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Full-Text Articles in Life Sciences

Conservation Of Open-Canopy-Associated Wildlife: Multi-Scale Management Impacts On Imperiled Herpetofauna, Ethan Joseph Royal Aug 2022

Conservation Of Open-Canopy-Associated Wildlife: Multi-Scale Management Impacts On Imperiled Herpetofauna, Ethan Joseph Royal

Graduate Theses and Dissertations

The loss of open-canopy ecosystems throughout North America has precipitated declines in reptile and amphibian species associated with these habitat types. Current efforts to restore open-canopy ecosystems are underway in many areas, but the local distributions of, habitat characteristics required by and the effects of management actions on many herpetofauna species are poorly understood or entirely unknown. Research examining relationships among herpetofauna and their environments is often complicated by the extremely low detectability seen in many studies. We used landscape-scale, assemblage-level surveys to investigate the occupancy patterns and habitat associations of open-canopy-associated herpetofauna in two regions, as well as gain …


Biodiversity And Global Change In Terrestrial Ecosystems, Timothy J. Ohlert May 2022

Biodiversity And Global Change In Terrestrial Ecosystems, Timothy J. Ohlert

Biology ETDs

Terrestrial ecosystems are critical to human and ecological processes but many gaps in our knowledge remain regarding how terrestrial plant communities assemble and respond to global change. I used field experiments distributed around the world, including long-term experiments from the Sevilleta National Wildlife Refuge (SNWR) in New Mexico and deserts of the southwestern U.S., to evaluate the consequences of drought and other abiotic stressors on plant communities. Dominant grasses were particularly important for the productivity and structure of grasslands at SNWR. In general, the structure of desert plant communities had high resistance to extreme drought, though grasses and other perennial …


Pilfering Passerines? Inter-Class Competition: A New Direction In Foraging Ecology, Shannon Gillen May 2022

Pilfering Passerines? Inter-Class Competition: A New Direction In Foraging Ecology, Shannon Gillen

Masters Theses, 2020-current

Life in the epigeal layer below leaf litterfall often goes unexplored. Shrews (Soricidae, 1910) have foraged in this microhabitat for millions of years, carving out an existence in harsh habitats around the world, ranging from the tropics to subarctic boreal tundra. Two shrew species that inhabit the Shenandoah Valley of Virginia, the least shrew (Cryptotis parva) and northern short-tailed shrew (Blarina brevicauda), were the focus of this study. Shrews make epigeal foraging trails while they continually forage for food, and caching is a way to save this food for times of low and sporadic food availability. …


Risk-Prone And Risk-Averse Foraging Strategies Enable Niche Partitioning By Two Diurnal Orb-Weaving Spider Species, Mitchell D. Long May 2022

Risk-Prone And Risk-Averse Foraging Strategies Enable Niche Partitioning By Two Diurnal Orb-Weaving Spider Species, Mitchell D. Long

Electronic Theses and Dissertations

Niche partitioning is a major component in understanding community ecology and how ecologically similar species coexist. Temporal and spatial partitioning and differences in foraging strategy, including sensitivity to risk (variance), likely contribute to partitioning as well. Here, we approach this partitioning with fine resolution to investigate differences in overall strategy between two species of diurnal, orb-weaving spiders, Verrucosa arenata and Micrathena gracilis (Araneae: Araneidae), that share similar spatial positioning, temporal foraging window, and prey. Through field observation, we found that V. arenata individuals appear to increase spatial and temporal sampling to compensate for an overall risk-prone strategy that depends on …


Nitrogen Availability In Dune Systems And Its Effect On Root Fungal Endophyte Communities., Haley E. Sage May 2022

Nitrogen Availability In Dune Systems And Its Effect On Root Fungal Endophyte Communities., Haley E. Sage

College of Arts & Sciences Senior Honors Theses

As global change persists, changes in resource availability can influence plant-microbe interactions. To understand how resource availability can influence these interactions and species diversity, I focused this research on how varying nitrogen (N) levels affect root endophyte communities in the plant species Ammophila breviligulata, an ecosystem engineer in the dune system. I analyzed the relationship between nitrogen addition and microbial community composition across 60 plots treated with three nitrogen addition levels (control, low, and high) in a long-term experimental field site in the Lake Michigan dunes. I identified Ammophila breviligulata's root endophyte community after creating a culture collection and …


Incorporating Human Effects In Quantifying Mechanisms Of Stream Fish Community Structure Using Metacommunity Theory, Lauren E. Stoczynski May 2022

Incorporating Human Effects In Quantifying Mechanisms Of Stream Fish Community Structure Using Metacommunity Theory, Lauren E. Stoczynski

All Dissertations

Metacommunity theory incorporates local and regional factors to understand how biotic communities are structured across the landscape. Despite established knowledge of how humans impact aquatic systems, inclusion of anthropogenic factors in metacommunity studies have been largely ignored. Additionally, alpha, beta, and gamma diversity can all be explored at the metacommunity level to investigate mechanistic drivers of community structure. Beta diversity can be further partitioned into turnover and richness difference components, each with different mechanistic drivers. Streams provide an excellent study system for metacommunity research because of the dendritic structure of watersheds and the natural delineation that watershed boundaries provide. Large-extent …


Invasive Predators Affect Community-Wide Pollinator Visitation, Christina T. Liang, Aaron B. Shiels, William P. Haines, Manette E. Sandor, Clare E. Aslan Jan 2022

Invasive Predators Affect Community-Wide Pollinator Visitation, Christina T. Liang, Aaron B. Shiels, William P. Haines, Manette E. Sandor, Clare E. Aslan

USDA Wildlife Services: Staff Publications

Disruption of plant–pollinator interactions by invasive predators is poorly understood but may pose a critical threat for native ecosystems. In a multiyear field experiment in Hawai’i, we suppressed abundances of globally invasive predators and then observed insect visitation to flowers of six native plant species. Three plant species are federally endangered (Haplostachys haplostachya, Silene lanceolata, Tetramolopium arenarium) and three are common throughout their range (Bidens menziesii, Dubautia linearis, Sida fallax). Insect visitors were primarily generalist pollinators, including taxa that occur worldwide such as solitary bees (e.g., Lasioglossum impavidum), social bees (e.g., …


Soil Invertebrates In Agriculture: Assessing Ecosystem Services, Biodiversity Impacts, And Farmer Perceptions, Eva Kinnebrew Jan 2022

Soil Invertebrates In Agriculture: Assessing Ecosystem Services, Biodiversity Impacts, And Farmer Perceptions, Eva Kinnebrew

Graduate College Dissertations and Theses

Harmonizing biological diversity and crop production is a major goal towards building more sustainable food systems. Soil invertebrates are diverse and abundant organisms in agriculture, but relatively little is known about their benefits or how agricultural management impacts them. In this dissertation, I dig into the complex interactions between agricultural land use and soil invertebrate biodiversity to better inform farmer decision-making. I find that soil invertebrate communities have major potential contributions to agroecosystems (Chapter 2) and are shaped heavily by agricultural land use (Chapters 3, 4), but remain too uncertain to contribute to farmers’ management choices (Chapter 5). First, I …