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Ecology and Evolutionary Biology

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Articles 18031 - 18060 of 19672

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Belowground Resource Exploitation In Semiarid Plants: A Comparative Study Using Two Tussock Grasses That Differ In Competitive Ability, David M. Eissenstat May 1986

Belowground Resource Exploitation In Semiarid Plants: A Comparative Study Using Two Tussock Grasses That Differ In Competitive Ability, David M. Eissenstat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The relative competitive abilities of Agropyron desertorum and Agropyron spicatum were compared using Artemisia tridentata transplants as indicator plants. Although these two tussock grasses have similar shoot growth forms and shoot physiological characteristics, they have substantial differences in their competitive abilities. Artemisia had lower survival, growth, reproduction, and water potential when transplanted into neighborhoods of A. desertorum than in neighborhoods of A. spicatum.

Plant attributes associated with the differences in competitive ability were explored. Agropyron desertorum and A. spicatum have remarkably similar potential growth rates at warm soil temperatures. In a prolonged cold soil temperature treatment in the greenhouse, …


Estimating Optimum Overstory Vegetation Reduction For Increasing Understory Production, John A. Tanaka May 1986

Estimating Optimum Overstory Vegetation Reduction For Increasing Understory Production, John A. Tanaka

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to investigate analytical approaches for estimating the optimum (profit maximizing) rate of initial overstory kill for increasing seasonal forage availability on a specific ranch. The models were developed using the big sagebrush (Artemisia tridentata) - crested wheatgrass (Agropyron cristatum, A. desertorum) vegetation type on a Utah cow-calf-yearling operation as an example. The models should be applicable on any ranching situation where understory forage production is constrained by the establishment and growth of undesirable overstory vegetation.

Three model forms were developed and compared for their applicability to on-the-ground investment decision …


Carnivore Competition And Resource Use In The Serengeti Ecosystem Of Tanzania, George Walter Frame May 1986

Carnivore Competition And Resource Use In The Serengeti Ecosystem Of Tanzania, George Walter Frame

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coexisting ungulate-eating carnivores--lion, spotted hyena, cheetah, leopard, African wild dog, black-backed jackal, common jackal, and six species of vulture--are examined in East Africa's Serengeti ecosystem. Niche similarities year-round, by season, and by location are described using food, habitat, time of hunting, and other variables. Intraspecific niches of cheetah sex, age, and social groups show that male coalitions differ most from the others in hunting behavior and habitat use. Tests using the carnivore data failed to support hypotheses about niche breadth variation, niche overlap variation, range of food items, and niche inclusion. Densities of the five largest Carnivora in the 35,500 …


The Redevelopment Of Plant Community Diversity On A Surface Coal Mine In Southwestern Wyoming, Thomas Joseph Hatton May 1986

The Redevelopment Of Plant Community Diversity On A Surface Coal Mine In Southwestern Wyoming, Thomas Joseph Hatton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study was initiated in 1981 to investigate the redevelopment of plant communities on a recontoured, surface-mined site in southwestern Wyoming. The landscape pattern of vegetation was compared with topographic position, the initial topsoil pattern, and cultural practices including shrub planting density, shrub planting pattern and topsoil treatments for the years 1982-1985. In addition, differences in vascular plant species diversity within these various factors and treatments were determined, along with the trend in intracommunity (alpha), intercommunity (beta) and landscape (gamma) diversity for the entire study area.

The influence of site factors and tested cultural practices on the differentiation of the …


A Market Analysis For Adult Outdoor Education In Five Western States, Karla Joy Vanderzanden May 1986

A Market Analysis For Adult Outdoor Education In Five Western States, Karla Joy Vanderzanden

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Organizations that offer Outdoor Education programs for adults are concerned with how to best attract people to their programs. Effective program design begins with a clear understanding of the people to be served. A marketing orientation--meeting the needs of participants--has begun to pervade non-profit management; specific information on the adult market for Outdoor Education remains limited. The purpose of this study was to identify and characterize segments based upon the benefits people seek from such an experience. Secondly, this analysis describes current programs 1n a five state region and identifies discrepancies between available and needed services.

A mail survey of …


Intercept Feeding As A Means Of Reducing Deer-Vehicle Collisions, Peggy Wood May 1986

Intercept Feeding As A Means Of Reducing Deer-Vehicle Collisions, Peggy Wood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Intercept feeding was tested for its efficacy in reducing deer-vehicle collision frequency by diverting deer movement patterns away from highways using alfalfa hay as an attractant. Ratios of roadkills in control vs. treatment zones of three highway segments indicated that feeding reduced collision frequency. Spotlighting counts of live deer were significantly higher (P < 0.001) in the control than in the treatment zone, supporting the effectiveness of feeding in keeping deer distant from the highway. In a benefit:cost analysis, the benefits accrued by reducing collision frequency exceeded the costs of feeding on each highway both years, with one exception: in 1986 one of the highways demonstrated that particular features of an area may not be conducive to effectively attracting deer away from a highway. I recommend intercept feeding be used with alternate techniques, so that the most appropriate technique is applied in each situation to reduce collision risk.


Effect Of Short Duration Grazing On Soil Moisture Depletion And Plant Water Status In A Crested Wheatgrass Pasture, Jon M. Wraith May 1986

Effect Of Short Duration Grazing On Soil Moisture Depletion And Plant Water Status In A Crested Wheatgrass Pasture, Jon M. Wraith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A short duration grazing system was utilized to determine the effects of intensive periodic defoliation during spring on soil moisture depletion patterns and plant water status in a crested wheatgrass (Agropyron cristatum and A. desertorum) pasture in central Utah. Exclosures were constructed to compare grazed and ungrazed responses. Soil moisture was monitored to a depth of 193 cm at one to two week intervals from mid-April to late-September using a neutron moisture gauge. Predawn and midday leaf water potentials were estimated using a pressure chamber technique. The two paddocks included in the study were grazed three times between …


Animal Nutritional Response To Sward Structure Under Short Duration Grazing Management, Kenneth C. Olson May 1986

Animal Nutritional Response To Sward Structure Under Short Duration Grazing Management, Kenneth C. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A ten-paddock short duration grazing cell was stocked with yearling heifers at a stocking rate of 0.7 ha per animal unit month and a stocking density of 0.14 ha per animal unit. A continuously-season- long-grazed (CSLG) pasture was used as a control. It was stocked at the same stocking rate, but at a stocking density of 1.4 ha per animal unit. Grazing periods in SDG paddocks were two or three days. Dietary quality was assessed by crude protein · content and in vitro digestibility of esophageal fistula estrusa samples. Three variables of ingestive behavior were measured, including ingestion rate, biting …


The Report Of The Southern Western Australian Shark Working Group., P. Millington Apr 1986

The Report Of The Southern Western Australian Shark Working Group., P. Millington

Fisheries Management Papers

The southern Western Australian Shark Working Group was formed to investigate the southern shark fishery and advise the Minister for Fisheries on options for future management. Membership comprised six fishermen from regional professional fishermen's associations and two Fisheries Department officers. The Working Group considered that each shark fisherman obtaining an entitlement should then be restricted in the length of fishing gear he can use and the number of months he can fish. The individual's time and gear entitlement would be approximately that length of gear being used and time spent fishing in a period shortly before the bench mark date. …


Disease Incidence Of Demersal Finfishes From The Southern And Western Branches Of The Elizabeth River, Virginia, Randal D. Owen Apr 1986

Disease Incidence Of Demersal Finfishes From The Southern And Western Branches Of The Elizabeth River, Virginia, Randal D. Owen

Biological Sciences Theses & Dissertations

Fishes from the industrialized environs of the Elizabeth River, Virginia were surveyed for external evidence of disease during June through October 1984. A highly significant (p < 0.001) incidence of disease was found in demersal fishes collected by otter trawl from a site in the industrially contaminated Southern Branch compared to a less contaminated Western Branch site. Cataracts, fin erosion and dermal lesions were the most commonly occurring anomalies in the Southern Branch finfish.

Static, solid-phase toxicity tests employing sediment collected from the Southern Branch site resulted in an immediate toxic stress in the spot, Leiostomus xanthurus, which resulted in 100% mortality within 24 hours, compared with no mortalities in control systems. Spot exposed to control, i.e., pollution free, and diluted Southern Branch sediments innoculated with the pathogenic bacterial species, Vibrio anguillarium, developed significant (p ≤ 0.020) cases of fin erosion at a mean total bacterial community density …


Organic Matter Budgets And Models For Four Plant Communities In The Great Dismal Swamp, J. Patrick Megonigal Apr 1986

Organic Matter Budgets And Models For Four Plant Communities In The Great Dismal Swamp, J. Patrick Megonigal

Biological Sciences Theses & Dissertations

Budgets and models of organic matter dynamics were developed for one mesic and three seasonally flooded plant communities in the Dismal Swamp. Components included aboveground parts, belowground parts, litter and soil organic matter (SOM).

Net primary- production was significantly greater on them flooded sites. Comparisons show that the Dismal Swamp is highly productive despite relatively low nutrient inputs.

Budget calculations showed that over 65% of the total input to SOM comes from roots. Leaves contributed about 70% of the aboveground inputs.

The model predicted that species composition, aboveground biomass and turnover rates on the cedar site will become quite similar …


Variations In Radial Maze Performance Under Different Levels Of Food And Water Deprivation, Robert H.I. Dale, William A. Roberts Mar 1986

Variations In Radial Maze Performance Under Different Levels Of Food And Water Deprivation, Robert H.I. Dale, William A. Roberts

Scholarship and Professional Work - LAS

Four groups of rats were tested on an eight-arm radial maze under a free-choice procedure. The subjects were maintained at either 80% or 100% of their preexperimental free-feeding weights through restricted access to either food or water. Water-deprived subjects received water in the maze; food-deprived subjects received food. Water-deprived subjects learned the task faster than food-deprived subjects. The four groups developed different response patterns. These were measured by the mean transition size, the average angular distance (in 45° units) between consecutively chosen arms. Rats foraging for food and water developed different search strategies, with water-deprived subjects exhibiting lower mean transition …


Origins Debate: Part I - Background, Russell W. Maatman Mar 1986

Origins Debate: Part I - Background, Russell W. Maatman

Pro Rege

For part 2 see Pro Rege vol. 14, June 1986, pp. 9-19. For part 3 see Pro Rege vol. 15, September 1986, pp. 22-30.


The Prairie Naturalist Volume 18, No. 1. March 1986 Mar 1986

The Prairie Naturalist Volume 18, No. 1. March 1986

The Prairie Naturalist

Paul B. Kannowski, Editor

Nikki R. Seabloom, Assistant Editor

Douglas H. Johnson, Book Review Editor

TABLE OF CONTENTS

INVASION PATTERN MAPPING OF NON-SEEDED SPECIES ON A SHALLOWLY DISTURBED SEEDED SITE ▪ C. E. Grygiel, C. D. Bonham, and E. F. Redente

CHANGES IN THE LICHEN FLORA OF PIPESTONE NATIONAL MONUMENT, MINNESOTA ▪ G. D. Willson and T. W. Vinyard

INTERPOPULATION VARIABILITY IN MOUTHPARTS IN Scaphiopus bombifrons IN NEBRASKA (AMPHIBIA: PELOBATIDAE) ▪ T. L. Potthoff and J. D. Lynch

PLANTS AND INVERTEBRATES IN A PRAIRIE WETLAND DURING DUCK BROOD-REARING J. W. McCrady, W. A. Wentz, and R. L. Linder

OCCURRENCE OF …


The Prairie Naturalist Volume 18, No. 3 September 1986 Mar 1986

The Prairie Naturalist Volume 18, No. 3 September 1986

The Prairie Naturalist

Paul B. Kannowski, Editor

Nikki R. Seabloom, Assistant Editor

Douglas H. Johnson, Book Review Editor

TABLE OF CONTENTS

HABITAT SELECTION AND MOVEMENT PATTERNS IN SANDHILLS RODENTS ▪ C. A. Lemen and P. W. Freeman

THE HERPETOFAUNA OF THE WEAVER DUNES, WABASHA COUNTY, MINNESOTA ▪ P. A. Cochran

MULTIPLE EGG CLUTCH PRODUCTION IN THE GREAT PLAINS TOAD ▪ J. J. Krupa

MAMMALS OF THE KONZA PRAIRIE RESEARCH NATURAL AREA, KANSAS ▪ E. J. Finck, D. W. Kaufman, G. A. Kaufman, S. K. Gurtz, B. K. Clark, L. J. McLellan, and B. S. Clark

AQUATIC INVERTEBRATES IN LEVEL DITCHES AND ADJACENT EMERGENT …


Genetic Engineering, W. John Hayden Jan 1986

Genetic Engineering, W. John Hayden

Biology Faculty Publications

Why do so many biologists express so little concern for biology as a whole and such contempt for fields other than their own? The current debate on release of genetically engineered organisms into the environment, specifically, J. E. Fox's recent reply (Letters, 18 Oct., p. 237) to an earlier letter by R. K. Colwell et al. (12 July, p. 111), offers a case in point.


Relationship Between Diameter Breast High And Diameter Near Ground Line For Hardwood Species In Arkansas, Richard A. Kluender, Jimmie L. Yeiser Jan 1986

Relationship Between Diameter Breast High And Diameter Near Ground Line For Hardwood Species In Arkansas, Richard A. Kluender, Jimmie L. Yeiser

Journal of the Arkansas Academy of Science

The relationship of diameter breast high (DBH) and diameter near ground line (DNG) was investigated for three groups of Arkansas hardwoods from four physiographic regions in the state. The relationship between DBH and DNG did not vary significantly across species groups or physiographic regions. Equations of both linear and non-linear form were developed to estimate DBH from DNG. The relationships between DBH and DNG is used to estimate timber volume, growth, and value from residual stumps. The relationship is also useful in harvesting system design and cost estimation in operational forestry.


Mountain Pine Beetle Outbreaks In The Rocky Mountains: Effects On Fuels And Fire In Lodgepole Pine Forest (Abstract), W H. Romme, D H. Knight, J Fedders Jan 1986

Mountain Pine Beetle Outbreaks In The Rocky Mountains: Effects On Fuels And Fire In Lodgepole Pine Forest (Abstract), W H. Romme, D H. Knight, J Fedders

The Bark Beetles, Fuels, and Fire Bibliography

Changes in fuels were studied in northwestern Wyoming by sampling a sequence of ten stands that had been heavily damaged by beetles from 1 to 20 years earlier. Leaf litter increased only slightly (3-6%) for six years, and large woody fuels (which contribute much less to flammability) increased steadily and substantially (up to 16 x) for at least 20 years. Other fuel categories did not change significantly. While flammability may be increased during the first year or two after a beetle infestation because dead leaves are still on the trees, the risk of destructive fire during years 2-20 may be …


The Case For Hunting On National Wildlife Refuges, Harvey K. Nelson Jan 1986

The Case For Hunting On National Wildlife Refuges, Harvey K. Nelson

Hunting Collection

Public land management agencies are faced with greater challenges today than ever before in responding to the recreational needs of society. As Will Rogers so aptly stated, "Land, they make so little of it nowadays" (Steinhart 1986). The U.S. Fish and Wildlife Service (FWS) also must face these challenges in management of national wildlife refuges (NWRs). There is a growing demand by the American people to utilize and enjoy NWRs in a variety of ways. Managers are faced with the dilemma of determining how much and what kind of management and utilization of natural resources is appropriate without compromising the …


The Case For Hunting, William L. Robinson Jan 1986

The Case For Hunting, William L. Robinson

Hunting Collection

My purpose at this symposium is to present the case for hunting. I am a wildlife ecologist by training and profession, and I am also a hunter. As a hunter, I am sensitive to criticisms of this pursuit, as any hunter should be. Some people question how, with knowledge of the nature and functioning of ecological systems, I can go out with a gun and kill grouse, ducks, and deer. I respond that, indeed, my understanding of ecology and the nature of man enhances my enjoyment of hunting.


Effects Of Early Experience Upon Adaptiveness Of Horses, J. C. Heird, R. W. Bell, S. G. Brazier Jan 1986

Effects Of Early Experience Upon Adaptiveness Of Horses, J. C. Heird, R. W. Bell, S. G. Brazier

Equines Collection

Experimentation with laboratory animals, encompassing the range of usual species (mice, rats, cats, clogs, and primates), has conclusively demonstrated that handling by humans during early life facilitates subsequent development in terms of health and viability, reduced emotional reactivity, more adaptive responses to a variety of stressors (both biological and behavioral adaptations), and increased ability to adapt to changing circumstances as exemplified by increased ability to learn and solve problems (seeM. Bornstein 1985, for recent review).

Two studies (described below) (Heircl et a!. 1981; Whitaker 1982) conducted at Texas Tech University (TTU) have extended these findings regarding the beneficial effects of …


Wildlife And Nature Liberation, Michael W. Fox Jan 1986

Wildlife And Nature Liberation, Michael W. Fox

Conservation Collection

Humane ethics--animal welfare--and animal rights are not incompatible with ecologically sound wildlife stewardship. They are an integral part of it, from treating wildlife for necessary research purposes humanely, to finding humane ways to control the populations of species that are out of balance and thus threatening the viability of other species and the diversity and integrity of the ecosystem. That mistakes may be made in stewardshipmanagement policies is inevitable. It is, for instance, difficult to know if the sudden abundance of one or more species and the dwindling of others is part of the natural process of succession and should …


Wildlife Conservation And Animal Rights: Are They Compatible?, Michael Hutchins, Christen Wemmer Jan 1986

Wildlife Conservation And Animal Rights: Are They Compatible?, Michael Hutchins, Christen Wemmer

Conservation Collection

The purpose of this paper is to explore the philosophical tenets of the animal rights/humane ethic as they relate to the environmental ethic and, more specifically, as they relate to wildlife management and conservation. The two ethics will be compared in an effort to identify potential sources of conflict. Recent criticisms of the animal rights ethic, most notably by Fox (1978, 1979), Rodman (1977), Callicott (1980), Gunn (1980), and Hutchins et al. (1982) have identified several major discrepancies. The implications of these differences will be discussed.


Assault On Eden: Destruction Of Latin America's Rain Forests, Douglas R. Shane Jan 1986

Assault On Eden: Destruction Of Latin America's Rain Forests, Douglas R. Shane

Ecology Collection

In the seemingly distant world of Latin America's rain forests, man's greed and desperation have resulted in a fire which threatens to obscure our ability to observe life's poetry: The continuing destruction of the earth's tropical rain forests is one of the most serious environmental problems confronting humanity today: Intact, these vital organisms offer an understanding of the planet's past and a key to our future; destroyed, they threaten catastrophe of global consequence.


Social Ecology And Behavior Of Coyotes, Marc Bekoff, Michael C. Wells Jan 1986

Social Ecology And Behavior Of Coyotes, Marc Bekoff, Michael C. Wells

Ethology Collection

Behavioral patterns are subject to natural selection and behavior like any other attributes of an animal, which contributes to individual survival. The chapter summarizes a long-term study of coyotes that was conducted in the Grand Teton National Park, in the northwest comer of Wyoming. There is remarkable agreement in the results stemming from a limited number of field projects concerned with the social behavior and behavioral ecology of coyotes, and some general principles concerning social ecology, scent marking, predatory behavior, time budgeting, and reproductive and care-giving patterns can be developed that are applicable not only to coyotes but to many …


A Study Of Changes In Algal Population Density Diversity And Distribution And Changes In Physical And Chemical Characteristics Of Lake Elsinore, Robert H. Nyman Jan 1986

A Study Of Changes In Algal Population Density Diversity And Distribution And Changes In Physical And Chemical Characteristics Of Lake Elsinore, Robert H. Nyman

Theses Digitization Project

No abstract provided.


Specimen Catalog, James S. Findley Jan 1986

Specimen Catalog, James S. Findley

Division of Mammals - Field Notes and Catalogs

No abstract provided.


Field Notes, James S. Findley Jan 1986

Field Notes, James S. Findley

Division of Mammals - Field Notes and Catalogs

No abstract provided.


Interactions Between Response Stereotypy And Memory Strategies On The Eight-Arm Radial Maze, Robert H.I. Dale, Nancy K. Innis Jan 1986

Interactions Between Response Stereotypy And Memory Strategies On The Eight-Arm Radial Maze, Robert H.I. Dale, Nancy K. Innis

Scholarship and Professional Work - LAS

Three groups of water-deprived rats collected water from the ends of the 8 arms of an 8-arm radial maze. Sighted subjects, and subjects blinded either with or without pre-enucleation experience on the radial maze, all retrieved the water efficiently. Most of the subjects exhibited the same response stereotypy, regularly choosing 8 adjacent arms of the maze, then stopping in the center of the maze. The strategies underlying this performance were analyzed by interrupting trials and rotating the maze 180° after the subject had made 3 choices. Sighted subjects depended on extramaze stimuli, naive-blind subjects depended on intramaze stimuli and experienced-blind …


Spatial And Temporal Response Patterns On The Eight-Arm Radial Maze, Robert H.I. Dale Jan 1986

Spatial And Temporal Response Patterns On The Eight-Arm Radial Maze, Robert H.I. Dale

Scholarship and Professional Work - LAS

Six maze-experienced hooded rats were timed during five trials on which they collected water from all arms of an eight-arm radial maze, then made five more choices. All subjects frequently exhibited a “task-completion pause:” The subjects rarely spent more than 1 sec in the center of the maze between choices until they had entered all eight arms, then stopped in the center of the maze. In contrast, the time spent in each arm gradually increased until all of the water had been obtained, then decreased slightly. Four subjects began every trial by choosing eight consecutive adjacent arms. The task-completion pause …