Biology Commons^™

Ecological Speciation In A Multi-Trophic Complex: Gall Midges, Goldenrods, And Parasitoids, Brenda L. Wells

Browse all Theses and Dissertations

The importance of ecological interactions in the origin and maintenance of species diversity remains unclear. The current study assesses how ecological interactions shape the process of evolutionary diversification using a gall midge-host plant system in Ohio involving the gall midge, Asteromyia carbonifera (Diptera: Cecidomyiidae), and its goldenrod (Solidago) host-plants. A. carbonifera form four morphologically distinctive gall morphs and differ genetically. I studied phenology, host-plant specialization, and parasitism at three field sites in Southwestern Ohio. Phenology was assessed for twelve weeks while host-plant distribution and pressure from parasitoids were measured by monthly plot and rearing gall collections. Relative gall frequencies and …

The Ecology Of The Peaks Of Otter Salamander (Plethodon Hubrichti) In Sympatry With The Eastern Red-Backed Salamander (Plethodon Cinereus), Norman Reichenbach, Andrew Kniowski

Faculty Publications and Presentations

The Peaks of Otter Salamander, Plethodon hubrichti, is found along a 19 km length of the Blue Ridge Mountains, Virginia, USA, often in sympatry with the Eastern Red-backed Salamander, P. cinereus. In a sympatric area of Bedford County, Virginia, we conducted a mark-recapture study on a 10 × 10 m site. Surface densities of salamanders increased as the number of days without precipitation prior to a collection event increased. This suggests vertical movements in response to surface moisture. When salamanders returned to the surface after rain, individuals appeared to “shuffle” between rocks and likely, leaf litter. That is, we were …

Population Ecology And Reproductive Biology Of The Diamondback Watersnake, Nerodia Rhombifer (Serpentes: Colubridae), In Southernmost Texas, Ruben D. Zamora

Theses and Dissertations - UTB/UTPA

Nerodia rhombifer is a polytypic, semi-aquatic snake with a broad geographical distribution ranging from the American Midwest southward to Chiapas, Mexico. Although relatively abundant throughout much of its range, few ecological studies of the species have been conducted. This study provides basic population ecology information in a subtropical habitat. Population data were obtained in a mark-recapture study at Santa Ana National Wildlife Refuge, Hidalgo County, Texas, from August 1995 to December 1998. Specimens taken elsewhere in Hidalgo County provided information on the reproductive biology. This study provides the first absolute density estimates from anywhere within the species’ range. Quantitative information …

The Influence Of Environmental Factors On The Activity And Movement Of Bufo Nebulifer (Coastal Plain Toad) In A Disturbed Area, Crystal Salinas

Theses and Dissertations - UTB/UTPA

Toads in the family Bufonidae are poorly studied in southern Texas. Bufo nebulifir, a native bufonid, has been studied in its northern and southern range limits (east Texas and northern Mexico). South Texas' sub-tropical climate could impact the length of the activity period for B. nebulifer in yet unrecorded ways. This study resolves whether environmental factors correlate to Bufo nebulifer's activity, presence, and movement, using a mark-recapture method. The study was conducted for one year during February 2008 to March 2009. Environmental factors, especially rainfall and temperature were significantly correlated (PB. nebulifer . The active period of B. …

Determination Of Dispersal Patterns Of The Small-Mouthed Salamander (Ambystoma Texanum) In Eagle Creek Park (Indianapolis, In), Stacey Diane Summitt

Undergraduate Honors Thesis Collection

Urbanization and the increasing threat of habitat fragmentation are contributing to the significant declines in amphibian populations world-wide. Ambystomatid species are particularly susceptible to habitat fragmentation because they migrate yearly across upland forests to their breeding sites. Habitat changes could be altering the genetic structure in these species; however few studies have focused on this topic and more generally, examined the dispersal patterns of Ambystomatids. In 2003, Clark, Cripe, and Stachniw conducted a study on “Metapopulation Structure of Ambystoma texanum in Eagle Creek Park (Indianapolis, IN) and the Potential for Gene Flow.” They hypothesized that distance limits the dispersal of …

Differential Response Of Amp Activated Protein Kinase (Ampk) And Hsp70 To Temperature Stress In The Gastropod, Nucella Lapillus, Emily Zimmermann

All Theses And Dissertations

Populations of the gastropod Nucella lapillus are polymorphic for shell color, with light-colored shells predominating on warmer, wave-protected shores and dark-colored shells limited primarily to cooler, wave-exposed shores. During thermal stress, darker shells attain higher body temperatures than lighter shells. These results suggest that heat stress may determine field distribution patterns. However, there is currently little evidence of physiological consequences of thermal stress in these organisms. Following the guiding hypothesis that heat stress leads to cellular energy depletion, we explored whether the central energy regulator AMP-activated Protein Kinase (AMPK) is activated by heat stress. We compared this response in both …

Granite Rock Outcrops: An Extreme Environment For Soil Nematodes?, Erin Austin, Katharine Semmens, Charles Parsons, Amy M. Treonis

Biology Faculty Publications

We studied soil nematode communities from the surface of granite flatrock outcrops in the eastern Piedmont region of the United States. The thin soils that develop here experience high light intensity and extreme fluctuations in temperature and moisture and host unique plant communities. We collected soils from outcrop microsites in Virginia (VA) and North Carolina (NC) in various stages of succession (Primitive, Minimal, and Mature) and compared soil properties and nematode communities to those of adjacent forest soils. Nematodes were present in most outcrop soils, with densities comparable to forest soils (P > 0.05). Nematode communities in Mature and Minimal soils …

Cuscuta Jepsonii (Convolvulaceae): An Invasive Weed Or An Extinct Endemic?, Mihai Costea, Saša Stefanović

Biology Faculty Publications

Despite their ecological significance, parasitic plants face more conservation challenges than do autotrophic plants. This is especially true for the groups that include weedy or invasive species such as Cuscuta. While approximately half of the Cuscuta (dodders) species may require conservation measures, the genus as a whole is sometimes posted on governmental lists of noxious or quarantine weeds. Our study challenges this stereotype and uses the case of C. jepsonii (Jepson’s dodder) to illustrate the precarious biodiversity and conservation status faced by many dodder species. Until now, Jepson’s dodder has been known only from its type collection. Consequently, its …

The Indirect Effects Of Cheatgrass Invasion: Grasshopper Herbivory On Native Grasses Determined By Neighboring Cheatgrass, Julie Beckstead, Susan E. Meyer, Carol K. Augsperger

Biology Faculty Scholarship

Invasion biology has focused on the direct effects of plant invasion and has generally overlooked indirect interactions. Here we link theories of invasion biology and herbivory to explore an indirect effect of one invading species on associational herbivory (the effect of neighboring plants on herbivory) of native species. We studied a Great Basin shadscale (Atriplex confertifolia)-bunchgrass community in western Utah, U.S.A.This community is dominated by native bunchgrasses, invaded by cheatgrass (Bromus tectorum), and home to large populations of grasshoppers (Xanthippus corallipes and Melanoplus confusus). Observations of associational herbivory provided support for the attractant-source hypothesis for one of two native species …

Cheatgrass (Bromus Tectorum) Biocontrol Using Indigenous Funtal Pathogens, Susan E. Meyer, David L. Nelson, Suzette Clement, Julie Beckstead

Biology Faculty Scholarship

Cheatgrass (Bromus tectorum) is an exotic winter annual grass weed that has invaded millions of hectares in the Intermountain West. Restoration of cheatgrass-invaded wildlands is generally impractical without some form of cheatgrass control. We are investigating the possibility of manipulating indigenous fungal pathogens that already occur on cheatgrass for short-term biocontrol in conjunction with restoration seedings. Three potential biocontrol organisms have been identified. The head smut pathogen (Ustilago bullata) and the chestnut bunt pathogen (Tilletia fusca) infect at the seedling stage and prevent seed set, while the black-fingers-of-death pathogen (Pyrenophora semeniperda) kills seeds in the seed bank. Both head smut …

The Reproductive Ecology Of Graptemys Geographica In The Central Canal, Kati Keppen Rush

Undergraduate Honors Thesis Collection

Life for all organisms involves carefully managing a limited amount of resources. In many cases these resources affect how organisms Jive on a daily basis. In addition to competition from other species, organisms face competition within their own species, populations, and niches. Those individuals that manage their resources effectively will increase their chances of survival, reproduction, and the continuation of their genes in the gene pool. Studies that focus on life history characteristics of organisms aim to understand the mechanisms used by organisms to increase the chances that their genes will remain in thegenepoolpasttheirown Iifetime.Thegoal ofthesemechanisms istoensuresurvival and maximize reproduction. …

Population Dynamics Of Freshwater Invertebrates In Beltrami County, Amanda Johnson

Honors Capstones

Capstone submitted as a graduate requirement for the BSU Honors Program.

On Estimating The Exponent Of Power-Law Frequency Distributions, Ethan P. White, B. J. Enquist, J. L. Green

Biology Faculty Publications

Power-law frequency distributions characterize a wide array of natural phenomena. In ecology, biology, and many physical and social sciences, the exponents of these power-laws are estimated to draw inference about the processes underlying the phenomenon, to test theoretical models, and to scale up from local observations to global patterns. Therefore, it is essential that these exponents be estimated accurately. Unfortunately, the binning-based methods traditionally utilized in ecology and other disciplines perform quite poorly. Here we discuss more sophisticated methods for fitting these exponents based on cumulative distribution functions and maximum likelihood estimation. We illustrate their superior performance at estimating known …

Ecological Genomics: Understanding Gene And Genome Function In The Natural Environment, M. C. Ungerer, L. C. Johnson, M. A. Herman

School of Biological Sciences: Faculty Publications

The field of ecological genomics seeks to understand the genetic mechanisms underlying responses of organisms to their natural environments. This is being achieved through the application of functional genomic approaches to identify and characterize genes with ecological and evolutionary relevance. By its very nature, ecological genomics is an interdisciplinary field. In this review, we consider the significance of this new area of study from both an ecological and genomic perspective using examples from the recent literature. We submit that by considering more fully an ecological context, researchers may gain additional insights into the underlying genetic basis of ecologically relevant phenotypic …

Implications Of Introduced Mule Deer On Santa Catalina Island, California : Their Impacts, Population Ecology, And Management, Thad A. Manuwal

Theses and Dissertations

A small group of mule deer were introduced to Santa Catalina Island in the early
1930s. The mule deer population increased through the 1940s and 1950s and remains widespread and abundant today. Large browsing ungulates are not native to Santa Catalina Island and there is concern that nonnative mule deer are damaging endemic trees and shrubs on the island when foraging. This study was designed to develop quantitative information on diets, foraging behavior, movements, and population biology of mule deer on Catalina Island.

Diet analysis indicated mule deer are consuming a wide variety of native and
endemic plants found on …

Fresh Water Ecology Unit For Secondary Education Science Courses, Eric L. Hyer

Theses and Dissertations

Science means “to know", a process for gaining knowledge and an understanding of the natural world. Students need to be involved in active learning. In other words, they must do science, not just hear about it. Good science encourages students to gain knowledge by doing science: observing, questioning, exploring, making and testing hypotheses, comparing predictions, evaluating data, and communicating conclusions. This unit plan is designed to incorporate the components of fresh water, ecology, water quality, and a class-wide science project. Each lesson addresses selected standards from the state core curriculum and has specific objectives that are tied to the learning …

Population Responses Of Wood Frog (Rana Sylvatica) Tadpoles To Overwintered Bullfrog (Rana Catesbeiana) Tadpoles, Leroy J. Walston, Stephen J. Mullin

Faculty Publications

A fundamental goal in ecology is to understand how environmental variation influences the distribution of individuals within a population. In this study, we used laboratory experiments to examine the population responses of sympatric Wood Frog (Rana sylvatica) tadpoles to native overwintered Bullfrog (Rana catesbeiana) tadpoles. For periods of up to two weeks, we measured growth, activity, and refuge use of Wood Frog tadpoles in small mesocosms with and without an overwintered Bullfrog tadpole present. Bullfrog tadpoles had a negative effect on the growth of Wood Frog tadpoles allotopic (naive) to Bullfrogs, whereas the presence of Bullfrogs had no effect on …

Schweinitz’S Sunflower Helianthus Schweinitzii Torrey And Gray, (Asterales: Asteraceae) In Upper Piedmont South Carolina, Steven E. Fields

Journal of the South Carolina Academy of Science

No abstract provided.

Spatial And Temporal Patterns Of Anadromous Fish Passage At Boshers Dam Vertical Slot Fishway On The James River, Richmond, Virginia, Matthew Thomas Fisher

Theses and Dissertations

Boshers dam vertical slot fishway, James River, Virginia, U.S.A., opened in 1999 and restored connectivity to 543.3 km of spawning habitat for anadromous fish. The fishway also allowed local movement of resident species. Video observation from 2001-2005 was used to evaluate environmental predictors of American shad (Alosa sapidissima) and sea lamprey (Petromyzon marinus) passage. The ecological effects of restoring connectivity to upstream habitat for gizzard shad (Dorosoma cepedianum) and blue catfish (Ictalurus furcatus) are also discussed. Regression analysis determined that the best predictor of increased daytime American shad passage is higher water temperatures and discharge and for increased daytime sea …

Coexistence Of The Niche And Neutral Perspectives In Community Ecology, Mathew A. Leibold, Mark A. Mcpeek

Dartmouth Scholarship

The neutral theory for community structure and biodiversity is dependent on the assumption that species are equivalent to each other in all important ecological respects. We explore what this concept of equivalence means in ecological communities, how such species may arise evolutionarily, and how the possibility of ecological equivalents relates to previous ideas about niche differentiation. We also show that the co-occurrence of ecologically similar or equivalent species is not incompatible with niche theory as has been supposed, because niche relations can sometimes favor coexistence of similar species. We argue that both evolutionary and ecological processes operate to promote the …

Genetic Assessment Of Rare Blackbanded Sunfish (Enneacanthus Chaetodon) Populations In Virginia, Diana Marie Kercher

Theses and Dissertations

Enneacanthus chaetodon, the blackbanded sunfish, has become increasingly rare throughout its distribution in the Eastern United States. In Virginia, E. chaetodon maintains an endangered status and individuals persist in six populations. Mitochondrial DNA (mtDNA) and microsatellite data were assessed to determine the genetic characters and gene diversity of the Virginia populations. The results of these analyses were then compared to five additional populations; four from New Jersey and one from North Carolina that were known to have relatively good fitness and were not impacted severely by habitat alteration. The results of this study are relevant to selection of proper management …

The Biology Of Canadian Weeds. 131. Polygonum Aviculare L., Mihai Costea, François J. Tardif

Biology Faculty Publications

A review and assessment of biological information as well as personal data are provided for Polygonum aviculare in Canada. The species has been revised taxonomically and the six subspecies that occur in Canada are presented. Three of the subspecies, P. aviculare subsp. aviculare, P. aviculare subsp. neglectum and P. aviculare subsp. depressum are weeds introduced to Canada from Europe. A fourth subspecies, P. aviculare subsp. buxiforme is apparently native to North America. The geographical distribution of the latter four subspecies is very wide. Plants exhibit a high phenotypic plasticity and genetic variability, and they easily adapt to a multitude …

The Large Genome Constraint Hypothesis: Evolution, Ecology And Phenotype, Charles A. Knight, Nicole A. Molinari, Dmitri A. Petrov

Biological Sciences

• Background and Aims If large genomes are truly saturated with unnecessary ‘junk’ DNA, it would seem natural that there would be costs associated with accumulation and replication of this excess DNA. Here we examine the available evidence to support this hypothesis, which we term the ‘large genome constraint’. We examine the large genome constraint at three scales: evolution, ecology, and the plant phenotype.

• Scope In evolution, we tested the hypothesis that plant lineages with large genomes are diversifying more slowly. We found that genera with large genomes are less likely to be highly specious – suggesting a large …

On The Enigmatic Distribution Of The Honduran Endemic Leptodactylus Silvanimbus (Amphibia: Anura: Lep Todactylidae), W. Ronald Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Most species of the frog genus Leptodactylus occur in South America, and all authors who have treated the zoogeography of the genus have concluded that it originated somewhere in South America (e.g., Savage 1982). Savage (1982,518) summarized the historical herpetofaunal units of the Neotropics as follows: "All evidence points to an ancient contiguity and essential similarity of a generalized tropical herpetofauna that ranged over tropical North, Middle, and most of South America in Cretaceous-Paleocene times. Descendents of this fauna are represented today by the South and Middle American tracks (Elements). To the north of this fauna ranged a subtropical-temperate Laurasian …

The Challenge Of Environmental Protection, Jennifer Mattei

Biology Faculty Publications

Connecticut is in the midst of a demographic transition to a period of lower population growth. These demographic changes will help check the pressures exerted on the state's natural resources by population growth. Water, air, soil, energy sources, food, fisheries, forests, and biodiversity are common pool resources upon which we depend in ways that transcend political boundaries. Those governing Connecticut should help turn the state into a model of how to manage natural resources by halting forest fragmentation, reducing pollution, and promoting environmental science education.

Density Effects On Growth, Survival And Diet Of June Sucker (Chasmistes Liorus): A Component Allee Effect In An Endangered Species., David Barrett Gonzalez

Theses and Dissertations

Density-dependence is considered one of the most important regulators of population growth, and it has been documented across a wide variety of species. Typically, population growth rate and components thereof decline with increasing density (i.e., negative density-dependence); however, in species that exhibit high population densities and social behavior, positive density-dependence (i.e., Allee effect) may occur at low density. June sucker, a federally endangered lake sucker endemic to Utah Lake, Utah, USA, occurred historically at high density, and it exhibits coordinated feeding behavior. These characteristics indicate a potential for the existence of an Allee effect at current low population densities. To …

Two-Phase Species-Time Relationships In North American Land Birds, Ethan P. White

Biology Faculty Publications

The species-time relationship (STR) is a macroecological pattern describing the increase in the observed species richness with the length of time censused. Understanding STRs is important for understanding the ecological processes underlying temporal turnover and species richness. However, accurate characterization of the STR has been hampered by the influence of sampling. I analyzed species-time relationships for 521 breeding bird survey communities. I used a model of sampling effects to demonstrate that the increase in richness was not due exclusively to sampling. I estimated the time scale at which ecological processes became dominant over sampling effects using a two-phase model combining …

Scale Model Of A Soil Aggregate And Associated Organisms: A Teaching Tool For Soil Ecology, Mary Anne Bruns, Loren B. Byrne

Arts & Sciences Faculty Publications

Soil is a complex habitat for diverse biota. A significant challenge in teaching soil ecology is our inability to observe organisms as they live and interact in the soil. The objective of this article is to describe an interactive class project to help students visualize the sizes of different groups of soil organisms and to relate these to soil structural components. This project was carried out by students in an upper-level undergraduate soil ecology class. It involved the design and construction of a 4000× scale model of a soil aggregate and its associated organisms. The body of the model was …

Regional Ecological Resource Assessment Of The Rio Grande Riparian Corridor: A Multidisciplinary Approach To Understanding Anthropogenic Effects On Riparian Communities In Semi-Arid Environments, Jay Raney, Amy Neuenschwander, Frank W. Judd, Gene Paull, Melba Crawford, Robert I. Lonard, Tatiana Encheva, Thomas Tremblay, William White

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Riparian ecosystems of the Southwestern United States are among the most productive ecosystems of North America. The rapid decline of these ecosystems throughout the United States, including the Lower Rio Grande Valley, has made riparian conservation a focal issue. This was a multidisciplinary study of riparian communities along the Lower Rio Grande Valley of Texas and Mexico. The objectives of this research project were to: (1) acquire and analyze high-resolution, remotely sensed data from multiple sensors; (2) integrate existing and new field data and remotely sensed data into a geographic information system (GIS); (3) ascertain whether the native vegetation communities …

The Biology Of Canadian Weeds. 126. Amaranthus Albus L., A. Blitoides S. Watson And A. Blitum L., Mihai Costea, François J. Tardif

Biology Faculty Publications

A review of biological information is provided for three species of the genus Amaranthus: A. albus L., A. blitoides S. Watson and A. blitum L. The last species has been revised taxonomically and a new subspecies for Canada is presented—A. blitum subsp. emarginatus (Moq. ex Uline & Bray) Carretero, Munoz Garmendia & Pedrol. Amaranthus albus and A. blitoides are native to the U.S.A. and introduced to Canada. Both species are annual ruderal and agrestal weeds. During the past 100 yr the two species have spread across most provinces of Canada, but the greatest frequency and abundance have been …