Vibrio vulnificus and V. parahaemolyticus are naturally occurring estuarine bacteria and the leading causes of seafood-borne illness in the United States. Multiple outbreaks due to raw oyster consumption in the last decade has lead to much research to remediate these bacteria from oysters destined for the half-shell market. The focus of this research was to investigate the efficacy of icing and high salinity exposure as two post-harvest treatments for the reduction in numbers of V. vulnificus and V. parahaemolyticus in commercial quantities of shellstock oysters. The icing experiment was conducted in the summer of 2006, and the high salinity trials were done in September 2007. Treatments for the icing experiment include: (1) on-board icing immediately after harvest exposed to minimal handling and shipping; (2) on-board icing immediately after harvest exposed to typical industry shipping and handling practices; (3) dockside icing approximately 1-2 hours prior to docking; and (4) no icing. In most instances during icing and cold storage, there were no statistically significant differences in V. vulnificus and V. parahaemolyticus counts by treatment or time. The only exceptions occurred in August samples, in which case V. vulnificus and V. parahaemolyticus counts in dockside and non-iced oysters were significantly higher than the immediately iced on-board samples. Treated (iced) oysters had significantly higher gaping after one week in cold storage than did non-iced oysters. For the high salinity exposure research, oysters were relocated to an area of full strength sea water (>30 ppt) to measure change in both V. vulnificus and V. parahaemolyticus. Oysters placed at ambient air temperatures over night had significantly higher numbers of both V. vulnificus and V. parahaemolyticus than when they were first harvested. Due to safety concerns and equipment failure, the experiment could not be completed, but preliminary results indicate a significant decrease in V. vulnificus and V. parahaemolyticus counts after one week of exposure to sea water. However, one week was insufficient time to reduce either V. vulnificus or V. parahaemolyticus to non-detectable numbers. Overall, post-harvest icing did not substantially reduce V. vulnificus or V. parahaemolyticus in oysters, and icing negatively impacted oyster survival during subsequent cold storage. High salinity exposure showed promise in V. vulnificus and V. parahaemolyticus reduction; however, the logistics of relocating oysters to full strength sea water need to be closely evaluated.

Wood products are treated with biocides to prevent biodegradation by bacteria, fungi, and insects. Much attention is being directed towards testing of metal-free organic preservative systems. The major disadvantage of organics is that they are biotransformed by micro-organisms in soil and wood. This study explored the biotransformation of the fungicide tebuconazole by a bacteria species (Pseudomonas fluorescens), the mold (Trichoderma harzianum), the white rot fungus (Phanerochaete chrysosporium) and the brown rot (Meruliporia incrassata). After incubation of cultures spiked with tebuconazole, samples were analyzed for chemical remaining and metabolites. M. incrassata, T. harzianum, and the bacterium all cleaved the 1, 2, 4 triazole ring on tebuconazole and performed oxidation reactions forming the alcohol and carboxylic acid oxidation products of the tert butyl moiety on tebuconazole. P. chrysosporium which exhibited the lowest minimum inhibitory concentration (highest tebuconazole efficacy), did not degrade tebuconazole to measurable amounts. T. harzianum, with the highest MIC (lowest efficacy), degraded tebuconazole to the largest extent and tolerated it at concentrations below 200ppm. These suggested that the ability of a fungus to degrade a biocide contributes to the efficacy. The oxidation of tebuconazole was reduced when P450 inhibitors were added to the cultures leading to the conclusion that enzymes involved in the oxidation are cytochrome P450 dependent. Furthermore, the microsomal extract from T. harzianum exhibited a maximum peak at 440-460nm when CO was bubbled into Na2S2O4 treated samples. Testing metal chelators EDTA and TEMED as synergistic additives to tebuconazole showed that EDTA reduced the magnitude of oxidation most likely by binding ions important in the enzymatic system. TEMED had no significant effect while the P450 inhibitors PB and ABT gave the best performance in terms of reducing tebuconazole depletion. T. harzianum was able to germinate and grow in the presence of tebuconazole and all additives used leading to the conclusion that in addition to biotransformation, there are other mechanisms which this species uses to tolerate tebuconazole. While molds and bacteria species are not responsible for decay, they may metabolize a biocide into a less potent derivative making the environment more suitable to wood degrading basidiomycetes and insects.

The Henslows Sparrow (Ammodramus henslowii) is a grassland species of concern that winters in prairies and open pine savannas across the Gulf Coastal Plain. Previous studies have indicated that these birds occur at higher densities in recently burned habitats in winter, but this has never been examined over a large geographic area containing multiple habitat types. The objectives of the study were to identify areas of important winter habitat in Louisiana, to examine the relationship between time since burn, bird density, and bird condition, and to determine vegetation structure and composition used by birds. We found most of the new potential habitat and the highest numbers of birds in two specific ecoregions, the Lower West Gulf Coastal Plain and the East Gulf Coastal Plain (east and west) suggesting that these may be most important for wintering Henslows Sparrows. Time since burn explained little variation plot selection overall. Bird densities in the east peaked in the first winter after burn, while densities in the west were higher 1-2 years post burn, indicating that habitats in these regions may respond differently to fire. Vegetation measurements were not helpful in interpreting bird abundance patterns across plots, suggesting that characteristics of suitable habitat may vary widely across ecoregions. However, within a plot the probability of flushing a bird increased with increasing herbaceous density at ground level, and with increasing cover of the plant genera Andropogon and Rhynchospora, so Henslows Sparrows may be responding to structural components of the habitat on a small scale. Sex ratios and bird body condition, including mass, fat storage, and feather growth, did not vary with burn year. Therefore I found no evidence for any sex-related winter hierarchy. Results of this research will help land managers make decisions with appropriate consideration for the larger variation in bird abundance and vegetation associations found across a regional scale. We recommend a two year rotation of prescribed fire to maintain high numbers of Henslows Sparrows, and caution against more frequent fire rotations in the west.

The U.S. has dramatically altered its wood product imports and exports during the past few years, and at present, it is the leading wood product importer in the world. An understanding of market structures, factors in selecting foreign suppliers and the emphasis they place on environmental issues/certification are critical to understand from the perspective of wood products importers in the U.S. Sri Lanka exports wood products to U.S. markets. Sri Lankas wood product manufacturing sector is characterized by small companies, low volumes of production, inefficient processing techniques, and outdated processing equipment. However, Sri Lankan wood products are generally of good quality. Given sufficient institutional and technological assistance, this sector has potential to grow. In order to derive maximum benefits from emerging global markets and opportunities, it is important to identify the current trade and development barriers that exist in Sri Lanka from the perspective of wood product exporters. Two studies were conducted for this thesis. First, a study of U.S. wood products importers was conducted using a mail survey and the second study surveyed Sri Lankan wood products exporters via personal interviews. Results identify three wood product importer segments in the U.S. market. Although these three segments did not differ in terms of sources of information they use or buyer selection criteria, they differed significantly on their emphasis on environmental claims/certification, consistent supply and fair prices in foreign buyer selection. Certification and marketing, product attributes, client contact, supply of quality products, and timber species and supplier reputation are the factors valued most by U.S importers when selecting foreign suppliers. A plurality of respondents import certified products with Forest Stewardship Council (FSC) being the most accepted certification program followed Sustainable Forestry Initiative (SFI). Sri Lankan wood products exporters are small in scale and many of them are newcomers to the export market. Inefficient internal and external transportation procedures, lack of supportive government policies, lengthy custom procedures, lack of experienced labor, old production technology, and difficulty in meeting buyers delivery schedules are the prominent constraints and issues facing Sri Lankas wood products export sector. Although a majority of respondents export non-certified products, they are willing to know more about forest certification if it can help develop international markets. Both U.S. wood products importers and Sri Lankan exporters are not willing to pay the cost of certification.

Export-led strategies are very crucial to achieving growth and goals of developing and transition economies such as Ghana. As a result, export strategies are being adopted in many developing countries. Although such export strategies might be in place, the deployment of resources and tax payers money involved often calls for the investigation of programs and initiatives that exist and perceptions by industry if they are working. Furthermore, Ghana wood exports to the US, a historically major market, have been declining over the past six years. Therefore, there is the need to determine if export constraints to the US market exist. The objective of the study was to assess Ghanas wood products export sector strategies and performance, and further assess export constraints to the US market. The study indicated that the wood export industry in Ghana perceives that government-led programs and initiatives are not working effectively. There was significant difference in responses based on firm size and product groups. It is therefore suggested that the Government and public and private sector institutions in the wood export sector coordinate activities and creating an enabling environment for Ghana wood products exporters to compete favorably in the international market. In assessing the export constraints to the US, results indicated that respondents have difficulty finding reliable buyers and face a lack of understanding of the US classification and grading system. In addition, large volumes required by US importers are also a major barrier in exporting to the US. There were significant differences in responses based on firm location, firm size and product group. Overall, respondents indicated there was no comprehensive and well documented export strategy in place. This calls for the development of a detailed national export strategy that will address the needs of wood products exporters to make Ghanas wood product industry competitive in international markets.

Relative abundance and species richness of saproxylic beetles and nesting, roosting, and foraging ecology of pileated woodpeckers were studied in recent partial cuts and uncut forest during the summers of 2006 and 2007. Relative abundance of saproxylic beetles was greater in one-year old cuts than uncut forest during 2006 but was not consistent during 2007. The number of dead trees, period of capture, and trapping year also influenced beetle abundance. Species richness was similar in partial cuts and uncut forest. Characteristics of habitat used by pileated woodpeckers for nesting and roosting in one-year-old and two-year-old partial cuts and uncut forest were similar. Woodpeckers used five species of trees that were between 42 and 150 cm diameter at breast height (dbh) for nesting (n = 24, 60.5 ± 3.02; mean ± SE) and roosting (n = 15, 70.3 ± 7.03). Baldcypress (Taxodium distichum) was selected in all treatments. Nests (22 of 24) and roosts (12 of 15) were predominantly in boles of live trees (vigorous to decadent). Nest and roost sites contained more trees >50 cm dbh than were available in random plots. Foraging observations were conducted in 20 territories of radio- and non-radio-tagged pileated woodpeckers. Pileated woodpeckers spent the highest proportion of their foraging time excavating (58%), followed by pecking (14%), gleaning (14%), scaling (7%), berry-eating (4%), and probing (3%). They foraged on live boles (41%), dead branches (27%), live branches (13%), dead boles (10%), and vines (9%). Woodpeckers preferred bitter pecan (Carya aquatica), avoided sugarberry (Celtis laevigata), and used overcup oak (Quercus lyrata) in proportion to availability. They avoided dbh classes 10-20, selected dbh classes 50-70, and used dbh classes 30-40 in proportion to their availability in most treatments. In partial cuts, extremely large trees (dbh classes 80-90+) were selected. Pileateds either avoided vigorous and decadent trees for foraging or used them in proportion to their availability. Woodpeckers preferred trees in early stages of decay in all treatments but in two-year-old partial cuts they preferred trees in late stages of decay. Scat of pileated woodpeckers contained Pheidole ants, carpenter (Camponotus) ants, beetles (Coleoptera), and seeds of poison ivy.

Understanding den selection for the Louisiana black bear (Ursus americanus luteolus) may provide insight into habitat requirements of the subspecies and assist in conservation and management efforts. With that goal, I assessed den selection of female Louisiana black bears at multiple spatial scales in northern and central Louisiana. I used 230 den-years to examine den type (tree or ground), microhabitat characteristics at dens, and effects of landscape characteristics on den selection. We also evaluated tree availability and reuse. Solitary and parturient females selected tree dens more frequently (65%) than ground dens. However, tree dens were not required for successful denning and reproduction. Ground dens were consistently located in upland habitat with dense understory. An evaluation of ground den locations relative to landscape composition and configuration indicated that ground dens were positively associated with proximity to water, greater proportions of water, and smaller patch sizes of water. Tree dens were predominantly located in baldcypress (86%) surrounded by water (80%), likely selected for the presence of a suitable cavity and were positively associated with proximity to edge and higher proportions of swamp and water habitat than surrounding areas. A survey of available tree dens indicated that densities of tree dens were comparable to other southeastern areas with sustainable bear populations, which suggested that tree den densities are likely adequate to support a population. Tree dens were associated with similar landscape characteristics across my northern and central study areas, which suggested that landscape variables may be used by managers to identify where tree dens should occur and may prioritize conservation efforts in these areas. Due to the variety of habitat types suitable for ground dens, it was not feasible to identify optimal habitat for ground dens based solely on variables that reflected land cover.

Wood residue produced by forest products industry has been recognized as a potential fuel that can generate energy to run the industry. A survey was done among forest products industry to get a general idea about energy produced from woody biomass created from forest industry in Louisiana, USA. The industry was classified into primary and secondary forest products industry. The study provided information regarding utilization and wastage of wood residue. Survey response rate was 25 percent. It addressed problems faced by wood residue energy development and came up with solution to solve them. When survey results were compared to previous survey, done in 1994, it clearly showed an increase in production and utilization of wood residue. One more thing worth noting was the reduction in number of secondary forest products industry. The study estimated a production 15,076,937 tons of wood residue by the forest product industry. Results showed that majority of wood being produced in the industry went un-utilized. In primary forest products industry most respondent used their residue in energy production. But in secondary sector, residue was not utilized. Residue of secondary forest product industry such as wood chips and shavings were used in various sectors. Some of them were bedding for horse farms, mulching, for erosion control in canals and as fuel in furnaces. But nearly ninety percent of residue went to landfills. By contrast, there were industries which had a great demand for wood residue as a fuel. We discovered a need for better communication between producers and utilizers. This study also produced an interactive online directory, from which industry needing wood residue can contact producers. One major reason for non-utilization of wood residue in secondary sector was due to comparatively small production that was distributed widely across the state. Cost of transportation restricted them from being a viable option. Lack of information about producers and consumers also played a role.

Site preparation after clearcuts directly affects surrounding small mammal populations. Differences in bed row spacing and arrangement of debris can impact structure and composition of vegetation communities, which influence small mammal habitat. We surveyed vegetation and small mammals in 2 different row spacings (14 ft and 20 ft) and 2 different debris distributions (piled and scattered) in 4 clearcuts owned by Weyerhaeuser in Louisiana during 2006-2007. Our objectives were to examine effects of row spacing and debris distribution on vegetation, to look at responses of small mammal densities to row spacing and debris distribution, and to see how small mammals responded to resulting vegetation. Study areas included 2 clearcuts in north Louisiana and 2 in south Louisiana. All study areas were newly harvested loblolly pine (Pinus taeda) plantations. Sampling techniques in the field included vegetation surveys and live trapping of small mammals. General trends included the following: vegetation responses to treatments were overall uniform throughout treatments. In year 2, grass, forbs, and woody vegetation proliferated in both row spacings and debris arrangements. Vines grew in predominantly in 20 ft spacing. Small mammal responses to treatments depended on species examined. Peromyscus spp. favored all study areas irrespective of treatment. House mouse (Mus musculus) used mostly 14 ft spacings and the combination of 20 ft spacing with piled debris. Cotton rat used both spacings and preferred piled debris. Small mammals responded to changes in vegetation as succession progressed. Woody vegetation, grass, forbs, and vines were important predictors in habitat selection. Both row spacings and debris arrangements in this study benefited small mammals. Future research could examine later successional stages and how wildlife adapt to changing vegetation.

The overall goal of coastal wetland restoration is to achieve ecological equivalence through the reproduction of structural and functional characteristics. This study sought to examine ecological equivalence using a chronosequence of temporal replicates of created marshes using traditional structural measures of equivalence and tested the use of stable isotopes as a measure of functional equivalence. The objectives of this study were to: (1) compare measures of structural equivalence at created and reference marshes; (2) use stable isotope analysis of blue crab muscle and hepatopancreas tissues to compare functional equivalence at created and reference marshes; and (3) determine if there is any age effect indicative of marsh development trajectories. The study was carried out at four marshes created with dredged material (524 years old) that were each paired with adjacent reference marshes on the Sabine National Wildlife Refuge, Louisiana during the spring and fall of 2007. At each marsh, quantitative measures of structural equivalence and functional equivalence were collected. Paired contrasts indicated that created and reference marshes supported equivalent plant and nekton populations, but differed in soil characteristics. Specifically, created marshes had consistently lower soil organic matter compared to reference marshes with no apparent age effect. A laboratory study was conducted in order to determine blue crab tissue specific isotope turnover rates. The hepatopancreas tissue had a half-life of approximately 10 days while the muscle tissue had a half-life of approximately 22-39 days. Comparison of mean hepatopancreas and muscle δ¹³C and δ¹⁵N isotope values found that the blue crabs at the youngest created marsh (5 yrs.) occupy the lowest trophic position compared to all other marshes. Overall, the results indicate that while vegetation and nekton community characteristics suggest that structural equivalency is achieved relatively rapidly (< 5yrs), functional equivalence, as measured by trophic support, may take longer to occur (> 8 years). Stable isotope techniques may give coastal managers an important tool to investigate the complex trophic connections within these estuarine food webs and to determine if and when these marshes will achieve functional equivalence.