Northern bobwhite (Colinus virginianus) populations have been declining throughout their range during the past 30 years primarily because of a result of loss of early successional habitat. Specifically, intensive silviculture practices and reduction in the use of prescribed fire has led to this loss. I studied effects of management practices (selective herbicides, mowing, and prescribed fire) on male and covey distribution, and brood-rearing habitats on Jackson-Bienville Wildlife Management Area (JBWMA). Specifically, I used calling surveys to assess landscape characteristics associated bobwhite distribution. I also measured vegetation and arthropod response, using imprinted bobwhite chicks, pitfalls, and sweep nets, to different habitat manipulations. Male bobwhites were closely associated with early successional habitats, and negatively associated with the proportion of landscape variables associated with 16-29 year old pine stands. Several vegetation characteristics were affected by the use of herbicides, mowing, and burning; however, arthropod response was not similar. Imprinted chicks selected arthropod orders similar to wild chicks, although they did not consume a large quantity of arthropods. These data indicates habitats on JBWMA may not be of the quality needed for brood-rearing. Future research should focus on long-term effects of manipulations (selective herbicides, mowing, and burning) on northern bobwhite populations. Managers should focus on creating early successional habitats across forested landscape, and continue to search for methods to enhance these habitats for northern bobwhites.

Random strandboards from mixed southern wood species were manufactured using calcium borate (CB) and zinc borate (ZB) as chemical additives and polymeric methylene diphenylmethane disocyanate (pMDI) as resin. There were four target levels of borate loading and two levels of resin content. Panel properties, including modulus of elasticity (MOE), modulus of rupture (MOR), internal bond (IB) strength, linear expansion (LE), thickness swelling (TS), leachability, and swelling and strength retention properties under cyclic relative humidity, were measured. The influence of borate content, borate type, and resin content on various properties was analyzed. It was found that the addition of borate negatively impacted the mechanical and physical properties of the boards. The influence of ZB and CB on both mechanical and physical properties was similar. The increase of resin content improved the properties significantly, especially TS. A certain portion of borate leached out from test samples under the water-soaking conditions. There was a higher initial leaching rate and the leaching rate decreased with the lapse of leaching time. Panels with higher initial borate loading level had higher leaching rate for all panel types. The leaching rates of ZB and CB treated samples were similar. The increase of resin content helped reduce TS and boron leaching. Compared with PF-bonded boards, leaching rate was significantly reduced for the pMDI-bonded panels. Under cyclic humidity exposure condition, the addition of borate negatively influenced the maximum TS, residual TS, and mechanical properties. The effects of ZB and CB on the maximum TS, residual TS, and mechanical properties were similar. The increase of resin content significantly reduced residual TS, but had no influence on maximum TS and mechanical properties. The addition of borate did not have significant influence on the strength retention of the boards under long term cyclic humidity exposure condition.

I analyzed data from an experimental aerial transect survey, using stratified random sampling, to estimate wintering populations of greater scaup (Aythya marila) and lesser scaup (Aythya affinis) (hereafter scaup) in off-shore waters along the coast of Louisiana during winters 2000-2002. My objectives were to evaluate anecdotal reports of large numbers of scaup in off-shore waters of Louisiana during winter, and to develop estimates and confidence intervals for numbers of scaup in this area. My analysis yielded estimates of 815,700, 420,600, and 791,000 scaup in off-shore Louisiana for years 2000-2002, respectively. Confidence intervals were 1,087,000 to 545,000, 594,300 to 247,000, and 1,351,900 to 230,200 for years 2000-2002, respectively. Although large numbers of scaup were observed off-shore each year, numbers observed in most strata varied widely from year to year. Coefficients of variation (CV) for these estimates ranged from 17 to 35 percent. Highest densities of scaup were found in bays off the central Louisiana coast followed by the southwest and southeast coasts. Highest CVs were found along the southwest and southeast coasts and in the area south of Atchafalaya Bay. The precision of population estimates in these areas could be improved by increasing the number of transects. Comparisons of the number of scaup estimated in off-shore waters and that in the standard midwinter survey indicate that off-shore areas comprise 51 to 85% of the wintering population of scaup each year in Louisiana. When off-shore estimates are combined with in-shore estimates, the annual variability in total scaup is reduced greatly. It is not known whether variation in the proportion of scaup counted off-shore occurred because scaup preference for off-shore and in-shore areas varied annually, or because shorter-term weather conditions differed during surveys. The resulting high variability therefore may mask true trends in wintering scaup populations. I recommend the addition of off-shore surveys for scaup to improve the accuracy of current mid-winter scaup estimates.

Two laboratory feeding trials were conducted to quantify differences in the digestibility and absorption of dietary amino acids provided in intact protein or in purified amino acid mixtures. In the first experiment, 36 channel catfish (346 ± 47 g) were force-fed one of six practical feed ingredients (blood meal, corn meal, fish meal, meat and bone meal, soybean meal or wheat middlings), or a mixture of crystalline amino acids designed to duplicate the amino acid composition of each of the practical ingredients. Apparent digestibility coefficients (ADC) were calculated for 15 amino acids in each practical ingredient and in each amino acid mixture. An average ADC of all amino acids in each treatment also was calculated. Very few differences in the ADCs of individual amino acids were observed. However, in all ingredients but two, the mean ADCs of amino acids in fish fed purified amino acids were significantly higher than the mean ADCs of amino acids in fish fed intact protein. In the second experiment, 468 channel catfish (396 ± 49 g) were force-fed the same ingredients and amino acid mixtures used in the digestibility trial, and blood was collected from the hepatic portal vein at 1-h intervals for 12 h after feeding. In four of the six ingredients tested, postprandial concentrations of 2-8 amino acids in blood plasma were significantly higher and reached peak levels earlier (1-3 h after feeding) in fish fed purified amino acids than in fish fed intact protein. Results indicated that protein was well digested by channel catfish regardless of its source. However, soybean protein appeared to be digested more slowly than the other proteins tested. The efficiency with which supplemental amino acids are utilized might be reduced if slowly digested proteins compose a major portion of the diet, because of temporal differences in the absorption of amino acids from different dietary sources. If so, the effectiveness of amino acid supplementation could vary with the ingredient composition of the diet to a greater extent than has previously been recognized.

This research demonstrated model development for important wood properties using near infrared spectroscopy (NIR); it considered the effect of outside sources of error, and the ability of NIR to measure fiber morphology. Strength, stiffness, and density were successfully modeled from wood samples taken throughout 10 longleaf (Pinus palustris Mill) trees. Principal components and multiple linear regression were compared for performance in prediction of density, strength, and stiffness. I found both modeling techniques to yield similar prediction accuracies. However, I found that density could be estimated through Beer-Lamberts law since the absorbance at all wavelengths increased with density. Also, 5 of 6 wavelengths needed to predict strength were also needed to predict stiffness lending support that similar chemical morphology controls the covariance between strength and stiffness. Klason lignin, extractives, and microfiber angle (MFA) were also measured throughout the tree. I found extractives, lignin, and MFA to decrease from the pith outward regardless of height. A theoretical model was built attempting to explain how lignin content and MFA co-vary. Theoretical and empirical spectroscopic models both predicted MFA with nearly similar root mean square error and supported that lignin was a probable factor responsible for the covariance in spectra with MFA. Tracheid length was another secondary trait investigated. I demonstrated that tracheid length could be predicted with an R2 of 0.71 due to NIR spectra response with age. Accurate tracheid length prediction was possible due to systematic variation of chemistry with age except for at ring 1 and 4 where some other unknown factor was responsible. Finally, blue stain and machine variability were investigated as two sources of extraneous error. It was of interest to know if the common extraneous error would bias a prediction equation. With proper modeling, I found I could avoid the blue stain variation present in the spectra when modeling modulus of elasticity (MOE), modulus of rupture (MOR), density, lignin, and extractives. However, when a calibration was built from one machine and then applied to a population of scans made from a separate machine, blue stain became problematic and prediction of MOE, MOR, and extractives were biased.

Sustainable management and conservation of the extensive bottomland hardwood forest resource in the southeastern U.S. requires a good understanding of basic structural and competitive relationships within these forests. To gain an insight into these relationships, plot information from stands in Arkansas, Louisiana, and Mississippi were analyzed. The effects of individual tree attributes, distance-dependant, and distance-independent competition measures on 5-yr radial growth of red oak crop trees were examined. Selected species included cherrybark oak (Quercus pagoda Raf.), water oak (Q. nigra L.), and Nuttall oak (Q. nuttallii Palmer). Spatial continuity of tree variables was explored through geostatistical analysis. Finally, spatial distribution patterns of all species, the intraspecific pattern of cherrybark oak, water oak, and sweetgum (Liquidambar styraciflua L.), and the interspecific pattern of their pairs was examined with point pattern analysis. In the analysis of 5-yr radial growth, the crown class score (from Meadows et al. 2001) accounted for a large portion of tree diameter growth. However, average plot-level characteristics failed to account for a significant proportion of the variability in tree growth. The basal area of trees taller than the crop trees and located within 2.5 mean crown radii had the highest negative correlation with crop tree 5-yr radial growth. Red oaks were likely exerting the greatest competition. Crop tree radial growth was also positively associated with the basal area of other red oaks taller than the crop tree and located between 3 and 4 mean crown radii from the crop tree (the indirect neighbors). Geostatistical analysis demonstrated that spatial continuity of unsuppressed tree attributes extended to a distance equal to 4 times the mean crown radius, suggesting that when resources are nonlimiting, multiple trees may be able to coexist and grow well in close proximity. Spatial point pattern analysis indicated that when species were combined, they were frequently aggregated and sometimes overdispersed. Plots with larger trees were more likely to exhibit overdispersion suggesting a shift to this pattern as trees grow. Interspecific and intraspecific pattern analyses suggested that strong interspecific competition resulted in species segregation, while weaker intraspecific competition led to aggregations of conspecifics.

A continuing challenge for wood and wood-based composite building materials has been durability--the power of resisting agents or influences which tend to cause changes, decay, or dissolution; lastingness. In the case of wood-based products, this often requires a resistance to biological degradation and moisture related dimensional instability (particularly in particle and flake or strand boards). Borden Chemical Company has developed a new low molecular weight phenol formaldehyde additive, PD-112, to improve durability in composite wood products. This study investigated PD-112s contribution to durability in oriented strand board (OSB) through laboratory testing of treated southern pine strandboard panels versus untreated control panels. Tests examined mechanical properties, as well as resistance to degradation by water infiltration, mold, decay fungi and termite attack. PD-112 treatment significantly reduced moisture induced thickness swelling without adverse effects on strength properties. Modulus of rupture (MOR) and modulus of elasticity (MOE) increased somewhat, while internal bonding strength (IB) increased greatly with increasing PD-112 treatment. PD-112 imparted good termite resistance to pine strandboard. Treatments gave excellent resistance to decay by selected brown rot fungi, and moderate resistance to growth of selected mold fungi.

I examined nest attendance patterns for 132 Gadwall (Anas strepera) females breeding in the prairie pothole region located in Towner County, North Dakota from May to July 2000 - 2001. Overall, Gadwall had a daily incubation constancy of 76.5 ± 10.8%, and daily recess frequency of 2.2 ± 1.1 with each recess lasting 179.8 ± 133.8 minutes. Unlike other waterfowl species, Gadwall increased incubation constancy and decreased recess frequency as daily high temperature increased and showed no change in constancy with precipitation. Gadwall incubation constancy did not fit the body-size hypothesis, as Gadwall have a lower incubation constancy compared to species smaller in size. This may be because Gadwall have the latest peak clutch initiation of all dabbling ducks, providing the advantage of dense nesting cover and warmer ambient temperature compared to earlier nesting species. Of the 132 females, 19 (14%) delayed nocturnal incubation resulting in a significant difference in incubation constancy (P= 0.001) and recess frequency (P = 0.001) from those that did not delay nocturnal incubation. However, components of the incubation rhythms, after the onset of nocturnal incubation were similar for both groups.

This study examined the effects of intrahabitat variability on marsh edge use by fishes and decapod crustaceans. The objectives were to (1) identify quantitative measures of habitat complexity that describe the structural design of marsh edge habitats, and (2) examine differences in nekton use between cut-bank and gently sloping marsh edge habitats. The study was conducted in Barataria Bay, Louisiana at 75, 10-m marsh edge study sites. Monthly seining was conducted in fall 2003 and spring 2004 and measures of habitat complexity were recorded at each sample location. Indices of tidal inundation and site exposure to wind and wave action were calculated. Results showed significantly greater complexity (i.e., irregularity, elevation, bank height, bank undercut, vegetation densities and percent vegetated cover) at cut-bank edges over gently sloping edges (P < 0.0001). Nekton diversity (fall: P = 0.0236, spring: P = 0.0297) and mean abundance of bay anchovy Anchoa mitchilli (fall: P = 0.0010) were also significantly greater at cut-bank edges over gently sloping edges. Lower mean elevation at gently sloping edges resulted in significantly greater levels of inundation over cut-bank edges (P < 0.0001), providing earlier and prolonged use of inner marsh habitats. Mean abundances of marsh residents that frequent the vegetated marsh surface (naked goby Gobiosoma bosc (fall: P = 0.0055), gulf killifish Fundulus grandis (fall: P = 0.0280), and grass shrimp Palaemonetes pugio (fall: P = 0.0017) were significantly greater at gently sloping edges over cut-bank edges. Several associations were observed between nekton community parameters and measures of habitat complexity, including strong positive correlations between species diversity (fall: P < 0.0001, spring: P < 0.0001), species richness (fall P = 0.0001, spring P = 0.0029), and exposure to wind and wave action. Differences in use between cut-bank and gently sloping edges and associations between nekton variables and measures of habitat complexity suggest that differences in habitat structure exist among marsh edge habitats and that these differences do influence habitat selection by nekton. This study highlights the need for methods that provide more explicit identification of EFH by determining relationships between productivity and the different habitats used by aquatic organisms.

The goal of this study was to develop several techniques that utilize the use of geothermal water that can contribute to increased profitability for commercial catfish producers. The primary objectives of this study were to: 1) determine the heating requirement using degree-days of channel catfish spawning 2) improve the efficiency of artificial spawning and, 3) evaluate the effectiveness of stocking outdoor ponds and pools with channel catfish fry. The heating requirement for channel catfish spawning was determined to be between 99 and 129 degree days at the peak of spawning. There was no difference in degree-day values between spawns collected from heated ponds, and those collected from ambient ponds. There was also no difference in the weight and fertilization percentages between the egg masses collected before and after the start of natural spawning. In artificial spawning, female-female and male-female pairs showed no differences in the volume of unfertilized eggs collected, spawning latency, and neurulation in trials conducted before and after the start of natural spawning. Spawning behavior and egg release proved to be the most accurate way to determine the optimum time to manually strip female broodstock. Survival of fry before the start of regular spawning was greater in pools then in 0.04-ha ponds but that there was no difference in the stocking of sacfry or swim-up fry before or after the start of regular spawning in ponds or pools. The size, growth rate and number of fingerlings harvested are all affected by the survival percentage of fry stocked. Lower survival results in fewer fingerlings that grow faster and larger. Survival was mostly affected by the date of stocking and the number of growing days the fingerlings remained in the ponds or pools. These results support the use of geothermally heated ponds to increase the productivity of commercial catfish producers by providing better control over spawning, increased opportunities for artificial spawning, production of improved seedstock (including hybrids), and lengthened growing period for channel catfish fry. Future research needs to focus on improving these techniques and develop methods for efficient use of geothermal water in commercial catfish production.