Brooks 1987, Kazakou et al. 2008, Kruckeberg 1984, Proctor and Woodell 1975, Raja-karuna et al 2009). Serpentine loosely refers to a broad group of minerals associated with the weathering of ultramafi c (high iron and magnesium-rich) rocks found along continental margins and orogenic belts. Soils associated with such rocks often differ from more widespread soils, being less fertile and having high concentrations of some heavy metals. …

Serpentine Geoecology Of Eastern North America: A Review, Nishanta Rajakaruna, Tanner B. Harris, Earl B. Alexander

Biological Sciences

Serpentine outcrops are model habitats for geoecological studies. While much attention has been paid to serpentine outcrops worldwide, the literature on eastern North American serpentine and associated biota is scant. This review examines the available literature, published and unpublished, on geoecological studies conducted on serpentine in eastern North America, from Newfoundland through Québec and New England south to Alabama. Most serpentine outcrops in the region have been mapped, but there have been few intensive mineralogical and pedological investigations. The limited soil analyses available suggest elevated levels of heavy metals such as Ni, near-neutral pH values, and Ca∶Mg ratios < 1, characteristic of serpentine soils worldwide. Botanical studies to date have largely focused on floristic surveys and the influence of fire exclusion and grazing on indigenous vegetation. To date, 751 taxa of vascular plants belonging to 92 families have been reported from serpentine outcrops in the region. Two taxa, Agalinis acuta …