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Effects Of White-Tailed Deer Herbivory On The Growth And Survival Of Seedlings In A Coastal Wetland Forest, Seth Taylor Bordelon

LSU Master's Theses

Studies in upland forests of the northeastern and upper mid-western U.S. indicate that high densities of white-tailed deer can reduce vegetation abundance, survival, and richness through over-browsing. In the southern U.S., few studies have examined the effects of deer herbivory on vegetation, and even fewer have done so in forested wetlands. At Jean Lafitte National Park's Barataria Preserve in south Louisiana, managers were concerned that white-tailed deer were concentrating and limiting forest regeneration near a walking trail, where hunting is not allowed. An exclosure study was started there in December 2002 and was conducted through July 2004 to quantify the …

Rich Mesic Forests: Edaphic And Physiographic Drivers Of Community Variation In Western Massachusetts, J. Bellemare, G. Motzkin, D. R. Foster

Biological Sciences: Faculty Publications

Rich Mesic Forest, a Northeastern variant of the species-rich Mixed Mesophytic Forest association of eastern North America, is an Acer saccharum-dominated forest type typically associated with calcareous bedrock and nutrient-rich, mull soils. Rich Mesic Forest (RMF) is a priority for conservation in the Northeast due to its limited areal extent, high plant species richness, and numerous rare taxa, yet the community characteristics and environmental correlates of this forest type are incompletely understood. This study undertook a quantitative classification of RMF of the northeastern edge of the Berkshire Plateau in western Massachusetts. Cluster analysis of data from ten sites identified two …

Response Of Sagebrush Steppe Species To Elevated Co2 And Soil Temperature, Melissa S. Lucash, Blake Farnsworth, William E. Winner

Environmental Science and Management Faculty Publications and Presentations

Elevated atmospheric CO₂ may cause long-term changes in the productivity and species composition of the sagebrush steppe. Few studies, however, have evaluated the effects of increased CO₂ on growth and physiology of species important to this ecosystem. Since the response of plants to elevated CO₂ may be limited by environmental factors, soil temperature was also examined to determine if low soil temperatures limit CO₂ response. To determine how CO₂ and soil temperature affect the growth of species native to the sagebrush steppe, bottlebrush squirreltail [Elymus elymoides (Raf.) Swezey], Thurber needlegrass (Stipa thurberiana Piper), …

Temporal Variation In Nutrient Uptake Capacity By Intact Roots Of Mature Loblolly Pine, Melissa S. Lucash, J. Devereux Joslin, Ruth D. Yanai

Environmental Science and Management Faculty Publications and Presentations

Nutrient uptake is generally thought to exhibit a simple seasonal pattern, but few studies have measured temporal variation of nutrient uptake capacity in mature trees. We measured net uptake capacity of K, NH+ 4, NO 3 −, Mg and Ca across a range of solution concentrations by roots of mature loblolly pine at Calhoun Experimental Forest in October 2001, July 2001, and April 2002. Uptake capacity was generally lowest in July; rates in October were similar to those in April. Across a range of concentrations, antecedent nutrient solution concentrations affected the temporal patterns in uptake in July but not in …

Protecting Biodiversity: A Guide To Criteria Used By Global Conservation Organizations, Elizabeth A. Gordon, Oscar E. Franco, Mary L. Tyrrell

Yale School of the Environment Publications Series

No abstract provided.

Identification Of 'Structural Alerts' And Associated Mechanisms Of Action Of Mammary Gland Carcinogens In Female Rodents, Shanna Tommika Moss

LSU Master's Theses

A new structure-activity relationship (SAR) approach to modeling was utilized to study mammary gland carcinogens. A set of chemicals tested for mammary tumorigenesis that have been analyzed in the Carcinogenic Potency Database (CPDB) were subjected to several computational analyses in an attempt to predict each chemical’s carcinogenic potential. A total of six learning sets (rat and mouse mammary gland carcinogen, CPDB rat and mouse, and female-specific rodent models) were developed and validated using a SAR modeling algorithm called categorical-SAR (cat-SAR). The predictive cat-SAR program evaluates active and inactive compounds of known biological activity and predicts their biological activity from this …

Identifying Asphalt Construction As A Point Source Emitter Of Volatile Organic Compounds Near The Louisiana State University Ozone Monitoring Station, Sean Jason Kice

LSU Master's Theses

The EPA has classified Baton Rouge as a non-attainment area for ozone pollution for many years. Since then Photochemical Assessment Monitoring Stations (PAMS) and other ozone monitoring stations around the metropolitan area have monitored for ozone, NOx, and more than 50 volatile organic compounds (VOCs) which are considered precursors to ozone pollution. Traditionally, automobile engines and industrial plants and refineries have been blamed as major point sources for VOC emissions and the ozone pollution they cause. This research focuses on another possible point source for failing ozone levels at one of the ozone monitoring stations located on the campus of …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: Rappahannock River (1985-2003), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below. In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: James River (1985-2003), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below.

In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Do Predator Exclusion, Position, And Plant Architecture Influence Hydrilla-Dwelling Macroinvertebrate Communities?, Jonathan C. Fisher

LSU Master's Theses

Hydrilla verticillata invaded south central Louisiana during the 1970s subsequently becoming the dominant submerged macrophyte in floodplain habitats of the Atchafalaya River Basin. The effects of hydrilla on littoral habitat structure, water quality, fish, and macroinvertebrates have been pervasive, and I hypothesized that dense hydrilla stands would also impact vertebrate predation on resident macroinvertebrates, although predation effects would likely be mediated by bed position. During 2003 and 2004, I conducted exclosure experiments in the Atchafalaya River Basin with artificial substrates to test for variations in hydrilla bed macroinvertebrate communities caused by predation, plant architecture, and bed position. To determine invertebrates …

Environmental Factors Influencing Incubation Constancy And Recess Frequency In Gadwall (Anas Strepera) In The Prairie Pothole Region Of North Dakota, Nicole F. Lorenz

LSU Master's Theses

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 …

Environmental Benefits Realized From Eradication Of The Non-Indigenous Insect Anthonomus Grandis Boheman, The Cotton Boll Weevil, Marc Stephen Bordelon

LSU Master's Theses

At least one third of the insecticide used in agriculture has been used to control the boll weevil in cotton. Historically, these insecticides have been toxic to humans and harsh on the environment. In addition, the intensive use of chemical insecticides to control the boll weevil results in the disruption of naturally occurring biological control factors that regulate other insect pest populations causing a chain reaction of secondary pest populations that require treatment followed by resurgence and repeat treatment. This situation has resulted in the development of resistance to insecticides, high control costs and unacceptable levels of chemical insecticide contamination …

Influences On The Establishment Of County Wildfire Risk Mitigation: The Case Of California's Fire Safe Councils, Timothy Richard Soileau

LSU Master's Theses

In response to increased annual wildfire destruction and insufficient wildfire mitigation approaches from the federal government, the state of California adopted Public Resources Code Sections 4290 and 4291 in the year 1991. These laws force the removal of fire-causing agents from public and private areas, and establish what is known as defensible space. Defensible space is defined in Section 4291 as the area within the perimeter of a parcel, development, neighborhood, or community where basic wildland fire protection practices and measures are implemented, providing the key point of defense from an approaching wildfire or escaping structure fire. One method to …

Detection And Evaluation Of Temperature Effects On Cell Proliferation In Somatic Tissues Of The Eastern Oyster, Crassostrea Virginica, By Flow Cytometry, Fernando Jimenez

LSU Master's Theses

The goal of this thesis was to evaluate temperature effects on cell proliferation of eastern oyster somatic tissues for the development of an oyster cell line. Understanding the in vivo cell proliferation of an organism is essential for the development of cell culture. Cell proliferation can be measured by identifying nuclear cellular proteins involved in growth regulation and cellular transformation. The primary objectives of this study were to: 1) develop an assay to evaluate cell proliferation, 2) develop an assay to analyze nuclear RNA content, and 3) evaluate temperature effects on cell proliferation in somatic tissues. Proliferating cell nuclear antigen …

Effect Of Estradiol-17b On The Gonadal Developemnt Of Diploid And Triploid Female Eastern Oysters, Roberto Quintana

LSU Master's Theses

Declines in annual oyster landings and problems associated with seasonal reduction of oyster meat yields have increased interest for development of techniques to produce oysters with enhanced growth characteristics. Research interest has been focused on developing improved lines by induction of polyploidy. The goal of the present study was to evaluate the enhancement of gonadal development of triploid oysters, by the use of the hormone estradiol 17-â (E2) to produce viable eggs for the development of tetraploid broodstocks. Previous studies with the Pacific oyster, Crassostrea gigas, have shown: (1) the need to use the larger eggs of triploid females to …

A Bioeconomic Supply Model For Louisiana Nutria And Impacts On Wetlands Conservation Associated With Economic Incentives, Cheikhna Ould Dedah

LSU Master's Theses

Nutria (Mayocastor) were first introduced to Louisiana in 1938. With few natural predators and high prolific productivity, they became well established in the surrounding coastal marsh within a few years. Prior to 1980’s, as a result of high demand for nutria products from European countries, harvest pressure was sufficient to keep the population in ‘check’ with their wetlands capacity. By the mid-1980’s, however, prices had fallen sharply, culminating in declining annual harvests and an increasing population. Because of their feeding habits, the increased nutria population has resulted in a substantial amount of wetland degradation. In this thesis, a long-run bioeconomic …

Evaluation Of A Novel Method Of Predicting Estrogen Activity Of A Group Of Structurally Diverse Compounds, Daniel Consoer

LSU Master's Theses

The number of environmental chemicals found to have some level of endocrine activity has led to concern about the possible effects these compounds could have on human health and the health of other species, populations, and possibly whole ecosystems. The United States Environmental Protection Agency has been charged with testing a large number of these compounds, called endocrine-disrupting chemicals or hormonally active agents for hormonal activity. Limited testing resources have led to a call for alternate methods of screening, possibly for use in prioritizing this list to assist in efficient allocation of resources for further testing. This study describes a …

Designation Of The Southwest National Wildlife Refuge Complex As Wetlands Of International Importance Under Ramsar, Convention On Wetlands Of International Importance, Mitchell Ward Coffman

LSU Master's Theses

The historical loss and continued threat of loss of Louisiana wetlands is a major environmental concern for the United States and the world. In 1971, the Ramsar Convention, an international environmental treaty was ratified to specifically address conservation planning and land use management issues involving wetlands of the world. Ramsar provides an international designation award called, the Wetlands of International Importance List, which formally acknowledges globally important wetland landscapes. Ramsar outlines specific criterion nominated wetland sites must possess for consideration of this listing.

The Southwest Louisiana National Wildlife Refuge Complex is an excellent candidate for nomination to the Ramsar Convention …

Macroinvertebrate Community Of Ecology Of Lowland, Subtropical Streams In Louisiana, Michael Douglas Kaller

LSU Doctoral Dissertations

Freshwater ecosystems, particularly streams and rivers, have been the subject of prodigious research. Unfortunately, in comparison to neighboring regions, the Gulf of Mexico coastal plain has not received as much attention. Therefore, I collected data on the macroinvertebrates of these streams to begin the understanding of the relationships between community structure and environmental characteristics. In contrast to the hypothesized ancestral streams of these macroinvertebrates, coastal plain streams are commonly devoid of rocks leaving only woody debris as usable hard substrates and are typically lower in dissolved oxygen. I examined habitat selection by colonization of woody debris with large and small …

Long-Term Freshwater Input And Sediment Load From Three Tributaries To Lake Pontchartrain, Louisiana, Kangsheng Wu

LSU Doctoral Dissertations

Lake Pontchartrain and the drainage basin have experienced environmental degradation because of human settlement, land use and climate changes. A thorough understanding of hydrologic trends and variability associated with the changes is critical for sustainable water resources management and ecosystem restoration in the region. This study examined freshwater inflow (1940-2002) and suspended solids loadings (1978-2001) from three upper Lake Pontchartrain watersheds that contribute to the lake estuary: the Amite, Tickfaw, and Tangipahoa river watersheds. The relationships of freshwater inflow and suspended solids loadings with climate variables and population growth were investigated. Using observed daily discharge, a spatially-distributed hydrologic model (SWAT) …

Winter Bird Use Of The Chinese Tallow Tree In Louisiana, Michael John Baldwin

LSU Master's Theses

Chinese tallow (Triadica sebifera) is a non-native invasive tree that is of particular concern in the Southeastern United States. It has become naturalized in a variety of habitats and can be found in monospecific stands. The use of tallow woodlands by overwintering birds is poorly documented. I compared use of tallow woodlands to use of bottomland hardwood forests by birds in the Mermentau River Basin, Louisiana. Species richness and evenness were greater in the bottomland hardwood sites. Three species were more abundant in tallow woodlands, six species were more common in bottomland hardwoods, and six species exhibited no difference between …

Temporal And Spatial Harvest Patterns Of River Otter In Louisiana And Its Potential Use As A Bioindicator Species Of Water Quality, Daniel Gustavo Scognamillo

LSU Doctoral Dissertations

Louisiana is the leading state in number of river otters used in reintroduction programs in other states and in the production of pelts. However, habitat loss and degradation have prompted concern about the status of otter populations. This dissertation undertakes a spatial and temporal analysis of river otter harvest activity and examines environmental factors related to monitoring mercury levels in streams in Louisiana. Harvest data for 1957-2004 were analyzed to identify spatial and temporal trends in otter harvest activity. Changes have occurred in the last 20 years in the spatial dynamics of otter harvest in Louisiana, these include an increasing …

Effects Of Body Size On Goose Behavior: Lesser Snow Goose And Ross's Goose, Jon Einar Jonsson

LSU Doctoral Dissertations

Body size is highly variable among geese, both at intra- and interspecific levels. Interspecific variation in several behaviors has been attributed to differences in body size in geese: incubation constancy, tendency to maintain family units, and time spent foraging. Body size has important physiological implications for birds, mostly because mass-specific metabolic rate is greater for birds of smaller mass. The Body-size Hypothesis predicts that smaller species deplete their energy reserves at relatively faster rates than do larger species. Hypotheses and conclusions concerning effects of body size on waterfowl behavior often are based on comparisons of species that confront different climates, …

Comparative Studies Of Sperm Cryopreservation Of Diploid And Tetraploid Pacific Oysters, Qiaoxiang Dong

LSU Doctoral Dissertations

This dissertation addressed comparative studies of sperm cryopreservation of diploid and tetraploid Pacific oysters, Crassostrea gigas, with an emphasis on the development of standardized and optimized protocols. This includes comparative ultrastructural differences between sperm from diploid and tetraploid oysters, methods for the rapid estimation of sperm concentration, optimization of cryopreservation, and evaluation of the mechanisms for sperm agglutination (formation of clumps or elongated "noodles") in thawed samples. Currently, cryopreserved sperm has not been commercialized in any aquatic species, and standardization and optimization could greatly benefit the potential commercialization of its use. In oysters specifically, cryopreserved sperm from tetraploids would facilitate …

Riding Out The Risks: An Ethnographic Study Of Risk Perceptions In A South Louisiana Bayou Community, Susan Camille Manning

LSU Master's Theses

This ethnographic study explores the risk perceptions of a small unincorporated coastal community in southeastern Louisiana. This community has experienced social and environmental change due to events including tropical storms and hurricanes, erosion, subsidence, oil and gas activities, development, and the impact of global seafood markets. Many global risk perception studies have focused on the perception of risk to human health and property connected with natural and technological disasters, but few have explored the issue of minorities and small at-risk communities. To explore this theoretical and methodological gap, this study uses a variety of qualitative ethnographic methods to examine a …

Nitrate Reductase Activity In Macroalgae And Its Vertical Distribution In Macroalgal Epiphytes Of Seagrasses, Erica Young, Paul Lavery, Beverley Van Elven, Mat Dring, John A Berges

Research outputs pre 2011

Macroalgal epiphytes within seagrass meadows make a significant contribution to total primary production by assimilating water column N and transferring organic N to sediments. Assimilation of NO3 – requires nitrate reductase (NR, EC 1.6.6.1); NR activity represents the capacity for NO3 – assimilation. An optimised in vitro assay for determining NR activity in algal extracts was applied to a wide range of macroalgae and detected NR activity in all 22 species tested with activity 2 to 290 nmolNO3 – min–1 g–1 frozen thallus. With liquid-N2 freezing immediately after sample collection, this method was practical for estimating NR activity in field …

The Use Of Culmen Length To Determine Sex Of The American White Pelican, Brian S. Dorr, D. Tommy King, Patrick Gerard, Marilyn G. Spalding

United States Department of Agriculture Wildlife Services: Staff Publications

Culmnen length has been suggested as being diagnostic for sex in the American White Pelicans (Pelecanus erythrorhynchos). However, the literature on the use of culmen length to determine sex is inconsistent, with reported overlap in culmen lengths for males and females ranging from 1 mm to >120 mm. Morphological measurements from 188 American White Pelicans collected in Mississippi and Louisiana whose sex was determined by dissection and gonadal inspection were measured. The use of culmen length alone was used to determine gender for this sample by establishing the minimum obsewed culmen length for males and the maximum observed …

Evaluation Of Cocoa- And Coffee-Derived Methylxanthines As Toxicants For The Control Of Pest Coyotes, John J. Johnston

United States Department of Agriculture Wildlife Services: Staff Publications

Methylxanthines were quantified in coffee, tea, and chocolate products. Tarajuilie tea from India, cocoa powder, and cocoa nibs contained the highest levels of methylxanthines. Theobromine, caffeine, and theophylline combined in the ratios observed in tea and chocolate were ingested by coyotes. Although both mixtures induced acute toxicity, the symptoms accompanying the chocolate methylxanthine mimic were preferable. Manipulation of the ratios of methylxanthines in the chocolate mimic led to the identification of a 5:1 theobromine/caffeine mixture as a promising coyote toxicant. This mixture was then administered to coyotes using the coyote lure operative device (CLOD). Mortality occurred in every coyote that …

Avian Use Of Commercial Sunflower And Grain Crops Compared To Usda Wildlife Conservation Sunflower Plots In North Dakota., Heath M. Hagy, George M. Linz, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

North Dakota and South Dakota produce about 70% of the sunflower grown in the United States. Blackbird depredation, particularly in the Prairie Pothole Region (PPR), can be a major problem that results in some producers abandoning sunflower. Reduced acreage of an otherwise profitable crop is important economically and might harm migratory bird populations relying on the shrub-like habitat in sunflower fields for food and cover. In 2004 in an effort to reduce blackbird damage, USDA Wildlife Services provided funds to growers to plant Wildlife Conservation Sunflower Plots (WCSP). Growers were instructed to plant 8-ha units of oilseed sunflower near shelterbelts …

Epizootiology Of Sin Nombre And El Moro Canyon Hantaviruses, Southeastern Colorado, 1995–2000, Charles H. Calisher, J. Jeffrey Root, James N. Mills, Joan E. Rowe, Serena A. Reeder, Emily S. Jentes, Kent Wagoner, Barry J. Beaty

United States Department of Agriculture Wildlife Services: Staff Publications

Sin Nombre virus (SNV) is an etiologic agent of hantavirus pulmonary syndrome. To better understand the natural history of this virus we studied population dynamics and temporal pattern of infection of its rodent hosts in southeastern Colorado (USA) from 1995 to 2000. We present evidence for the presence of two hantaviruses, SNV in deer mice (Peromyscus maniculatus) and El Moro Canyon virus in western harvest mice (Reithrodontomys megalotis), at our study sites. Sin Nombre virus appeared only sporadically in deer mouse populations; overall prevalence of antibody to SNV was 2.6%. El Moro Canyon virus was enzootic: …