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open access

Effects of Natural/anthropogenic Stressors and a Chemical Contaminant on Pre and Post Mycorrhizal Colonization in Wetland Plants

Description: Arbuscular mycorrhizal fungi, colonizing over 80% of all plants, were long thought absent in wetlands; however, recent studies have shown many wetland plants harbor arbuscular mycorrhizae (AM) and dark septate endophytes (DSE). Wetland services such as biodiversity, shoreline stabilization, water purification, flood control, etc. have been estimated to have a global value of $14.9 trillion. Recognition of these vital services is accompanied by growing concern for their vulnerability and continu… more
Date: August 2013
Creator: Twanabasu, Bishnu Ram
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Bioconcentration and Morphological Effects of Triclosan on Three Species of Wetland Plants

Description: Triclosan (TCS) is an antimicrobial compound found in several types of common household products. After being washed down the drain, TCS will then end up in the local watershed. Although numerous studies have been conducted to evaluate the fate and effects of TCS in aquatic environments, there have been no studies evaluating the role arbuscular mycorrhizal fungi (AM) play in a plants response to TCS exposure. Three species of wetland plants native North Texas were inoculated with AM spores and … more
Date: May 2013
Creator: Smith, Caleb M.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Examining the Shade/flood Tolerance Tradeoff Hypothesis in Bottomland Herbs Through Field Study and Experimentation

Description: While there is growing evidence that shade/flood tolerance tradeoffs may be important in distributions of bottomland hardwood trees and indications that they should apply to herbs, no studies have definitively explored this possibility. Four years of field data following historic flooding were supplemented with a greenhouse experiment designed to identify interactions congruent with tradeoffs. Fifteen bottomland species were grown in two levels of water availability and three levels of shade ov… more
Date: May 2012
Creator: Sloop, Jordan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Integrating Selective Herbicide and Native Plant Restoration to Control Alternanthera philoxeroides (Alligator Weed)

Description: Exotic invasive aquatic weeds such as alligator weed (Alternanthera philoxeroides) threaten native ecosystems by interfering with native plant communities, disrupting hydrology, and diminishing water quality. Development of new tools to combat invaders is important for the well being of these sensitive areas. Integrated pest management offers managers an approach that combines multiple control methods for better control than any one method used exclusively. In a greenhouse and field study, we t… more
Date: December 2011
Creator: Adams, Justin
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Bioconcentration of Triclosan, Methyl-Triclosan, and Triclocarban in the Plants and Sediments of a Constructed Wetland

Description: Triclosan and triclocarban are antimicrobial compounds added to a variety of consumer products that are commonly detected in waste water effluent. The focus of this study was to determine whether the bioconcentration of these compounds in wetland plants and sediments exhibited species specific and site specific differences by collecting field samples from a constructed wetland in Denton, Texas. The study showed that species-specific differences in bioconcentration exist for triclosan and triclo… more
Date: August 2011
Creator: Zarate, Frederick M., Jr.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Anatomical and Morphological Responses of Cardiospermum Halicacabum L. (Balloon Vine), to Four Levels of Water Availability

Description: C. halicacabum (Sapindaceae) is an invasive plant that is considered a nuisance species in Texas riparian environments. Little is known of the tolerance of C. halicacabum to flooding and drought; however, this information may provide insight into the characteristics that contribute to C. halicacabum purported invasiveness. C. halicacabum seedlings (n = 92) were exposed to one of four levels of water availability (flooded, saturated, intermediate and dry) over six weeks under greenhouse conditio… more
Date: May 2011
Creator: Dempsey, Matthew Anthony
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Solvent Effects and Bioconcentration Patterns of Antimicrobial Compounds in Wetland Plants

Description: This study looked at effects of organic solvents dimethylsulfoxide, dimethylformamide and acetone at 0.01%, 0.05% and 0.1% concentration on germination and seedling development wetland plants. Even at 0.01% level, all solvents affected some aspect of seed germination or seedling growth. Acetone at 0.01% was least toxic. Root morphological characteristics were most sensitive compared to shoot morphological characteristics. This study also looked at bioconcentration patterns of antimicrobial comp… more
Date: May 2011
Creator: Adhikari, Sajag
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Role of N-Acylethanolamines in Plant Defense Responses: Modulation by Pathogens and Commercial Antimicrobial Stressors

Description: N-acyl ethanolamines (NAEs) are a class of lipids recently recognized as signaling molecules which are controlled, in part, by their degradation by fatty acid amide hydrolase (FAAH). On the basis of previous studies indicating increased NAE levels in a tobacco cell suspension-xylanase elicitor exposure system and the availability of FAAH mutants, overexpressor and knockout (OE and KO) genotypes in Arabidopsis thaliana, further roles of NAEs in A. thaliana plant defense was investigated. The com… more
Date: August 2010
Creator: Vadapalli, Vatsala
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Comparison of Heteranthera Dubia (Jacq.) MacM.-associated Macroinvertebrates Between Georgraphical Regions in the United States

Description: Macroinvertebrates associated with the aquatic plant, water stargrass (Heteranthera dubia), were sampled from 12 waterbodies in four regions of the United States from June to August 2005. Taxa richness, evenness, and diversity were lowest in the Lower Midwest (LMW) region, and higher in Northern sites, especially the Upper Midwest (UMW), and Northeast (NE). While relative abundance varied from site to site and region to region, utilization of the plant by functional groups remained fairly const… more
Date: May 2010
Creator: Harms, Nathan Earl
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

The impact of climate and flooding on tree ring growth of Fraxinus pennsylvanica in north-central Texas.

Description: Tree cores of Fraxinus pennsylvanica were used in a dendrochronological analysis investigating the species' responses to climate and flooding. The objective was to develop a model that incorporates the effects of precipitation, temperature, and flooding on radial growth in this species in north-central Texas. The trees exhibited strong climatic signals. The study clearly shows that all three factors have significant impacts on tree ring growth both prior to and during growth; however, the natur… more
Date: December 2009
Creator: Komperod, Mari
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

The impact of invertebrates to four aquatic macrophytes: Potamogeton nodosus, P. illinoensis, Vallisneria americana and Nymphaea mexicana.

Description: This research investigated the impact of invertebrates to four species of native aquatic macrophytes: V. americana, P. nodosus, P. illinoensis, and N. mexicana. Two treatments were utilized on each plant species, an insecticide treatment to remove most invertebrates and a non-treated control. Ten herbivore taxa were collected during the duration of the study including; Synclita, Paraponyx, Donacia, Rhopalosiphum, and Hydrellia. Macrophyte biomass differences between treatments were not measu… more
Date: August 2008
Creator: Nachtrieb, Julie Graham
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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