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Articles 3781 - 3810 of 3961

Full-Text Articles in Ecology and Evolutionary Biology

Is Nature Our Birthright?, Nancy Heneson Jan 1981

Is Nature Our Birthright?, Nancy Heneson

Ecology Collection

It is of course impossible to escape the notion of self-interest in our relationship with nature. In fact, it is "unnatural," if one understands (and, one is forced to say nowadays, believes in) evolution. However, there is no real justification for either disguising this as stewardship or perverting it into dominionism. Every organism has an impact on the environment, and it is not only idealistic but biologically nonsensical to argue that we should leave everything alone. However, when decisions on policy are made which direct the future use of land, plants and animals, at least let the rationale not be …


Die Erforschung Der Herpetofauna Der Mongolischen Volksrepublik: Situation Und Perspektiven, Günther Peters Jan 1981

Die Erforschung Der Herpetofauna Der Mongolischen Volksrepublik: Situation Und Perspektiven, Günther Peters

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

First paragraph:

Die Landschaften der Mongolei sind arm an Reptilien- und Amphibienarten. Dieser Umstand mag die Frage aufwerfen, ob herpetologische Untersuchungen in Beschränkung auf das Territorium der MVR eine nennenswerte Perspektive haben könnten, nachdem Artenspektrum und Verbteitung der Species annähernd vollständig erkundet sind. Ein Herpetologe wird zweifellos für seine Arbeit auch in diesem Land eine Zukunft sehen, doch muß wohl von vornherein eingestanden werden, daß das Volumen der Probleme dieses Faches hinter denen der übrigen Disziplinen der Vertebratenzoologie und der Entomologie in einem bescheidenerem Rahmen verbleibt. Dies gilt sowohl im rein wissenschaftlichen als erst recht auch im angewandten Bereich ihrer …


Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson Dec 1980

Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson

Publications (WR)

This manual contains detailed descriptions of biological, chemical and physical sampling and analytical procedures used at the Lake Mead Limnological Research Center. The manual was prepared in response to requests made by numerous individuals involved in the Las Vegas Valley Water Quality Program. This manual represents what we consider to be a reasonably complete compilation of methods useful in studying both general and specific limnological questions. While each section is sufficiently detailed to be of use to investigators with little experience in limnological methodology, the methods can be used on a wide variety of lakes and reservoirs, with relatively little …


The Prairie Naturalist Volume 12, Numbers 3 And 4. September–December 1980 Oct 1980

The Prairie Naturalist Volume 12, Numbers 3 And 4. September–December 1980

The Prairie Naturalist

THE FLORA AND SANDHILLS PRAIRIE COMMUNITIES OF ARAPAHO PRAIRIE, ARTHUR COUNTY, NEBRASKA ▪ K. H. Keeler, A. T. Harrison and L. S. Vescio

USE OF ULTRASONIC SOUND TO ESTIMATE BODY FAT DEPOTS IN THE MALLARD ▪ G. A. Baldassarre, R. J. Whyte and E. G. Bolen

NORTHERN MOCKINGBIRD BREEDING IN NORTH DAKOTA ▪ D. Child, J. Fontaine, T. Gatz, M. Johnson and J. Oswald

SPRING ARRIVAL OF BIRDS AT WOODWORTH, NORTH DAKOTA ▪ K. F. Higgins, L. M. Kirsch, and J. M. Callow

HYBRIDIZATION AND TAXONOMIC STATUS OF GREATER PRAIRIE CHICKENS AND SHARP-TAILED GROUSE (HYBRIDIZATION IN GROUSE) ▪ D. W. …


Litter Production And Nutrient Content Of Litter In The Seasonally Flooded Dismal Swamp, Marta M. Gomez Oct 1980

Litter Production And Nutrient Content Of Litter In The Seasonally Flooded Dismal Swamp, Marta M. Gomez

Biological Sciences Theses & Dissertations

Litter production was studied in four plant communities in the Great Dismal Swamp, Virginia, that differ primarily in species composition and flooding regime. Greatest leaf deposition occurred in the more flooded communities, maple-gum (Acer-Nyssa) with 536 g m-2 yr-1 and cypress (Taxodium distichum (L.) Richard) with 528 g m-2 yr-1, followed by the cedar (Chamaecyparis thyoides (L.) BSP) and mixed hardwood (Quercus-Acer-Nyssa-Liquidambar) communities with 506 g m-2 yr-1 and 455 g m-2 yr-1, respectively. Litter nutrient concentrations were generally higher in the cypress and maple-gum stands, indicating greater nutrient availability …


The Prairie Naturalist Volume 12, Number 2. June 1980 Jun 1980

The Prairie Naturalist Volume 12, Number 2. June 1980

The Prairie Naturalist

COMPOSITION OF BEAVER CACHES ON THE TONGUE RIVER IN MONTANA ▪ J. E. Swenson and S. J. Knapp

GRAY PARTRIDGE WINTER MOVEMENTS AND HABITAT USE IN NORTH DAKOTA ▪ J. W. Schulz

ANNOTATED CHECKLIST OF MAMMALS OF NEBRASKA ▪ J. K. Jones, Jr. and J. R. Choate

OBSERVATIONS OF SEVERAL ARCTIC GULLS IN NORTH DAKOTA ▪ C. A. Faanes and T. A. Gatz

WINTER FOOD HABITS OF NEBRASKA BOBCATS (Felis rufus) C. J Mahan

NOTE

The Meadow Jumping Mouse in Southeastern Montana ▪ W. L. Matthews


Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson Jun 1980

Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson

Publications (WR)

Density currents are commonly formed in reservoirs because of temperature or salinity induced density differences between inflowing and receiving waters. Anderson and Pritchard (1951) were among the first to demonstrate this in their investigations of density currents in Lake Mead. They found that the Colorado River formed an underflow in Lake Mead during the winter, an overflow in the spring and an interflow in the summer and fall. Wunderlich and Elder (1973) have since described the hydromechanics of these types of flow patterns, and density currents have been reported for several other large reservoirs (Carmack et al. 1979, Johnson and …


Nutrient Interactions Among Reservoirs On The Colorado River, Larry J. Paulson, John R. Baker Jun 1980

Nutrient Interactions Among Reservoirs On The Colorado River, Larry J. Paulson, John R. Baker

Publications (WR)

Interactions among physical, chemical and biological processes in reservoirs can significantly alter the characteristics of the discharge (Neel 1963, Wright 1967, Hannan 1979) that, in turn, can influence the ecology of the river downstream .(Ward and Stanford 1979). Investigations of the Colorado River, system reveal that reservoir-induced changes in the river can also affect downstream reservoirs. The formation of Lake Powell, in 1963 was accompanied by reductions in suspended sediment and nutrient loading and changes in the seasonal temperature and discharge cycles of the Colorado River. In this paper, we evaluate how these changes have influenced the nutrient and trophic …


Production Of Mountain Whitefish (Prosopium Williamsoni) In Altered And Unaltered Reaches Of Two Intermountain Streams In Their Alluvial Flood Plains, Michael J. Ottenbacher May 1980

Production Of Mountain Whitefish (Prosopium Williamsoni) In Altered And Unaltered Reaches Of Two Intermountain Streams In Their Alluvial Flood Plains, Michael J. Ottenbacher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Estimates of production and related parameters (growth rate, density, standing crop) were made for populations of mountain whitefish in altered and "unaltered" areas of the Blacksmith Fork and Logan River, Utah from spring 1975 through summer 1976. Capture records of marked whitefish were also analyzed to describe fish movement and check on assumptions implicit in the population estimator.

Mean weights and instantaneous growth rates of whitefish were similar at all sites for comparable size/age groups. Among sites, differences in production per sampling interval and annual production were due mainly to differences in standing crop and/or age structure.

Estimates of mountain …


Resource Partitioning In Breeding Populations Of Marsh Hawks And Short-Eared Owls, Susan C. Linner May 1980

Resource Partitioning In Breeding Populations Of Marsh Hawks And Short-Eared Owls, Susan C. Linner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During the 1979 breeding season four pairs of northern harriers, or marsh hawks (Circus cyaneus) and four pairs of short-eared owls (Asio flammeus) were studied in Cache Valley, Utah. The study was concerned solely with diurnal resource utilization, and did not examine the owls' nocturnal activities. The home range of each harrier pair overlapped substantially with that of an owl pair. Percent habitat overlap for hawk-owl pairs varied from 39 percent to 72 percent. Observations were made to determine if differences existed in their utilization of habitat and food resources, or in their daily and seasonal …


Effects Of Host Plant Patch Size And Surrounding Plant Type On Insect Population Dynamics, Lynn A. Maguire May 1980

Effects Of Host Plant Patch Size And Surrounding Plant Type On Insect Population Dynamics, Lynn A. Maguire

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of the present study was to investigate how plant spatial patterns and insect behavior interact to influence the population dynamics of insects using the plants. The study included three phases: l) field experiments using collards (Brassica oleracea) and the crucifer insect fauna; 2) simulation models representing the population dynamics of an insect herbivore as functions of insect dispersal behavior and host plant patch size; and 3) model-field syntheses integrating model predictions and field variability estimates to choose an appropriate spatial scale for future field experiments or applications.

In field experiments on surrounding plant type, collards were …


Macrobenthic Communities Of An Industrialized Seaport Ecosystem: The Southern Branch Of The Elizabeth River, Virginia, Steven D. Hawthorne Apr 1980

Macrobenthic Communities Of An Industrialized Seaport Ecosystem: The Southern Branch Of The Elizabeth River, Virginia, Steven D. Hawthorne

Biological Sciences Theses & Dissertations

Macrobenthic invertebrates of an industrialized seaport ecosystem were studied seasonally from October, 1977 through July, 1978. Five stations were selected along the Southern Branch of the Elizabeth River, Virginia. The stations ranged from an area of heavy industrialization to a non-urbanized environment. At each station, bottom water was measured for salinity, temperature, dissolved oxygen, and pH. Within each sampling area, macrobenthic infauna! invertebrates were collected from in and out of channel sites along with sediment samples for various types of physicochemical analysis.

Community structure was spatially homogeneous at station sites and throughout the stations along the River. Slightly acidic pH …


Mountain Beaver Problems In The Forests Of California, Oregon And Washington, John E. Borrecco, Robert J. Anderson Mar 1980

Mountain Beaver Problems In The Forests Of California, Oregon And Washington, John E. Borrecco, Robert J. Anderson

Vertebrate Pest Conference Proceedings: 9th (1980)

Mountain beavers (Aplodontia rufa) cause considerable damage to forest trees in the Pacific Northwest. Feeding injuries result in mortality, growth losses, deformity of trees, and understocked plantations. Losses are most severe in new plantations with significant damage problems also occurring in sapling stands. Trapping, and placing physical barriers around individual trees, are the most common methods of control. Both methods are costly but effective in reducing damage.


The Prairie Naturalist Volume 12, Number 1. March, 1980 Mar 1980

The Prairie Naturalist Volume 12, Number 1. March, 1980

The Prairie Naturalist

RESIDUAL SEEDS AS POTENTIAL SPRING WATERFOWL FOODS IN SMALL, MAN-MADE IMPOUNDMENTS ▪ G. A. Baldassarre

NOTES ON THE NATURAL HISTORY OF BATS FROM BADLANDS NATIONAL MONUMENT, SOUTH DAKOTA ▪ J. P. Farney and J. K. Jones, Jr.

PRAIRIE CHICKEN DOMINATED SHARP-TAILED GROUSE INTERACTION ▪ R. A. Schmidt

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA— 1979 ▪ R. N. Randall

THIRD NESTING OF CATTLE EGRET IN NORTH DAKOTA ▪ R. A. Schmidt

FIRST BREEDING RECORDS OF THE WHITE-FACED IBIS IN NORTH DAKOTA ▪ R. A. Schmidt

NOTES

Pinon Jay in North Dakota ▪ R. N Randall, J. Swanick and O. Swanick

Gray-crowned …


Evaluation Of Impacts Associated With Reregulation Of Water Levels In Lake Mohave, Larry J. Paulson, John R. Baker, U.S. Water And Power Resources Service Mar 1980

Evaluation Of Impacts Associated With Reregulation Of Water Levels In Lake Mohave, Larry J. Paulson, John R. Baker, U.S. Water And Power Resources Service

Publications (WR)

The U.S. Water and Power Resources Service is considering reregulating Lake Mohave water levels to increase the net power benefit from Hoover Dam. Reregulation will not increase the generation capacity of the Hoover powerplant but it will enable the plant operation to be increased when the energy has greater monetary value. Energy generated at different times of the year has different market value, the highest being in January-March and July- September. By generating more power during these periods more net monetary benefit can be derived from Hoover Dam. The total volume of water released from Hoover Dam over an annual …


Botanical And Ecological Aspects Of Coastal Raised Peatlands In Maine : And Their Relevance To The Critical Areas Program Of The State Planning Office, Ian A. Worley Jan 1980

Botanical And Ecological Aspects Of Coastal Raised Peatlands In Maine : And Their Relevance To The Critical Areas Program Of The State Planning Office, Ian A. Worley

Maine Collection

Botanical and Ecological Aspects of Coastal Raised Peatlands in Maine : and Their Relevance to the Critical Areas Program of the State Planning Office.

by Ian A. Worley

A Report Prepared for the Maine Critical Areas Program, State Planning Office, 184 State Street, Augusta, Maine 04333.

Planning Report No. 69 (January 1980)

Contents: Foreword / Abstract / Table of Contents / List of Figures / List of Tables / Acknowledgements / Introduction / Natural History and Ecology of the Coastal Raised Peatlands / Selection of Coastal Peatlands Recommended for Evaluation by the Critical Areas Program / General Evaluation of Coastal …


A Limnological Study Of 43 Selected Maine Lakes, Derrill J. Cowing, Matthew Scott Jan 1980

A Limnological Study Of 43 Selected Maine Lakes, Derrill J. Cowing, Matthew Scott

Maine Collection

A Limnological Study of 43 Selected Maine Lakes

by Derrill J. Cowing and Matthew Scott

U.S. Geological Survey : Water-Resources Investigations 80-69

Prepared in cooperation with the Maine Department of Environmental Protection

U.S. Geological Survey, 26 Ganneston Drive, August, Maine 04330


Repopulation Of Fishes In Riley Creek, Coles County, Illinois Following Nitrogen Fertilizer Pollution, Kim James Carney Jan 1980

Repopulation Of Fishes In Riley Creek, Coles County, Illinois Following Nitrogen Fertilizer Pollution, Kim James Carney

Masters Theses

The repopulation of stream fishes was studied from 17 May 1979 to 25 October 1979 following a major kill (100% mortality) caused by nitrogen fertilizer pollution in Riley Creek, Coles County, Illinois. The extent of recovery was determined by comparing post-kill collections with pre-kill survey data that was collected on 25 October 1978.

Repopulation began six days after the abatement of the pollution source. It is suggested that the initial source of repopulation was from the nearest undamaged tributary. The first three reinhabitants in order of appearence were: stonerollers (Campostoma anomalum); creek chubs (Semotilus atromaculatus); and …


A Guide To The Threatened And Endangered Vascular Plants Of The Lake Mead National Recreation Area, James S. Holland, Wesley E. Niles, Charles L. Douglas, Dennis R. Schramm Jan 1980

A Guide To The Threatened And Endangered Vascular Plants Of The Lake Mead National Recreation Area, James S. Holland, Wesley E. Niles, Charles L. Douglas, Dennis R. Schramm

Publications (WR)

This illustrated guide was prepared to provide the botanical community, land managers, and other interested persons with a reference that describes and locates the twelve plant taxa currently being considered by the Fish and Wildlife Service for threatened or endangered status in or around the Lake Mead National Recreation Area. The guide is intended to assist managers of government agencies in determining the presence of these species and in defining management programs for their protection. The guide should be consulted prior to any construction project. If a potential conflict is identified, an onsite evaluation should be conducted early in the …


Influence Of Dredging And High Discharge On The Ecology Of Black Canyon, Larry J. Paulson, Theron G. Miller, John R. Baker, U.S. Water And Power Resources Service Jan 1980

Influence Of Dredging And High Discharge On The Ecology Of Black Canyon, Larry J. Paulson, Theron G. Miller, John R. Baker, U.S. Water And Power Resources Service

Publications (WR)

The Water and Power Resources Service is considering dredging in Black Canyon to create a larger forebay to accommodate higher peak discharges and reverse flows for proposed modifications to Hoover Dam. The Black Canyon area from Hoover Dam to Willow Beach supports a heavily utilized trout fishery and is important habitat for the razorback sucker (Xyrauchen texanus) and possibly bonytail chub (Gila elegans). The Water and Power Resources Service initiated this investigation to determine what effect dredging and higher peak-discharges would have on the ecology of Black Canyon.


Nebraska Trapping, George Schildman, Frank Andelt, Jim Brunner Jan 1980

Nebraska Trapping, George Schildman, Frank Andelt, Jim Brunner

Nebraska Game and Parks Commission: Publications

Fur bearers and trapping played an important role in the exploration and development of Nebraska. The harvest of our fur-bearer resource is part of every Nebraskan's heritage. Wise use of the resource and consideration for other people's property and personal rights can insure that trapping will remain a part of the heritage of future generations. The purpose of this publication is to help insure this heritage ... through the educational process. Knowledge of and respect for the resource, as well as consideration for other people, are the keys to perpetuating trapping as an outdoor activity. While primarily designed to assist …


Phytoplankton Studies Within The Virginia Barrier Islands I. Seasonal Study Of Phytoplankton In Goose Lake, Parramore Island, Harold G. Marshall Jan 1980

Phytoplankton Studies Within The Virginia Barrier Islands I. Seasonal Study Of Phytoplankton In Goose Lake, Parramore Island, Harold G. Marshall

Biological Sciences Faculty Publications

The phytoplankton of Goose Lake, an oligohaline lake on Parramore Island, was studied for one year. The populations consisted primarily of ultraplankton and nanoplankton-sized forms with diatoms and chlorophyceans dominant most of the year. A general pattern of seasonally higher cell concentrations in early summer and fall was noted, with an unidentified ultraplankton-sized component prominent throughout the collection period. A list of 154 species is given.


Predation Of Upland Game And Its Management, Roger Wells Dec 1979

Predation Of Upland Game And Its Management, Roger Wells

Great Plains Wildlife Damage Control Workshop Proceedings

There is probably no greater topic that elicits greater emotion in public wildlife discussions than that of predation. A variety of groups each with their own particular special interest surround the topic.

Some advocate complete protection of predators on the premise that their activities merely result in a "balance of nature." The opposite viewpoint argue just as strongly for the total elimination of Predators of valued wildlife in order to have greater number for man's enjoyment.


The Prairie Naturalist Volume 11, Number 4. December 1979 Dec 1979

The Prairie Naturalist Volume 11, Number 4. December 1979

The Prairie Naturalist

THE STATUS OF HERONS, EGRETS AND IBISES IN NORTH DAKOTA ▪ J. T. Lokomoen

RANGE EXPANSION OF BAIRD'S SPARROW IN SOUTH DAKOTA ▪ H. A. Kantrud and C. A. Faanes

NESTING RECORDS OF THE WOOD THRUSH IN NORTH DAKOTA ▪ S. O. Lambeth and D. O. Lambeth

SOME ECOLOGICAL ASPECTS OF MARBLED GODWITS AND WILLETS IN NORTH DAKOTA ▪ K. F. Higgins, L. M. Kirsch, M. R. Ryan and R. B. Renken

NOTES ON THE INCUBATION BEHAVIOR OF BLACK-BELLIED WHISTLING DUCKS ▪ E G. Bolen and E. N. Smith

NOTES

Red Fox Captures Sharp-tailed Grouse at the Lek ▪ S. …


A Biotic Analysis Of The Dobbs Park Natural Area With Emphasis On Spatial Distribution Of Trees In The Old-Growth Forest Section, Ronald L. Helms Sep 1979

A Biotic Analysis Of The Dobbs Park Natural Area With Emphasis On Spatial Distribution Of Trees In The Old-Growth Forest Section, Ronald L. Helms

All-Inclusive List of Electronic Theses and Dissertations

Dobbs Park is a 105-acre tract, located at the east edge of Terre Haute, Indiana. Community types range from grass-forb to a 14-acre mature deciduous forest. The tract was divided into 36 units from which 14 community types were developed. The large number of community types appears to be a product of discontinued tillage or grazing within various sections of the tract at different times. The mature forest is largely upland depressional, much of which is subject to periodic pending. Dominants among the 34 tree species present are elms (Ulmus americana, rubra and thomasii) and ashes (Fraxinus americana and pennsylvanica) …


The Prairie Naturalist Volume 11, Number 3. September 1979 Sep 1979

The Prairie Naturalist Volume 11, Number 3. September 1979

The Prairie Naturalist

DISTRIBUTION AND NATURAL HISTORY OF AMPHIBIANS AND REPTILES IN WESTERN NEBRASKA WITH ECOLOGICAL NOTES ON THE HERPETILES OF ARAPAHO PRAIRIE ▪ R. E. Ballinger, J. D. Lynch and P. H. Cole

AVIAN MORTALITY FROM A SEVERE HAIL STORM ▪ J. L. Piehl

EFFECTS OF A SUMMER STORM ON BIRD POPULATIONS ▪ D. H. Johnson

SEXING AND AGING CRITERIA FOR THE WHITE PELICAN ▪ G. R. Lingle and N. F. Sloan

CANVASBACK DUCK RECOVERS FROM COMPOUND LUXATION TO WING ▪ H. A. Doty

SECOND NORTH DAKOTA RECORD OF LOUISIANA WATERTHRUSH ▪ C. A. Faanes

FIRST NESTING RECORD OF A LOUISIANA HERON …


The Prairie Naturalist Volume 11 , Number 2. June 1979 Jun 1979

The Prairie Naturalist Volume 11 , Number 2. June 1979

The Prairie Naturalist

SPECIES WITH EXTRA FLORAL NECTARIES IN A TEMPERATE FLORA (NEBRASKA) ▪ Kathleen H. Keeler

PLANTS OF MOUNT GOLIATH RESEARCH NATURAL AREA ▪ Jeanette Hartman and Rod Mitchell

STATUS OF THE STURGEON CHUB (HYBOPSIS GELIDA) AND SICKLEFIN CHUB (HYBOPSIS MEEKI) IN NORTH DAKOTA ▪ Robert C. Reigh and Dean S. Elsen

OBSERVATIONS ON COYOTE BIOLOGY IN NORTH-CENTRAL MISSOURI ▪ Fred B. Samson and Bill D. Hill

DESTRUCTION TO NESTING BIRDS ON A MARSH BAY BY A SINGLE STORM ▪ Martin K. McNicholl

BOOK REVIEWS

Presentations on Predators ▪ Staff

Migratory Game Birds ▪ Ronald A. Ryder

Wolf …


Biology, Reproductive Potential And The Impact Of Fishing Pressure On The Bluegill Fishery Of Pelican Lake, Uintah County, Utah, Bob D. Burdick May 1979

Biology, Reproductive Potential And The Impact Of Fishing Pressure On The Bluegill Fishery Of Pelican Lake, Uintah County, Utah, Bob D. Burdick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Certain aspects of the biology of two species of fish, bluegill (Lepomis macrochirus) and largemouth bass (Micropterus salmoides), and the assessment of fishing pressure upon the sport fishery of Pelican Lake, Uintah County, Utah, a 680 ha warmwater lake, were studied between April 1, 1976 and June 30, 1978. The growth rate of bluegills (sexes combined) was fairly rapid; the mean back-calculated total lengths from ages one through nine were 55, 112, 166, 194, 211, 229, 245, 256 and 259 mm. The growth of largemouth bass was 104, 194, 271, 316, 350, 405 and 416 mm …


Some Effects Of A Grazer, Hyalella Azteca On Ecosystem Level Properties In Aquatic Microcosms, Martin D. Werner May 1979

Some Effects Of A Grazer, Hyalella Azteca On Ecosystem Level Properties In Aquatic Microcosms, Martin D. Werner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study to determine some ecosystem level effects of an aquatic invertebrate grazer, Hyalella azteca, was performed in aquatic ix microcosms. Impact of the grazer was assessed in three general areas: 1) inorganic nutrient levels of the microcosm water column, 2) productivity and respiration of the biotic community, and 3) plant community composition in the microcosms.

The grazing amphipod caused inorganic phosphorus and nitrogen (except ammonia) levels to be elevated in the microcosms. The increase was due, at least partially, to excretion of nutrients into the water by the amphipod. The presence of H. azteca did not significantly …


Development And Validation Test Of A Mule Deer Habitat Rule, Glenn Gephart May 1979

Development And Validation Test Of A Mule Deer Habitat Rule, Glenn Gephart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A mathematical description of Rocky Mountain mule deer (Odocoileus hemionus hemionus) habitat was developed and subjected to validation testing using correlation and multiple regression statistical techniques. Data were collected on a central Utah study area, which was divided into mountain and desert regions.

Data on deer utilization and several habitat components from 86 study plots visited in 1976 were used to develop a habitat rule. Data from 46 study plots visited in 1977 were used to test the accuracy of the rule. Deer utilization was determined from pellet group counts on 20 0.001 ha pellet plots at each …