This study was designed to examine home range sizes and habitat use of blacktail redhorse Moxostoma poecilurum in West Fork Thompson Creek, Louisiana. Blacktail redhorse are a common non-game species found in Louisiana and other southeastern states. Adult blacktail redhorse (N=40; 187-273 mm total length) were implanted with radio transmitters and tracked twice weekly from February to September 2006 and from February to July 2007. To assess blacktail redhorse diet I analyzed 32 stomachs from fish collected by backpack electrofishing. I also conducted mark-recapture surveys of fish sampled monthly from May 2006 until July 2007. To assess homing ability in blacktail redhorse, I radio-tagged 10 individuals in 2007 and relocated them downstream (0.8 or 1.6 km) from their capture location. Results showed that implanted fish exhibited extremely high mortality or expulsion rates with 70% of all implanted transmitters being lost, even though retention rates in the laboratory were very high. On numerous occasions, I directly and indirectly observed avian and mammalian predators foraging in the study area, which likely explains high transmitter loss. Individual 95% linear home range sizes varied from 25 to 3,900 meters, with several fish having multiple home ranges, while others remained in the same pool throughout the study. Blacktail redhorse were observed foraging throughout the diel period, and their diet was primarily composed of chironomid (55%) and heptageniid larvae (17%). Similar to other redhorse species, blacktail redhorse were benthic feeders and foraging behaviors appear very similar to that of black redhorse Moxostoma duquesnei. Few marked individuals were recaptured (6 of 130) as indicated by mark-recapture sampling. The homing study showed only one individual moved back to its capture location. Small sample sizes and short study times limited both the mark-recapture and homing studies. Overall, blacktail redhorse exhibited a preference for pools with clay boulders, complex habitat, and undercut banks. The high levels of predation observed throughout this study and its impact on blacktail redhorse abundance suggest that local predation pressures structure this portion of the population and may be a driving force in structuring the entire headwater stream fish community in this area.

Over the last century, the aquatic macrophyte community of the Atchafalaya River Basin (ARB) has become increasingly dominated by invasive species. I used digital photography and GIS software to determine ARB macrophyte community composition by measuring percent cover of each plant species within five 0.25-m2 quadrats sampled from 108 sites in 2005 and 103 sites in 2006. Macrophyte community data and measurements of soil and water physicochemistry at each site were used to investigate environmental associations of the macrophytes inhabiting bayou, lake, excavated canal, and swamp habitats. Analyses indicated substantial differences in physicochemical conditions among habitats, but none of the 20 macrophyte species collected during the study exhibited consistent preferences for specific habitat types. Percent coverage of invasive plants was greater than native plants across all habitat types in both years, with invasive plant richness increasing in 2006 with the arrival of giant salvinia (Salvinia molesta). Common salvinia (Salvinia minima) appeared to have the greatest impact on the native plants, exhibiting inverse abundance relationships with six of fourteen species (43%). Comparisons of slopes from areal coverage â dry weight regressions based on macrophytes that were photographed, collected, and dried from quadrats sampled at 26 sites in 2006 suggested that invasive species accumulated more biomass per unit area than ecologically similar native taxa. In both years, terrestrial plants were observed in association with floating mats of other macrophyte species, apparently taking advantage of the mats as âterrestrialâ substrate. Submerged plants exhibited few significant differences in abundance among the four habitats, although they did tend to occur where floating plants were not abundant. There were few physicochemical differences among vegetated and non-vegetated sites for native or invasive plants, although pH was lower at vegetated sites (versus non-vegetated) for both native (2005) and invasive (2005 and 2006) plants. Canonical discriminate function analysis revealed substantial changes in plant community composition and physicochemistry between the two years at approximately 25% of the study locations. These changes highlight the dynamic nature of the littoral zone and the multiplicity of deterministic and stochastic factors that likely affect the composition of the resident macrophyte community in the ARB.

Little information is available concerning survival, habitat use, and movements of mallards (Anas platyrhychos) wintering on the Gulf Coast Chenier Plain (GCCP). Quantitative data on these parameters would be useful in making effective management decisions by GCCP waterfowl managers. Accordingly, I radio-marked 135 female mallards during winters 2004-2005 and 2005-2006 in southwestern Louisiana. My estimated survival rate for both winters combined was 0.68 ± 0.06 and did not differ by female age. Hazard ratios indicated that radio-marked females were 21-24 times more likely to die during hunted time periods than during non-hunted time periods. Estimated hunting and non-hunting mortality rates were 0.279 ± 0.062 (± SE) and 0.067 ± 0.029 (± SE), respectively, and did not differ between winters. Estimated product limit survival rates were 0.81 ± 0.05 (± SE) and 0.54 ± 0.09 (± SE) for HIGH and LOW condition birds, respectively. I found that diurnal use of areas closed to hunting was greater during hunted time periods in winter 2005-2006 than in winter 2004-2005. Nocturnally, use of areas closed to hunting was greater during SHUNT than during POST, and immatures used CLOSED lands more so than did adults. Diurnally, use of MARSH was 3.3 times greater than that of other habitats during both winters. Use of RICE and IDLE appeared to be related to availability of these habitats within the core study area. RICE acreage and use was greater in winter 2004-2005 than in winter 2005-2006, whereas IDLE acreage and use was greater in winter 2005-2006 than in winter 2004-2005. Female mallards used freshwater marsh habitats extensively; brackish or salt marsh was used much less frequently. Diel movements of female mallards generally were short (mean ± SE = 5.0 ± 0.2 km) and mean flight distances of individual females (n = 141) ranged from 3-15 km. My results suggest that mallards wintering in this area would benefit from programs and activities that target freshwater marsh for restoration and management. Management activities that increase mallard foraging habitats on areas closed to hunting may decrease hunting mortality rates and possibly increase female body condition.

The concept of forest certification, a relatively recent development in forestry, is based on the use of market-based incentives to encourage sustainable forest management practices. Since the majority of forests in US South are privately owned, certifying forests owned by non-industrial private forest (NIPF) landowners is an important issue. From the demand perspective of certification, pressure from non-governmental environmental organizations and consumer awareness has prompted major wood products retailers to state preferences for certified wood products. In the US, wood product demand in the retail home centers sector is second only to the home building industry. In addition, home center retailers have been shown to be a primary driver of forest and wood products certification. In order to ascertain NIPF landowner and leading home center retailer perceptions of forest certification, two mail surveys were conducted. We surveyed 1,200 randomly selected NIPF landowners each in Louisiana and Mississippi, and the top 500 home retail centers in the United States. Results of the landowner survey indicate that a significant proportion of respondents believe certification could benefit NIPF landowners. Results suggest that many of the negative or neutral attitudes NIPFs hold towards certification are partially due to a lack of information and knowledge on the subject. Many respondents are skeptical of the publics willingness to support certification. However, they believe that certification can contribute to improving the forestry profession and forest management. It was also evident that the cost of certification will continue to be a main certification issue with over three-quarters of respondents being unwilling to pay anything for certification. Results from the home center study frame certification-related issues from the perspective of wood products retailers looking for the best way to market their products. Only a few leading wood products retailer respondents are currently participating in certification. Product quality, fair prices and supply issues are regarded as main concerns rather than safeguarding against environmental retaliation in order to be successful. Results indicate that, in general, price premiums for certified products are rare. However, niche markets exist that offer higher prices for certified products. Forest Stewardship Council (FSC) and Sustainable Forest Initiative (SFI) certification schemes are most preferred and accepted by retailer respondents. None of the respondent companies experienced any unexpected costs due to certification.

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.