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Some Population Parameters of Quercus Stellata in the Texas Cross Timbers
This population study of Quercus stellata in the Texas Cross Timbers evaluates that population by observation and sampling of 220 upland forest stands. The Texas Cross Timbers is divided into the East Cross Timbers (ECT) and the West Cross Timbers (WCT) by the Fort Worth Prairie.
Date:
December 1972
Creator:
McCluskey, Richard L.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
A Floristic Study of the Woody Vegetation of the North American Cross Timbers
This research represents the first systematic collection of the woody plants throughout the Cross Timbers. It provides the first keys to these plants in their vegetative condition, plant descriptions, distribution maps, and some quantitative measurements used for descriptive purposes. Descriptions of the woody plants were constructed as an aid in verification after a specimen has been identified by use of the keys. The measurements given pertain only to the woody plants as they occur in the Cross Timbers. Distributional maps are provided for all the taxa considered in this research. With the exception of those species which have the ecological amplitude to grow throughout the Cross Timbers, the distribution of the majority of the remaining species seems to be most strongly influenced by average annual precipitation. In a few instances, conditions associated with latitude appear to govern the distribution of species or varieties within the Cross Timbers. Throughout the Cross Timbers, post oak (Quercus stelta), blackjack oak (Quercus marilandica), and hickory (Caraa texan) dominate the upland forests. The streamside forests are dominated by willow (alix nigra), cottonwood (Populus deltoides), and hackberry (Celtis laevi ata). The variation in the vegetation of the Cross Timbers is not due to any change in …
Date:
December 1974
Creator:
Harrison, Thieron Pike
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Structure, Composition, and Regeneration of Cross Timbers Forest Fragments in Different Land Use Contexts
Throughout its current range, the Cross Timbers forest ecosystem is vulnerable to land-use change. In this study, we examined the surrounding land use matrix on the vegetation structure, composition and regeneration of six Cross Timbers forest fragments in Denton County, Texas (north of the Dallas-Fort Worth metroplex). Two fragments adjacent to agricultural land, two to residential neighborhoods, and two formally protected forest sites were selected. In summer 2015, five 100 m2 plots were randomly established in each fragment at least 200 meters from the edge. In each plot, all live and dead trees ≥ 3 cm diameter were identified and their height and diameter at breast height (DBH at 1.3 m aboveground) measured. Evidence of dumping (presence of trash) was recorded as an index of human frequentation. Differences in vegetation structure among the forest fragments were found. Most notably, fragments adjacent to agriculture contained 25% to 50% fewer trees per hectare than all other sites (Kruskal-Wallis, p < 0.02), especially trees <10 cm DBH. However, residential fragments had fewer trees that were ≥15 cm DBH compared to the other fragments, indicating that these are the youngest of the forest patches surveyed. Trash was observed in 60% of plots surveyed at …
Date:
May 2015
Creator:
Dunn, Ingrid
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Developing a Forest Gap Model to Be Applied to a Watershed-scaled Landscape in the Cross Timbers Ecoregion Using a Topographic Wetness Index
A method was developed for extending a fine-scaled forest gap model to a watershed-scaled landscape, using the Eastern Cross Timbers ecoregion as a case study for the method. A topographic wetness index calculated from digital elevation data was used as a measure of hydrologic across the modeled landscape, and the gap model modified to have with a topographically-based hydrologic input parameter. The model was parameterized by terrain type units that were defined using combinations of USDA soil series and classes of the topographic wetness index. A number of issues regarding the sources, grid resolutions, and processing methods of the digital elevation data are addressed in this application of the topographic wetness index. Three different grid sizes, 5, 10, and 29 meter, from both LiDAR-derived and contour-derived elevation grids were used, and the grids were processed using both single-directional flow algorithm and bi-directional flow algorithm. The result of these different grids were compared and analyzed in context of their application in defining terrain types for the forest gap model. Refinements were made in the timescale of gap model’s weather model, converting it into a daily weather generator, in order to incorporate the effects of the new topographic/hydrologic input parameter. The precipitation …
Date:
August 2014
Creator:
Goetz, Heinrich (Heinrich Erwin)
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Geology as a Georegional Influence on Quercus Fagaceae Distribution in Denton and Coke Counties of Central and North Central Texas and Choctaw County of Southeastern Oklahoma, Using GIS as an Analytical Tool.
This study elucidates the underlying relationships for the distribution of oak landcover on bedrock and soil orders in two counties in Texas and one in Oklahoma. ESRI's ArcGis and ArcMap was used to create surface maps for Denton and Coke Counties, Texas and Choctaw County, Oklahoma. Attribute tables generated in GIS were exported into a spreadsheet software program and frequency tables were created for every formation and soil order in the tri-county research area. The results were both a visual and numeric distribution of oaks in the transition area between the eastern hardwood forests and the Great Plains. Oak distributions are changing on this transition area of the South Central Plains. The sandy Woodbine and Antlers formations traditionally associated with the largest oak distribution are carrying oak coverage of approximately 31-32% in Choctaw and Denton Counties. The calcareous Blackland and Grand Prairies are traditionally associated with treeless grasslands, but are now carrying oak and other tree landcover up to 18.9%. Human intervention, including the establishment of artificial, political and social boundaries, urbanization, farming and fire control have altered the natural distribution of oaks and other landcover of this unique georegion.
Date:
December 2007
Creator:
Maxey, George F.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Assessing Rainfall Interception by Urban Tree Canopies in Denton, Texas
Rainfall interception is one mechanism by which tree canopies can reduce surface runoff in urban areas. The objectives of this research were to: 1) quantify rainfall interception by urban tree canopies, and 2) determine the influence of vegetation and microenvironmental factors on rainfall interception rates. In the city of Denton, Texas, 30 mature post oak (Quercus stellata) and blackjack oak (Quercus marilandica) trees were selected for study. Trees were assigned to one of three categories: clusters of trees on greenspace (CG), isolated trees on greenspace (IG), and isolated trees surrounded by pavement (IP). Throughfall (the volume of water that travels through the canopy and reaches the soil surface) collectors were placed beneath these trees and rainfall collectors were placed in nearby open areas. Throughfall and rainfall were collected daily from 19 March to 4 July. Interception was calculated as the difference between throughfall and gross rainfall. Over the study period, there were 27 days with measurable rainfall; daily rainfall ranged from 1-51 mm. Over the sampling period, rainfall interception for individual trees ranged from -10% to 49%, indicating high spatial variability in interception. Percent interception was highest for the CG treatment (22.7 ± 3.8 SE), intermediate for IG (27.4 ± …
Date:
May 2017
Creator:
Edington, Patrick
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Testing the scale dependence of models of resource competition and environmental conditions for forest structure and dynamics. Final performance report
The goal of this research was to evaluate and integrate gradient models and resource competition models to kinds of explanation of forest community structure and dynamics previously developed at different spatial scales. Progress was made in several areas of empirical gradient modeling and on issues regarding use of resource-competition models for use in forest modeling: Empirical gradient modeling: scaled rank variance, data transformation, applications, stand mapping, scale comparisons; Resource competition: resource limitation experiments, resource competition modeling; parameterization of resources competition models.
Date:
December 1, 1995
Creator:
Knox, R.G. & Harcombe, P.A.
Object Type:
Report
System:
The UNT Digital Library
The Influence of Local Forage Variability on White-tailed Deer (Odocoileus virginianus) Body Size at Fort Hood, Texas
Nutritional quality and availability is thought to regulate geographic patterns of variability in animal body size due to phenotypic plasticity. The purpose of this study is to determine how vegetation quality, abundance and population density influence white-tailed deer (Odocoileus virginianus) body size on a subregional spatial scale at Fort Hood, Texas. Harvest and census records are used to test the hypothesis that white-tailed deer exhibit phenotypic plasticity (e.g. larger body size) in response to differences in vegetation quality and availability. Results from these analyses suggest that forage quality and abundance alone is not a main driver of white-tailed deer body size. Analysis of deer population density (generally) resulted in an inverse relationship with body size. Areas with high quality forage and low population density support larger deer while areas with low quality forage and high density support smaller than average deer. The few exceptions occur in areas exhibiting poor quality forage and low population density or high forage quality and high density. Results from this study suggest that continued overcrowding of deer within isolated areas may eventually lead to efficiency phenotypic conditions producing smaller sized deer. These results could prove useful in interpreting deer population responses to harvest management. For …
Date:
December 2015
Creator:
Eddins, Amy C.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Bulletin of the Texas Archeological Society, Volume 59, 1988
Annual journal of the Texas Archeological Society documenting research and findings of members as well as activities of the organization.
Date:
1989
Creator:
Texas Archeological Society
Object Type:
Journal/Magazine/Newsletter
System:
The Portal to Texas History
Ecoregions of Texas
A report on the the development of areas known as ecoregions in Texas with environmental information for each region.
Date:
December 27, 2007
Creator:
Griffiths, Glenn; Bryce, Sandy; Omernik, James & Rogers, Anne
Object Type:
Report
System:
The Portal to Texas History
Comparison of Bare Root vs. Potted Plants, Species Selection, and Caging Types for Restoration of a Prairie Wetland, and Quantitative Analysis and Descriptive Survey of Plant Communities and Associations at Lewisville Lake Environmental Learning Area (LLELA), Lewisville, TX
Lewisville Lake Environmental Learning Area (LLELA) is an 809-hectare property in Denton County, TX. A study of the vegetation community identified 466 species in 104 families, with 25% of the species from only two families, Asteraceae and Poaceae. The property demonstrates the characteristics of an early successional community, dominated by weedy species. Prairie communities are dominated by Johnson grass and ragweed, with climax tall grass prairie communities only in areas that have been planted with native grass seed. Forest communities are similarly in an early successional stage, dominated by the hackberry-elm-ash alliance, with small remnants of native Cross Timbers found in isolated patches. Species richness and diversity were highest in the forests and lowest in the wetlands; evenness, though not different across ecosystems, demonstrated a strong seasonal component. The species list was compared with previously reported lists for Denton County, and 256 species identified had not been previously reported for the county. A wetland restoration study was conducted to determine if there was a difference in survival and growth between potted transplants with intact root systems and bare-root transplants. Two different mesh sizes were used for protection, and the success of the different caging was evaluated. Of eight species, only …
Date:
May 2007
Creator:
Buckallew, Robin R.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Soil and Forest Variation by Topography and Succession Stages in the Greenbelt Corridor, Floodplain of the Elm Fork of the Trinity River, North Texas.
The Greenbelt Corridor (GBC), located in a floodplain of the Elm Fork of the Trinity River, contains patches of bottomland forest and serves as part of Lake Lewisville’s flood control backwaters. This study examines forest structure and composition in relation to topographic position and forest stage in the GBC. Thirty two plots were surveyed within various stage classes, topographic positions, and USDA soil types. Trees were identified and measured for height and DBH. Density, basal area, and importance value for each of species was calculated. Soil and vegetation were analyzed using ANOVA, Principal Component Analysis, Canonical Correlation, Canonical Correspondence Analysis and Cluster Analysis. Tests confirmed that calcium carbonate and pH show significant differences with topographic positions but not with forest stage. Potassium shows no significant difference with soil texture class. Sand shows a strong negative correlation with moisture, organic matter, organic carbon and negative correlation with calcium carbonate and potassium. Silt shows positive correlation with moisture, organic matter, organic carbon, and calcium carbonate. Clay shows strong positive correlation with moisture, organic matter and organic carbon but negative correlations with pH. Swamp privet is dominant tree types in wetland forest. Sugarberry cedar elm, green ash and American elm are widely distributed …
Date:
August 2011
Creator:
Rijal, Rajan
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Interpreting Prehistoric Patterns: Site Catchment Analysis in the Upper Trinity River Basin of North Central Texas
Archaeologically site catchment analysis produces valuable information regarding prehistoric subsistence strategies and social organization. Incorporating archaeological data into catchment analyses is an effective strategy to develop regional models of prehistoric site selection and settlement patterns. Digital access to data permits the incorporation of multiple layers of information into the process of synthesizing regional archaeology and interpreting corresponding spatial patterning. GIS software provides a means to integrate digital environmental and archaeological data into an effective tool. Resultant environmental archaeology maps facilitate interpretive analysis. To fulfill the objectives of this thesis, GIS software is employed to construct site catchment areas for archaeological sites and to implement multivariate statistical analyses of physical and biological attributes of catchments in correlation with assemblage data from sites. Guided by ecological, anthropological and geographical theories hypotheses testing evaluates patterns of prehistoric socio-economic behavior. Analytical results are summarized in a model of prehistoric settlement patterns in North Central Texas.
Date:
December 2004
Creator:
Williams, Marikka Lin
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Collected Papers from Past Texas Archeological Society Summer Field Schools
Series of articles documenting four Texas Archeological Society Field Schools, describing each of the projects including the environment, cultural context, and archaeological findings.
Date:
2008
Creator:
Perttula, Timothy K.
Object Type:
Book
System:
The Portal to Texas History
State of Texas Environmental Priorities Project, Volume 2: Ecological Workgroup Report
Appendix to the final report of the State of Texas Environmental Priorities Project compiled by the ecological workgroup: "It presents the analysis of the Ecological Workgroup and its comparative ecological risk ranking of environmental problems facing Texas" (p. 1.1).
Date:
June 1997
Creator:
State of Texas Environmental Priorities Project
Object Type:
Report
System:
The Portal to Texas History
Archeological Investigations at the Santa Maria Creek Site (41CW104) Caldwell County, Texas
Report on the excavations at the Santa Maria creek site in Caldwell County, Texas during 2006 and 2007. The report includes a discussion of research methods, analysis of the findings, and history of the area.
Date:
March 2013
Creator:
Rogers, Robert; Ellis, Linda W.; Harris, Brandy; Wallace, Candace; Rush, Haley; Shipp, Julie et al.
Object Type:
Report
System:
The Portal to Texas History
Ecology and Recolonization of Benthic Macroinvertebrates in a Groundwater-dependent Stream in North Central Texas During a Supra-seasonal Drought
Extreme climatic events such as droughts are known to eliminate aquatic biota and alter community structure and function. Perennial headwater springs provide important drought refugia to benthic macroinvertebrates and an important source of colonists via drift or aerial adults to intermittent streams post-drought. During a supra-seasonal drought in North-central Texas summer and fall 2006, benthic macroinvertebrates from persistent groundwater-dependent macrohabitats of varying hydrological connectivity and riparian shading were studied: perennial riffles, connected pools, shaded disconnected pools, and full sun disconnected pools. Riffles were a distinct habitat with significantly higher taxa richness, proportion of lotic taxa, diversity and evenness than other macrohabitats. Macrohabitats were found to be important refugia for 106 benthic macroinvertebrates and 4 microcrustacean taxa. Throughout the extreme drought, perennially flowing habitats were refugia to 19 taxa (17.9% total taxa) not collected in disconnected pools. Shaded disconnected pools contained lotic taxa not previously known to be able to complete their lifecycles in lentic habitats, emphasizing the importance of groundwater effluent and shading. With the resumption of flow at a downstream intermittent site of Ash Creek in mid-October 2006, an annual recolonization study was conducted comparing the perennial headwaters’ benthic macroinvertebrate taxa richness, densities and community ecology with the downstream …
Date:
May 2012
Creator:
Burk, Rosemary A.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Archaeological Investigations at Five Prehistoric Sites at Lewisville Lake, Denton County, Texas
This report describes the results of excavations performed by the Institute of Applied Sciences at the Lewisville Lake project, Denton County, Texas.
Date:
1998
Creator:
Ferring, C. Reid & Yates, Bonnie C.
Object Type:
Book
System:
The UNT Digital Library
Evaluating Tree Seedling Survival and Growth in a Bottomland Old-field Site: Implications for Ecological Restoration
In order to assess the enhancement of seedling survival and growth during drought conditions, five-hundred bare-root seedlings each of Shumard oak (Quercus shumardii Buckl.) and green ash (Fraxinus pennsylvanica Marsh.) were planted each with four soil amendments at a Wildlife Management Area in Lewisville, Texas. The treatments were a mycorrhizal inoculant, mulch fabric, and two superabsorbent gels (TerraSorb® and DRiWATER®). Survival and growth measurements were assessed periodically for two years. Research was conducted on vegetation, soil, and site history for baseline data. Both superabsorbent gels gave significant results for Shumard oak survival, and one increased green ash diameter. For overall growth, significant results were found among DRiWATER®, mycorrhizae, and mulch treatments.
Date:
August 2007
Creator:
Boe, Brian Jeffrey
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Regional Water Plan: Region L (South Central Texas), 2016, Volume 1. Executive Summary and Regional Water Plan
Water plan for Region L (South Central Texas) describing water resources and suppliers in the area, usage statistics and forecasts, water needs, recommended water management strategies for the suppliers and counties, drought management, funding plans, and information on the creation of the plan.
Date:
December 2015
Creator:
South Central Texas Regional Water Planning Group
Object Type:
Report
System:
The Portal to Texas History
Pre-impoundment Environmental Study of Ray Roberts Lake
"This report presents the results of the pre-impoundment investigations" of Ray Roberts Lake. The purpose of the study is "to improve understanding of the impact of [U.S. Army Corps of Engineers] water resource projects, to provide the basis for evaluating the projects' effects on fish and wildlife resources, and to provide the opportunity for better planning and development of water resource projects and natural resource management" in the Lake Ray Roberts area, located in Denton County, Texas (p. 3).
Date:
May 1988
Creator:
University of North Texas. Institute of Applied Sciences.
Object Type:
Report
System:
The UNT Digital Library
Post-impoundment Study of Ray Roberts Lake Year-Six
"This report presents the results of investigations conducted six years following the impoundment of Ray Roberts Lake." The purpose of the study is "to improve understanding of the impact of [U.S. Army Corps of Engineers] water resource projects, to provide the basis for evaluating the projects' effects on fish and wildlife resources, and to provide the opportunity for better planning and development of water resource projects and natural resource management" in the Lake Ray Roberts area, located in Denton County, Texas (p. 3).
Date:
December 1995
Creator:
University of North Texas. Institute of Applied Sciences.
Object Type:
Report
System:
The UNT Digital Library
Post-impoundment Study of Ray Roberts Lake Year-Ten
"This report is the final chapter of a long-term project to assess the environmental impacts associated with the construction and operation of Ray Roberts Lake during its first ten years" (p. ii). The purpose of the study is "to improve understanding of the impact of [U.S. Army Corps of Engineers] water resource projects, to provide the basis for evaluating the projects' effects on fish and wildlife resources, and to provide the opportunity for better planning and development of water resource projects and natural resource management" in the Lake Ray Roberts area, located in Denton County, Texas (p. 3).
Date:
December 1999
Creator:
University of North Texas. Institute of Applied Sciences.
Object Type:
Report
System:
The UNT Digital Library
Pre-impoundment Environmental Study of Ray Roberts Lake
"This report presents the results of the pre-impoundment investigations" of Ray Roberts Lake. The purpose of the study is "to improve understanding of the impact of [U.S. Army Corps of Engineers] water resource projects, to provide the basis for evaluating the projects' effects on fish and wildlife resources, and to provide the opportunity for better planning and development of water resource projects and natural resource management" in the Lake Ray Roberts area, located in Denton County, Texas (p. 3).
Date:
December 1987
Creator:
University of North Texas. Institute of Applied Sciences.
Object Type:
Book
System:
The UNT Digital Library