Rice straw fiber can be considered as important potential reinforcing filler for thermoplastic composite because of its lignocellulosic characteristics. It is thus of practical significance to understand and predict the thermal decomposition process of rice straw fibers. A method proposed by Málek, esták, and co-workers was used to investigate and model thermal decomposition process of common natural fibers with detailed analysis on rice straw system. Assuming a global model occurring within the entire degradation of natural fibers with consideration of fiber as one pseudo-component, model can be used to describe both isothermal and non-isothermal degradation process of most selected fibers within acceptable error limits of 3 and 5%, respectively. The parameters of kinetic model were given in this dissertation. The model obtained has practical significance for introducing straw fiber into some engineering plastics with comparatively lower melting temperature. Influences of different rice straw components, and compatibilizers on various properties of rice-straw based polymer composites were also investigated. Rice straw fibers can work well with both VHDPE and RHDPE as reinforcing filler. Also, different components of rice straw had no significant influence on mechanical properties of composites. The PE-g-MA/EPR ratio affected mechanical properties of composites modified by combined compatibilizers. The optimum PE-g-MA/EPR ratio was considered to be 2:1 and 1:1 for PE-g-MA/uEPR and PE-g-MA/EPR-g-MA modified composites, respectively. At the optimum ratio, composites modified by combined compatibilizers showed better strength and impact toughness, and acceptable modulus compared to those modified by either EPR or EPR-g-MA. It was found that 13% weight loss seemed to be the limit for rice straw to maintain its strength in a composite system. High-temperature one-step extrusion was feasible for manufacturing HDPE/nylon-6/rice-straw composites without significant strength loss caused by thermal degradation of fiber. The two-step method failed to exhibit better performance than the one-step method.

The delay in early height growth (EHG) has been a limiting factor for artificial regeneration of longleaf pine (Pinus palustris Mill.). Simple Sequence Repeat (SSR) markers have been used to map the genome and quantitative trait loci controlling the EHG in a backcross family (longleaf pine x slash pine) x longleaf pine. A total of 228 locus specific SSR markers were screened against 6 longleaf pine recurrent parents and a sample of 7 longlef x slash pine hybrid parents. In total, 135 polymorphic markers were identified. Based on the genetic variance in EHG, available sample size, and the number of SSR marker polymorphisms, a half-sib family with a common paternal parent (Derr488) and 6 longleaf maternal parents were selected from 27 backcross families as the final mapping population. One hundred and twenty three (123) polymorphic markers showed polymorphisms across the half-sib family. An individual linkage map was built for each full-sib family first, and then the linkage maps from different full-sib families were integrated by common orthologous SSR markers with software JoinMap (ver3.0). There were 112 polymorphic markers mapped to the integrated map which contained 16 linkage groups. The observed map length was 1874.3 cM and covered 79.85% of genome. The estimated 95% confidence interval for genome length was 1781.3-2411.6 cM. Seventeen (17) QTLs were identified by single marker regression using 305 backcross progenies. For the interval mapping, the tallest and shortest 8 percent of seedlings were selected for QTL detection (phase I), and then random selections of 8 percent of the seedlings from the rest of the population and 25 seedlings from both tails of the within family distributions were used for unbiased QTL verification and mapping (phase II). Nine QTLs were detected and verified as associated with the 5 growth traits under P=0.05 chromosome-wide threshold. There was only weak evidence of QTL stability during the three years of growth under this study.

White-tailed deer are an important economic and recreational resource in Louisiana. A basic understanding of population dynamics is essential to ensure sound management, but baseline information in Louisiana is lacking. Likewise, the notion of Quality Deer Management (QDM) continues to gain momentum in Louisiana. Our objectives were to evaluate space use, survival, and mortality for a deer herd managed under a QDM regime in south Louisiana. We captured 65 deer in West Baton Rouge and Iberville Parishes during 2007 and 2008, radio-marked 37 males and 11 females, and ear-marked an additional 10 males and 7 females. Home ranges (95%) for adult males during spring, summer, and fall were 153.9, 70.4, and 118.0 ha, respectively and were 119% and 68% larger during spring and fall than summer. Female home ranges were 67.3, 53.9, and 25.2 ha during spring, summer, and fall, respectively. Juvenile (1.5 yr-old) males increased space use 169% in spring (231.6 ha) relative to summer (86.1 ha), and maintained 50% larger home ranges than adults in spring. Survival estimates for adult males during spring, summer, and fall were 100, 95, and 55%, respectively. Mean annual survival for adult males was 53%. No mortalities were observed in spring or summer for 1.5 yr-old males, but ear-tag returns and harvest records indicated 1.5 yr-old males were being harvested at a rate approaching 20%. Mean annual mortality rates from harvest (40%) were greater than for non-harvest sources of mortality (16%). Non-hunting mortality included both natural causes (9%) and deer-vehicle-collisions (9%). We observed smaller home ranges than anticipated or seen previously, suggesting that landowners managing small (<300 ha) tracts of property may be able to practice QDM at scales thought to be ineffective at improving herd dynamics. Due to low non-hunting mortality, young males (&le;2.5-yr) are likely to survive to the next age class if protected from harvest, but ultimately have a small chance of reaching maturity (5.5+) because males are generally harvested as they approach the antler restriction in place. Managers should seek to increase fall survival for males if management objectives include increasing the frequency of harvesting males &ge;3.5 yrs-old.

Populations of many North American secretive marsh birds (SMBs) have declined over the past 30 years, primarily as a function of wetland loss. Ranges for many of these species encompass Louisiana and researchers have investigated various characteristics associated with breeding populations in coastal wetlands, yet similar knowledge is lacking for other parts of the state. I investigated distributions and habitat characteristics associated with breeding SMBs in wetlands and rice fields of the lower Mississippi Alluvial Valley (MAV) of northeast Louisiana. In the 2007 and 2008 breeding seasons we conducted repeated bird surveys in 118 wetlands and 76 rice fields. Common Moorhens (Gallinula chloropus), Least Bitterns (Ixobrychus exilis) and Purple Gallinules (Porphyrula martinica), were the most commonly detected species in wetlands while breeding King Rails (Rallus elegans) and American Coots (Fulica americana) were rare. I built predictive wetland habitat models for Common Moorhens, Least Bitterns and Purple Gallinules in each year based on vegetation characteristics recorded within 100 m (local) and 1 km (landscape) of wetland sampling points. In general, local areas with greater coverage of water and robust emergent vegetation seem to attract breeding SMBs. No other local upland habitat characteristics or landscape cover variables were consistently, significantly associated with occupancy for any species across years. Wetlands dominated by robust emergent vegetation are rare in this region and birds may have to utilize them wherever they are available, disregarding other local and landscape habitat features. In 2007 no breeding individuals from any of these species were encountered in rice fields and only 7 rice sites were occupied by any species in 2008. Rice in the MAV does not reach a height adequate to support breeding SMBs (~ 65-70 cm) until late May at the earliest, 1-2 months after the breeding season commences. However, King Rails, Least Bitterns, Common Moorhens and American Coots were all observed in rice fields between June and August of both years. Thus, it is possible that rice fields in the MAV are used by late season breeders or birds rearing a second brood.

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.