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Full-Text Articles in Life Sciences

Yields From 18-Year-Old Aspen Via Total Tree Harvesting, M. K. Benson, D. W. Einspahr Jun 1972

Yields From 18-Year-Old Aspen Via Total Tree Harvesting, M. K. Benson, D. W. Einspahr

Aspen Bibliography

Described are the results of harvesting the above-ground parts of an 18-year-old aspen stand and the observations made on the initial suckering of the new stand. The yields for the stand of 17.7 cunits per acre were greater than predicted yields of comparable material for the site at age 35. Suckering on the area the first year after cutting averaged 37,000 aspen stands per acre and 2.6 feet in height.


Influence Of A Soil Microfloral Crust On Hydrologic And Chemical Properties Of Soils In Southeastern Utah, Walter L. Loope May 1972

Influence Of A Soil Microfloral Crust On Hydrologic And Chemical Properties Of Soils In Southeastern Utah, Walter L. Loope

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Cryptogamic soil crusts within the Colorado Plateau were studied to determine their effect on infiltration rates, potential sediment production, permeability, and several chemical properties of the soil. Six different crust stages were identified. Undisturbed soil cores were used to determine intrinsic permeability under three treatments and disturbed soil samples were analyzed for pH, percent organic matter, soil texture, Ca+Mg content and total conductivity.

It was found that the cryptogamic crust had little effect on soil chemical properties. Analysis of undisturbed soil core data indicates that high cryptogamic cover tends to decrease intrinsic permeability; this effect was reinforced when cores were …


Early Life History Of The Mountain Whitefish Prosopium Williamsoni (Girard) In The Logan River, Utah, Lawrence Guy Brown May 1972

Early Life History Of The Mountain Whitefish Prosopium Williamsoni (Girard) In The Logan River, Utah, Lawrence Guy Brown

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Growth and food habits of 399 Age 0 mountain whitefish from the Logan River, Utah, were studied between March, 1970, and April, 1971. At the end of their first six months of life, whitefish were 86-96 mm total length and weighed 6-8 grams (wet). Total temperature experience was 2,950-3,430 degree-days above 32° F. The length-weight relationship for Age 0 mountain whitefish was best described by three stanzas with slopes of 4.3333 for fish 12.5-17.0 mm total length, 3.4437 for fish 17.0-55.0 mm total length, and 2.8043 for fish 50.0-112.0 mm total length. Scalation commenced at 30-35 mm total length and …


An Analysis Of Stock Densities And Harvest Of The Cutthroat Trout Of The Snake River, Teton County, Wyoming, John W. Kiefling May 1972

An Analysis Of Stock Densities And Harvest Of The Cutthroat Trout Of The Snake River, Teton County, Wyoming, John W. Kiefling

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An intensive creel census and marking program was conducted in 1969 and 1970 to make possible population estimates and estimates of harvest of cutthroat trout in the Snake River in Teton County, Wyoming. Stock density determinations made in one of the five study areas provided an estimate of 400 and 992 cutthroat trout, eight inches or more in length, per mile of stream in 1969 and 1970 respectively.

Harvest data provide an estimate of 5,207 and 5,903 cutthroat trout harvested in 1969 and 1970 respectively. The harvest estimates obtained in this study are not comparable to those made in 1967 …


Some Aspects Of Conditioning Behavior In Rainbow Trout, Salmo Gairdneri, Reed E. Harris May 1972

Some Aspects Of Conditioning Behavior In Rainbow Trout, Salmo Gairdneri, Reed E. Harris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Effects of exercise, social facilitation, and delayed conditioning after vi exercise on the learning behavior of 5 to 6-inch rainbow trout, Salmo gairdneri, was measured in a conditioned avoidance response apparatus. The conditioning schedule contained an intertrial interval between alternate presentations of conditioned (light) and unconditioned (shock) stimuli. This randomization eliminated learning losses found in a previous study. Mean percentage avoidance, the measurement of learning, did not decrease significantly during conditioning trials. Exercised fish learned avoidance better than did non-exercised fish. Mean percentage avoidance for fish exercised at 0.5 ft/sec was 66.3; at 1.0 ft/ sec, 1.5 ft/sec, and …


Population Biology Of The Black-Tailed Jackrabbit (Lepus Californicus) In Northern Utah, L. Charles Stoddart May 1972

Population Biology Of The Black-Tailed Jackrabbit (Lepus Californicus) In Northern Utah, L. Charles Stoddart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Population biology of the black-tailed jackrabbit population on a 250-square-mile area in Curlew Valley, northern Utah, was studied from 1962-70. During this period the fall population density index increased from 40.0 in 1962, to 60.6 in 1963, decreased progressively to a low of 21.2 in 1967, then increased the following 3 years to a high of 185.0 in 1970.

Breeding was synchronous with four conception periods each year; in some years a fifth conception period was evident. The first conception period occurred about the last half of January; other periods followed at 40-day intervals indicating a 40-day gestation period and …


Reproduction And Hematology Of The Cache Elk Herd, Thomas B. Follis May 1972

Reproduction And Hematology Of The Cache Elk Herd, Thomas B. Follis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The initial three years of a 10-year reproductive study of elk involved three major phases. A fourth was added because of convenience. Objective 1 was to ascertain pregnancy rates in yearling and mature elk by rectal palpation, associate these rates with subsequent fall cow/calf ratios, and to test concurrently an ultrasonic fetal heart detector. Rectally observed anatomical changes in gravid uteri of cattle were directly applicable to elk. Ultrasonic detections of pregnancies in elk and deer were unsuccessful.

Pregnancy rates in the 1969-70 winter of 100 and 0 percent, respectively, for 19 adult and five yearling elk were associated with …


Population Ecology Of Uinta Ground Squirrels, Norman A. Slade May 1972

Population Ecology Of Uinta Ground Squirrels, Norman A. Slade

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The behavior and ecology of Uinta ground squirrels (Spermophilus armatus) at the Utah State University Forestry Field Station northeast of Logan, Utah were studied from 1964-1971 to determine the role of behavior in population regulation. From 1965 to 1968, data were collected to establish population norms. In 1968, the population density was reduced experimentally to help elucidate regulatory processes. This paper compares the dynamics of the population before and after the population reduction.

Before the density reduction, juvenile survival was lower than that of yearlings and adults. The disappearance of juveniles was associated with their tendency to disperse …


Forest Fuel Accumulation -- A Growing Problem, Marvin Dodge Jan 1972

Forest Fuel Accumulation -- A Growing Problem, Marvin Dodge

The Bark Beetles, Fuels, and Fire Bibliography

Discusses the problem caused by accumulation of forest fuels in the wild-land forests of the western USA under the policy of total fire protection pursued there for many years, and emphasizes the need to find economical and practical ways of reducing fuel hazards in these forests, especially by means of prescribed burning under conditions in which low-intensity fires can be achieved.


Aldo Leopold's "Land Ethic": An Ecological Extension Of Albert Schweitzer's "Reverence For Life", John Lee Weaver Jan 1972

Aldo Leopold's "Land Ethic": An Ecological Extension Of Albert Schweitzer's "Reverence For Life", John Lee Weaver

Undergraduate Honors Capstone Projects

As a member of the world community, and in the process of becoming a professional ecologist, I have begun a search for a personal ecological ethic to guide my actions. Two of the paths I have taken in my search are Albert Schweitzer's Reverence for Life ethic and Aldo Leopold's Land Ethic. They are relevant because each has extended the scope of ethics beyond Homo Sapiens. Their thoughts, with similarities and dissimilarities, form herein my travels.


Aspen Minnesota's No. 1 Tree, George Rossman, Bob Rossman, Allen Rossman Jan 1972

Aspen Minnesota's No. 1 Tree, George Rossman, Bob Rossman, Allen Rossman

Aspen Bibliography

For thousands of years after the last glaciers disappeared from northern Minnesota, the forces of nature worked to develop a magnificent forest of predominantly white and red pine. Stands of big pines covered more than 5 million acres.


Deer And Aspen, American Box Board Co. Jan 1972

Deer And Aspen, American Box Board Co.

Aspen Bibliography

He's a big eater.


Economic Operability - Factors Affecting Harvest And Transport Costs, Dennis P. Bradley, Frank E. Biltonen Jan 1972

Economic Operability - Factors Affecting Harvest And Transport Costs, Dennis P. Bradley, Frank E. Biltonen

Aspen Bibliography

No abstract provided.


Natural Succession In North-Central Minnesota, Henry L. Hansen, Vilis Kurmis Jan 1972

Natural Succession In North-Central Minnesota, Henry L. Hansen, Vilis Kurmis

Aspen Bibliography

No abstract provided.


An Allometric Model For Bole Biomass Estimates Of Spruce And Aspen In Southwestern Colorado, Thomas D. Landis Jan 1972

An Allometric Model For Bole Biomass Estimates Of Spruce And Aspen In Southwestern Colorado, Thomas D. Landis

Aspen Bibliography

No abstract provided.