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Full-Text Articles in Physical Sciences and Mathematics

Benthic Diatom Community Dynamics In The Colorado River: Interactive Effects Of Periodic Dessication And Current Regime, Christopher Gerard Peterson Dec 1984

Benthic Diatom Community Dynamics In The Colorado River: Interactive Effects Of Periodic Dessication And Current Regime, Christopher Gerard Peterson

Publications (WR)

The response to periodic desiccation of periphyton communities developed in eddy environments or in areas exposed to variable, direct current was examined. Algal communities were incubated on clay tiles for between 2 and 12 weeks in the Colorado River, directly below Hoover Dam from October, 1983 - January, 1984. Mean daily discharge from the dam decreased over this period. To assess the influence of these discharge changes on community dynamics, samples collected over the first 12 weeks of the investigation were compared to samples of the same age collected over the final 8 weeks.

The small diatom taxon Achnahthes spp …


The Prairie Naturalist Volume 16, No. 4. December 1984 Dec 1984

The Prairie Naturalist Volume 16, No. 4. December 1984

The Prairie Naturalist

Paul B. Kannowski, Editor

Nikki R. Seabloom, Assistant Editor

Douglas H. Johnson, Book Review Editor

TABLE OF CONTENTS

VEGETATION PATTERNS IN RELATION TO TOPOGRAPHY AND EDAPHIC VARIATIONS IN NEBRASKA SAND HILLS PRAIRIE ▪ P. W. Barnes, A. T. Harrison and S. P. Heinisch

GREAT BLUE HERON NESTING BIOLOGY ON THE JAMES RIVER IN SOUTH DAKOTA ▪ E. M. Dowd and L. D. Flake

OVENBIRDS AT THE PERIPHERY OF THEIR RANGE IN WESTERN NORTH DAKOTA ▪ R. B. Hopkins

BREEDING BIRD COMMUNITY COLONIZATION OF SOWN STANDS OF NATIVE GRASSES IN NORTH DAKOTA ▪ K. F. Higgins, T. W. Arnold and R. …


A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson Nov 1984

A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson

Publications (WR)

Several limnological studies have been conducted in Lake Mead during the past decade. The recent studies clearly show that most of Lake Mead is deficient in nutrients, especially phosphorus, and very low in productivity. The reservoir-wide average total phosphorus concentration for 1981 - 1982 was only 9 mg/m3. This is below levels found In most oligotrophic lakes and reservoirs. Algal biomass, as measured by chlorophyll-a, averaged only 1.5 mg/m3. That also places Lake Mead in the oligotrophic range. Transparency, as measured by a Secchi disc, averaged 9-5 m in Lake Mead during 1981-1982. That far exceeds …


The Prairie Naturalist Volume 16, No. 3. September 1984 Sep 1984

The Prairie Naturalist Volume 16, No. 3. September 1984

The Prairie Naturalist

Paul B. Kannowski, Editor

Nikki R. Seabloom, Assistant Editor

Douglas H. Johnson, Book Review Editor

TABLE OF CONTENTS

GRASSLAND HABITAT MANAGEMENT USING PRESCRIBED BURNING IN WIND CAVE NATIONAL PARK, SOUTH DAKOTA ▪ J. D. Forde, N. F. Sloan and D. A. Shown

BODY TEMPERATURES AND BEHAVIORAL ACTIVITIES OF HIBERNATING

PRAIRIE RATTLESNAKES, Crotalus viridis, IN ARTIFICIAL DENS ▪ K. R. Marion and O. J. Sexton

NEW VASCULAR PLANT RECORDS FOR NORTH DAKOTA ▪ D. T. Disrud, W. T. Barker and R. H. Warner

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA - 1983 ▪ R. N. Randall

COMPARISON OF PLANKTON POPULATIONS IN THREE …


The Prairie Naturalist Volume 16, No. 2. June 1984 Jun 1984

The Prairie Naturalist Volume 16, No. 2. June 1984

The Prairie Naturalist

Paul B. Kannowski, Editor

Nikki R. Sea bloom , Assistant Editor

Douglas H. Johnson, Book Review Editor

TABLE OF CONTENTS

AUTUMN WEIGHTS OF PLAINS SHARP-TAILED GROUSE IN MONTANA ▪ J. E. Swenson and R. L. Eng

VEGETATION PROFILE AND GRASSLAND BIRD RESPONSE TO SPRING BURNING ▪ G. E. Huber and A. A. Steuter

WETLAND PRESERVATION CONFLICTS IN NORTH DAKOTA: ECONOMIC INCENTIVES AND LANDOWNER ATTITUDES ▪ R. D. Saylor, R. A. Stromstad and M. E. Winger

COLLEMBOLA OF SOUTHWESTERN NORTH DAKOTA: SPECIES COMPOSITION AND HABITAT DISTRIBUTION ▪ B. L. Benner and P. B. Kannowski

NEW RECORDS OF EARTHWORMS FROM KANSAS (Oligochaeta: …


Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde May 1984

Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde

Publications (WR)

Zooplankton samples collected from throughout Lake Mead, in 1981-1982, demonstrate the presence of a statistically significant seasonal and spatial heterogeneity in zooplankton densities. Seasonally, the major zooplankton groups were most abundant in the spring and fall, coincident with maxima in chlorophyll-a concentrations. Successions among the various rotifers, cladocerans and copepods present in the reservoir were influenced by food availability, diapause, predation by planktivorous fish and, possibly, water temperatures.

Spatial heterogeneity in zooplankton densities was unrelated to water temperature, pH, conductivity and dissolved oxygen concentrations, but was related to the abundance of phytoplankton (chlorophyll-a concentrations) and fish. Statistical analyses indicate that …


The Role Of Nannoplankton In The Phytoplankton Dynamics Of Four Colorado River Reservoirs (Lakes Powell, Mead, Mohave, And Havasu), Jeffrey John Janik May 1984

The Role Of Nannoplankton In The Phytoplankton Dynamics Of Four Colorado River Reservoirs (Lakes Powell, Mead, Mohave, And Havasu), Jeffrey John Janik

Publications (WR)

Phytoplankton species composition and community size structure were studied in four warm-monomictic Colorado River reservoirs; lakes Powell, Mead, Mohave, and Havasu from March 1981 to February 1982. Sampling was done at approximately monthly intervals from several stations in each reservoir. The Utermohl technique was used to enumerate phytoplankton. The phytoplankton assemblage was divided into the following six size classes using microscopic techniques; netplankton (>64 um), and nannoplankton (>5, 5-11, 12-21, 22-44, and 45-64 um).

Total phytoplankton biomass and community size structure were different among these four reservoirs with considerable spatial and temporal variation present. Average reservoir-wide areal weighted …


The Prairie Naturalist Volume 16, No. 1. March 1984 Mar 1984

The Prairie Naturalist Volume 16, No. 1. March 1984

The Prairie Naturalist

Paul B. Kannowski, Editor

Nikki R. Seabloom, Assistant Editor

Douglas H. Johnson, Book Review Editor

TABLE OF CONTENTS

MORTALITY OF RACCOONS IN NORTH DAKOTA ▪ E. K. Fritzell and R. J. Greenwood

THE EFFECTS OF MOWING ON THE RODENT COMMUNITY OF A NATIVE TALL GRASS PRAIRIE IN EASTERN NEBRASKA ▪ C. A. Lemen and M. K. Clausen

PARASITES OF FISH FROM THE JAMES AND SHEYENNE RIVERS, JAMESTOWN RESERVOIR COMPLEX, AND LAKE ASHTABULA IN NORTH DAKOTA ▪ M. D. Forstie and H. L. Holloway

LEAD POISONING OF SANDHILL CRANES (Grus canadensis) ▪ R. M. Windingstad, S. M. Kerr, and …


Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency Feb 1984

Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency

Publications (WR)

At the request of the U.S. Bureau of Reclamation, Boulder City, Nevada, the U.S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory at Las Vegas collected multispectral scanner imagery of Las Vegas Wash on October 1, 1982.

A combined maximum likelihood classification and editing procedure was used to classify the multispectral scanner imagery into 12 categories of land cover. The classification identified four categories of marsh vegetation, one category of riparian, two categories of mixed scrub, and two desert categories. Turbid water and cultivated land formed an "other" category. Area tabulations were formed by georeferencing the classification to the Universal Transverse …


Factors Affecting Reproductive Success Of Bonytail Chubs And Razorback Suckers In Lake Mohave, Michael A. Bozek, Larry J. Paulson, James E. Deacon, U.S. Department Of Interior, Fish And Wildlife Service Jan 1984

Factors Affecting Reproductive Success Of Bonytail Chubs And Razorback Suckers In Lake Mohave, Michael A. Bozek, Larry J. Paulson, James E. Deacon, U.S. Department Of Interior, Fish And Wildlife Service

Publications (WR)

Razorback suckers (Xyrauchen texanus) and bonytail chubs (Gila elegans) were once widespread throughout the Colorado River system. The ranges and populations of these native species and others have declined in the past 50 years. Bonytail chubs appear to be extremely rare and possibly nearing extinction in the Upper Colorado River Basin. The razorback sucker is widely distributed in the upper river but is considered rare throughout most of that range and is also rare in the Grand Canyon. Razorback suckers are abundant only in a few habitats in the upper river. They congregate and spawn over …


Las Vegas Wash Advanced Water Quality Study: Final Report, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation Jan 1984

Las Vegas Wash Advanced Water Quality Study: Final Report, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation

Publications (WR)

The purpose of the Las Vegas Wash Advanced Water Quality Study is to determine the existence, extent, and mechanisms of nutrient and toxin stripping in Las Vegas Wash under present conditions and under future conditions, both with and without construction of the proposed salinity control unit as described by the Bureau of Reclamation (USBR, 1982b). This study was performed for the Lower Colorado Region Division of Planning by personnel of the Environmental Sciences Section of the Division of Research and Laboratory Services, E&R Center, Denver, Colorado. Work on the study began in February 1983.

The general approach adopted for this …


Breeding Birds In Cedar Stands In The Great Dismal Swamp, Karen A. Terwilliger, Robert K. Rose Jan 1984

Breeding Birds In Cedar Stands In The Great Dismal Swamp, Karen A. Terwilliger, Robert K. Rose

Biological Sciences Faculty Publications

The Great Dismal Swamp located in the coastal plain on the Virginia- North Carolina border, has long been recognized as a vegetationally distinctive region with many unusual geological and biological features. Formerly at least twice the currently estimated size of 85,000 hectares (Carter 1979), the Great Dismal Swamp is still shrinking because of a dropping water table caused by more than 200 years of logging, ditching, and other human activities. In 1973, the Union Camp Corporation donated a 19,871-hectare tract located near Suffolk, Virginia. to The Nature Conservancy, which transferred the land to the U.S. Fish and Wildlife Service. This …