Life Sciences Commons^™

Analysis Of The Slo Bay Microbiome From A Network Perspective, Lien Viet Nguyen

Master's Theses

Microorganisms are key players in the ecosystem functioning. In this thesis, we developed a framework to preprocess raw microbiome data, build a correlation network, and analyze co-occurrence patterns between microbes. We then applied this framework to a marine microbiome dataset. The dataset used in this study comes from a year-long time-series to characterize the microbial communities in our coastal waters off the Cal Poly Pier. In analyzing this dataset, we were able to observe and confirm previously discovered patterns of interactions and generate hypotheses about new patterns. The analysis of co-occurrences between prokaryotic and eukaryotic taxa is relatively novel and …

Assessing Cryptic Dispersal And Movement In The Lompoc Kangaroo Rat, Katherine A. Belnick

Biological Sciences

Lompoc kangaroo rats (LKR, Dipodomys heermanni arenae) are small rodents that reside in sand dunes from Pismo to Orcutt, including the Oceano Dunes State Vehicular Recreation Area (SVRA), in Oceano, CA. In the SVRA, some of these individuals live in habitat islands, which are habitat fragments of dense vegetation disrupted by empty, bare sand in between them. Recreational vehicle activity is permitted in the Oceano Dunes, which has caused persistence habitat fragmentation. Kangaroo rats are known to disperse between habitat islands and are suspected to do so via a special type of dispersal: cryptic dispersal. This dispersal mode, if it …

Rapid Warming Events In A Small Coastal Upwelling Embayment, Tatjana E. Ellis

Physics

Temperature variability in the nearshore coastal ocean influences various biological processes and can drive changes in biodiversity and habitat range. Despite recent progress, there are still significant gaps in the understanding of drivers of temperature variability in upwelling bays, particularly at higher frequencies. In this study, we analyzed a decade of nearshore temperature measurements both inside and outside a small coastal embayment located in central California [San Luis Obispo (SLO) bay], as well as temperature data from satellites, to characterize rapid warming events. We found that rapid warming events, defined using rates of temperature change across different thresholds, occurred more …

Habitat Heterogeneity Affects The Thermal Ecology Of The Federally Endangered Blunt-Nosed Leopard Lizard, Nicole Gaudenti

Master's Theses

Global climate change is already contributing to the extirpation of numerous species worldwide, and sensitive species will continue to face challenges associated with rising temperatures throughout this century and beyond. It is especially important to evaluate the thermal ecology of endangered ectotherm species now so that mitigation measures can be taken as early as possible. A recent study of the thermal ecology of the federally endangered Blunt-Nosed Leopard Lizard (Gambelia sila) suggested that they face major activity restrictions due to thermal constraints in their desert habitat, but that large shade-providing shrubs act as thermal buffers to allow them …

Selection Of Overwintering Microclimate By Migratory Western Monarch Butterflies, Kiana Saniee

Master's Theses

Migratory species are expected to demonstrate habitat selection that occurs at multiple spatial and temporal scales. Western monarch butterflies migrate seasonally to overwinter in groves at geographically predictable locations along the California coast. To date, overwintering habitat selection by western monarch butterflies has been studied assuming that habitat selection occurs where overwintering aggregations form, meaning at the spatial scale where monarchs form dense overwintering aggregations within overwintering groves. We argue that since western monarch butterflies are migratory, studies of habitat selection could have commingled selection at different scales into a single spatial scale. This likely leads to ignoring some levels …

Reciprocal Transplant And Machine Learning Study Of Oak Mistletoe On Three Host Oak Species In Santa Margarita, California, Ella Abelli-Amen

Master's Theses

At Santa Margarita Ranch, California, oak mistletoe (Phoradendron villosum) parasitizes valley oak and blue oak but cannot be found growing on coast live oak despite its abundance and ability to parasitize coast live oak in other areas. It seems as though this species of mistletoe is specializing on certain host oak trees, but the mechanisms of this specialization are unknown. In order to investigate this pattern, we utilized a type of machine learning in GIS called supervised classification as well as a reciprocal transplant study in the field. The three species of oak trees were classified with 87% accuracy using …

Natural And Experimental Noise Affects Acoustic Communication In Songbirds, Veronica Arlene Reed

Master's Theses

Background noise is ubiquitous and can impair acoustic communication and influence signaling behavior in animals. Despite evidence demonstrating myriad effects of anthropogenic noise on animal communication, precisely how natural background noise influences communication and behavior remains unclear. Yet, natural sources of background noise, such as rushing rivers or crashing ocean surf, share similar power spectra to sources of anthropogenic noise and can occur at high amplitudes, potentially masking acoustic signals.

To investigate the effects of water-generated noise on songbird behavior, we experimentally broadcast landscape-level playbacks of ocean surf and river noise in coastal California, USA, and riparian habitat in Idaho, …