Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 36

Full-Text Articles in Entire DC Network

Patterns Of Distribution And Dispersion Of Silver Carp In An Oxbow Lake, Jordan Besson May 2023

Patterns Of Distribution And Dispersion Of Silver Carp In An Oxbow Lake, Jordan Besson

Theses and Dissertations

Oxbow lakes are highly productive waterbodies that host multiple life stages of many freshwater aquatic species. Oxbow lakes also provide habitat to Silver Carp (Hypophthalmichthys molitrix), which has enabled populations to grow and expand within the United States. Silver Carp are undesirable because they can compete for resources with native fishes. My goal was to identify patterns of distribution and dispersion of Silver Carp in Moon Lake, Mississippi, to assist and inform precise harvesting of fish. I implanted thirty-five adult Silver Carp with acoustic tags that I released into Moon Lake. I observed that Silver Carp were disproportionately …


The Impact Of Environmental Education Delivery Methods And Outreach Messaging On Attitudes, Interests, And Intended-Behavior Changes Toward Nature, Vanessa Elizabeth Hoffman May 2023

The Impact Of Environmental Education Delivery Methods And Outreach Messaging On Attitudes, Interests, And Intended-Behavior Changes Toward Nature, Vanessa Elizabeth Hoffman

Theses and Dissertations

Environmental education (EE) is important for environmental awareness and stewardship. Involving youth and adults in EE ensures current and future generations will conserve natural resources. This thesis explores impacts of delivery methods on participants’ environmental attitudes and behaviors toward nature through middle school classroom- and camp-based EE instruction, focus group interviews with rural minority youth, and adult responses to aquatic conservation outreach messaging. I observed no difference in environmental attitudes between online versus in-person delivery of EE lessons for middle-schoolers. Outdoor-based learning may be more impactful for EE than experiential, classroom-based learning. Focus group outcomes suggested youth EE programs should …


Climate, Physiology, And Distributions: The Role Of Thermal Physiology In Biological Invasions, Sean D. Powers Jan 2023

Climate, Physiology, And Distributions: The Role Of Thermal Physiology In Biological Invasions, Sean D. Powers

Theses and Dissertations

Climate is a primary factor influencing species range dynamics, particularly for ectotherms whose body temperature is closely tied to the surrounding conditions. While range shifts of ectotherms are attributed to climate warming, the mechanism driving these shifts are not well understood. Studies in macrophysiology demonstrate that the interaction of climate with thermal physiology plays a key role in determining large-scale spatial and temporal patterns for many temperature-sensitive physiological traits. This work has revealed a clear relationship between thermal tolerance breadth and range size. However, more recent analyses of this relationship demonstrate that thermal tolerance breadth only provides a partial explanation …


Effects Of Post-Fire Disturbance Responses Of Microstegium Vimineum On Native Hardwood Seedling Growth And Survival, Zachary A. Chandler Dec 2022

Effects Of Post-Fire Disturbance Responses Of Microstegium Vimineum On Native Hardwood Seedling Growth And Survival, Zachary A. Chandler

Theses and Dissertations

Invasions by alien understory plant species have gradually become a worldwide challenge in maintaining forest biodiversity and ecosystem productivity. Notably, Microstegium vimineum, a C4 grass native to Japan, has increased dominance in mixed deciduous hardwood forests of the southeastern United States, largely due to its shade tolerance and ability to spread through rhizomes. Microstegium vimineum also proliferates after prescribed fire, a common management tool used in the region to restore forests to desired conditions, and may compete with hardwood seedlings, hindering restoration efforts. Using two upland deciduous hardwood forest research sites in Marshall and Tate Counties, Mississippi, this study …


Seasonal Comparison On The Effectiveness Of Control Methods For Microstegium Vimineum In The North Carolina Piedmont, Casey Beam Dec 2022

Seasonal Comparison On The Effectiveness Of Control Methods For Microstegium Vimineum In The North Carolina Piedmont, Casey Beam

Theses and Dissertations

Microstegium vimineum, or Japanese stilt grass, is an invasive species that readily outcompetes native vegetation and is of poor forage quality for wildlife. This species is widespread throughout the southeastern United States, including North Carolina. Much of this region is privately owned and there is a gap in the literature providing succinct information about the best methods of treatment, timing of treatment, and effects of treatment on native herbaceous plants in this region. In two parts, this study seeks to address this gap by employing treatments that are easily accessible to landowners at different times during the growing season and …


Evaluating The Influence Of Ecosystem Characteristics And Species Traits On Exotic Species Distributions, Adrián Lázaro-Lobo Aug 2021

Evaluating The Influence Of Ecosystem Characteristics And Species Traits On Exotic Species Distributions, Adrián Lázaro-Lobo

Theses and Dissertations

Natural dispersal mechanisms and biogeographical barriers have shaped species' native distributional ranges over millions of years. However, over the last few centuries, humans have dispersed species beyond their natural ranges. Those species that undergo explosive population growth and rapid expansion in the introduced region are considered as invasive because they have the potential to cause negative effects on desirable species and/or ecosystem services. In chapter II, I identified what ecosystem characteristics are more closely associated with successful establishment of exotic and native species, to have a better idea of where to concentrate our efforts and resources to prevent invasion events …


Oak Regeneration: Impacts Of Prescribed Fire And Invasive Species, Caleb Desmond Goldsmith Aug 2021

Oak Regeneration: Impacts Of Prescribed Fire And Invasive Species, Caleb Desmond Goldsmith

Theses and Dissertations

Across the central and eastern United States, upland oaks are experiencing regeneration complications. This thesis comprises two studies evaluating challenges in regenerating upland oaks. One study evaluates upland Quercus spp., Carya spp., and Acer rubrum L. response to prescribed fire and impacts on seedling growth and mortality. This study found prescribed fire promoted oak growth when canopy cover was < 77%. Oaks displayed lower percent mortality and higher resprout capacity after fire compared to red maple. The second study investigates impacts of Microstegium vimineum presence on Quercus alba L., Liriodendron tulipifera L., and Acer rubrum L. seedlings under different light and moisture environments. Microstegium vimineum presence decreased growth of both sweetgum and red maple; white oak was less impacted, likely because of its conservative growth strategy and high-water use efficiency. Oaks’ conservative growth strategy may offer more resiliency compared to its competitors in response to prescribed fire and Microstegium vimineum.


Native Plant Allelopathy: A Potential Approach To Limit Invasive Grass Encroachment In Thorn Forest Restoration, Emily A. Mullins Dec 2020

Native Plant Allelopathy: A Potential Approach To Limit Invasive Grass Encroachment In Thorn Forest Restoration, Emily A. Mullins

Theses and Dissertations

Less than 5% of the Tamaulipan thorn forest remains in the United States. For this reason, there have been many attempts at restoration of this ecosystem. Oftentimes these attempts are unsuccessful due to the high prevalence of invasive African grasses that outcompete the seedlings. In an effort to improve the efficacy of these restoration efforts, native plant allelopathy has been examined for its ability to exclude invasive guineagrass. Native species were surveyed and selected species were tested for allelopathy in laboratory bioassays. The species that exhibited allelopathy in the laboratory were then evaluated in pot experiments for their ability to …


A Lake Divided: Regional Shifts In Trophic Niche Structure Of Lake Powell Fishes Corresponding To The Invasion Of Quagga Mussels, Nathan Richard St Andre Dec 2020

A Lake Divided: Regional Shifts In Trophic Niche Structure Of Lake Powell Fishes Corresponding To The Invasion Of Quagga Mussels, Nathan Richard St Andre

Theses and Dissertations

Introduced species can become invasive and cause catastrophic alterations to the system they invade. Both zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena bugensis) have caused significant ecosystem alterations wherever they have invaded. These Dreissena species have caused changes in water quality and biodiversity and have disrupted energy pathways which can have cascading effects on other trophic levels. Recently quagga mussels invaded Lake Powell, a reservoir located in the southwestern USA, creating the possibility of a trophic cascade that could alter energy flow in the reservoir and change the trophic niche structure of the fishes in the lake. However, due …


An Analysis Of Temperate Deciduous Shrub Phenology In Downer Woods, University Of Wisconsin-Milwaukee, Wisconsin, Usa, Chloe Rehberg May 2020

An Analysis Of Temperate Deciduous Shrub Phenology In Downer Woods, University Of Wisconsin-Milwaukee, Wisconsin, Usa, Chloe Rehberg

Theses and Dissertations

Shrub species, both native and non-native, are an important component of temperate deciduous forest ecosystems but are an often-overlooked and under-studied functional group. Shrubs tend to leaf-out earlier than trees in spring and retain their leaves later in autumn thus extending the overall growing season and the carbon uptake period of the forest ecosystem. In this study, a range of 5- native and 3- non-native shrub species were identified in a deciduous urban woodlot, and the phenology was monitored over a 3-year period on the University of Wisconsin-Milwaukee campus. The aim of this work was to determine any variation in …


Sampling Techniques For Research And Management Of Cichlid Species In Lentic Systems, Jason Matthew Bies May 2019

Sampling Techniques For Research And Management Of Cichlid Species In Lentic Systems, Jason Matthew Bies

Theses and Dissertations

Introduced cichlid species are increasingly more common in tropical freshwater systems and expanding in range, often with negative consequences to receiving systems. To better understand, monitor, and manage these populations, improved cichlid sampling protocols are required. The goal of this study was to (1) evaluate diel electrofishing and gill netting sampling catch efficiency, and (2) compare two non-lethal methods for extracting stomach contents from Butterfly Peacock Bass Cichla ocellaris. This study suggests that electrofishing, particularly at night, may be a more appropriate gear for sampling cichlid species in the littoral zone of reservoirs, as gill nets were more time intensive, …


Genetic Diversity Comparison Among Invasive Fish Populations (Nemipterus Randalli And Serranus Cabrilla) From Mediterranean And Red Sea Coastal Waters Using Cytochrome C Oxidase Subunit I (Coi), Joel Ogwang Feb 2019

Genetic Diversity Comparison Among Invasive Fish Populations (Nemipterus Randalli And Serranus Cabrilla) From Mediterranean And Red Sea Coastal Waters Using Cytochrome C Oxidase Subunit I (Coi), Joel Ogwang

Theses and Dissertations

Since the Suez Canal connected the Red Sea with the Mediterranean, several fish species have migrated between the two seas. Nemipterus randalli has crossed from the Red Sea to the Mediterranean (Lessepsian migration) whereas Serranus cabrilla is considered to have crossed in the reverse direction (anti-Lessepsian migration). Genetic variation between populations of these fish species on either side of the Suez Canal might provide valuable information on their patterns of migration. In this study, 600 bp of cytochrome c oxidase subunit I (COI) sequences were used to compare genetic diversity of populations of N. randalli from the eastern Mediterranean with …


Beta Diversity Provides Evidence Of Niche Based Assembly In Temperate Forest Understory Assemblages Of Mississippi, David Steven Mason Dec 2018

Beta Diversity Provides Evidence Of Niche Based Assembly In Temperate Forest Understory Assemblages Of Mississippi, David Steven Mason

Theses and Dissertations

Assembly is a process that shapes the abundance and identity of species in a community. Niche and neutral theory explain assembly processes with mechanisms driven by either species differences, or functional equivalence and stochastic dispersal. In 2017 I sampled vegetation and environmental variables at 59 sites in the Noxubee National Wildlife Refuge and Tombigbee National Forest of Mississippi to explore forest understory community assembly. I developed and assessed a framework of predictions concerning general patterns and underlying mechanism. Evidence of dispersal limitation and functional equivalence were expected under neutral theory. Local environmental characteristics, surrounding landscape variables, and fire were significant …


Investigating Effectiveness Of Wild Pig Policy And Legislation In The U.S., Andrew Lane Smith May 2018

Investigating Effectiveness Of Wild Pig Policy And Legislation In The U.S., Andrew Lane Smith

Theses and Dissertations

The legislative procedures regarding wild pigs in the United States are expanding in scope and priority, however, the uniformity of legislation is entropic at best. Each state addresses the issues of wild pigs differently and treatment is based on a priority of resource concerns. An evaluation was conducted at the national level of federal, state, and local policy with regards to wild pig control. Additionally, successful and unsuccessful legislation is evaluated to determine commonalities in the social, economic, and ecological factors contributing to the success or failure of legislation. Information collected provides state legislatures with sample model legislation that can …


Recreational Firewood Movement As A Vector Of Non-Native Woodborers In Mississippi, Matthew John Thorn Aug 2017

Recreational Firewood Movement As A Vector Of Non-Native Woodborers In Mississippi, Matthew John Thorn

Theses and Dissertations

Recreational firewood collected from campers in Mississippi State Parks was investigated for factors associated with insect presence and their diversity. Insects were found in 20% of firewood and evidence of past feeding was found in 64.8%. Representatives of 35 families of insects were reared from collected firewood. These included representatives of Buprestidae, Cerambycidae, Curculionidae, Formicidae, and Rhinotermitidae. The effects of firewood age, moisture content, and source were also examined as effects on insect presence in firewood. At the same time, a survey of campers’ beliefs and attitudes about non-native woodborers was conducted. Exposure to public awareness campaigns had the strongest …


Assessment Of Chinese Privet (Ligustrum Sinense Lour.) Control Measures, And Selection Of Most Cost Effective Management Regimes, Fabio Jose Benez Secanho May 2017

Assessment Of Chinese Privet (Ligustrum Sinense Lour.) Control Measures, And Selection Of Most Cost Effective Management Regimes, Fabio Jose Benez Secanho

Theses and Dissertations

Chinese privet (Ligustrum sinense) is an invasive plant species in the United States (U.S.). This study utilized the most effective control measures found in the literature, and used financial analysis to identify the most cost effective management regimes to eradicate this species under different conditions. Management regimes were assessed using simulated scenarios created using six components, based on real parameters from the southern U.S.: infestation level, field coverage, stand density, herbicide application method, herbicide, and mechanical removal of privet. Financial impact on land expectation values (LEV) was analyzed and discussed for each simulated area conditions. Results suggest that the most …


Calculating Evapotranspiration Of Arundo Donax Along The Rio Grande, Jose R. Escamilla Jr. Dec 2016

Calculating Evapotranspiration Of Arundo Donax Along The Rio Grande, Jose R. Escamilla Jr.

Theses and Dissertations

Invasive species have been recorded to cause large economic and ecological impacts on various ecosystems and their services. Locally, giant reed (Arundo donax L.), a woody grass native to the Mediterranean, adversely impacts riparian ecosystems in southwestern United States by aggressively displacing their native flora and fauna. Giant reed also has become a cause of concern for national water security, especially in water-limited areas of the arid southwestern United States. The main objective of this study is to provide the first, landscape-level estimates of water use by giant reed in the United States. Evapotranspiration was monitored using the eddy …


Relationships Between Texas Tortoise Carapace Length, Home Range Size, And Habitat Selection At Sites With Invasive Grass, Kiley V. Briggs May 2016

Relationships Between Texas Tortoise Carapace Length, Home Range Size, And Habitat Selection At Sites With Invasive Grass, Kiley V. Briggs

Theses and Dissertations

Invasive grasses in south Texas have the potential to negatively impact the threatened Texas tortoise (Gopherus berlandieri) by reducing the availability of preferred foods (forbs) and may cause tortoises to travel farther, lead to reduced carapace length, and reduce the availability of refugia from heat stress. I used compositional analysis, regression, and ANOVA to explore relationships between invasive grasses and habitat use, home range size, and carapace length, as well as compared daily maximum temperatures between tussocks of an invasive and native grass. Forbs were ranked higher in use over invasive grasses in compositional analysis, but not strongly so (p …


Allelopathy In The Non-Native Macrophyte, Myriophyllum Spicatum And Its Influence On Trophic Dynamics In Aquatic Systems, Daniel J. Sullivan Aug 2015

Allelopathy In The Non-Native Macrophyte, Myriophyllum Spicatum And Its Influence On Trophic Dynamics In Aquatic Systems, Daniel J. Sullivan

Theses and Dissertations

Non-native macrophytes structurally impact aquatic assemblages, yet little is known regarding how they influence energy pathways in freshwater ecosystems. Allelopathy in Eurasian watermilfoil- Myriophyllum spicatum has been shown to target basal epiphytic organisms resulting in differences in assemblage structure of colonizing epiphyton between M. spicatum and native M. sibiricum. I conducted a growth chamber experiment to investigate the hypothesis that differences in assemblage structure of colonizing epiphyton between these two macrophytes influence trophic dynamics within aquatic systems. My data suggest M. spicatum produces higher concentrations of allelochemicals, resulting in a more diverse epiphytic assemblage compared to M. sibiricum. This could …


Biomass And Decomposition Dynamics Of Invasive Chinese Tallow (Triadica Sebifera) In The Southeastern United States, Allison M. Stoklosa Dec 2014

Biomass And Decomposition Dynamics Of Invasive Chinese Tallow (Triadica Sebifera) In The Southeastern United States, Allison M. Stoklosa

Theses and Dissertations

Recent and anticipated global change has focused concern on the role of forests in ecosystem functioning and carbon sequestration. Of key importance is identifying relevant factors that drive carbon and nutrient dynamics and the consequences of changes in these processes. Systems undergoing invasion by invasive woody species are particularly prone to changes. This study examined the branch and crown biomass and decay dynamics for the invasive Chinese tallow tree in Mississippi, USA as well as the influences of stand and site conditions on biomass modeling and arthropod contributions to fine woody debris decay. Coupling biomass and decay models presents a …


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 …


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. …


Dispersal And Management Of Invasive Aquatic Plants In Mississippi Waterways, Amanda Louise Fernandez Dec 2013

Dispersal And Management Of Invasive Aquatic Plants In Mississippi Waterways, Amanda Louise Fernandez

Theses and Dissertations

To understand the flow of water as a factor that influences aquatic vegetation communities and aquatic plant dispersal, custom-made Global Positioning System (GPS) drones were used to monitor the movement of water in Aliceville Lake, Columbus Lake, and Ross Barnett Reservoir, MS. In each reservoir, the drones drifted in the wind-generated surface current. Analysis of wind speeds suggests that a certain wind speed may be necessary to overcome gradient flow. Wind direction and wind speed should be incorporated in future spatial simulation models for aquatic plant dispersal and distribution. An herbicide evaluation on Cuban bulrush (Oxycaryum cubenese) was conducted to …


Population Genetic Structure Of Bromus Tectorum In The American Desert Southwest, Desiree Rochelle Eldon Dec 2013

Population Genetic Structure Of Bromus Tectorum In The American Desert Southwest, Desiree Rochelle Eldon

Theses and Dissertations

Following its introduction to North America in the late nineteenth century, Bromus tectorum L., an inbreeding invasive winter annual grass, has become dominant on millions of hectares of sagebrush steppe habitat throughout Intermountain Western North America. It appears that within the last 30-40 years, B. tectorum has expanded its range southward into the Mojave Desert and also into more climatically extreme salt desert environments. Previous research using microsatellite markers and experimental studies has suggested that lineages found in desert habitats are genetically distinct from those found in the sagebrush-steppe habitat and possess suites of traits that pre-adapt them to these …


Mechanisms And Patterns Of Invasion In Macrophyte Communities, Jonathan Paul Fleming Dec 2012

Mechanisms And Patterns Of Invasion In Macrophyte Communities, Jonathan Paul Fleming

Theses and Dissertations

Aquatic plants (macrophytes) are important components of freshwater ecosystems and serve numerous purposes, physical and biological, that help to structure aquatic communities. Although macrophytes represent an essential component of stable aquatic communities, invasive macrophytes may negatively alter ecosystem properties. Non-native, invasive species have been identified as a major cause of biodiversity loss and the increasing prevalence of invasive species has prompted studies to help understand their impacts and to conserve biodiversity. Studying mechanisms of invasion also gives insight into how communities are structured and assembled. This study examined mechanisms that contribute to macrophyte invasion. First, I reviewed literature concerning mechanisms …


Multi-Scale Population Genetic Analysis Of Cogongrass (Imperata Cylindrica) In The Southeastern United States: Introduction History, Range Expansion, And Hybridization, Rima D. Lucardi Dec 2012

Multi-Scale Population Genetic Analysis Of Cogongrass (Imperata Cylindrica) In The Southeastern United States: Introduction History, Range Expansion, And Hybridization, Rima D. Lucardi

Theses and Dissertations

Biological invasions are a significant area of research due to perceived negative environmental and economic impacts. The study of biological invasions has identified three broad components involved in successful invasions: propagule pressure, abiotic and biotic conditions. Propagule pressure is the product of introduced propagules and the frequency of those introductions, and is considered a driver in all stages of invasion. Data to quantify propagule pressure is often unavailable, and therefore, this research approached genetic information to produce estimates of propagule pressure in the successful invasion of cogongrass (Imperata cylindrica) in the United States. The following research utilized molecular methodologies to …


A Survey Of Invasive Exotic Ants Found On Hawaiian Islands: Spatial Distributions And Patterns Of Association, Camie Frandsen Martin Dec 2012

A Survey Of Invasive Exotic Ants Found On Hawaiian Islands: Spatial Distributions And Patterns Of Association, Camie Frandsen Martin

Theses and Dissertations

An intensive sampling of all ant species encountered on 6 Hawaiian Islands: Big Island, Maui, Oahu, Kauai, Molokai, and Lanai took place between 1988 and 1996. Species presence and absence was recorded at each site. Using remote sensing, variables were added insitu and used throughout my analysis. Species accumulation curves suggest that sampling was comprehensive. There is a significant trend between island area and species richness which validates the Theory of Island Biogeography for invasive species. Islands were found to be significantly nested by area, order, and tourism. Cluster analysis shows a link between elevation, land-use and island, and species …


Spatial Patterns Of Herbaceous And Woody Recruitment In A Recently Restored Mixed Tidal Regime Freshwater Wetland, James B. Deemy May 2012

Spatial Patterns Of Herbaceous And Woody Recruitment In A Recently Restored Mixed Tidal Regime Freshwater Wetland, James B. Deemy

Theses and Dissertations

Ecological restoration of a converted wetland was characterized within a recently drained impoundment along the James River in Charles City County, Virginia. Colonizing vegetation was assessed over three growing seasons in both tidal and non-tidal environments. Study objectives were to (1) examine geospatial relations of recruitment patterns among colonizing species over three growing seasons, (2) quantify species composition and potential differences between extant species cover and soil seed banks across restored and natural wetland habitats and (3) assess geospatial patterns to develop a GIS model of bald cypress (Taxodium distichum L.) recruitment. The two most common native colonizing species during …


An Invasive Species Reduces Aquatic Insect Flux To Terrestrial Food Webs, Steven S. Merkley Jul 2011

An Invasive Species Reduces Aquatic Insect Flux To Terrestrial Food Webs, Steven S. Merkley

Theses and Dissertations

Although it is well documented how introduced species can negatively affect native species, we only poorly understand how they may alter ecosystem functions. We investigated how an invasive fish affected the flux of aquatic insects to terrestrial food webs using mesocosms in a desert spring ecosystem. We compared aquatic insect emergence between alternative community states with monocultures and polycultures of two native species of fish, least chub (Iotichthys phlegethontis) and Utah chub (Gila atraria) plus, introduced western mosquitofish (Gambusia affinis). We tested three hypotheses: (1) aquatic insect biomass will be greater than terrestrial insect …