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  Partner: UNT Libraries
 Department: Department of Biology
 Country: United States
Light Spectra Distributions in Temperate Conifer-Forest Canopy Gaps, Oregon and in Tropical Cloud-Forest Canopy, Venezuela

Light Spectra Distributions in Temperate Conifer-Forest Canopy Gaps, Oregon and in Tropical Cloud-Forest Canopy, Venezuela

Date: December 1997
Creator: Monteleone, Susan Elaine
Description: Light spectra distributions were measured in two different montane forests: temperate and tropical. Spectral light measurements were made in different sized canopy gaps in the conifer forest at H. J. Andrews Experimental Forest in Oregon, USA. Researchers at Oregon State University created these gaps of 20 m, 30 m, and 50 m in diameter. In the tropical cloud forest, spectral light measurements were made in two plots that were permanently established at La Mucuy Parque Nacional in Venezuela, in collaboration with researchers at Universidad de Los Andes. In both studies, spectra and distributions of physiologically active light were analyzed: red, far-red, R/FR ratio, and blue light.
Contributing Partner: UNT Libraries
Analysis of Phytoplankton Responses to Water Chemistry Dynamics in a Moderately Eutrophic North Texas Reservoir

Analysis of Phytoplankton Responses to Water Chemistry Dynamics in a Moderately Eutrophic North Texas Reservoir

Date: May 1998
Creator: Banks, Kenneth E. (Kenneth Edward)
Description: Canonical correspondence analysis (CCA) was used to explore relationships between measured environmental variables and in situ phytoplankton communities in a moderately eutrophic North Texas Reservoir.
Contributing Partner: UNT Libraries
Evaluation of a Constructed Wetland to Reduce Toxicity from Diazinon at the Pecan Creek Wastewater Treatment Plant, Denton, TX

Evaluation of a Constructed Wetland to Reduce Toxicity from Diazinon at the Pecan Creek Wastewater Treatment Plant, Denton, TX

Date: May 1996
Creator: Baerenklau, Amy L. (Amy Lyn)
Description: The City of Denton Pecan Creek Wastewater Treatment Facility has periodically failed effluent toxicity testing. A Toxicity Identification Evaluation has determined that Diazinon in the effluent is contributing to the observed toxicity. Chlorpyrifos is also implicated as a factor. The City of Denton constructed a half acre experimental wetland to remove Diazinon related toxicity. Results from spiking and microcosm experiments indicate that the wetland can reduce the Diazinon.
Contributing Partner: UNT Libraries
Development and Application of an Assessment Protocol for Watershed Based Biomonitoring

Development and Application of an Assessment Protocol for Watershed Based Biomonitoring

Date: May 1998
Creator: Schwartz, Joseph Howard
Description: With numerous bioassessment methodologies available, a regional protocol needs to be developed to ensure that results are comparable. A regional assessment protocol was developed that includes collecting five benthic macroinvertebrate samples, identifying organisms to genus, and calculating the following metrics: Number of Taxa, Total Number of Individuals, Simpson's Diversity Index, Shannon's Diversity Index, Percent Contribution of Dominant Taxa, Hilsenhoffs Biotic Index, and Percent Contribution of Dipterans. Once the protocol was developed, it was used to assess the Bayou Chico tributaries and watershed. All three tributaries had been significantly impacted by human activity as had the watershed as a whole. This study indicates that a regional protocol could be developed and is appropriate for biomonitoring at the watershed scale.
Contributing Partner: UNT Libraries
Life History and Case-building Behavior of Molanna Tryphena Betten (Trichoptera: Molannidae) in Two East Texas Spring-fed Streams

Life History and Case-building Behavior of Molanna Tryphena Betten (Trichoptera: Molannidae) in Two East Texas Spring-fed Streams

Date: December 1998
Creator: Gupta, Tammi Spackman
Description: The life history and case-building behavior of Molanna tryphena from two spring-fed tributaries in East Texas were studied from January 1997 to May 1998.
Contributing Partner: UNT Libraries
A Comparison of Predicted and Actual Trophic Status of Lake Ray Roberts, TX Based on Chlorophyll A

A Comparison of Predicted and Actual Trophic Status of Lake Ray Roberts, TX Based on Chlorophyll A

Date: May 1999
Creator: Lytle, Lili Lisa
Description: Two years before impoundment, the trophic status of Lake Ray Roberts was predicted by applying the total phosphorus input into the Organization for Economic Cooperation and Development (OECD) eutrophication model. Predicted mean summer epilimnetic (MSE) chlorophyll a of Elm Fork arm, Isle duBois arm and Main Body were in the eutrophic category of the OECD model. Observed MSE chlorophyll a two years after impoundment of Elm Fork arm, Isle duBois and Main Body had not reached their predicted means and were at the mesotrophic-eutrophic boundary of the OECD model. Six years after impoundment, observed MSE chlorophyll a for Main Body, was closer to its predicted mean and in the eutrophic category of the OECD model. Six years after impoundment, Elm Fork arm was the most productive area of Lake Ray Roberts. Observed means of chlorophyll a, total phosphates, suspended solids and turbidity were often highest in the Elm Fork arm. Wastewater effluent from Gainesville and Valley View, TX, had an impact on productivity in Elm Fork arm.
Contributing Partner: UNT Libraries
Biological and Toxicological Responses Resulting from Dechlorination of a Major Municipal Wastewater Treatment Plant Discharge to the Trinity River

Biological and Toxicological Responses Resulting from Dechlorination of a Major Municipal Wastewater Treatment Plant Discharge to the Trinity River

Date: August 1995
Creator: Guinn, Richard J. (Richard Joe)
Description: Federal regulations such as the Clean Water Act (P.L. 92-500), and its amendments, direct the Environment Protection Agency (EPA) to implement programs to control the releases of conventional pollutants and toxics into the waterways of the United States. The EPA began requiring treatment plants to conduct toxicity tests (biomonitoring) of their effluent discharges. To control toxicity caused by chlorination of wastewater discharges, the EPA also began requiring some treatment facilities to dechlorinate their wastewater before discharging. This research was funded by the EPA to document the changes that occurred in the Trinity River from the dechlorination of the effluent from Ft. Worth's Village Creek municipal wastewater treatment plant. The study occurred over a two year period beginning in August 1990. A wide variety of biological field assessments and toxicological assays were used to measure various responses. Seven river stations, covering approximately twenty river miles, and the treatment plant effluent were assessed. Two of the river stations were upstream from the treatment plant and used as reference sites. The remaining five river stations were downstream from the treatment plant, spread out over seventeen river miles. The study evaluated the impact of chlorination prior to dechlorination, which served as a baseline. Responses ...
Contributing Partner: UNT Libraries
Primary Productivity and Nutrient Relationships in Garza-Little Elm Reservoir

Primary Productivity and Nutrient Relationships in Garza-Little Elm Reservoir

Date: May 1973
Creator: Smith, Jerry Allen
Description: A large, multi-basin, reservoir (Garza-Little Elm Reservoir) in north central Texas was studied to determine the relative effects of various parameters on primary productivity. The basins were impounded several years apart,thus allowing the influence of age on water chemistry and biota to be considered. Another principal influence on water quality was secondary sewage effluent that entered one basin from a nearby source.
Contributing Partner: UNT Libraries
The Response of Aquatic Insect Communities and Caged In situ Asiatic Clams (Corbicula fluminea) to Dechlorinated Municipal Effluent in the Trinity River in North Texas

The Response of Aquatic Insect Communities and Caged In situ Asiatic Clams (Corbicula fluminea) to Dechlorinated Municipal Effluent in the Trinity River in North Texas

Date: December 1994
Creator: Spon, Sandra T. (Sandra Teresa)
Description: Dischargers to the Trinity River in North Texas were required to dechlorinate their effluents in 1990-91. Field surveys were conducted above and below an outfall to determine the response of resident immature insects and caged in situ juvenile Asiatic clams to chlorinated and dechlorinated effluent. Within six months after dechlorination began, insect community composition and C. fluminea survival significantly improved at stations below the outfall. Significantly lower clam growth within one mile below the dechlorinated effluent indicated the presence of non-chlorine toxicants. Effects from chlorinated and dechlorinated effluent exposure were comparable between Ceriodaphnia dubia lab tests and in situ C. fluminea.
Contributing Partner: UNT Libraries
Callibaetis Floridanus (Ephemeroptera: Baetidae) Life History and Production in a West Texas Playa

Callibaetis Floridanus (Ephemeroptera: Baetidae) Life History and Production in a West Texas Playa

Date: May 1998
Creator: Anderson, Gregory (Gregory Mark)
Description: A life history study of Callibaetis floridanus was conducted over the wet cycle of a playa on the Southern High Plains of Texas from June through September 1995.
Contributing Partner: UNT Libraries
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