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LSU Historical Dissertations and Theses

Ecology

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Spatial Variability And Isotopic Studies Of The Prairie -Forest Transition Soil In Louisiana., Asfaw Bekele Jan 2001

Spatial Variability And Isotopic Studies Of The Prairie -Forest Transition Soil In Louisiana., Asfaw Bekele

LSU Historical Dissertations and Theses

The calcareous prairies of Louisiana are among the most endangered ecosystems in North America. The major threat to this ecosystem is the invasion by woody and herbaceous plants, primarily eastern red cedar (Juniperus virginiana ). The restoration and management of these rare plant communities require a thorough understanding of the soils supporting them. Geostatistical, fractal, and stable isotopic procedures were integrated to study the soil and vegetation spatial variability. The prairie soil was alkaline, the forest soil was acidic, and the transition soil was neutral. The spherical model described the spatial variability of virtually all the soil properties considered with …


American Alligator Nesting Ecology In Impounded Marsh Habitat, Louisiana., Steven Richard Reagan Jan 2000

American Alligator Nesting Ecology In Impounded Marsh Habitat, Louisiana., Steven Richard Reagan

LSU Historical Dissertations and Theses

The goal was to monitor a large number of female alligators over a 3-year period to obtain information on alligator nesting ecology. This dissertation, although designed to estimate annual nesting rates, provides additional meaningful information on methods of capture, tag retention rates, nest spacing patterns, segregation of size classes, nest site fidelity, the relationship between attendance and nest success, the effects of fire ants on alligator nest success, the relationship between hatchling alligators and their mother, and hatchling dispersal. Passive integrated transponder (PIT), monel web, and cranial mounted reflector tags were evaluated for marking and identifying alligators. Use of harmonic …


Airbirds: Adaptative Strategies To The Aerial Lifestyle From A Life History Perspective., Manuel Marin-Aspillaga Jan 1998

Airbirds: Adaptative Strategies To The Aerial Lifestyle From A Life History Perspective., Manuel Marin-Aspillaga

LSU Historical Dissertations and Theses

"Airbirds" are defined as those birds that are adapted to almost constant life on the wing and do not perch, except for breeding and roosting. They use the air as the only medium in which to find and gather food. One taxon meets that definition: the swifts (Apodidae). Foraging zones of airbirds can be segregated in terms of clutch size, commuting foraging distance, nestling period, and nestling feeding rate. This study looked at foraging behavior and nestling diet, incubation patterns and mode of development in cypseloidine swifts, that as a group has extreme life history patterns. In a temperate one-egg …


A Search For Biologically Active Phytochemicals From Endemic Plants Of The Southeastern United States., Steven Lynn Robbs Jan 1997

A Search For Biologically Active Phytochemicals From Endemic Plants Of The Southeastern United States., Steven Lynn Robbs

LSU Historical Dissertations and Theses

In an investigation of allelopathy in the Florida scrub, bioassays with terpenes were performed against: Lactuca sativa, Rudbeckia hirta, Leptochloa dubia and Schizachyrium scoparium. Cineole was phytotoxic against Rudbeckia at 17 ppm and Lactuca at 165 ppm. (S)-camphor was phytotoxic to Rudbeckia at 1 ppm, Lactuca at 28 ppm, and Leptochloa and Schizachyrium at 134 ppm. (R)-Camphor, myrtenol and myrtenal were phytotoxic against Rudbeckia at concentrations of 28, 25 and 15 ppm respectively. Farnesol stimulated the germination of Schizachyrium at concentrations up to 50 ppm and at 100 ppm it reduced the radicle length of all test species. Geraniol stimulated …


Ecological Studies Of Velvetbean Caterpillar, Anticarsia Gemmatalis Hubner, Pupae In Louisiana Soybean Fields., Joon-Ho Lee Jan 1989

Ecological Studies Of Velvetbean Caterpillar, Anticarsia Gemmatalis Hubner, Pupae In Louisiana Soybean Fields., Joon-Ho Lee

LSU Historical Dissertations and Theses

The microhabitat distribution of velvetbean caterpillar (VBC), Anticarsia gemmatalis Hubner (Lepidoptera: Noctuidae) was studied in soybean field cages and fields during 1985, 1986 and 1987. Larval density did not affect pupal horizontal distribution patterns related to direction and distance from the plant row. Pupae were found equally on both sides of soybean plant rows in a cage study. Pupae were found on and below the soil surface, but not on the plant. In 51 cm row spacing, both equal number and similar dispersion pattern of pupae were found on either side of the plant row. In 91 cm row spacing, …


The Legacy Of The Hawaiian Cultivator In Windward Valleys Of Hawaii. (Volumes I And Ii)., Ronald Norman Terry Jan 1988

The Legacy Of The Hawaiian Cultivator In Windward Valleys Of Hawaii. (Volumes I And Ii)., Ronald Norman Terry

LSU Historical Dissertations and Theses

The composition of a forest of relicts of cultivation in four uninhabited valleys in Kohala, Hawaii, is documented. A general hypothesis is made that arboreal distribution patterns are a function of both historical land use and ecological interaction since abandonment. The physical and historical geography of the valleys was investigated. Climate varies little, but distinct geomorphic zones offer differing biological environments. Prehistoric land use consisted of taro patches with intercropped banks. Talus slope gardens supported the Polynesian tree crops 'ohi'a 'ai (Eugenia malaccensis), kukui (Aleurites moluccana), 'ulu, (Artocarpus incisus), ti (Cordyline terminalis), and noni (Morinda citrifolia), important in today's flora. …


The Population Ecology And Nutrient Transport Of Gulf Menhaden In Fourleague Bay, Louisiana (Mortality, Growth, Feeding, Production, Migration)., Linda Ann Deegan Jan 1985

The Population Ecology And Nutrient Transport Of Gulf Menhaden In Fourleague Bay, Louisiana (Mortality, Growth, Feeding, Production, Migration)., Linda Ann Deegan

LSU Historical Dissertations and Theses

An ecological study of the young-of-the-year of three year-classes of gulf menhaden (Brevoortia patronus) was conducted from July 1981 to December 1983 in Fourleague Bay, Louisiana. This study documented gulf menhaden population ecology and the importance of gulf menhaden in the nutrient and energy balance of estuaries. Young-of-the-year gulf menhaden immigrated in winter and moved to tidal creeks and ponds, where they remained until midsummer. They then moved into open bays, where they remained until the fall. This migration pattern coincides with sequentially available, but spatially separate, productivity peaks in marsh and open bays. In the fall, they emigrated to …