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The Potential Impact Of Introduced Commensal Rodents On Island Flora, Gillian Key, Renata Platenberg, Andrew Easby, Kathleen Mais

Vertebrate Pest Conference Proceedings: 17th (1996)

The impact of introduced commensal rodents on island flora has been relatively little studied compared with their impact on the fauna. The effects on vegetation composition, regeneration, and decomposition are largely unknown, but potentially great. Preliminary studies were carried out in the Galapagos Islands between 1993 and 1994 on the diet of introduced rats, Rattus spp. and feral house mice, Mus musculus, seed recovery rates and subsequent germination rates of seeds. R. rattus diet was primarily vegetation and 48% of rats had seeds in their stomachs. Significant differences were found between body size and overall contribution of both …

Mongolian Rangelands: Rodent Problems And Approaches To Alleviate Damage, Dale L. Nolte

Vertebrate Pest Conference Proceedings: 17th (1996)

Rodents are a major constraint to forage production for livestock in Mongolia. A technical program to identify the magnitude of the problem and strengthen the research capabilities of Mongolian rodent specialists was initiated in 1994. The Brandt's vole is the most widespread and the most detrimental rodent to the steppes of Mongolia. Limited resources inhibit activities by the Mongolian Plant Protection Service to reduce rodent populations. Alternative means to monitor vole activity were developed. Laboratory and field trials showed that voles were susceptible to zinc phosphide treatment and indicated how bait acceptance could be improved.

Population Densities And Disease Surveys Of Wild Pigs In The Coast Ranges Of Central And Northern California, Rick A. Sweitzer, Ian A. Gardner, Ben J. Gonzales, Dirk Van Vuren, Walter M. Boyce

Vertebrate Pest Conference Proceedings: 17th (1996)

In 1994 and 1995, 233 different wild pigs were captured during population research at seven research sites focused primarily in the coastal regions of central and northern California. Mark-resight data and information on wild pig movements were used to assess wild pig population densities at those sites. Population densities ranged from 1.01 wild pigs/km² in Mendocino County in 1994 to 3.32 wild pigs/km² in Santa Clara County in 1995. Comparisons of population densities between years at three research sites suggested that wild pig populations increased in 1995 in response to favorable forage conditions after the wet fall and …

Evapotranspiration From A Saltcedar-Dominated Desert Floodplain: A Scaling Approach, S. D. Smith, A. M. Sala, Dale A. Devitt

Life Sciences Faculty Research

The purpose of this study was to investigate evapotranspiration (ET) from a variety of scales (leaf to landscape) in saltcedar-dominated floodplain vegetation along the lower Virgin River of southern Nevada. Leaf-level gas exchange indicated that saltcedar exhibits similar stomatal conductance as the sympatric phreatophytes arrowweed, mesquite, and willow. However, sap flow in saltcedar was higher per unit sapwood area than the other species, suggesting that it maintains higher leaf area per unit sapwood area. At the stand level, saltcedar ET was found to exceed potential ET early in the summer when soils were moist and the water table was near …

Diet And Seasonal Feeding Habits Of The Yellow Stingray, Urolophus Jamaicensis, T. Patrick Quinn

HCNSO Student Theses and Dissertations

Urolophus jamaicensis, the yellow stingray, is a common elasmobranch found on and around the coral reefs off Florida's southeastern coast. Its diet consists of polychaetes, crustaceans, nemerteans, sipunculids, nematodes, and chaetognaths with polychaetes and crustaceans comprising almost 67% of the stomach contents by volume. There does not appear to be any diet preference between the male and females stingrays. The seasonal changes in diet preference are limited to an increase in the proportion of polychaetes found in the stomach during spring when compared to fall.

Top-Down Cascade From A Bitrophic Predator In An Old-Field Community, Matthew D. Moran, Thomas P. Rooney, L. E. Hurd

Biological Sciences Faculty Publications

We tested the hypothesis that a bitrophic (third and fourth level) arthropod predator can exert a cascading, top-down influence on other arthropods and plants in an early successional old field. First-stadium mantids, Tenodera sinensis, were added to replicated open-field plots in numbers corresponding to naturally occurring egg hatch density and allowed to remain for ≈ 2 mo. Sticky-trap dispersal barriers around both control and mantid-addition plots allowed us to monitor emigration of arthropods continuously during the experiment. Biomass of herbivores, carnivores, and plants, and abundances of arthropod taxa within plots were determined at the beginning, middle, and end of …

Ultrastructure Of Cepedietta Virginiensis (Protista: Haptophrynidae), From The Gall Bladder Of The Pickerel Frog, Rana Palustris, In Arkansas, Chris T. Mcallister, Stanley E. Trauth

Journal of the Arkansas Academy of Science

No abstract provided.

Ecology And Community Relationships Of The River Cooter, Pseudemys Concinna In A Southern Illinois Backwater, Michael J. Dreslik

Masters Theses

In Illinois the River cooter, Pseudemys concinna, is an enigmatic endangered species. Even throughout its range, ecological studies on the River cooter are rare. During 1994 and 1995 I quantified the: growth rates and trends, population size and structure and dietary habits of a population from floodplain lake in Gallatin county, Illinois. Population estimation (Schnabel method) predicted 136 individuals at a density of 4.6 turtles/ha with a biomass of 3.6 Kg/ha. The sex ratio is slightly male biased (1:1.14). From back-calculated growth data, the von Bertalanffy growth model (Fabens' method) estimates males with a higher growth rate (k) and …

One-Year Study Of The Species Diversity And Relative Abundance Of Snakes And Lizards In The Jack Mountain Region Of Hot Springs County, Arkansas, Vincent A. Cobb, Jeff A. Summerhill

Journal of the Arkansas Academy of Science

No abstract provided.

Parental Investment In The Red-Eared Slider Turtle, Trachemys Scripta, Michael D. Marlen

Masters Theses

This study was conducted to determine egg and hatchling components of the red-eared slider (Trachemys scripta). In addition, energy components transferred from egg to hatchling were used to determine the level of parental investment in embryogenesis and hatchling care. Eggs of the red-eared slider, collected from central Illinois ponds, were obtained by inducing gravid females to lay by an injection of oxytocin. Egg and hatchling lipids were extracted with petroleum ether while egg and hatchling protein content was determined using the micro-Kjeldahl procedure. Eggs averaged 70.7% water by mass, and dry mass of whole eggs and egg yolks averaged 2.4g …

The Prairie Naturalist Volume 27, No.4 December 1995

The Prairie Naturalist

NEW DISTRIBUTIONAL RECORDS FOR MAMMALS IN KANSAS · D. W Sparks and J. R. Choate

CLAY-COLORED SPARROWS IN NORTH DAKOTA PARASITIZED BY BROWN-HEADED COWBIRDS ▪ G. P. Romig and R. D. Crawford

A NOTEWORTHY RECORD AND THE BREEDING DISTRIBUTION OF THE BLUE GROSBEAK IN NORTH DAKOTA ▪ L. D. Igl

NEAR LONGEVITY RECORD FOR THE SNOW GOOSE ▪ M T. Koenen and D. M. Leslie, Jr.

COMPARISON OF WATER CONSUMPTION BETWEEN TWO GRASSLAND EMBERIZIDS ▪ J. L. Zimmerman

FACTORS ASSOCIATED WITH DECLINING PROPORTION OF CITIZENS HUNTING IN SOUTH DAKOTA ▪ N. J. Dietz, K. F. Higgins, and R. D. Mendelsohn …

Wpa News 49 (1995), World Pheasant Association

Galliformes Specialist Group and Affiliated Societies: Newsletters

WPA News (November 1995), number 49

Published by the World Pheasant Association

Environmental And Edaphic Effects On Western Corn Rootworm (Coleoptera: Chrysomelidae) Overwintering Egg Survival, L. D. Godfrey, Lance J. Meinke, Robert J. Wright, Gary L. Hein

Department of Entomology: Faculty Publications

Western corn rootworm, Diabrotica virgifera virgifera LeConte, overwintering egg survival was studied at 3 soil depths (7.5, 15, and 30 cm), 3 soil textures (silty clay loam, loam, and sandy loam), and 2 surface residue treatments (with and without surface cover) at an eastern Nebraska site in 1989-1990 and 1990-1991. At a western Nebraska site, egg survival was evaluated at 3 soil depths (7.5, 15, and 30 cm), 2 surface residue regimes (with and without surface cover) within a fine sandy loam soil in 1989-1990. Overall, egg survival was low (30.0%) and intermediate (41.0%) at the eastern and western sites, …

Low Temperature Scanning Electron Microscopy Of Clay And Organic Constituents And Their Relevance To Soil Microstructures, C. Chenu, D. Tessier

Scanning Microscopy

Low temperature scanning electron microscopy (LTSEM) is essential for studying the microstructure of small-sized soil constituents such as clays and organic matter. These hydrated and swelling materials naturally undergo drastic changes in water potential and water content in soils. The cryofixation of clays and organic macromolecules by immersion in cryogens and their LTSEM observation are evaluated. The microstructures of clay minerals, polysaccharide macromolecules and their associations, as revealed by LTSEM, contribute to a better understanding of the water retention properties and physical stabilities of these major soil constituents.

Ard News August 1995

Agricultural Research Division: News and Annual Reports

CONTENTS:

COMMENTS FROM THE DEAN
HAZARDOUS MATERIALS TRAINING COURSE
THE CULTURE OF CREDIT
PLANTS AND INTELLECTUAL PROPERTY
IANR INTERDISCIPLINARY RESEARCH GRANTS PROGRAM
UNIVERSITY OF NEBRASKA AGRICULTURAL RESEARCH AND DEVELOPMENT CENTER RESEARCH AND EDUCATION BUILDING SYMPOSIUM/DEDICATION
WIDAMAN TRUST DISTINGUISHED GRADUATE ASSISTANT AWARD
HARDIN DISTINGUISHED GRADUATE FELLOWSHIP FOR 1995-1996
NOMINATIONS SOUGHT FOR JUNIOR FACULTY EXCELLENCE IN RESEARCH AWARD
GRANTS AND CONTRACTS RECEIVED JUNE AND JULY, 1995
NEBRASKA ENVIRONMENTAL TRUST NEWS
PROPOSALS SUBMITTED FOR FEDERAL GRANTS
NEW OR REVISED PROJECTS

The Prairie Naturalist Volume 27, No.2. June 1995

The Prairie Naturalist

WILDLIFE MORTALITY ASSOCIATED WITH OIL PITS IN WYOMING ▪ B.J. Esmoil and S.H. Anderson

DRAMATIC INCREASE OF LE CONTE'S SPARROW IN CONSERVATION RESERVE PROGRAM FIELDS IN THE NORTHERN GREAT PLAINS ▪ LD. Igl and D.H. Johnson

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA - 1994 ▪ R.N. Randall

DESCRIPTIONS OF WALLEYE STOCKS IN HIGH-ELEVATION RESERVOIRS, WYOMING ▪ T.D. Marwitz and W A. Hubert

NEW VASCULAR PLANT RECORDS FOR THE BLACK HILLS OF SOUTH DAKOTA AND WYOMING • G.E. Larson and J.R. Johnson

NOTES

A New Population of Small White Lady's-Slipper (Cypripedium candidum) in South Dakota ▪ S.E. Boettcher

Sandhill …

Wpa News 47 (1995), World Pheasant Association

Galliformes Specialist Group and Affiliated Societies: Newsletters

WPA News (May 1995), number 47

Published by the World Pheasant Association

Plant Community Changes Over 54 Years Within The Great Basin Experimental Range, Manti-La Sal National Forest, Scott C. Walker, David K. Mann, E. Durant Mcarthur

Aspen Bibliography

Plant community changes and natural succession over time impact forage values, watershed quality, wildlife habitat, and ecosystem dynamics. Comparisons were made between a vegetation map of community types completed in 1937 by the U.S. Forest Service, and vegetation maps compiled in 1990 of the same areas by satellite imagery, and through 1991 areal photo interpretation combined with ground truthing. The study area includes nearly all of the drainage in Ephraim Canyon located in central Utah which consists of 6,027 acres (2,439 ha). Elevation ranges from 6,600 to 10,400 feet (2,040 to 3,210 m). Vegetation types ranged from pinyon-juniper woodland through …

Ontogenetic Habitat Shift Of Juvenile Bear Lake Sculpin (Cottus Extensus), James R. Ruzycki

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bear Lake sculpin (Cottus extensus) exhibited an ontogenetic habitat shift during their first year of life. Soon after hatching in the littoral zone, the fry swam to the surface where they dispersed throughout the lake. Most juveniles that initially settled in the profundal zone returned to the littoral zone during their first summer. Patterns in the daily growth increments of otoliths confirmed the history of habitat residence and the individual size at the habitat switch. We used this habitat shift to test a μ/g model incorporating a growth rate-mortality risk trade-off. A trade-off occurred in the littoral …

Classification Of Vegetation And Analysis Of Its Recent Trends At Camp Williams, Utah Using Remote Sensing And Geographic Information System Techniques, Thomas G. Van Niel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Current vegetation classes were generated from remotely sensed data to provide coarse-level information for an ecosystem management plan developed at Camp Williams, Utah. Vegetation trend from 1973 - 1993 was also examined via satellite imagery. The data set consisted of Landsat Multispectral Scanner (MSS) and Thematic Mapper (TM) images from July or August of 1973, 1975, 1980, 1988, and 1993.

Two approaches were used to detect vegetation change. The first approach determined overall and cover type trend from standard digital image differencing of soil-adjusted vegetation index (SAVI) images. The second approach used an unsupervised classification of a composite SAVI image …

Phytoplankton In Mt. St. Helens Lakes, Washington, Cynthia Fay Baker

Dissertations and Theses

Phytoplankton communities in fifteen lakes in the Mt. St. Helens area were surveyed to assess the abundance and species present. Eleven of the lakes were inside the blast zone of the 1980 eruption and four were located outside the blast zone as a comparison. The hypothesis is that lakes will cluster together based on the algal species present and that some algae will be correlated with certain environmental conditions. A cluster analysis was performed to determine if the lakes would group together based on algal abundance. There did not appear to be any distinct clustering among the study lakes, but …

The Challenge And Opportunity Of Recovering Wolf Populations, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

The gray wolf once inhabited a wide variety of habitats throughout most of the northern hemisphere north of 20°N latitude. Because the animal preyed on livestock and competed with humans for wild prey, it was extirpated from much of its range outside of wilderness areas. Environmental awareness in the late 1960s brought for the wolf legal protection, increased research, and favorable media coverage. The species has increased in both Europe and North America, is beginning to reoccupy semiwilderness and agricultural land, and is causing increased damage to livestock. Because of the wolfs high reproductive rate and long dispersal tendencies, the …

The Effects Of Berry Extracts From Phytolacca Americana (Pokeweed) On Seed Germination, Kevin Blake Anderson

Honors Theses

Extracts from the berries of Phytolacca americana (Pokeweed) exhibit the ability to inhibit germination of a variety of seeds, including its own. This inhibition has been shown to be effective even in dilute samples of the extracts. However, it is not known whether the germination inhibition caused by these extracts is induced by physical or by chemical mechanisms. This research proposes that the germination inhibition is induced by chemical inhibitors present within the berries. In an attempt to uncover the chemical agent(s) responsible for the germination inhibition characteristics exhibited by berry extracts of Phytolacca americana (pokeberry extracts), several separation techniques …

Hydrellia Bicarina, N.Sp. (Diptera: Ephydridae), A Leafminer In Southern Watergrass, D. L. Deonier

Insecta Mundi

The species Hydrellia bicarina, n.sp. originally misidentified and described as Hydrellia spinicornis Cresson by Deonier (1971) is redescribed and illustrated. This species was first collectedon and reared from Southern Water Grass Luziola fluitans (Michaux) growing in shallow baytree swamps of southern Mississippi by Deonier (197 1). Based on the male and female genitalia and its natural history, this species is a member of the Hydrellia griseola species group.

Bibliography On Hydrellia Griseola Fallen (Diptera: Ephydridae) And Review Of Its Biology And Pest Status, Louis S. Hesler

Insecta Mundi

A bibliography is presented on Hydrellia griseola (FallBn), a cosmopolitan species of shore fly that is an agricultural pest throughout much of its range. The literature review includes 195 references and spans 180 years: from 1813, when H. griseola was first described (as Notophila griseola), to 1993. My review updates and extends by 110 years a previous review of this species. The host plant associations, bionomics, distribution, pest status, and control of this species are reviewed. The known host plants of larval H.griseola are listed. My survey of the literature supports the hypothesis that H. griseola is increasing its …

Biological Processes: Relationships Between Earthworms And Soil Temperature, Edwin C. Berry, Jerry K. Radke

Journal of the Minnesota Academy of Science

Soil fauna play important roles in many soil processes and conditions which relate to agricultural systems. Earthworms are credited with enhancing soil fertility and soil physical properties by their feeding and burrowing activities. Most research on earthworms has focused on the warmer seasons of the year and relatively little is known about earthworm activity and survival during the portion of the year with frozen soils. Earthworms may survive winter by acclimatization, aestivation, or by burrowing to deeper depths where the soil is not frozen. More research is needed on the fate of earthworms in frozen soils. Suggested research areas include: …

Observations On Extant Populations Of The Softshell Clam, Mya Arenaria Linné, 1758 (Bivalvia: Myidae), From Georgia (Usa) Estuarine Habitats, Erik Rasmussen, Richard W. Heard

Gulf and Caribbean Research

The softshell clam, Mya arenaria Linné, 1758, is reported from Georgia (USA) estuarine habitats based on studies conducted between 1969 and 1972. Observations on Georgia estuarine habitats where extant populations of softshell clams occurred are described. On several occasions, fresh shells with periostracum and tissue remnants were found in a brackish drainage system on Sapelo Island. These shells represent the first southern records of extant populations of softshell clams from such a specialized habitat type. Living specimens of M. arenaria from the benthos and specimens in the stomach contents of stingrays (Dasyatis sabina) were collected at four stations …

The Palmer Lter: A Long-Term Ecological Research Program At Palmer Station, Antarctica, Raymond C. Smith, Karen S. Baker, William R. Fraser, Eileen E. Hofmann, David M. Karl, John M. Klinck, Langdon B. Quetin, Barbara B. Prezelin, Robin M. Ross, Wayne Z. Trivelpiece, Maria Vernet

CCPO Publications

THE ANTARCTIC marine ecosystem-the assemblage of plants, animals, ocean, sea ice, and island components south of the Antarctic Convergence is among the largest readily defined ecosystems on Earth (36 X 106 km2 ) (Hedgpeth, 1977; Petit et al., 1991). This ecosystem is composed of an interconnected system of functionally distinct hydrographic and biogeochemical subdivisions (Treguer and Jacques, 1992) and includes open ocean, frontal regions, shelf-slope waters, sea ice, and marginal ice zones. Oceanic, atmospheric, and biogeochemical processes within this system are thought to be globally significant, have been infrequently studied, and are poorly understood relative to more accessible marine ecosystems …

Getting The Lay Of The Land: Introducing North American Native Grasslands, Anthony Joern, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

The expected catastrophic extinction of species (already under way in many places) will alter the planet’s biological diversity so profoundly that, at the known rate of extinction, it will take millions of years to recover. Yet few ecologists study extinction. Indeed, very little ecology deals with any processes that last more than a few years, involve more than a handful of species, and cover an area of more than a few hectares. The temporal, spatial and organizational scales of most ecological studies are such that one can read entire issues of major journals and see no hint of impending catastrophe. …

Interaction Of Diffuse Competition And Insect Herbivory In Limiting Brittle Prickly Pear Cactus, Opuntia Fragilis (Cactaceae), Jutta C. Burger, Svata M. Louda

Svata M. Louda Publications

We tested the effects of above- and below-ground competition and evaluated insect herbivory on the growth of a common cactus (Opuntia fragilis) in Sandhills prairie. Our purpose was to determine the independent and joint contribution of these factors to the variation observed in cactus size and local abundance. We manipulated ambient prairie vegetation and surface water availability in a full factorial design. When Opuntia fragilis was released from competition with surrounding vegetation, it grew significantly larger in the second growing season, both in terms of number and size of new cladodes. Ramets grown within live prairie vegetation averaged …