This dissertation research focused on three questions: (1) what is the current carbon stock in Louisianas forest ecosystems? (2) how will the biomass carbon stock respond to future climate change? and (3) how vulnerable are the coastal forest resources to natural disturbances, such as hurricanes? The research utilized a geographic information system, remote sensing techniques, ecosystem modeling, and statistical approaches with existing data and in-situ measurements. Future climate changes were adapted from predictions by the Community Climate System Model on the basis of low (B1), moderate (A1B), and high (A2) greenhouse gas emission scenarios. The study on forest carbon assessment found that Louisianas forests currently store 219.2 Tg of biomass carbon, 90% of which is stored in wetland and evergreen forests. Spatial variation of the carbon storage was mainly affected by forest biomass distribution. No correlation was identified between carbon storage in watersheds with the average watershed slope and drainage density. The modeling study on growth response to future climate found that forest net primary productivity (NPP) would decline from 2000 to 2050 under scenario B1, but may increase under scenarios A1B and A2 due primarily to minimum temperature and precipitation changes. Uncertainties of the NPP prediction were apparent, owing to spatial resolution of the climate variables. The remote sensing study on hurricane disturbance to coastal forests found that increases in the intensity of severe weather in the future would likely increase the turn-over rate of coastal forest carbon stock. Forest attributes and site conditions had a variety of effects on the vulnerability of forests to hurricane disturbance and thereby, spatial patterns of disturbed landscape. Soil groups and stand factors, including forest types, forest coverage, and stand density contributed to 85% of accuracy in the modeling probability of Hurricane Katrina disturbance to forests. In conclusion, this research demonstrated that quantification of forest biomass carbon, using geo-referenced datasets and GIS techniques, provides a credible approach to increase accuracy and constrain the uncertainty of large-scale carbon assessment. A combination of ecosystem modeling and GIS/Remote Sensing techniques can provide insight into future climate change effects on forest carbon change at the landscape scale.

Supercritical fluid extraction (SFE) of oxeye daisy (Chrysanthemum leucanthemum L.) seed, heartwood of Port-Orford cedar (POC) (Chamaecyparis lawsoniana), Alaska yellow cedar (AYC) (Chamaecyparis nootkatensis), and Eastern red cedar (ERC) (Juniperus virginiana L), and Chinese tallow (Sapium sebiferum L. Roxb. ) seed was investigated in this study and compared with other extraction methods. For the oxeye daisy seed extraction, Soxhlet extraction (SE) with hexane, microwave assisted extraction (MAE), and supercritical fluid extraction (SFE) were conducted. The results showed that as the extraction temperature decreased from 100 °C, the extraction rate increased until 30 °C using SFE. With an increase of extraction pressure from 100 bar to 300 bar, the extraction rate increased using SFE. Most ultraviolet waves did not pass through the oxeye daisy oils at a wavelength range 200 nm to 300 nm when the oil concentration was 0.4% (v/v). The MAE oil and SFE showed stronger DPPH radical-scavenging ability than SE oil at the same concentration. For the three cedars extraction, samples were supercritical fluid extracted with CO2 and Soxhlet extracted with hexane. The extracted oils were evaluated against two common wood decay fungi, brown-rot fungi (Gloeophyllum trabeum) and white-rot fungi (Trametes versicolor). The result showed that the SFE yield of ERC, AYC, and POC was 3.27%, 3.22%, and 3.29%, respectively. The SE yield of ERC, AYC, and POC was 0.80%, 0.71%, and 1.52%, respectively. The statistical analysis showed that SFE cedar oils had higher antifungal activities than SE cedar oils against both fungi. In vitro studies showed that AYC oil had the strongest antifungal activity, followed by POC oil and ERC oil. For the Chinese tallow seed extraction, SFE and SE were conducted. 5% or 10% methanol (MeOH) was added to the supercritical CO2 as a modifier. The results showed that the collecting time could significantly affect the extraction yield. The extraction yield with 10% MeOH (32.61%) is higher than with 5% MeOH (30.85%) or without MeOH (30.75%). More components could be extracted when using a modifier based on GC-MS analysis. In sum, supercritical fluid extraction showed several advantages in the extraction of plant oils over Soxhlet extraction.

The red-cockaded woodpecker (Picoides borealis; hereafter RCW) is a cooperative breeder endemic to open old-growth pine savannah ecosystems in the southeastern United States (Jackson 1994). The RCW was listed as federally endangered in 1973, after a population decline due to habitat loss. Habitat fragmentation produces isolated populations of RCWs, which in turn ultimately limits the success of the species. RCW biologists and managers counteract effects of fragmentation by aggregating recruitment clusters and translocation. Although several studies examined subadult RCW translocation, detailed studies examining adult translocation have been limited. My study was conducted on a 3500 ha area owned by Plum Creek Timber Company located in Morehouse Parish, Louisiana from 2006 to 2008. My primary objective was to evaluate the success and feasibility of using adult RCWs for translocation and augmentation of existing populations. Plum Creek managers translocated 41 RCWs, consisting of 12 potential breeding groups (PBGs) and 5 single bird groups (SBGs) to suitable habitat at the Morehouse Parish Conservation Area (hereafter MPCA). Fifty-nine percent of the translocated RCWs remained on the MPCA and 45% of individual RCWs became breeders. Forty-four percent of translocated RCWs were breeding in year 2, suggesting that translocated adult RCWs can beneficially augment the population after 2 breeding seasons. Fledgling numbers contributed by translocated RCWs ranged from 11-30% of the total fledglings on the MPCA. There were 5 PBGs established on the MPCA from translocated RCWs and 20% of the fledglings had ≥1 translocated parent. Microhabitat characteristics and landscape features were not important predictors of occupancy for RCWs on available clusters within the MPCA or translocation success. Success rates for translocation in our study were lower than previous studies where subadults were translocated. Nevertheless, because previous research has suggested that demographically isolated groups have a high risk of abandonment and thus do not contribute to the recovery of the species (Walters and Priddy 2005), the success rates I observed suggest that translocating adult groups may be a useful tool in RCW recovery.

My research focused on how fish communities are responding to watershed land use and instream habitat in tributaries of the Lower Bogue Chitto River. To address this question I electrofished and seined 10 sites in four tributaries of the Bogue Chitto River a total of 4 times each over the course of 15 months in 2007 and 2008. I characterized habitat by measuring water flow, water depth, substrate size, woody debris, temperature, and dissolved oxygen, and quantified heterotrophic plate counts, nutrients, and chlorophyll a concentrations at the end of the sampling period each year. Watershed land cover was measured with 2001 USGS Land use/Land cover data, and my analysis focused on cultivated cropland and pasture land, as well as forested and herbaceous wetlands. Many of the most common fishes responded positively to differences in stream characteristics, particularly increased nitrate and agricultural development, and decreased wetlands, which are typically characteristic of anthropogenic stream impacts. Other fishes responded to increased flow and substrate size, which appeared to characterize less disturbed stream conditions. Overall, fish diversity was negatively associated with distance from the mainstem Bogue Chitto River. These results suggest that in nutrient limited systems, some fishes respond positively to anthropogenic alterations, and that watershedbased characteristics are more important than local habitat variables in predicting fish assemblage composition and abundance in these streams.

Creep behavior of natural fiber/polymer composites (NFPCs) was studied in response to the increasing application of this material as structural building products. Factors that influence creep behavior of the composites were investigated by analyzing creep curves of several different NFPC systems, which were designed for overall performance of the composites. Among different models, the 4-element Burgers type was mostly used for quantitative characterization of the creep curves to compare the properties of different composites. The parameters from the 4-element Burgers model were easily interpretable due to their physical meanings. Generalized Burgers models provided better fit by introducing extra Kelvin units, but they are more complicated. Indexed Burgers models performed better for creep curves within the primary stage in terms of both characterization and prediction. Creep prediction was attempted through two approaches: modeling and accelerated testing. Burgers models were proven unsuitable for long-term prediction if the creep test time was not long enough. Comparatively, the indexed Burgers and 2-parameter power law models performed better for prediction purposes. Accelerated creep tests were conducted at higher temperatures, and smooth curves were obtained based on the time-temperature superposition (TTS) principle. The accuracy of long-term prediction was unable to be evaluated due to the lack of long-term experimental data. Several factors were shown to affect the creep resistance of NFPCs. These include polymer matrix type, natural fiber loading, additives, temperature, and weathering treatment. PVC had higher creep resistance than HDPE, and HDPE showed better creep resistance than ultra-high molecular weight polyethylene (UHMWPE). Introducing engineering plastics to form microfibrils in HDPE matrix improved its creep performance. Certain recycled plastics had smaller creep deformation than the corresponding virgin resin. Adding natural fibers into polymer matrix greatly enhanced its creep resistance. The effect of a coupling agent on creep property of NFPCs was dependent on its modulus and coupling effect. UVA, an ultrafine titanium dioxide, slightly reduced the creep deformation of HDPE composites at a low loading level. Higher temperatures led to not only larger instantaneous deformations, but also to higher long-term creep rates. Weathering treatment also affected the creep properties of polymer and NFPCs.

The alligator gar Atractosteus spatula is a large, long-lived, physostomous fish that inhabits aquatic habitats throughout the central U.S., ranging from Oklahoma southward to the Gulf of Mexico. Unfortunately, the alligator gar has declined significantly in abundance throughout much of its historic range and is now considered vulnerable to localized extirpation. The goal of this study was to provide basic data on the ecology and life history of a commercially-exploited alligator gar population in south Louisiana. This study also focused on age determination and alternate aging techniques such as sectioned otoliths and sectioned scales. From 10 April 2007 through 21 May 2008, alligator gar were collected with jug lines from Bayou DuLarge and surrounding areas with the aid of a local commercial fisher. A total of 203 male, 125 female and 1 unsexed alligator gar were collected. Sex ratio was approximately 1:1 for catch by month. Overall, female alligator gar were longer, heavier, and had larger girths than males. Alligator gar predominately fed on fishes (34%), although crustaceans (4%) and non-food items (5%) were also found. Based on gonadosomatic index values, spawning occurred from March through May. Gar ages ranged from 1 to 26 years with a mean age of 5 years for males based on sectioned otoliths (N = 194) and sectioned scales (N = 144). Mean age for females based on sectioned otoliths (N = 122) was 5.5 years, and 5.8 years based on sectioned scales (N = 71). In my sample, it appeared male and female alligator gar matured by age 5. The growth rate (k value from von Bertalanffy growth equation) was 0.323 ± 0.017, and annual survival from a catch curve was estimated to be 79.9% (Z = 0.225). Sectioned otoliths yielded the highest precision between readers (0.46, Average Percent Error) and presented fewer complications during age determination as compared to sectioned scales. Life history and age information from this study will aid with understanding the complex and variable nature of the Bayou DuLarge alligator gar population and will be useful to agencies in the development of future management programs for this unique species.

Colonization of natural areas by Chinese privet (Ligustrum sinense Lour.) threatens biodiversity and preservation of native habitat in the southeastern United States. High rates of seed production and dispersal, coupled with clonal growth, result in a competitive advantage when introduced to novel areas. Land managers have attempted to control L. sinense through prolonged flooding, prescribed fire, and herbicide application with little success. I determined presence of L. sinense invasion in four sites in Louisiana and assessed key reproductive, growth, and survivorship characteristics defining its life course. I used vegetation surveys, germination trials, dendrochronology, and demographic models to elucidate stages in L. sinenses life cycle that contribute most to population growth. Populations of L. sinense have the potential for rapid growth. I germinated seeds under growth chamber, greenhouse, and field conditions. Stage-based matrix projection models showed the finite rate of population increase (λ) ranged from 1.48 in the field to 2.26 in the growth chamber. I used elasticity analysis to identify the proportional contribution of remaining in a stage (P), growing to a subsequent stage (G), and fecundity (F) to population growth, and perturbed matrices to mimic management strategies. A 50% reduction in PSEEDLING, PJUVENILE, and PSMALL ADULT reduced λ to 1.66 in the growth chamber and 1.63 in the greenhouse. Under field conditions, a 50% reduction in all Pi was required to bring λ to 1, so that populations were stationary. Reductions in FADULT did not immediately cause a decline in population growth. Approaches that target multiple life stages may be more successful for managing L. sinense. Using field germination rates, reduction of FLARGE ADULT by 50%, plus a 50% reduction of GSEEDLING and GJUVENILE, and PSMALL ADULT and PLARGE ADULT made population growth stationary (λ = 1.04). Management techniques that increase annual mortality of specific life stages may be more cost effective than targeting all individuals within a population. This study has identified transitions that contribute most to population growth over a range of growing conditions and indicated management options that may streamline control of this invasive plant.

The aqueous leaf extract of Rubus suavissimus (Chinese sweet leaf tea) was active in inhibiting angiogenesis, which could be used to suppress adipogenesis and cause weight loss. Following this revelation and approach, the anti-obesity effect was thoroughly investigated in normal and obese rat models. The investigations began with the preparation of quality-controlled extract. First, the crude extraction methods were examined leading to the characterization of the chemical composition. Second, the impure components were removed by alcohol precipitation and column chromatography, resulting in a standardized sweet leaf tea extract (RUS). Third, three bioavailable compounds identified from the urine analyses were re-constituted to form the purified sweet leaf tea extract (GER), which accounted for 27% by weight of the RUS. These standardized and purified sweet leaf tea extracts were then evaluated for their anti-obesity effect in normal and obese-prone rats. Both RUS and GER reduced body weight gain by 7% (p =0.999) in normal rodents but statistical analyses failed to show any significance due to small sample size. Amazingly, it was discovered that the use of the tri-compounds combination (GER) produced the same anti-obesity effect as the standardized extract (RUS). Consequently, new experiments were focused on the GER using obese-prone rats as the study model. GER showed a significant anti-obesity effect by reducing 22% (p¡Ü 0.001) weight gain compared to the high-fat diet control group. Total abdominal fat was reduced significantly by 48%, indicating that the lost body mass was mainly due to the loss of body fat. Other benefits of the Chinese sweet leaf tea extract included lowered blood glucose, cholesterol, and triglycerides. Food intake was not affected. No adverse effects were observed. This research provides exciting insights about the novel use of the Chinese sweet leaf tea as a safe and effective anti-obesity agent beyond its historic use as a natural sweetener. Human clinical investigations are strongly warranted to determine the effective doses and long-term use safety in combating obesity or managing body weight.

Forestry is a major contributor to the Ghanaian economy and has the potential to increase its contribution if a number of challenges are overcome. Over the past 15 years, Ghana has modified its forest policies, laws, and regulations, but still faces serious challenges with illegal logging and unsustainable forest management. At the same time, Ghanas major wood product trading partner, the European Union (EU), is requesting that Ghana, under the Voluntary Partnership Agreement (VPA), ensures that wood products from Ghana to the EU are legally produced. Additionally, several EU wood product importers have requested their suppliers in Ghana to meet certification requirements. To date, efforts by Ghanaian companies to achieve certification have not been successful. Certification can potentially address forest management challenges facing tropical countries like Ghana, while enhancing the export of wood products to environmentally sensitive markets, such as the EU. This research was conducted to identify the underlying causes for Ghanaian companies inability to meet certification requirements and the implications for forest management and timber exports from Ghana. The research was conducted in Ghana from May to August 2009. Mail surveys supported by field assessment of forest management practices were the main research methods used. In addition, interviews were conducted with key contacts from the four groups studied: policymakers, loggers, wood processors/exporters, and wood product importers from Ghana. Results suggest that current forest management practices in Ghana are unsustainable. Forest management certification was found to have a positive impact on forest management, but is unlikely to be an effective mechanism in influencing overall forest management practices. Respondents identified illegal logging, corruption, and weak enforcement of forest laws as the key impediments to sustainable forestry in Ghana. In spite of the increasing demand for certified wood products by European importers, results indicate that Europe is the primary destination for respondent wood exports. The most significant conclusion is that the government should undertake institutional roles reform to transfer key forest management functions to companies that adhere to government standards, while addressing the underlying factors of corruption, illegal logging, and weak enforcement of forest laws through a broader stakeholder consultative process.

The effects of bait type, trap-soak duration, and a trap entrance modification were evaluated from February through May 2008 in a 1.29 ha crawfish (red swamp crawfish, Procambarus clarkii) pond in southwest Louisiana. Commercial pyramid traps with three entrance funnels, 1.9-cm square-mesh vinyl-coated welded metal wire, were used. In trial 1, crawfish catch was evaluated in traps baited with Atlantic menhaden (Brevoortia tyrannus), a formulated dry bait, or a menhaden+formulated bait mixture, each at 24-h and 48-h soak durations. In trial 2, the escape of marked crawfish was evaluated in the presence or absence of bait at 24-h and 48-h soak durations. In trial 3, the catchability of traps with modified entrances, designed to reduce crawfish escape, were evaluated at 24-h and 48-h trap-soak durations. In trial 1, menhaden alone was the most effective bait in February and March, all baits were equally effective in April, and the formulated bait alone was most effective in May. Overall, crawfish catch per unit effort (CPUE) with a 24-h soak duration was 36% and 27% higher in number and weight than the 48-h soak. Mean crawfish size increased when trap-soak duration was increased from 24-h to 48-h. In trial 2, traps containing no marked crawfish caught significantly more crawfish in both number (37%) and weight (30%) than traps with marked crawfish indicating that the presence of crawfish in traps prior to baiting decreased catch. Mean crawfish escape from traps ranged from 29 to 34%, and the presence or absence of bait had no significant effect on escape; however, the mean escape rate following a 48-h trap-soak duration (39%) was nearly twice that of a 24-h soak (22%). Crawfish CPUE with modified traps was 20% higher with a 48-h trap-soak duration. Modification of the trap entrance funnels with plastic cable ties appeared to reduce the rate of crawfish egress from the traps between 24-h and 48-h.