A large river system typically derives the majority of its biomass from production within the floodplain. The Neches River in the Big Thicket National Preserve is a large blackwater river that has an extensive forested floodplain. Organic carbon was analyzed within the floodplain waters and the river (upstream and downstream of the floodplain) to determine the amount of organic carbon from the floodplain that is contributing to the nutrient dynamics in the river. Dissolved organic carbon was significantly higher at downstream river locations during high discharge. Higher organic carbon levels in the floodplain contributed to increases in organic carbon within the Neches River downstream of the floodplain when Neches River discharges exceeded 10,000 cfs. Hurricane Rita passed through the Big Thicket National Preserve in September 2005. Dissolved organic carbon concentrations recorded after Hurricane Rita in the Neches River downstream of the floodplain were significantly higher than upstream of the floodplain. Dissolved organic carbon was twice as high after the hurricane than levels prior to the hurricane, with floodplain concentrations exceeding 50 ppm C. The increase in organic carbon was likely due to nutrients leached from leaves, which were swept from the floodplain trees prior to normal abscission in the fall. A continuum of leaf breakdown rates was observed in three common floodplain species of trees: Sapium sebiferum, Acer rubrum, and Quercus laurifolia. Leaves collected from blowdown as a result of Hurricane Rita did not break down significantly faster than leaves collected prior to abscission in the fall. Processing coefficients for leaf breakdown in a continuously wet area of the floodplain were significantly higher than processing coefficients for leaf breakdown on the floodplain floor. The forested floodplain of the Neches River is the main contributor of organic carbon. When flow is greater than 10,000 csf, the floodplain transports organic carbon directly to the river, providing a source of nutrition for riverine organisms and contributing to the overall health of the ecosystem.

This dissertation compiles information related to Caddo archaeology and history and examines in detail the collections from various Historic Caddo sites and Spanish missions. The study uses materials from these sites, along with the archival records from early European expeditions and colonization efforts, to try to identify archaeological correlates of the groups that constituted the Hasinai Caddo. The objective is to determine if specific attributes of ceramic style and technology reflect the position and geographical extent of the principal tribes of the Hasinai Caddo as indicated by the historical records. To accomplish this I examined numerous collections from clusters of historic period sites in the Neches and Angelina River valleys of east Texas, including sites occupied by the Hasinai Caddo and two of the three Spanish missions discovered in east Texas. The study analyzes, organizes, and characterizes distinct ceramic assemblages and other artifacts in the collections. Another goal of this research is to better define the periods of use and chronological relationships of Historic Caddo sites. Ceramic frequency seriations of established types, supported by other evidence, demonstrate chronological orderings reflected in the collections. The cultural landscape of the Hasinai Caddo, broadly characterized, consisted of sedentary groups living in dispersed farmsteads as thriving agriculturalists, organized in a complex hierarchy of social and spiritual leaders. Sustained contact with Spanish missionaries brought trade materials and technology in tandem with social objectives and policies, many aimed at replacing Caddo cultural identity under the guise of religious conversion, relocation, and trade. While the number of Caddo groups identified in the ethnohistoric record decreased as time passed, it is clear from the archives that groups of the Hasinai endured and maintained distinct affiliations during the contact period. The ceramic analyses support the historic record on this point and demonstrate how assemblages are part of well-established and persistent ceramic traditions. At the same time, the study documents distinct archaeological signatures that may represent socio-cultural, political, and/or economic differences in the Hasinai Caddo. Evidence also demonstrates how the Hasinai Caddo were both willing participants in, and at the same time rejected, the Spanish mission system. / text

In 2011, Texas experienced the worst drought in recorded history. This has escalated concerns regarding environmental flows needed to sustain freshwater and estuarine systems as human needs are addressed during drought periods. In this thesis, I analyze fish assemblages and water quality variables in order to observe the effects of drought in the lower Neches River below the saltwater barrier located upstream from Beaumont, Texas. Fish and water quality samples were taken during drought conditions during fall 2011 and summer 2012, after a season of rain. During fall 2011, sites surveyed above the barrier had lower salinity but similarly low dissolved oxygen (DO) levels compared with sites surveyed below the barrier. Salinity levels during fall 2011 were relatively high (reaching up to 15 ppt), whereas salinity during summer 2012 never rose above 1.5 ppt. For gillnet samples obtained during fall 2011, fish species richness was higher in December following a series of rain events than during drought conditions in October and November. Although fish species richness was similar between fall 2011 and summer 2012, species composition varied greatly. For seine samples obtained during summer 2012, species richness was higher during May and July (when the barrier was open) than during June and August (when the barrier was closed). Species richness was lowest for sites in closest proximity to a paper mill effluent discharge pipe located below the barrier. Also, species richness was higher at sites above the barrier than at sites below the barrier regardless of whether or not the barrier was closed. Multivariate statistical analyses of gillnet samples revealed a large amount of compositional overlap among fish assemblages, regardless of time period and location; however, analyses of seine samples revealed that fish assemblages above the barrier were different than those from samples obtained below the barrier and that fish assemblages varied based on time period. Results indicate that, during periods of low flow, water quality deteriorates in the Lower Neches River below the saltwater barrier. During these periods of environmental degradation, fish assemblages have reduced diversity and sensitive freshwater species decline in abundance, with some absent from survey samples.

Thesis (Ph. D.)--University of North Texas, Dec., 2007. / Title from title page display. Includes bibliographical references.

Geographic information systems and remote sensing software were used to analyze data to determine the area and volume of the proposed Fastrill Reservoir, and to examine seven alternatives. The controversial reservoir site is in the same location as a nascent wildlife refuge. Six general land cover types impacted by the reservoir were also quantified using Landsat imagery. The study found that water consumption in Dallas is high, but if consumption rates are reduced to that of similar Texas cities, the reservoir is likely unnecessary. The reservoir and its alternatives were modeled in a GIS by selecting sites and intersecting horizontal water surfaces with terrain data to create a series of reservoir footprints and volumetric measurements. These were then compared with a classified satellite imagery to quantify land cover types. The reservoir impacted the most ecologically sensitive land cover type the most. Only one alternative site appeared slightly less environmentally damaging.