Past events and present environmental conditions may alter vegetation cover and composition over decadal timescales by exerting persistent effects on modern vegetation patterns and consequently influencing species distribution and abundance. My aim was to reconstruct vegetation and analyze cover during early-European settlement in Brazos County using historical sources, mainly the surveyor’s files from the Original Texas Land Survey. The decoded trees from the surveyor’s notes resulted in 24 witness and bearing tree species being recorded, the most abundant species on the uplands was Post Oak (Quercus stellata) and for bottomlands was Pin Oak (Quercus phellos). Using the distances and directions given in the surveyor’s notes for witness and bearing trees, coordinates were calculated and species classified according to their National Wetland Indicator’ (NWI) status. Indicator kriging was performed to create a continuous vegetation cover of Brazos County by interpolating the point biogeographical data (i.e., witness trees, bearing trees and stake, mound and post locations) that had been spatially located and mapped onto the shapefile. The vegetation map showed 49% of vegetation in the county was covered by grassland during pre-European settlement. Most of these prairie areas were located in the northern portion of the county along the Old San Antonio Road. The bottomland forests covered 15% of Brazos County along the Navasota and Brazos Bottoms. Major expanses of bottomland hardwood occurred in the northwest of the county and at the confluence of the Navasota and Brazos rivers in the south. The Upland Oak Woodlands, mainly dominated by Post Oaks covered 36% of landscape, occurred mainly towards the western and eastern parts of the county and were interspersed with Grasslands. The vegetation map was verified using old photographs, traveler’s accounts and field checking for bottomland hardwoods. This research proves that the OTLS is a valid source for vegetation mapping during Pre-European settlement and for analyzing the tree species present at that time and helps in protecting and conserving our pristine environment at the present time.

This study was designed to integrate a mailing list-based survey with an internetbased presentation/response in order to take into account the trend toward selfadministration that is evident in everyday interactions with automated services that have taken the place of personal interactions. A random sample of 2,999 was taken from applicants for Triploid Grass Carp Permits from the Texas Parks and Wildlife Department. A forty-nine question survey was constructed containing five sections: general pond characteristics, physical pond characteristics, aquatic vegetation, fish and other wildlife, and management goals. The primary emphasis of this study was to determine what specific problems Texas pond owners faced, how widely these problems occurred, and where pond owners got the information they used to deal with pond management problems. A secondary emphasis of the project was to examine the potential presented by the Internet for use in this type of information gathering and distribution for Texas Cooperative Extension. An overall response rate of 21.3% (excluding non-deliverables and unusable submitted surveys) was obtained. Summary statistics for each question were calculated and then compared in order to gain a clearer picture of the pond management practices employed by Texas pond owners. These results indicated some initial discrepancies between pond owners?? management practices and current management recommendations, most dramatically where aquatic vegetation was concerned. The internet-based survey methodology worked effectively to lower the cost of distribution and the workload of data entry when compared to the mail survey. These benefits outweighed the disadvantages caused by survey error with the new methodology.

The barrier islands of the gulf coast of the U.S. have been shaped and changed by hurricanes for centuries. These storms can alter the vegetation of the barrier islands by redistributing sediments, scouring off vegetation, physical damage to the plants, and by salt stress following the storm. Hurricanes also alter the mammal communities of the barrier islands through direct mortality and by altering vegetative communities. It is important to understand how the vegetation of barrier islands recovers after major hurricanes because the vegetation provides the structure that maintains and builds these islands. Following the landfall of Hurricane Katrina in August of 2005, I studied the changes in the herbaceous ground cover and the density of woody plants in Gulf Islands National Seashore in Mississippi from the winter of 2005 to the summer of 2007. Growth from existing plants and seed banks quickly revegetated the islands after the storm. The amount of live ground cover increased and bare ground decreased on each island and in every vegetation type. Most woody plant species also showed a net increase in density, with the exception of pine (Pinus elliottii) and Florida rosemary (Ceratiola ericoides). The regeneration of woody species and the uniform increase in the live ground cover seemed to indicate that the vegetation of the islands was not irreversibly impacted. I also studied the changes in the composition of mammal populations in Gulf Islands National Seashore from the winter of 2005 to the summer of 2007. Prior to the storm 11 terrestrial mammal species were recorded in studies of the barrier islands. In the 2 years following Hurricane Katrina, I recorded only 1 of the 7 species on Cat Island, 5 of the 9 species on Horn Island and 2 species each on East Ship, West Ship, and Petit Bois Islands (which previously had 4, 4, and 2 each). Populations of mammals that used multiple vegetation types (raccoons [Procyon lotor], nutria [Myocastor coypus], and eastern cottontail [Sylvilagus floridanus]) seemed to show more tolerance to hurricane disturbance than more specialized species (black rat [Rattus rattus], marsh rice rat [Oryzomys palustris]). I also recorded at least one colonization event by river otter (Lutra canadensis), a species not recently recorded on the islands. This research serves as a baseline for future comparison following similar storms.

Th. doct.--Sciences de la terre--Vriji Universiteit te Amsterdam, 1985. / Bibliogr. p. 174-185.

Thesis (Ph.D.)--University of Wollongong, 2009. / Typescript. Includes bibliographical references: leaf182-203.

Thesis (M.A.)--California State University, Chico. / Includes abstract. "Located in the Chico Digital Repository." Includes bibliographical references (p. 40-44).

Thesis (M.S.)--Oregon State University, 2003. / Typescript (photocopy). Includes bibliographical references (leaves 100-103). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 2003. / Typescript (photocopy). Includes bibliographical references (leaves 60-72). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 102-114).

published_or_final_version / Mechanical Engineering / Master / Master of Philosophy