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Liana Habitat Associations And Community Structure In A Bornean Lowland Tropical Forest, Saara J. Dewalt, Kalan Ickes, Reuben Nilus, Kyle E. Harms, David F.R.P. Burslem Oct 2006

Liana Habitat Associations And Community Structure In A Bornean Lowland Tropical Forest, Saara J. Dewalt, Kalan Ickes, Reuben Nilus, Kyle E. Harms, David F.R.P. Burslem

Faculty Publications

Lianas (woody vines) contribute substantially to the diversity and structure of most tropical forests, yet little is known about the importance of habitat specialization in maintaining tropical liana diversity and the causes of variation among forests in liana abundance and species composition. We examined habitat associations, species diversity, species composition, and community structure of lianas at Sepilok Forest Reserve, Sabah, Malaysia in northeastern Borneo among three soil types that give rise to three distinct forest types of lowland tropical rain forest: alluvial, sandstone hill, and kerangas (heath) forest. Alluvial soils are more nutrient rich and have higher soil moisture than …


Species-Habitat Associations In A Sri Lankan Dipterocarp Forest, C. V.S. Gunatilleke, I. A.U.N. Gunatilleke, S. Esufali, K. E. Harms, P. M.S. Ashton, D. F.R.P. Burslem, P. S. Ashton Jul 2006

Species-Habitat Associations In A Sri Lankan Dipterocarp Forest, C. V.S. Gunatilleke, I. A.U.N. Gunatilleke, S. Esufali, K. E. Harms, P. M.S. Ashton, D. F.R.P. Burslem, P. S. Ashton

Faculty Publications

Forest structure and species distribution patterns were examined among eight topographically defined habitats for the 205 species with stems ≥ 1 cm dbh inhabiting a 25-ha plot in the Sinharaja rain forest, Sri Lanka. The habitats were steep spurs, less-steep spurs, steep gullies and less-steep gullies, all at either lower or upper elevations. Mean stem density was significantly greater on the upper spurs than in the lower, less-steep gullies. Stem density was also higher on spurs than in gullies within each elevation category and in each upper-elevation habitat than in its corresponding lower-elevation habitat. Basal area varied less among habitats, …


The Epidemiology Of West Nile Virus In Louisiana, Karen Ruth Gruszynski Jan 2006

The Epidemiology Of West Nile Virus In Louisiana, Karen Ruth Gruszynski

LSU Doctoral Dissertations

West Nile virus (WNV), a member of the genus Flavivirus transmitted by mosquitoes, first appeared in the New York in 1999. Within five years WNV was detected throughout the contiguous 48 states causing disease in reservoirs and accidental hosts alike. In Louisiana, WNV was first detected in 2001 with one human case, ten equine cases, and six dead birds reported. The introduction of WNV into Louisiana presented an unique opportunity to observe an emerging disease unfold, so a study was launched to gain insight into the epidemiology of WNV in Louisiana. The first component, an environmental predictive model for West …


Dendrochronological Analysis Of Productivity And Hydrology In Two Louisiana Swamps, John Blake Amos Jan 2006

Dendrochronological Analysis Of Productivity And Hydrology In Two Louisiana Swamps, John Blake Amos

LSU Master's Theses

Modified river flows and land subsidence have subjected many coastal swamp forests in the delta of the Mississippi River to greatly altered flooding, sediment, and nutrient regimes. These areas have become inundated to greater depth, duration, and frequency and either are connected to the river and receive drastically increased sediment and nutrients (riverine swamps) or have become disconnected from riverine flooding (stagnant swamps) and receive little or no sediment and nutrient input. To better understand how these changes are affecting ecosystems, dendrochronological techniques for baldcypress (Taxodium distichum L. Rich.) were used at three sites in each of two contrasting swamps …


Freshwater Mussel Communities Of The Florida Parishes, Louisiana: The Importance Of Spatial Scale, Anne Raynie Bambarger Jan 2006

Freshwater Mussel Communities Of The Florida Parishes, Louisiana: The Importance Of Spatial Scale, Anne Raynie Bambarger

LSU Master's Theses

The Southeastern United States has the most diverse and imperiled freshwater mussel (Unionidae) fauna in the world. The community structure and decline of these organisms is the result of complex interactions between biotic and abiotic factors, but the limited spatial scale of most community studies has failed to elucidate the underlying mechanisms shaping community structure. Basing community assessments solely on microhabitat variables alone has lead to stark contradictions in management recommendations and opposing definitions of habitat requirements for these organisms. However, with the introduction of GIS technology into aquatic management, it is now feasible to include variables from larger spatial …


Modeling The Effects Of Endocrine Disrupting Chemicals On Atlantic Croaker: Understanding Biomarkers And Predicting Population Responses, Cheryl Anne Murphy Jan 2006

Modeling The Effects Of Endocrine Disrupting Chemicals On Atlantic Croaker: Understanding Biomarkers And Predicting Population Responses, Cheryl Anne Murphy

LSU Doctoral Dissertations

A number of environmental stressors have been shown to interfere with reproductive and behavioral processes of fish by interfering with endocrine function. Most biomarkers of endocrine disturbance tend to be static measurements from dynamic systems making them difficult to evaluate within the context of an individual, or subtle effects that do not relate well to endpoints of ecological significance. I present an approach that uses a series of models, based on Atlantic croaker, to extrapolate laboratory results to indicators of individual and population health. First, I created a physiologically based model that simulates vitellogenesis in a female fish. The model …


The Regulation Of Genes Involved In Trichome Development, Matthew Lloyd Brown Jan 2006

The Regulation Of Genes Involved In Trichome Development, Matthew Lloyd Brown

LSU Doctoral Dissertations

Arabidopsis thaliana is an organism that can be used as a model for most of the processes that occur in flowering plants. The leaf hairs, or trichomes, of Arabidopsis thaliana are macroscopic single cells that have been used as a model system for cell fate determination, cell expansion, cell cycle regulation, cell wall deposition, as well as other processes. Initiation of the trichome cell fate is controlled by a complex of genes including GLABRA1 (GL1), TRANSPARENT TESTA GLABRA (TTG), and GLABRA3 (GL3). This work examines the role of GL3 in trichome initiation and uses plants expressing varying levels of GL3 …


Art Informing Science Education: The Potential Contributions Of Ornithological Illustration To Ecology Education, Vanessa Hunt Jan 2006

Art Informing Science Education: The Potential Contributions Of Ornithological Illustration To Ecology Education, Vanessa Hunt

LSU Doctoral Dissertations

Birds serve as an excellent group of organisms from which to introduce the study of ecology, being of inherent aesthetic interest to many otherwise uninterested in science, and are also ubiquitous in the immediate environment of many students. By extension, images of birds might serve as a valuable resource for the ecology educator, and bird artists – as a subset of ecologists - might provide useful models for expertise in ecology. This study examines the potential contributions of bird artists and bird art to education in ecology at the high school and college level. Eight contemporary bird artists were interviewed …


The Relationship Of Crime And Oil Development In The Coastal Regions Of Louisiana, Asha D. Luthra Jan 2006

The Relationship Of Crime And Oil Development In The Coastal Regions Of Louisiana, Asha D. Luthra

LSU Doctoral Dissertations

This project examines the relationship between patterns of crime and the development of the oil and gas extraction industry in the coastal regions of Louisiana. The suggestion of a link between these phenomena has often been made, but little systematic research has been conducted to determine if there is indeed a crime-oil development nexus. Limited previous research has focused primarily on the issue of “boom and bust” cycles on some forms of deviant behavior, but the data and the methods used were inadequate, and thus, the resulting conclusions were often misleading or possibly erroneous. During the course of this project, …


Phenolic Composition And Antioxidant Activity Of Sweetpotatoes [Ipomoea Batatas (L.) Lam], Malkeet Singh Padda Jan 2006

Phenolic Composition And Antioxidant Activity Of Sweetpotatoes [Ipomoea Batatas (L.) Lam], Malkeet Singh Padda

LSU Doctoral Dissertations

The influence of numerous factors on sweetpotato phenolic content and antioxidant activity was determined. Simplified, robust, and rapid methodologies were developed to quantify total phenolics and individual phenolic acids in sweetpotatoes. Quantification of total phenolic content using Folin-Denis reagent provided more reliable results than Folin-Ciocalteu reagent. Individual phenolic acids were quantified by reversed-phase high performance liquid chromatography (HPLC) and the best separation was achieved using a 5-µm, 4.6 × 250 mm column with a mobile phase of 1% (v/v) formic acid aqueous solution: acetonitrile: 2-propanol (70:22:8), pH 2.5. Methanol and ethanol provided higher phenolic extraction efficiency than acetone. In general, …


Historical Fire Regimes In Southeasern Pine Savannas, Jean Marie Huffman Jan 2006

Historical Fire Regimes In Southeasern Pine Savannas, Jean Marie Huffman

LSU Doctoral Dissertations

Southeastern coastal plain pine savannas lack direct evidence of past fire regimes. As a result, uncertainty exists regarding the range of variation in frequency and seasonal timing of past fire regimes and the relative importance of anthropogenic and lightning-ignited fires. Characterization of past fire regimes is needed for effective restoration and management of these high-biodiversity ecosystems. I used dendrochronologically dated fire scars from stumps of old growth longleaf pines in a large coastal, mainland pine savanna and from dead slash pines on a small, coastal barrier island in north Florida to explore past fire regimes. In the mainland savanna, 71 …


Uncovering Bacterial Diversity On And Below The Surface Of A Hyper-Arid Environment, The Atacama Desert, Chile, Danielle Rene Bagaley Jan 2006

Uncovering Bacterial Diversity On And Below The Surface Of A Hyper-Arid Environment, The Atacama Desert, Chile, Danielle Rene Bagaley

LSU Master's Theses

The Atacama Desert in Chile extends from latitudes 17º S to 28º S between longitudes 69º W and 71º W. It has been reported that surface soils in the hyper-arid region contain low numbers of culturable heterotrophic bacteria. These soils are considered Mars-like and offer an ideal setting to investigate the application of life detection systems. Thirty-three surface sites were sampled to examine further the extent of the hyper-arid region. We also excavated four soil pits, 40 cm to 90 cm in depth, to explore subsurface microbial communities. One pit was dug in a southern region of the desert compared …