Browsing by Subject "Biological diversity"
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Item Aquatic invertebrate biodiversity model to gauge effluent strength(Texas Tech University, 1996-12) Parker, Timothy LeeBiodiversity is a word that has been applied to numerous ecological and biological fields In the past few decades. Many governmental agencies and environmental conservation special interest groups have been preaching the importance of having biodiversity in a healthy ecological or biological system. The same technology used to analyze tree species diversity, fish population diversity, plant species diversity, natural stream species diversity, etc. has applicability to wastewater treatment. By determining the biodiversity of a wastewater effluent, the level of impact that the effluent has on the environment can be determined. The wastewater treatment stream can be thought of as a dynamic system with a biodiversity of microflora that treats Incoming wastewater. A biodiversity index can be determined by analyzing a waste stream for Its macro- and microinvertebrates (Mollusca, Crustacea, Plecoptera, Ollgochaeta, etc.). This biodiversity index is used to rate a waste stream as either clean, moderately polluted, or heavily polluted. Traditional (BOD,COD,TSS, Bioassay, basin hydraulics, etc.) methods of wastewater analysis in addition to macro- and micro-invertebrate analyses were used to analyze the current wastewater pond of an existing industrial park's wastewater treatment plant. The wastewater was then analyzed using the biodiversity index approach to gauge effluent strength. This approach of using biodiversity as a means of rating the effluents strength (as developed within this thesis) has much promise for determining more precisely the impact the discharge wastewater will have on its receiving stream.Item Microbial biodiversity along an arid watershed(Texas Tech University, 1997-12) Ziehr, Lori Lynn HerrmannThe watershed approach to long-term research can provide critical data on ecosystem processes and changes resulting from anthropogenic factors in parks and natural preserves. Over the last fifteen years, a Watershed Ecosystem Research Network has been established at eleven National Parks and preserves in the United States. The Pine Canyon Watershed at Big Bend National Park is the newest addition to the network. The watershed comprises approximately 30 square miles and encompasses five vegetation zones, from upland closed canopy forest to lowland desert sub-shrub biomes. As a component of the larger Pine Canyon Watershed Program, the objectives of this research were to determine seasonal patterns in microbial biomass and functional biodiversity and to determine the relationships between nutrient dynamics, soil characteristics, and microbial activity along the Pine Canyon Watershed at Big Bend National Park, Texas. Two 100 X 30 m belt transects, 30 m, wide, were established in each biome in November 1995 and January 1996. Along these transects, extractable ammonium and nitrate, soil organic matter content, pH, soil moisture, soil microbial biomass carbon, and microbial functional diversity (using the BIOLOG system) were measured at different dates beginning in November 1995 and ending in January 1997. Rainfall and soil temperatures were recorded throughout the year. Changes in the functional status, activity levels, and size of soil microbial communities in arid ecosystems should provide a means of assessing ecosystem function in response to climate change or anthropogenic disturbance. Upper elevational forested sites, dominated by several species of oak, juniper, and pine, had the highest amounts of microbial biomass carbon and highest microbial functional diversity along the elevational gradient. A significant interaction between site and sampling time existed for microbial biomass carbon and microbial functional diversity (p < 0.001). Soil ammonium concentrations, organic carbon content, and soil moisture were correlated most strongly with microbial biomass carbon along the elevational gradient. Ammonium concentration and soil moisture were correlated most strongly with aspects of microbial functional diversity (total utilization and substrate richness) along the elevational gradient. Within sites, soil moisture was the only parameter significantly correlated with microbial biomass carbon. Soil moisture and nitrogen concentrations were correlated significantly with microbial functional diversity within sites. Microbial biomass carbon fluctuated seasonally for most sites, being highest in the summer and lowest in the winter. Microbial functional diversity in the upper elevational forested sites did not vary seasonally, while lower desert sites did so. This suggests that the upper elevational forested sites are more stable than the lower desert sites in responding to seasonal moisture inputs and other potential disturbances. Changes in patterns of precipitation that are likely to occur from global warming may have the greatest impact on lower desert ecosystems.Item Species diversity of aquatic macroinvertebrates in playa lakes: island biogeographic and landscape influences(Texas Tech University, 1997-12) Hall, Dianne L.Patterns of species diversity have long intrigued ecologists. This fascination has resulted in numerous theories explaining differences among sites in species diversity. Two such theories are those pertaining to island biogeography and landscape ecology. They differ in the import placed on patch versus matrix characteristics. Island biogeographic theory suggests that patch characteristics are the foremost influences on diversity. Conversely, landscape ecology proposes that attributes of the surrounding matrix are of primary significance. Playas of the Southern High Plains are an excellent environment in which to study the relative influence of patch versus matrix characteristics. They are numerous and surrounded by a mosaic of landuse practices. These ephemeral lakes differ greatly in size and contain an abundance of aquatic macroinvertebrates. Macroinvertebrates were sampled three times over a two month period and were categorized as resident or transient species based on life history characteristics. Species richness and diversity were analyzed for the effects of landuse practices, basin size, and surface area via analysis of covariance. In addition, G-tests of independence were used to analyze the influence of landuse practices and surface area on species composition. Surrounding landuse practices were found to influence resident species richness and species composition; total species richness was sensitive to basin size. Surface area affected total, resident, and transient species richness, resident species diversity, and species composition. However, all relationships were contingent on sampling period. Regression analyses revealed that resident species richness and diversity were influenced more by island biogeographic characteristics than by landscape attributes. However, the converse was true for transient species richness and diversity. Neither resident nor transient species richness and diversity were related strongly to differences in water quality. Both island biogeographic and landscape characteristics affect the diversity of macroinvertebrates in playa lakes. However, the extent of the influence of these two factors is dependent on life history strategy of the biota and time since inundation. The idiosyncratic pattern of species diversity is a reflection of the stochastic nature of playa inundation overlain by the effects of island biogeographic and landscape processes.Item Species diversity of aquatic macroinvertebrates in playa lakes: island biogeographic and landscape influences(Texas Tech University, 1997-12) Hall, Dianne L.Patterns of species diversity have long intrigued ecologists. This fascination has resulted in numerous theories explaining differences among sites in species diversity. Two such theories are those pertaining to island biogeography and landscape ecology. They differ in the import placed on patch versus matrix characteristics. Island biogeographic theory suggests that patch characteristics are the foremost influences on diversity. Conversely, landscape ecology proposes that attributes of the surrounding matrix are of primary significance. Playas of the Southern High Plains are an excellent environment in which to study the relative influence of patch versus matrix characteristics. They are numerous and surrounded by a mosaic of landuse practices. These ephemeral lakes differ greatly in size and contain an abundance of aquatic macroinvertebrates.Item The distribution and diversity of Texas vertebrates: an ecoregion perspective(Texas Tech University, 1999-12) Holt, Eric AllenOne goal of this thesis was to provide information on the distribution and diversity of Texas vertebrates in a manner that can be used by decision-makers to assist in locating future biodiversity reserves. My objectives were to use the ecoregion as the unit of measure for describing the distribution and diversity of Texas vertebrates by determining: 1. which species live in each ecoregion, 2. the species richness for each ecoregion, 3. the number of threatened and endangered species living in each ecoregion, 4. coefficient of community values, as a measure of uniqueness, for each ecoregion pair. 5. the number of species living in each ecoregion that are found only in that ecoregion, and 6. the current amount of land in each ecoregion currently managed by state and federal agencies for the protection of biodiversity. In addition, several theories including island biogeography, habitat heterogeneity, dimatic stability, productivity, and latitude have been proposed to explain why more species live in one area than another. A second goal of my research was to assess how well these theories explained vertebrate diversity in Texas. Specifically. I tested the following null hypothesis: Ho: The number of vertebrate species living in the ecoregions of Texas is not related to the diversity of habitats found within ecoregions, the spatial location of ecoregions, or climatic factors influencing the ecology of ecoregions. To test this overall null hypothesis I used simple linear regression to evaluate the relationship between habitat (Table 1.1), location (Table 1.2), and climate (Table 1.3) and the variation in vertebrate richness among the ecoregions of Texas.