Life Sciences Commons^™

The Effects Of Drought And Shade On Bottomland Hardwood Regeneration, Charles Joseph Pell

LSU Doctoral Dissertations

Floodplain forests support a high diversity of tree species adapted to regenerate under fluctuating water and light availability. Regeneration regulates species composition, and shade and flood tolerance influence the likelihood of regeneration. Regeneration failure of shade-intolerant and flood-tolerant tree species commonly occurs in southcentral and southeastern floodplain forests of the United States, also known as bottomland hardwoods (BLHs). In many BLHs reduced flooding has resulted in a dryer floodplain. These changes in flooding are linked to recent shifts in species composition. The mechanisms controlling regeneration in BLHs and these composition shifts are poorly understood. In a controlled germination experiment, I …

Willingness Of Non-Industrial Private Forest Landowners To Obtain A Private Versus Public Consultation, Erika Largacha

LSU Master's Theses

Promoting conservation practices among family forests landowners play a critical role to enhance forest health and ecosystem services. Several certification programs recognize such efforts, but participation among landowners varies based on their characteristics, program requirements, and incentives. One crucial step of certification is to obtain a forest management plan, but acquisition among landowners remains extremely low. Several studies suggest connecting landowners with foresters as the key element towards the adoption of forest management plans. Because foresters are typically employed by public forestry agencies or as private self-employed consultants, landowners' willingness to work with either may differ. As far as we …

Degumming Of Hemp Fibers Using Combined Microwave Energy And Deep Eutectic Solvent, Bulbul Ahmed

LSU Master's Theses

Hemp is considered as one of the sustainable agricultural fiber materials. Degumming or surface modification of hemp bast is needed to produce single fibers for ensuing textile and industrial applications. The traditional degumming process necessitates a high amount of alkali, which causes detrimental environmental pollution. This study offers a new method to degum hemp fibers with reduced use of harmful alkali and precious water resources. In this work, hemp bast fibers were degummed by using combined microwave energy and deep eutectic solvent (DES). The properties of hemp fibers manufactured by this method were investigated and compared with the traditional alkali …

Environmental Perception In Colombia's Páramo Protected Areas, Juliana Delgado

LSU Master's Theses

This thesis analyzes the gap between farmers' environmental perceptions in Téquita, a small village in Colombia, and the definition of protected areas has led to a conflict for the use of natural resources. I examine if the protected area's policies have dealt with the social and ecological issues in the páramos and recognized the social construction of the landscape, farmers' identities, and their interpretations about work and land. The case study focuses on Güina High Mountain in the Guantiva-La Rusia páramo complex, which recently the Colombian government declared as a protected area. In light of anthropologist Tim Ingold's meaning of …

Innovation And Competitiveness Of The Wood Furniture Industry In Kenya, Gilbert Osoro Ototo

LSU Doctoral Dissertations

The wood furniture industry in Kenya has been growing rapidly despite a decline in domestic timber supply. Although most furniture is made locally, a larger share is increasingly being imported from other countries, creating competition for domestic manufacturers. The government aims at shifting most of the demand to domestic producers to protect the sector and create jobs. However, lack of innovation has been cited as the main cause of diminishing competitiveness of the sector. Studies have shown that innovation plays a key role in creating new products, improving production processes, and establishing better business systems.

Innovation in the furniture sector …

Floodplain Forest Regeneration Dynamics In The Lower Mississippi River Alluvial Valley, Whitney Anne Kroschel

LSU Doctoral Dissertations

Floodplain forest species diversity is driven, in part, by variation in disturbance regime. Flood patterns create heterogeneity in microsite quality from small differences in elevation across a floodplain which, in turn, influence flood timing and duration. Differences in species’ regeneration niches in relation to hydrologic patterns can account for long-term coexistence of various species. In the past century floodplain forests have exhibited a wide range of changes in stand development and species composition as a result of altered hydrology in rivers and floodplains. I evaluated the role of regeneration in floodplain forest systems of the Lower Mississippi River Alluvial Valley …

Coastal Taxodium Distichum Growth Responses To Marine Influences And Stand Density, Stephanie Moothart

LSU Master's Theses

Ecological processes controlling transition areas of coastal wetlands between marshes (not forested) and swamps (forested) are poorly understood, despite important ecosystem services provided and strong interest in managing for ecosystem structure and function. The objective of this work was to identify how soil chemistry and stand density control individual-tree growth of the important coastal species baldcypress (Taxodium distichum (L.) Rich.) and pondcypress (Taxodium distichum var. imbricarium (Nutt.) Croom) along a coastal salinity gradient. Tree cores, soil samples, and stand density measurements were collected for sixty cypress trees at the coastal Joyce Wildlife Management Area, Louisiana, which is a …

Making Decision Adaptive To Price Uncertainty And Risk Preference: A New Decision-Making Model For Forest Management, Fan Zhang

LSU Doctoral Dissertations

While the forest grows, the price of timber fluctuates. Price uncertainty plays a key role in forestry due to the extended rotation length of growing trees. Like double sides of the same coin, risk preference and uncertainties should be considered together. This is because risk preference represents people’s attitude toward that uncertainty when making management decisions. Risk preference is especially an important issue for forest management because forests are exposed to substantial uncertainties during their long growing period. However, most existing relevant studies either simply overlook the risk preference issue or fail to consider it together with a practical forest …

Cogongrass (Imperata Cylindrica (L.) Beauv.) In Louisiana: Cause And Consequence, Lorissa A. Radunzel-Davis

LSU Master's Theses

Cogongrass (Imperata cylindrica (L.) Beauv.), an invasive species from East Asia, is found worldwide and is problematic in several countries. In the United States, it grows primarily in the Southeast, reducing biodiversity by growing in dense patches and potentially causing mortality and reducing value of native and planted pinelands due to a high burning temperature. Using Lee Memorial Forest, a Louisiana State University AgCenter property in Washington Parish as a study site, this thesis explores cogongrass in Louisiana with emphasis on soil microbes and soil legacy effects on native plant species. Cogongrass populations at Lee Memorial Forest were more …

Matrix Recharge In A Shrink-Swell Floodplain Forest Soil, Savannah R. Morales

LSU Master's Theses

Despite the global distribution of fine-grained Vertisols, the hydrology of these floodplain soils is still not well understood. Vertisols shrink and swell depending on soil moisture leading to a range of soil pore sizes, from large macropore cracks to smaller micropores, and consequently a range of hydraulic conductivities. Despite the plethora of research indicating the importance of both flooding and soil moisture in floodplain ecosystems, the specific role that flooding plays in soil moisture recharge has been less widely studied and remains of interest. Blue food dye and deuterated water were used as tracers to determine the role of the …

Changing Land-Use From Pinus Elliottii To Eucalyptus Bentamii In Southwest Louisiana Affects Understory Vegetation Richness, Diversity, And Functional Diversity Patterns, Andrea De Stefano

LSU Doctoral Dissertations

In the Western Gulf region of the United States cold-tolerant eucalyptus have been explored as pulpwood feedstock. However, non-native plantations may alter understory species diversity, modifying environmental conditions and soil characteristics. Few studies have compared eucalyptus plantations with other ecosystems to understand the impacts of converting these land uses on understory vegetation in the United States. Three plantations were selected: (1) slash pine (Pinus elliottii) established in 2008, (2) slash pine established in 2013, and (3) and Camden white gum (Eucalyptus benthamii) established in 2013. The objectives of this study were to: (1) investigate potential changes …

Bio-Based Polyurethane Foams Made From Microwave Liquefaction Of Biomass, Xingyan Huang

LSU Doctoral Dissertations

Polyurethane (PU) foam is one of the most versatile construction insulations due to its low density, low thermal conductivity, and high mechanical performance. However, it is still highly dependent on petro-based chemicals, i.e. polyol and isocyanate. In this work, biomass, such as rape straw, switchgrass, and yaupon holly (Ilex vomitoria) were liquefied using microwave energy to produce bio-based polyol in order to substitute petro-based polyol in the production of PU foam. Cellulose nanocrystals (CNCs) were also extracted from liquefaction solid residue. They were then applied to reinforce high bio-content PU foam. Moreover, lignin was fractionated from bio-polyol by …

Baldcypress And Black Willow Growth Response To Contrasting Flood Regimes, Climate, And Competition, In The Atchafalaya Basin, Louisiana, Alicia Louise Mcalhaney

LSU Master's Theses

Wetlands are dynamic ecosystems distinguished by their dependence on fluctuations of hydrologic influence. Although it is generally accepted that that flooding is a strong influence on growth, and that effects vary depending on whether water is stagnant or flowing, several aspects of flood characteristics and several tree species remain poorly investigated. One source of variability that has not been investigated is how flooding, climate, and competition among trees interact to control growth of individual trees. The objective of this study was therefore to 1) investigate effects of temporally varying hydrology and climate on growth of baldcypress and black willow trees …

Dynamics Of Resprouting And Forest Regeneration Following Anthropogenic Land Use In The Central Amazon Basin, Scott Lawrence Kosiba

LSU Doctoral Dissertations

Tree mortality is increasing with the effects of climate change and drought across the Amazon Basin while intense fires are becoming more prevalent. Tropical moist forest trees generally lack adaptations that protect against mortality during an intense fire, so anthropogenic burning typically kills high percentages of trees. Following disturbances where prescribed burning is used to limit woody encroachment and to fertilize the soil, abandoned land in central Amazonia becomes dominated by the pioneer tree genus, Vismia. Although the mechanisms by which Vismia comes to dominate previously-burned areas are not known, previous studies on anthropogenic land use and forest succession …

The Breeding Ecology Of White-Faced Ibis In The Lower Carson River Basin, Nevada, Eric Patrick Kelchlin

LSU Historical Dissertations and Theses

The Great Basin White-faced Ibis (Plegadis chihi) population is recognized as a Species of Management because of its small population size, limited number of traditional breeding sites, and vulnerability to habitat loss. The ability to predict future population trends and develop wetland management strategies is limited because many aspects of their breeding ecology and population dynamics are unknown. 1 examined White-faced Ibis nesting ecology and breeding habitat selection at the Lower Carson River Basin, Nevada, from 1995-1997, and the relationship between the local surface water conditions and trends in the number of breeding pairs from 1970-1997 on a local and …

Response Of The Fruittree Leafroller (Archips Argyrospila) To Salt Tolerant, Baldcypress (Taxodium Distichum) Seedlings, Rachel A. Rollason

Honors Theses

No abstract provided.