Wildfire has been suppressed in the nations forests for over a hundred years. The accumulation of forest fuels over time has created an urgent need to reduce fuel loads to prevent catastrophic wildfires from occurring, not only in our wildlands, but also in our Wildland/Urban Interfaces (WUIs). The residents who live within the WUI are particularly vulnerable to extreme wildfire events. As cities become more densely populated, increasing numbers of people are moving beyond the suburbs into the WUI. A complex matrix of structures and forested land, developing communities, and impinging forests exists within the WUI. This study utilized a survey instrument to elicit perceptions of wildfire risk and prescribed burning practices from residents within the WUI in the Florida parishes of southeastern Louisiana. Residents within the WUI show increasing interest in learning more about wildfire risk, acceptance for traditional forest management practices, such as prescribed burning, and willingness to interact with and receive education from the forest professionals in their region. The analysis of the data provides statistical support for the conclusion that the overall perception of wildfire risk is low and the acceptance of prescribed burning is high.

Tourism industry is one of the main drivers of the global economy and plays a key role in regional development. As negative environmental and socio-cultural impacts of mass tourism became apparent, the appeal of alternative forms of tourism, especially ecotourism, continued to gain a broad recognition. As a result, ecotourism became one of the fastest growing sectors in global tourism during the past decade. Being a fast-developing country with ample natural resources, Sri Lanka can benefit from adopting and promoting ecotourism. At present, Sri Lankas ecotourism resources remain largely under-utilized. With rising demand, ecotourism operators are under pressure to meet expectations of diverse consumers of their products. In this background, the need to define and distinguish ecotourists from other types of tourists has become important. The importance of using a behavioral approach to distinguish true ecotourists from other types of tourists is widely emphasized by tourism scholars. This study developed distinct motivational and behavioral profiles of visitors to forest-based attractions in Sri Lanka. Furthermore, understanding and predicting ecotourist behavior is important for ecotourism operators to better cater their target markets. Many authors have attempted to explain the recreational behavior through various behavioral theories. Based on Ajzen's (1991) Theory of Planned Behavior, this study proposed an ecotourism behavioral model of forest-based recreational areas in Sri Lanka, and incorporated knowledge and satisfaction in predicting ecotourism behavior. The role of previous visits in predicting future behavioral intentions in an ecotourism setting was modeled separately. The results identified four different types of tourists based on their behavioral and motivational characteristics i.e. ecotourists, picnickers, egoistic tourists, and adventure tourists. A typical ecotourist in Sri Lanka represents a relatively young recent high-school or university graduate, or a university student. The segment identified as egoistic tourists seems to be the most lucrative market segment to target from both environmental sustainability and business perspectives. The proposed ecotourism model suggests that knowledge and satisfaction are important determinants of ecotourism behavior. In addition, previous experiences of participating in ecotourism proved to be an important precursor of future behavioral intentions. Broad implications of visitor profiling and behavior modeling are also discussed.

In the 1980s, the term ecotourism emerged as a direct result of acknowledgment and reaction by travelers to global ecological practices. In reality, the concept of ecotourism carries wide applications, particularly for bio-diverse countries with unique natural attractions. Sri Lanka qualified as such a country, presenting a significant tourism resource base, that display natural and cultural phenomena, including forests, waterfalls, mountains, exotic flora and fauna, and a heritage equally as ancient and as rich as the Greeks and Romans. Ecotourism in todays dynamic global environment demands that ecotourism operators face a keenly competitive market in order to present an appealing ecotourism products and services to diverse customers. Therefore, an improved understanding of how tourists acquire knowledge about a destination and its services is important for marketing management decisions, designing of effective communication campaigns, and efficient service delivery. Consumer pre-purchase information search may be identified as one of the most compelling research fields in consumer behavior. However, scant evidence exists on how information is actually processed, prior to making travel decisions. This proposed model examines the causal relationship among information searching, information processing, destination image, and travel-related search outcomes pertaining to forest-based tourism, using a Structural Equation Modeling approach. The proposed model offers special attention to travelers information processing consequently influencing travel related outcomes. In addition, this study identified four distinct market segments, based on ecotourists utilization of external information sources in visiting forest-based tourism destinations in Sri Lanka: impulsive searchers, active seekers, passive seekers and, provider dependents. In the context of ecotourists actual travel related decisions, such as destination choice, estimated expenses and the length of stay at the destination, study findings suggest that provider dependents, followed by impulsive searchers are the most productive segments for destination marketers. Service providers are the primary source of information for provider dependents, while impulsive searchers tend to acquire travel related information through word of mouth communication.

The Gulf killifish (Fundulus grandis) is a topminnow native to the tidal marshes of the Gulf of Mexico. The species is prized by anglers as effective bait for catching popular sportfish and is of interest to aquaculturists and bait dealers due to its hardy nature. Limited seasonal availability and aquaculture of this species due to low fecundity and larval cannibalism of fry has led to increased incentive to improve cultural techniques. The purpose of this study is to determine the influences of temperature, salinity, and air incubation on embryogenesis of the Gulf killifish. Temperature was found to have a negative relationship with time to hatch and size at hatch when F. grandis eggs were incubated in 10 and 20 g/L saline treatments. Temperature did not significantly affect percent hatch at 10 g/L, but percent hatch displayed a positive relationship with temperature at 20 g/L. When incubated in 0.4, 7, 15, and 30 g/L salinity treatments, a negative relationship between salinity and rate of embryogenesis was detected. While larvae incubated in these salinities hatched at about the same size, reduced hatching percentages were reported in the 0.4 and 30 g/L treatments. A positive relationship between the rate of embryogenesis and temperature was observed in air incubated embryos. After reaching a stage of development when embryos are documented to hatch, temperature was observed to have a negative relationship with the extent of time hatch could be delayed. The results of this study can be used to improve culture practices for Gulf killifish. Larval size at hatch, percent hatch, and time to hatch can now be predicted across a range of temperatures and salinities. Warmer temperatures can be used to accelerate embryogenesis of air incubated embryos while colder temperatures can be used to extend the period of time hatch can be delayed.

Macroinvertebrates are reflective of their nearby environment and are popularly used to detect changes in water quality. In this thesis research, macroinvertebrates were collected to investigate aquatic effects of timber harvesting operations with and without the use of best management practices (BMPs) in a forested, low-gradient, subtropical watershed in central Louisiana. Habitat assessments, physicochemical and hydrologic measurements, and macroinvertebrate sampling were conducted nine times from 2006 to 2010 during the spring and late summer, at 13 site locations ranging from plot level to watershed outlet. Timber harvesting occurred in September of 2007. A total of 86,183 macroinvertebrates were identified from 634 samples and grouped into 31 metrics describing taxonomic and functional feeding groups (FFGs). Timber harvesting, regardless of BMP implementation, negatively affected 14% of the collected macroinvertebrates. Additionally, bivalve taxa and FFG scraper densities increased at all of the sites downstream of harvesting activities in the spring sampling events post-harvest. Macroinvertebrates were further explored with principal component (PC) analysis (PCA), generalized linear mixed models and zero-inflated models to discern their relationships with physical instream and riparian characteristics, and water chemistry parameters representative of the low-gradient, seasonal intermittent headwater streams. PCA composed 19 PCs that explained 81% of the variation within the physical and riparian parameters. Two PCs interpreted as describing stream intermittency helped explain densities in 5 of 19 interpretable metrics that made up over 83% of collected macroinvertebrates. Bivalve, scraper, and collector-filterer metrics were positively associated with PCs describing open canopy and immature or thinned riparian zones. Ephemeroptera, Plecoptera, and Trichoptera (EPT) densities were positively associated with dissolved oxygen (DO), and undercut banks, and negatively associated with higher levels of woody-debris, and nitrite concentrations. Intensively collected DO data suggested that the densities of amphipods, chaoborids, and isopods showed significantly positive relationships with increasing DO. This adds critical knowledge to spatiotemporal dynamics of macroinvertebrate communities in Louisianas low-gradient headwaters and the effectiveness of timber-harvest BMP implementation on stream health protection. The information can be utilized for the development of biological indices to help manage morphologically similar streams in subtropical climates.

The Amazon rainforest is experiencing rapid deforestation due to ranching, agriculture, and urban development, which often leads to remnant patches serving as refugia for forest organisms. By mist-netting passerines in 11 forest fragments (1-, 10-, and 100-ha patches) and nearby continuous forest at the Biological Dynamics of Forest Fragmentation Project near Manaus, Brazil, I conducted a series of studies to identify mechanisms that drive population changes in fragmented landscapes. First, I examined the age structure of bird populations from six ecological guilds in fragments and continuous forest. Immatures are the dispersing age group in birds, and their relative abundance in fragments was often driven by the age of regenerating second growth surrounding fragments. The relative abundance of adults, the resident age group, in fragments was often driven by patch size. Differences in how guilds responded to fragmentation depended on their dispersal propensity, measured with markrecapture techniques, with increasing dispersal propensity corresponding to increased relative abundance of immatures in fragments. Second, I quantified variation in the frequency of molting and breeding simultaneously (called moltbreeding overlap; MBO) among species. I propose that molting and breeding simultaneously requires a consistent or predictable environment, like a humid rainforest understory. Frequent moltbreeding overlap may preclude living in more seasonally fluctuating environments like rainforest fragments. Suboscines, particularly antbirds, had more frequent MBO and were more sensitive to fragmentation than oscine. Finally, I examined the consequences of fragmentation on hostectoparasite dynamics. Feather mites, haematophagous mites, and chewing lice showed similar richness and abundance on hosts that occupied either interior forests or fragment edges. In Thamnophilidae and frugivores, ectoparasite removal caused an increase in body condition, but only for hosts occupying interior forests and not those on fragment edges. Feather mites were beneficial to hosts in interior forest, but became harmful along edges, suggesting that fragmentation can alter delicate hostparasite dynamics in complicated ways. Understanding these relationships may help explain host population declines in fragmented landscapes.

The Mississippi and Atchafalaya rivers are the major sources of freshwater and nutrients to the Gulf of Mexico. Increased nutrient loads from these rivers exacerbate eutrophication in coastal receiving waters and contribute to the large area of hypoxia that develops seasonally in the Gulf. Levees along the Mississippi River have reduced contact between the river and the historic floodplain; this limits the ability of floodplain wetlands to naturally mitigate excess nutrients. However, the Atchafalaya River diverges from the Mississippi 217 km from the Gulf and enters a large river floodplain with a widely spaced levee system. This enhances the ability of the Atchafalaya River Basin to remove and sequester nutrients, potentially reducing downstream eutrophication. Overbank flow spreads river-water and sediment across the floodplain. Over time, sedimentation has filled in many of the open water areas on the floodplain, such that lakes are transitioning to baldcypress swamps and bottomland hardwood forests. These habitats differ in their available nutrient reservoirs and the rates at which they transform and store nutrients. This dissertation investigated the major retention and removal mechanisms for carbon, nitrogen, and phosphorus within bottomland hardwood forests, baldcypress swamps, and lakes of the Atchafalaya River Basin. These reservoirs include denitrification, sedimentation, and assimilation by aboveground biomass. Results estimate that nutrient retention and removal within bottomland hardwood forests ranges from 1,177,6051,561,805 t C yr-1, 46,04947,603 t N yr-1 and 20,04020,175 t P yr-1. Within baldcypress swamps, rates range from 493,953600,180 t C yr-1, 21,82122,364t N yr-1 and 2,1682,202 t P yr-1. Rates in the lakes were 57,490 t C yr-1, 5,1405,390 t N yr-1 and 2,550 t P yr-1. Total retention and removal for the entire basin is on the order of 1,177,6051,561,805 t C yr-1, 46,04947,603 t N yr-1, and 20,04020,175 t P yr-1. Rates varied by habitat, highlighting the need to consider habitat change when developing management strategies to improve water quality. Data from this dissertation can be used to parameterize nutrient models for the Atchafalaya River Basin, as well as for river diversions and floodplains with similar habitat types.

Zooplankters are important members of freshwater communities, facilitating the transfer of energy from primary production to higher trophic levels. Lentic floodplain systems are important in providing zooplankters with adequate habitat for growth and reproduction. Recently, The Nature Conservancy has been interested in cataloguing the aquatic taxa that inhabit the Ouachita River and floodplain in northern Louisiana, concurrent with an attempt to reestablish a river-floodplain connection with the river and eastern floodplain (the Mollicy Farms Unit, part of the Upper Ouachita National Wildlife Refuge). Sampling was conducted at seven sites along the Ouachita River and western floodplain monthly for one year to investigate zooplankton density and composition in relation to environmental variables and hydrology. Principal component analysis was used to illustrate relationships among zooplankton groups with environmental variables and sampling sites, and cladoceran taxa were found to be correlated to specific environmental variables by multivariate analysis of variance. Results indicated that highest densities were exhibited by rotifers, followed by copepods and cladocerans. Abundances of the zooplankton groups were correlated primarily with specific conductance, PO4, temperature, chlorophyll a, Secchi depth, and dissolved oxygen. Additionally, average densities of zooplankton groups were greater at floodplain sites than at sites near or within the river mainstem. During the low water phase, copepods and certain cladoceran taxa were found in greater densities than during the high water phase, indicating a potential concentration effect. These findings will contribute to our understanding of the interactions between environmental parameters and zooplankters within the Ouachita River and floodplain, as well as an overall understanding of zooplankton dynamics in river-floodplain systems.

The influence of sodium hydroxide treatment on the structure of cotton fibers was studied. Compared to raw cotton fibers, the entire bundles of mercerized fibers were converted into a swollen and roughened state. Fourier transform infrared spectrometry (FTIR) indicated that intermolecular hydrogen bonding was enhanced by mercerization treatment. Wide-angle X ray diffraction (WXRD) results showed decreased fiber crystallinity after mercerization. The structure of cellulose II fibers was more thermally stable than cellulose I fibers. Mechanical properties of cotton fiber-reinforced polyethylene oxide (PEO) composites demonstrated that both raw and mercerized cotton fibers enhanced their tensile strength of the PEO matrix, but both made the composites more brittle due to poor fiber dispersion in the PEO matrix. Cotton nano crystals (CNCs) were fabricated from both raw and mercerized cotton fibers by sulfuric acid hydrolysis combined with a high-pressure homogenization technique. Stable aqueous suspensions from both raw and mercerized CNCs were formed. Transmission electron microscopy (TEM) suggested that there was no obvious change in crystal morphology from raw and mercerized cellulose. Dry mercerized crystals had a much larger bulk density than the dry raw crystals. FTIR and WXRD data showed a clear transition from cellulose I (raw) to II (mercerized) cellulose crystal structure. TGA curves showed that cellulose II CNCs had better thermal stability properties. The storage modulus of cellulose II CNC suspensions at all temperatures were obviously larger than those of cellulose I crystal suspensions at the same concentration level. Cellulose II CNC suspensions/gels were shown to be more thermally stable in response to temperature changes. Dilute cellulose II crystal suspensions formed an ordered liquid phase displaying chiral nematic orientation in the direction of the vector director at a much lower concentration level compared with cellulose I crystal suspension. Both cellulose I CNC /PEO and cellulose II CNC/PEO composites showed increased tensile strength and elongation at break compared with these of the pure PEO. However, composites with cellulose II crystals exhibited larger tensile strength, and elongation at break than those from composites with raw crystals due to the enhanced hydrogen bonding. Thus, cellulose II nano crystals provide better reinforcement materials for manufacturing advanced nano-composites.

Compared to other distribution functions, the Weibull distribution has been more widely used in describing diameter distributions because of its flexibility and relative simplicity. Parameters of the Weibull distribution are generally predicted either by the parameter prediction method or by the parameter recovery method. The coefficients of the regression equations for predicting Weibull parameters, moments, or percentiles are often estimated by use of different approaches such as ordinary least squares (OLS), seemingly unrelated regression (SUR) or cumulative distribution function regression (CDFR). However, there is no strong rationale for preferring one method over the other. We developed and evaluated different methods of predicting parameters of Weibull distribution to characterize diameter distribution using data from the Southwide Seed Source Study. The SUR and the CDFR approaches were applied to ten different parameter prediction and parameter recovery methods. A modified CDFR approach was developed by modifying the CDFR technique such that the CDF is computed using information from diameter classes instead of individual trees as in the CDFR approach. These methods were evaluated based on four goodness-of-fit statistics (Anderson-Darling, Kolmogorov-Smirnov, negative Log-Likelihood, and Error Index). The CDFR approach provided better results than the SUR approach for all methods. The Modified CDFR approach consistently provided better results than the SUR approach, and was superior to the CDFR approach in all evaluation statistics but the Anderson-Darling statistic.