Alternative or supplemental management activities may be necessary to restore and enhance oyster production on Louisiana public oyster reefs. The production of wild oysters is variable due to anthropogenic and environmental factors that affect recruitment, growth and survival. The availability and structure of cultch material for larval recruitment and survival is particularly important to maintain oyster production. Beginning in 2011, the Sea Grant Oyster Hatchery on Grand Isle, LA and the Louisiana Department of Wildlife and Fisheries (LDWF) collaborated to test the survival of hatchery-produced spat and hatchery-produced larvae deployed on public oyster grounds and cultch plant sites. In 2011, a preliminary study was conducted on hatchery-produced spat survival in Hackberry Bay, LA, where 100% mortality of hatchery-produced spat was observed. Survival of hatchery-produced spat was also tested in Mississippi Sound, LA (Round Island site) and California Bay, LA, where sampling took place in September and November 2012 and January 2013. No hatchery-produced spat were collected at either of these sites, suggesting 100% mortality. No significant differences were observed between the numbers of wild spat oysters on treated plots, plots with hatchery-produced spat, to untreated plots (P>0.05). In 2012, LDWF released hatchery-produced larvae at four sites at Calcasieu Lake and the sites were monitored monthly using standard LDWF sampling procedures. For most of the sites, few to no spat existed. Possible causes of hatchery-produced spat and larval mortality are sedimentation, predation, water quality and absence of suitable settling material. To increase survival, future studies should focus on ways to minimize causes of hatchery-produced spat and larval mortality.

The continental scaup population (lesser [Aythya affinis] and greater scaup [A. marila] combined) has declined markedly during the past 20 years, and has remained below the population goal of the North American Waterfowl Management Plan since 1985. One hypothesis explaining the scaup population decline states that reproductive success has decreased because females presently are arriving on breeding areas in poorer condition than that historically (Spring Condition Hypothesis [SCH]). I tested the SCH by comparing fresh body masses (FBMs) and nutrient reserves (lipid, protein, and mineral) of lesser scaup at 4 locations (Louisiana, Illinois, Minnesota, and Manitoba) in the Mississippi Flyway between decades of the 1980s and 2000s. I found that mean FBMs of females were 58.5 g and 58.9 g lower in the 2000s than were those in the 1980s in northwestern Minnesota and near Erickson, Manitoba, respectively; mean FBMs of males similarly were 40.7 g lower in Minnesota. Mean lipid reserves of females in the 2000s were 28.8 g lower than those in the 1980s in northwestern Minnesota and 27.8 g lower near Erickson, Manitoba. Mean mineral reserves of females in the 2000s were 3.2 g lower than those in the 1980s near Erickson, Manitoba. Consequently, females arriving to breed near Erickson, Manitoba in the 2000s had accumulated lipid reserves for 4.1 fewer eggs and mineral reserves for 1 fewer egg than had those arriving to breed in the 1980s. Accordingly, my results clearly are consistent with predictions of the SCH and indicate that there has been a long-term decline in female body condition, reflected by declines in FBMs, lipids and mineral reserves, which could significantly reduce reproductive success.

Nearly 35,000 ha are used to grow crawfish in southwest and south-central Louisiana, and many of these ponds discharge into impaired water bodies. In 2002, proposed guidelines were published by the United States Environmental Protection Agency (USEPA) assigning effluent limitations and standards for some aquaculture production systems and exempting others (e.g. crawfish ponds). This research had three objectives relative to crawfish ponds: develop water discharge models; final drawdown effluent quality and seasonal mass loading of solids and nutrients; and identification of Best Management Practices (BMPs) that could reduce effluent discharge and improve effluent quality. Models for south-central and southwest Louisiana with a 15 cm storage capacity showed that excess precipitation overflow (final drawdown not included) can be decreased by 28% for a high precipitation year, 61% for an average precipitation year, and 100% for a low precipitation year. The major sources of effluent from crawfish ponds are (1) overflow during winter when precipitation exceeds evaporation, evapotranspiration, and infiltration and (2) discharge during the summer drawdown period. Pond evaporation and evapotranspiration combined are the greatest sources of water loss (68%) during a crawfish production cycle. During final drawdown, solids were high during the first 5% of pond water discharge due to poorly consolidated sediment in and around the drain and high during the last 20% of pond water discharge due to the poorly consolidated pond bottom sediments. During final drawdown: total suspended solids were reduced over a distance of 268 m by 28% at the Aquaculture Research Station (wide, shallow, non-vegetated ditch); total suspended solids increased over a distance of 268 m by 15% at the Rice Research Station (narrow, non-vegetated ditch); and total suspended solids were reduced over a distance of 268 m by 80% at the University of Louisiana at Lafayette Model Sustainable Agricultural Complex (deep vegetated ditch). To reduce solid and nutrient mass loading in crawfish pond discharge, ponds should be slowly drained from the top of the water column and avoid draining the last 20% of the pond volume. If that is not possible, then it is recommended to treat the last 20% of the pond volume by sending the discharge through deep vegetated ditches, settling basins, or constructed wetlands with a residence time of 4 d to 14 d.

The development of cointegration theories and the presence of nonstationarity in time series raised serious concerns about possible spurious estimations in forest products models. Based on the results of Hsiao (1997a, 1997b), all the virtues of two-stage least square (2SLS) hold if there are sufficient cointegration relations. Stationary null and nonstationary null unit root tests and monthly seasonal unit root tests were applied to the time series used in this dissertation. Cointegration tests with exogenous variables were performed to justify the 2SLS. A regional error correction model (ECM) with four regional lumber supply and demand equations and a U.S.-Canada supply and demand ECM were estimated. CUSUM tests did not find any structural changes. Both estimated models showed that the imported Canadian lumber and the U.S. lumber are substitutes. The estimated long-run and short-run own-price elasticities for demand and supply are inelastic for all the equations but the short-run supply equation for the West Coast. The long-run lumber supply equations have significant trends: annually -3% for the Inland West and 2% for the other regions. The popular maximum likelihood estimation for the restricted ECM cannot pass the test for the restrictions and is, therefore, not used for the regional structural lumber model. A series of univariate and multi-equation models were used as forecasting models. A combination of univariate model were shown to be the best forecasting models for lumber prices, and a combination of univariate and multi-equation models were shown to be the best forecasting models for lumber quantities. The selected combinations of models were shown to be the best with additional observations. It was also shown that lumber quantities could be forecasted better than lumber prices.

Branch and tree sap flux density (SFD) was measured to evaluate the effects of thinning, fertilization, and throughfall exclusion treatments on water use by loblolly pine (Pinus taeda L.) trees. Variations in SFD at different radial xylem depths were also examined to improve estimates of tree water use from sap flux density measured in the outer sapwood. This study was conducted in an 18-year-old loblolly pine plantation in central Louisiana in 1999. The results revealed that SFD was higher in the outer xylem than in the inner xylem and large trees had higher SFD than small trees. Thinning increased daily tree SFD and whole tree water use four years after re-treatment, but decreased stand-level tree water use. Fertilization increased tree SFD, whole-tree water use, and stand-level tree water use within the thinned plots. Throughfall exclusion decreased mean daily water use by branches and trees. SFD and water use at different levels of scale (branch, tree, and stand) changed with available soil water and microclimatic factors. Generally, SFD was positively related to photosynthetic photon flux density and vapor pressure deficit. Branch SFD was higher in the upper crown than in the lower crown. Fertilization significantly increased daily branch water use within the thinned plots, but did not significantly affect branch transpiration per unit leaf area. This study shows that tree and stand water use is affected by spatial variation in the canopy environment as well as climatic variables and forest cultural practices. Scaling up water use, carbon dynamics and growth from needle level to branch-, tree-, and stand levels under various global scenarios should account for cultural practice differences, within canopy variation, and changes in micro-environmental factors. Cultural practices, such as thinning and fertilization, significantly increased SFD and whole tree water use by accelerating leaf area development. Correlated changes in other physiological processes eventually alter tree growth. The ability to model tree and stand growth response through monitoring of whole tree and branch water use has the potential to substantially improve our understanding of forest responses to management and climate change and should be useful in policy decision making.

Termites cause serious damage to wood and wood products. In recent years, increasing attention has been paid to extractives from naturally decay resistant trees. In this study, we compared the termiticidal and antifungal effects of extractives from Alaska yellow cedar (AYC), Port-Orford cedar (POC), and Eastern red cedar (ERC). Pentane and Hexane-Acetone extractives from YC and POC, and pentane extractives from ERC were most favorable in terms of termite protection among the extractives we got. Weight loss of strips treated with 5000 ppm pentane extractives from Eastern red cedar, was significantly lower than those treated with solutions of pentane extractive from the other two species of wood at the same concentration or lower concentrations. Wood blocks treated with pentane extractives from ERC also exhibited significantly lower weight loss than other fractions from ERC and from the other two species at 5000 ppm after 3 weeks exposure to brown rot fungi. Weight loss of blocks treated with hexane-acetone extractives was significantly lower than other treatments after 6 and 9 weeks for the white rot decay test. Comparing the chemical components in the different tree parts in ERC, some difference were found between the needles, bark and the stem of ERC. Cedrol or widdrol were not detected in the extractives from needles extracted by hexane. From the TLC spectra there were small differences between the components in callus induced from ERC and the seedlings. GC-MS spectrum showed smaller types of components and a bigger difference of the peak areas between components in the callus. A higher concentration of cedrol was detected in the callus than that in the original seedlings. Widdrol was not detected in the extractives from callus or seedlings.

As global tilapia production grows, it is important to characterize varieties available for production and generate data on environmental tolerances. This study generated data on tolerances, adaptabilities and production characteristics of four tilapia varieties. Goals of this study were to: (1) compare growth of four tilapia varieties in two types of recirculating systems, (2) evaluate juvenile growth of seven tilapia varieties in fresh and brackishwater mesocosms, and (3) estimate cold tolerance of juveniles of four tilapia varieties in fresh and brackishwater. Nile tilapia (Oreochromis niloticus), blue tilapia (Oreochromis aureus), Mississippi commercial strain tilapia (MCS), and Florida red tilapia (FRT) were grown in a clear-water recirculating system for eight months. Blue tilapia yields were greater (P¡Ü 0.05) than those of Nile tilapia and FRT. Yields of Nile tilapia, MCS, and FRT were not significantly different. Seven tilapia varieties: Nile, blue, FRT, MCS, blue x FRT, Mozambique x Nile, and Nile x blue were grown in fresh and brackishwater mesocosms. Nile tilapia was stocked in three freshwater pools. Every other variety was stocked into six pools, in three of which salinity was increased to 23 ppt over 14 days. In freshwater, yield of MCS was greater (P¡Ü 0.05) than that of all other varieties. Four tilapia varieties: Nile, blue, FRT and MCS were subjected to three temperature reduction regimes: rapid (-0.5 C/ 5 h), moderate (-1 C/ 24 h) and gradual (-1 C/ 48 h) and to the moderate reduction regime at three salinities (0, 5 and 10 ppt). No significant differences were observed in cold tolerance among varieties within temperature reduction regimes. Salt did not improve the cold tolerance of blue, Nile and MCS but slightly improved that of FRT. Performance of four tilapia varieties: Nile, blue, MCS and FRT in four culture systems was ranked to develop index values. Cold tolerance of four tilapia varieties was described from an environmental standpoint, with no significant differences found between varieties. The influence of the temperature reduction regimes on cold tolerance was significant.

Waterfowl managers in Minnesota and other states are concerned that increased kill rates associated with the use of spinning-wing decoys (SWDs) may negatively affect local breeding populations of mallards (Anas platyrhynchos). I conducted 219 experimental hunts to evaluate hunting vulnerability of mallards to SWDs during the 2002 duck-hunting season in Minnesota. Following experimental hunts, I asked volunteer hunters to complete post-hunt questionnaires to document their hunting experience, and their use and opinions of SWDs. Finally, I used stable isotope methodology to determine natal origins of HY mallards killed during experimental hunts. I found that mallard flocks (≥1 duck) were 2.91 times more likely to respond (i.e., approached within 40 m of hunters) when SWDs were turned ON. Sizes of responding mallard flocks were 1.25 times larger, on average, when SWDs were turned ON than OFF. Mallards killed/hr/hunter/hunt averaged 4.71 times higher (P < 0.05) when SWDs were turned ON than OFF. More HY and AHY mallards were killed when SWDs were turned ON than OFF; however, AHYs were relatively less likely than were HYs to be killed with SWDs turned ON. Based on my stable isotope analysis, more local and migrant HY mallards were killed by hunters when SWDs were turned ON than OFF, but local HY mallards were not relatively more likely than were migrant HY mallards to be killed by hunters using SWDs in Minnesota. I found no evidence that SWDs reduced crippling nor allowed hunters to harvest relatively more drakes than hens. I estimated that if 46% and 79% of Minnesota hunters used SWDs in 2000 and 2002, respectively, Minnesota mallard harvest would increase by factors of 2. However, increasing use of SWDs may result in a partial re-distribution of annual mallard harvests if naïve ducks are harvested upon initial exposures to SWDs, and those ducks that survive migrations to wintering areas become habituated to SWDs, as suggested by my results. My study was confined to a single hunting season in Minnesota, and thus, did not assess whether vulnerability of mallards to hunters using SWDs varies among years or geographically. A multi-year, flyway-wide study is needed to make stronger and more rigorous inferences regarding potential changes in annual harvest rates of mallards due to increasing use of SWDs by hunters in North America.

This study investigated the chemical, physical, and mechanical properties of the bamboo species Phyllostachys pubescens and its utilization potential to manufacture medium density fiberboard (MDF). The result showed holocellulose and alpha-cellulose content increased from the base to the top portion. There was no significant variation in Klason lignin content or ash content from the base to the top portion of the bamboo. The outer layer had the highest holocellulose, alpha cellulose, and Klason lignin contents and the lowest extractive and ash contents. The epidermis had the highest extractive and ash contents and the lowest holocellulose and alpha-cellulose content. Specific gravity (SG) and bending properties of bamboo varied with age and vertical height location as well as horizontal layer. All mechanical properties increased from one year old to five year old bamboo. The outer layer had significantly higher SG and bending properties than the inner layer. The SG varied along the culm height. The top portions had consistently higher SG than the base. Bending strength had a strong positive correlation with SG. In order to industrially use bamboo strips efficiently, it is advisable to remove minimal surface material to produce high strength bamboo composites. Compression properties parallel to the longitudinal direction was significantly higher than perpendicular to the longitudinal direction. As expected, at the same panel density level, the strength properties of the fiberboard increased with the increasing of resin content. Age had a significant effect on panel properties. Fiberboard made with one year old bamboo at 8% resin content level had the highest modulus of rupture (MOR) and modulus of elasticity (MOE) among the bamboo panels, which was largely attributed to a higher compaction ratio as well as a higher percentage of larger fiber size. Fiberboard made with five year old bamboo at 8% resin level had the highest internal bond strength.

Since the accidental introduction of red imported fire ants (Solenopsis invicta Buren, RIFA) into Mobile, Alabama in the 1930s, the invasion of this species into other areas across the southeast has increased drastically. RIFA have been implicated in the disruption of ecosystems and decreases in biodiversity. Most research on effects of RIFA on vertebrates and invertebrates have focused on small spatial scales and single species. I examined established populations of RIFA in relation to native ground-dwelling arthropods and small mammal communities in longleaf-pine and pine-hardwood forests. I evaluated the efficacy of using Amdro® to control RIFA and determined the effect of RIFA predation on arthropod and small mammal communities. RIFA suppression occurred in April, August, and October 2003. In the longleaf-pine forest, RIFA suppression was effective in June between years (P = 0.088) and treatments (P = 0.093). This was consistent with an increase in cotton mice abundance on treated (17.7 ± 2.7) versus control (6.0 ± 2.5) plots (P = 0.035), with 90% of cotton mice captured during the June sampling period. Across seasons, significant differences were observed for Collembola in August between years (P = 0.001) and in December between treatments (P = 0.01). Likewise, abundance of Coleoptera was greater in December between years (P = 0.023) and in May between treatments (P = 0.002). In the pine-hardwood forest, RIFA suppression was effective in April and June (P = 0.001, P = 0.004, respectively) when compared across seasons. No significant differences were observed for any small mammal species captured in the pine-hardwood site. Acari were greater on treated (11.0 ± 1.7) than control (4.7 ± 1.9) plots (P = 0.067); however, no significant differences were observed for any invertebrate group across seasons. Although this study is in the initial phase of a 5-year project, the data suggests that RIFA may potentially affect the abundance of selected faunal species in forested ecosystems.