Life Sciences Commons^™

Pastoral Development Strategies In The Sahel And East Africa: Can The Mistakes Be Corrected?, Ahmed Musa Haji Ahmed

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

There is much controversy on the definition given to those people who raise livestock on the natural vegetation. Differences in the degree of their dependence on livestock and livestock products for food, as well as differences in the patterns of their movements, create the controversy. "Pure-pastoralists", "nomadic pastoralists", "semi - pastoralists", "semi-nomadic", "transhumant", and "semisedentary" are but some of the many terms used in the literature to describe them (see, for example, Johnson, 1969; Jacobs, 1965; McGee, 1986; Horowitz, 1981). To avoid much of the confusion created by the use of these terms, we use the definition of pastoralists as …

The Feasibility Of River Otter Reintroduction In Northern Utah, Joel P. Bich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this thesis is to document river otter (Lutra canadensis) distribution and reintroduction potential in northern Utah. Distribution was studied using data from 3 sources: 1) otter sighting records from Utah Division of Wildlife Resources; 2) surveys of Utah furbearer trappers and natural resources personnel; and 3) searches of streams for otter sign. Potential for river otter habitat/reintroduction was evaluated by assessing food, cover, and reintroduction attributes. Streams were ranked using an evaluation system based on data from the otter literature.

Forty-six positive otter sightings were made in Utah by trappers, natural resources personnel, and the …

The Effects Of Forest Harvesting On Small Mammals In Western Newfoundland And Its Significance To Marten, Brian Tucker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The depauperate fauna of Newfoundland provides a limited prey base for marten. Only two small mammal prey species, Microtus pennsylvanicus and Sorex cinereus, were found in any abundance in the old-growth forests of the study area. Of these two, Microtus displayed population fluctuations typical of most microtines. Analysis of marten scats indicated that Microtus is a very important prey item to the marten with other food. items being of lesser importance particularly when Microtus are abundant.

Trapping in various habitats indicated that Sorex densities were three to five times higher in logged areas compared to uncut areas. Unfortunately, the …

Control And Evaluation Of Big Game Browsing Damage To Commercial Fruit Orchards, William E. Stone

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Diversionary feeding, artificial feeding designed to divert animals away from areas where they might cause property damage, was tested for efficacy in reducing fruit orchard browsing by big game animals during two consecutive winters in Utah. Strategically placed attractive feedstuffs lured deer to feed stations and reduced fruit-bud browsing (1st year, P < 0.07; 2nd year, P < 0.01). Blossom and apple numbers were greater (P < 0.05) on trees in the feed (treatment) orchard than in the no feed (control) orchard in each year. However, higher (P < 0.05) apple production on trees where browsing was excluded in the treatment orchards compared to the control orchards indicated that intercept feeding did not increase crop production. Tree periodicity and other factors affecting apple production masked the effect of diversionary feeding on crop yield.

Two independent browsing damage assessment methods, a paired-tree technique and a harvest-inflation technique, predicted that the ratio of apples lost per browsed bud was 0.158 and 0.082, respectively. However, the values of the ratio varied widely with each method of estimation. Browsing damage differed ( …

Effect Of Fertilization On Woody Plant Chemistry: The Role In Diet Selection By Goats, Amanuel Gobena

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lack of forage quantity and quality limit livestock production during the dry season in northeast Brazil. Coppice produced following cutting of tree species in this area has the potential to increase forage quantity and quality during the dry season, because trees that coppice retain green foliage throughout most of the dry season. However, the palatability of coppice is often low.

From a theoretical standpoint, woody plants with inherently slow growth rate should be less palatable to herbivores than plants with inherently fast growth rates, because plants that grow slowly allocate more carbon to compounds such as tannins and resins that …

A New Approach To Forest Site Quality Modeling, David L. Verbyla

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multiple regression and discriminant analysis procedures are commonly used to develop forest site quality models. 'When they contain many independent variables relative to sample size, these models may be subject to predicton bias. Fit statistics such as R² in regression and classification tables in discriminant analysis show the apparent model accuracy but this may be a biased estimate of the model's actual accuracy. Sample splitting methods such as cross-validation and the bootstrap can be used to get an unbiased actual accuracy estimate.

A discriminant procedure called classification tree analysis uses cross-validation to build the classifier with the greatest estimated …

Nesting And Habitat Parameters For Selected Raptors In The Desert Of Northwestern Utah, David L. Peterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the effects of habitat parameters, disturbances and predation on the reproductive success of golden eagles (Aguila chrysaetos), ferruginous hawks (Buteo regalis), red-tailed hawks (Buteo jamaicensis) and prairie falcons (Falco mexicanus) in the desert area southwest of the Great Salt Lake in northwestern Utah.

The prairie falcon was the only species examined that had a normal reproductive output during the study years of 1984-1986. The prairie falcon was better able to utilize the avian prey species which were very difficult for the larger and slower raptor species to capture. During …

Inter-Seasonal Range Relationships Of Spanish Goats And Mule Deer In A Utah Oakbrush Community, Robert Alexander Riggs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three experiments were conducted to assess the potential for using Spanish goats to manage Gambel oakbrush winter range, dominated by Gambel oak (Quercus gambelii), for mule deer (Odocoileus hemionus). Summer-time food selection of goats, effects on plant community composition, and consequent effects on mule deer nutrition and foraging behavior were examined.

An apparent preference for juvenile oak browse, and low use of oak twigs was observed. Selection for juvenile browse may have been facilitated by the retarded phenology of oak as compared to that of associated flora. This differential was maintained by repeated browsing. Animal performance, …

Nutrient And Water Interrelationships Between Crested Wheatgrass And Two Shrub Species, Paul B. Baker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When crested wheatgrass (Agropyron desertorum) grows in mixture with sagebrush (Artemisia tridentata), its production declines. Its production increases when grown in mixture with fourwing saltbush (Atriplex canescens), according to previous reports. This study investigated soil water extraction and potassium (K) nutrition of the two shrubs to identify possible causes of the differential responses of crested wheatgrass.

Crested wheatgrass had reduced, rather than increased, nitrogen (N) and K yield in mixture with fourwing saltbush. No differences in N and phosphorous (P) concentrations were observed between sagebrush and fourwing saltbush, but fourwing saltbush had a much …

Acquisition Of Forgaging Skills By Lambs Eating Grass Or Shrub, Enrique R. Flores

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I studied the acquisition of foraging skills by lambs eating shrub or grass in three experiments. The general approach was to isolate those skills involved in prehending forage from those related to the acceptance of novel foods. Treatment lambs received 15 times more exposure to grass or shrub than did control lambs. Lambs were tested in 2.5 x 2.5 meter monocultures of shrub or grass 5 min/d, on two separate occasions. Height, bulk density and spatial arrangement of plant material were controlled during testing.

In Experiment 1, I studied the acquisition of foraging skills by lambs on monocultures of shrubs. …

Deer And Forestry In Germany: Half A Century After Aldo Leopold, Michael L. Wolfe, Friedrich-Christian V. Berg

Aspen Bibliography

No abstract provided.

A Seasonal Comparison Of Metabolic And Water Loss Rates Of Three Species Of Grasshoppers, Lynn J. Forlow, James A. Macmahon

Green Canyon Environmental Research Area, Logan Utah

1. 1. Seasonal differences in metabolic and water loss rates were examined in three related species of grasshoppers collected from shrub-steppe communities in Utah: Arphia conspersa, A. pseudonietana and

2. 2 cohorts of Trimerotropis pallidipennis. 2. No significant differences (P = 0.05) in metabolic rates were observed between seasons (early vs late), between genera (Arphia vs Trimerotropis) nor among species.

3. 3. Early season (spring) grasshoppers had a higher (but non-significant) mean water loss rate (±X ± SD in mg.g−1-hr−1) (4.81 ± 1.53) than late season (summer) grasshoppers (4.43 ± 1.43).

4. 4. Among species, early season A. conspersa had …

Douglas-Fir Beetle (Dendroctonus Pseudotsugae Hopkins, Coleoptera : Scolytidae) Brood Production On Douglas-Fir Defoliated By Western Spruce Budworm (Choristoneura Occidentalis Freeman, Lepidoptera : Tortricidae) In Logan Canyon, Utah, S E. Fredricks, M J. Jenkins

The Bark Beetles, Fuels, and Fire Bibliography

Douglas-fir beetle brood production was studied on Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) trees defoliated by the western spruce budworm between 1983 and 1985. Tallies were made of the number of attacks, total length and number of egg galleries, number of eggs deposited, number of larval tunnels, number of pupal chambers, and number of emerging beetles (per female and per unit area). Data analysis showed no significant differences among the three years studied. The number of emerging beetles per female parent was 0.59, and emergence per 90 cm2 was 2.32 beetles. Egg, larval, and pupal survivals were 47.5%, 30.0%, and 15.5%, …

Lodgepole Pine Vigor, Regeneration, And Infestation By Mountain Pine Beetle Following Partial Cutting On The Shoshone National Forest, Wyoming, Gene D. Amman, Gene D. Lessard, Lynn A. Rasmussen, Curtis G. O'Neil

The Bark Beetles, Fuels, and Fire Bibliography

Lodgepole pine stands were thinned in the Shoshone National Forest of northwestern Wyoming in 1979 and 1980 using different forms of partial cutting. Average losses of trees 5 inches diameter at breast height and larger to mountain pine beetles during the 5 years following thinning ranged from less than 1 percent in spaced thinnings to 7.4 percent in the 12-inch diameter limit cut, compared to 26.5 percent in check stands. Residual trees increased radial growth significantly, but change in growth efficiency is slow. Regeneration 5 years after thinning ranged between 1,160 and 3,560 seedlings per acre, with pine being favored …