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Full-Text Articles in Life Sciences

Fishes As A Template For Reticulate Evolution: A Case Study Involving Catostomus In The Colorado River Basin Of Western North America, Max Russell Bangs Dec 2016

Fishes As A Template For Reticulate Evolution: A Case Study Involving Catostomus In The Colorado River Basin Of Western North America, Max Russell Bangs

Graduate Theses and Dissertations

Hybridization is neither simplistic nor phylogenetically constrained, and post hoc introgression can have profound evolutionary effects. Most studies have focused on tractable model systems, rather than organisms with complicated phylogenetic histories. Finescale Sucker (genus Catostomus) in western North America is recognized as a paradigm of fish hybridization. Yet, its extent of historic and contemporary introgression is largely unstudied, an aspect that impedes the resolution of its phylogeny as a baseline for conservation. To explore reticulation in this group, I assayed variation of 20 Catostomus species across temporal and geographic scales by analyzing hundreds of samples and employing a combination of …


Migration Ecology Of American Woodcock (Scolopax Minor), Joseph Daniel Moore Dec 2016

Migration Ecology Of American Woodcock (Scolopax Minor), Joseph Daniel Moore

Graduate Theses and Dissertations

Improving the understanding of American woodcock (Scolopax minor) migration ecology has been identified as a priority information need for woodcock management. Developments in remote tracking technology and analytical techniques present an opportunity to gain insight into woodcock migratory connectivity and migration phenology and to evaluate the degree in which the current two-region (Eastern and Central) basis for woodcock management represents migratory movements. To analyze woodcock migration using band return records, I excluded observations that took place during the migratory period. Using this dataset, 17.9% of records showed crossover between management regions, higher than the < 5% crossover found in studies including non-migratory band returns. During autumn migration, woodcock from the Central Region largely migrated to destinations within the Central Region, whereas woodcock from the Eastern Region migrated to destinations across their wintering range, mixing with individuals from the Central Region. Between 2013 and 2016, I deployed 75 satellite transmitters on woodcock. I tracked the migration paths of 61 woodcock and documented 88 woodcock migrations. Average migration duration was longer during spring migration (53 days) than during autumn migration (31 days) because woodcock made a higher number of close-together migratory stopovers, not because woodcock stayed at individual stopovers longer during spring migration. Woodcock captured in the Central Management Region used 2 primary migrations routes: a Western Route and a Central Route. The Western Route ran north-south, connecting the breeding and wintering grounds of the Central Management Region. The hourglass-shaped Central Route connected an area on the wintering grounds reaching from Texas to Florida, to sites throughout northeastern North America. Woodcock following the Central Route funneled between the Appalachian Mountains and the Mississippi Alluvial Valley in western Tennessee during both autumn and spring migration. A higher than anticipated percentage (36%, n = 12) of marked woodcock captured in Texas and Louisiana and monitored during spring migration migrated to breeding-period sites in the Eastern Management Region, raising questions about the biological basis of managing woodcock as separate populations. The supplementary material includes woodcock capture information (Appendix I), information on individual stopovers (Appendix II), and migration maps for individual woodcock (Appendix III).


Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson Aug 2016

Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson

Graduate Theses and Dissertations

In the past decade, 29 shale basins have been actively developed across 20 states for extraction of natural gas (NG) via horizontal drilling/hydraulic fracturing (=fracking). This includes ~5000 wells within the Fayetteville shale of north-central Arkansas. Development often impacts both river- and landscapes, and management requires catchment-level evaluations over time, with organismal presence/absence as indicators. For this study next-generation sequencing was used to identify/characterize microbial communities within biofilm of eight Arkansas River tributaries, so as to gauge potential catchment influences. Streams spanned a gradient of landscape features and hydrological flows, with four serving as ‘potentially impacted catchment zones’ (PICZ) and …


Eucalyptus In Kenya; Impacts On Environment And Society, Brandy M. Garrett Kluthe Aug 2016

Eucalyptus In Kenya; Impacts On Environment And Society, Brandy M. Garrett Kluthe

Graduate Theses and Dissertations

Eucalyptus trees were introduced to Kenya a little over a century ago. European colonization along with the development of a railway system increased the demand for a fast growing wood source. The expansion of the tree across the fertile lands in Kenya raises concerns about the environmental impact on ecosystems where it has been introduced. These concerns include degraded soils, loss of water resources, co-introduction of ectomycorrhizal species, and allelopathy. Economic benefits to local landowners were also explored as well as the potential for large Eucalyptus woodlots to maximize the sequestration of CO₂ from the atmosphere. This was examined through …


Emergence Phenology And Nematode Associates Of The Woodwasp, Sirex Nigricornis F. (Hymenoptera: Siricidae), In Arkansas And Mississippi Forests, Jessica Ann Hartshorn May 2016

Emergence Phenology And Nematode Associates Of The Woodwasp, Sirex Nigricornis F. (Hymenoptera: Siricidae), In Arkansas And Mississippi Forests, Jessica Ann Hartshorn

Graduate Theses and Dissertations

Sirex nigricornis F. (Hymenoptera: Siricidae) is a native woodwasp in eastern North America that inhabits dead and dying pine trees during its univoltine development. Sirex noctilio is native to Eurasia and North Africa and was discovered in the northeastern United States in 2004 after a century of accidental introductions across the Southern Hemisphere. Since then, it has spread to seven states and southern Ontario. There is concern about its potential to negatively affect the multi-billion dollar pine timber industry of the southeastern United States. Effective monitoring tools are necessary to track the spread and establishment of S. noctilio. Deladenus siricidicola …


Dietary Effects On The Stoichiometry Of Growth, Regulation, And Wastes Of Ozark Stream Insect Detritivores, Halvor Matthew Halvorson May 2016

Dietary Effects On The Stoichiometry Of Growth, Regulation, And Wastes Of Ozark Stream Insect Detritivores, Halvor Matthew Halvorson

Graduate Theses and Dissertations

A widespread stressor, anthropogenic nitrogen (N) and phosphorus (P) pollution can increase resource nutrient content and alter animal community composition in freshwater ecosystems. In this dissertation, I used ecological stoichiometry theory to examine effects of diet nutrient content and leaf litter type on growth, regulation, and wastes of aquatic invertebrate detritivores. I tested effects of leaf litter diet carbon:phosphorus (C:P) on growth and stoichiometric regulation of the detritivorous caddisfly Pycnopsyche lepida and used results to determine a threshold elemental ratio of oak litter C:P=1620 that confers peak growth of this species. This empirical, growth-based approach provided a more accurate estimate …


The Role Of Hydrologic Regimes In Driving Morphologic Divergence And The Trait Compositions Of Fish Assemblages, Lindsey A. Bruckerhoff May 2016

The Role Of Hydrologic Regimes In Driving Morphologic Divergence And The Trait Compositions Of Fish Assemblages, Lindsey A. Bruckerhoff

Graduate Theses and Dissertations

The hydrologic regime is an important determinant of the ecological integrity of a stream. Hydrologic regimes are defined by the magnitude, timing, frequency, rate of change, and duration of high and low flow events and capture long term patterns of variability and predictability of water movement in a stream. Flow regimes influence many aspects of the biophysical environment in lotic systems; therefore organisms have adapted to natural flow patterns. We investigated how fish have adapted to flow regimes at both a population and community level. In the first study presented in this thesis, we hypothesized fish exhibit phenotypic divergence to …


Responses Of Semi-Aquatic Snakes To Drought, Philip Nicholas Vogrinc May 2016

Responses Of Semi-Aquatic Snakes To Drought, Philip Nicholas Vogrinc

Graduate Theses and Dissertations

Aquatic ecosystems and their associated wildlife are threatened by alteration in the frequency and intensity of precipitation events predicted to affect many regions as a consequence of global climate change. Semi-aquatic snakes serve important roles as predators and prey within aquatic ecosystems, yet little is known about the effects of drought on these species due to their secretive behavior. Long-term studies at an isolated wetland in South Carolina found that drought caused populations of banded watersnakes (Nerodia fasciata) and Florida green watersnakes (Nerodia floridana) to crash. Alternatively, black swamp snakes (Seminatrix pygaea) fared well, exhibiting a resistance strategy by aestivating …