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Small Mammals Matter? Linking Plant Invasion, Biotic Resistance, And Climate Change In Post-Fire Plant Communities, Rory Charles O'Connor Dec 2014

Small Mammals Matter? Linking Plant Invasion, Biotic Resistance, And Climate Change In Post-Fire Plant Communities, Rory Charles O'Connor

Theses and Dissertations

The introduction and establishment of exotic species can profoundly alter ecosystems. Two exotic species drastically changing the landscape of deserts in western North America are Bromus tectorum L. and Bromus rubens L. Through the buildup of biomass and slow decomposition rates in deserts these two exotic annual grasses can alter fire regimes that change the plant and animal community dynamics in the ecosystems. To better understand the ecological mechanisms that could restrict or alter the patterns of invasive plant establishment we established a replicated full factorial experiment in the Great Basin and Mojave Desert. The combinations of factors being manipulated …


Survival, Growth, And Settlement Of Dreissena Rostriformis Bugensis Veligers In Low And High Calcium Waters, Emma Ruhmann Aug 2014

Survival, Growth, And Settlement Of Dreissena Rostriformis Bugensis Veligers In Low And High Calcium Waters, Emma Ruhmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

Populations ofDreissena rostriformis bugensis(quagga mussels) have continued to spread throughout the western United States since their discovery in the Boulder Basin of Lake Mead, NV-AZ in early 2007. Today, quagga mussel specific research is still lacking and the physicochemical characteristics of aquatic systems required by quagga mussels to successfully establish is not fully understood. This includes an absence of research in aquatic environments in the western United States and on quagga mussel veligers (larval stage). Calcium is considered the defining factor for determining if a lake or river is suitable for quagga mussel establishment. The minimum calcium threshold for invasion …


A Passive Acoustic And Experimental Study Of Juvenile Blue Catfish, Ictalurus Furcatus, Sound Production And Agnostic Behavior In The Tidal Freshwater James River, Laura Morgan May 2014

A Passive Acoustic And Experimental Study Of Juvenile Blue Catfish, Ictalurus Furcatus, Sound Production And Agnostic Behavior In The Tidal Freshwater James River, Laura Morgan

Theses and Dissertations

Blue catfish, Ictalurus furcatus, are an invasive species in the James River, VA. They produce stridulation sounds and passive acoustic monitoring may prove useful in locating and monitoring their populations. Little is known about their behavior, therefore my goal was to examine agonistic behavior and the use of sound in defending a territory. This thesis consists of two manuscripts: 1) A passive acoustic study of the tidal freshwater James River, 2) An experimental study of agonistic behavior in juvenile Blue catfish, Ictalurus furcatus. The first study showed that three sounds (click, run croak) occurred more often in warmer months than …


Forest Edges Enhance Mate-Finding In The European Gypsy Moth, Lymantria Dispar, Lily Thompson Apr 2014

Forest Edges Enhance Mate-Finding In The European Gypsy Moth, Lymantria Dispar, Lily Thompson

Theses and Dissertations

Understanding movement capabilities of individuals within a landscape is essential to identifying the effects of habitat boundaries on species abundances, ranges, and spread rates. Movement barriers due to habitat fragmentation may reduce mate-finding ability in some species, particularly in heterogeneous landscapes containing low-density populations. This study focuses on the effects of habitat type and edge on mate-finding in an invasive defoliator, the European gypsy moth. Adult European gypsy moth males locate mates by following pheromones released by flightless females. Reduced mate-finding was expected in fields and near forest edges based on geographic variation in invasion rates and pheromone plume dynamics. …


The Effects Of Non-Native Species On Two Life-Stages Of The Eastern Oyster Crassostrea Virginica, Wei Yuan Jan 2014

The Effects Of Non-Native Species On Two Life-Stages Of The Eastern Oyster Crassostrea Virginica, Wei Yuan

Electronic Theses and Dissertations

Since their recent introductions into Florida waters, three nonnative species [Perna viridis Linnaeus, 1758 (Asian green mussel), Mytella charruana d'Orbigny, 1846 (charru mussel) and Megabalanus coccopoma Darwin, 1854 (pink titan acorn barnacle)] have expanded both north and south along the Atlantic coast. Very little research has been done to understand how these nonnative species interact with the native eastern oyster (Crassostrea virginica Gmelin, 1791), which is a keystone species that provides important ecological services and economic benefits. To test the potential effects of P. viridis, M. charruana and M. coccopoma on C. virginica, I addressed the following questions: 1a) Does …


Approaches To Improving Detection Of Invasive Fish Species In Western Lake Erie Through Analysis Of Monitoring Efficiencies And Metrics Of Community Distribution, Joshua Alan Southern Jan 2014

Approaches To Improving Detection Of Invasive Fish Species In Western Lake Erie Through Analysis Of Monitoring Efficiencies And Metrics Of Community Distribution, Joshua Alan Southern

Wayne State University Theses

Efficient monitoring programs are essential for the early detection of invasive species. The Ohio Department of Natural Resources (ODNR) monitoring program encompassing 21 years of fish survey data from western Lake Erie was evaluated using Chao biodiversity analysis to determine the efficiency and precision of collection strategies of trawl and gillnet sampling, at detecting rare or non-native species. Overall, ODNR sampling annually accounted for ~80% of extant fish species, leaving gaps in coverage where rare and invasive species may be overlooked and proliferate.Obtaining 90% efficiency would require an estimated doubling of previous sampling effort. Computer simulations calculating different proportions of …


Evaluation Of The Three-Dimensional Patterns And Ecological Impacts Of The Invasive Old World Climbing Fern (Lygodium Microphyllum), Alexis Maldonado Jan 2014

Evaluation Of The Three-Dimensional Patterns And Ecological Impacts Of The Invasive Old World Climbing Fern (Lygodium Microphyllum), Alexis Maldonado

Electronic Theses and Dissertations

Invasion by non-native species has had significant ecological and economic impacts on a global scale. In the state of Florida, Old World climbing fern (Lygodium microphyllum) is an invasive plant listed by FLEPPC as a category one invader with significant ecological impacts that threaten native plant diversity. This species relies on existing vegetative structures for support to climb into the forest canopy and forms dense mats that cover tree crowns. This subsequently affects the resources available to other species present. Quantifying the structural changes due to the presence of this species has proved logistically difficult, especially on a large spatial …


Effect Of Invasive Phragmites Australis And Its Control On Microbial Community Composition In A Freshwater Wetland, Jennifer K. Kirk Jan 2014

Effect Of Invasive Phragmites Australis And Its Control On Microbial Community Composition In A Freshwater Wetland, Jennifer K. Kirk

Master's Theses and Doctoral Dissertations

Wetlands support great species diversity and perform important ecosystem services like carbon and nutrient cycling, largely facilitated by microorganisms. Invasive plants, like Phragmites australis, reduce biodiversity and alter ecosystem services. I hypothesized that changes in soil bacterial communities would occur after Phragmites invasion and restoration efforts employing herbicide to remove Phragmites would further disrupt communities. This was tested in freshwater wetlands using terminal restriction fragment length polymorphism analysis of PCR amplified eubacterial DNA from soils dominated by Typha and Phragmites vegetation preceding and following herbicide application. Soil bacterial communities differed by vegetation type and indicated both seasonal and inter-annual effects. …