Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 13 of 13

Full-Text Articles in Life Sciences

Clonal Foraging In Perennial Wheatgrasses: A Strategy For Exploiting Patchy Soil Nutrients, L. D. Humphrey, D. A. Pyke Oct 1987

Clonal Foraging In Perennial Wheatgrasses: A Strategy For Exploiting Patchy Soil Nutrients, L. D. Humphrey, D. A. Pyke

Aspen Bibliography

1 Foraging by means of plasticity in placement of tillers in response to low- and high- nutrient patches was examined in the rhizomatous wheatgrass Elymus lanceolatus ssp. lanceolatus. Its ability to exploit soil nutrient patches was compared to that of the closely related but caespitose E. lanceolatus ssp. wawawaiensis. 2 Clones of 14 genets of each taxon were planted in boxes consisting of two 30 x 30 cm cells: the 'origin cell' where clones were planted, and the adjacent 'destination cell', with each cell containing soil with either low or high levels of nutrients. 3 The rhizomatous taxon, which can …


Response Of Breeding Birds To Commercial Clearcutting Of Aspen In Southwestern Colorado [Usa], V.E. Scott, G.L. Crouch Aug 1987

Response Of Breeding Birds To Commercial Clearcutting Of Aspen In Southwestern Colorado [Usa], V.E. Scott, G.L. Crouch

Aspen Bibliography

Breeding birds on an aspen forest in southwestern Colorado increased in species diversity after 25% of the timber sale area forest was clearcut in patches of 3 to 20 acres. Bird population density on the forest with clearcuts was not significantly different from that on an uncut forest. Of the 20 species evaluated, six were more and one was less abundant than on the uncut forest.


Greater Yellowstone Ecosystem, U.S. House Committee On Insular Affairs Jan 1987

Greater Yellowstone Ecosystem, U.S. House Committee On Insular Affairs

All U.S. Government Documents (Utah Regional Depository)

No abstract provided.


Project Reports 1987-1991, Various Authors Jan 1987

Project Reports 1987-1991, Various Authors

Annual Reports

No abstract provided.


Proceedings From The 24th Annual Marschall Italian Cheese Seminar, Various Authors Jan 1987

Proceedings From The 24th Annual Marschall Italian Cheese Seminar, Various Authors

Cheese Industry Conference

No abstract provided.


Western Spruce Budworm, M. H. Brooks, J. J. Colbert, R. G. Mitchell, R. W. Stark Jan 1987

Western Spruce Budworm, M. H. Brooks, J. J. Colbert, R. G. Mitchell, R. W. Stark

The Bark Beetles, Fuels, and Fire Bibliography

No abstract provided.


Microhabitat Selection And Diel Movements Of Juvenile Rainbow Trout (Salmo Gairdneri) Introduced Into Mid-Elevation Reservoirs In Utah, Wayne A. Wurtsbaugh, Roger Tabor Jan 1987

Microhabitat Selection And Diel Movements Of Juvenile Rainbow Trout (Salmo Gairdneri) Introduced Into Mid-Elevation Reservoirs In Utah, Wayne A. Wurtsbaugh, Roger Tabor

Watershed Sciences Faculty Publications

The distribution and movement patterns of fingerling rainbow trout stocked into reservoirs in Utah were investigated with · SCUBA observations and by vertical gill netting. For several weeks after stocking, fingerling trout (ca. 80 mm standard length) were strongly oriented to the shore, and selected habitats providing cover. During the underwater observations, no fish were seen below depths of 2 meters. Two weeks after stocking, the fingerlings were most abundant under docks near where they were planted, indicating that dispersal was relatively slow. Jacob's electivity indices for natural substrates in water 0-1.5 meter deep were in sand, gravel, cobble, boulders …


Importance Of Predation By Adult Trout On Mortality Rates Of Fingerling Rainbow Trout Stocked In East Canyon Reservoir, Utah, Wayne A. Wurtsbaugh Jan 1987

Importance Of Predation By Adult Trout On Mortality Rates Of Fingerling Rainbow Trout Stocked In East Canyon Reservoir, Utah, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Personnel from Utah State University, working in cooperation with the Utah Division of Wildlife Resources and the Utah Cooperative Fish and Wildlife Research Unit, are attempting to determine various sources of mortality of fingerling rainbow trout (Salmo gairdneri) stocked into mid-elevation reservoirs in the State. Returns of planted fish are often much below desired levels. Angler surveys indicate that in East Canyon Reservoir, fishermen harvest only about 30% of the fingerling trout stocked, and this is a much higher return than in many other waters.


The Association Of Seed And Cone Predator Populations And Cone Crop Production In Engelmann Spruce, Dawn E. Cameron Jan 1987

The Association Of Seed And Cone Predator Populations And Cone Crop Production In Engelmann Spruce, Dawn E. Cameron

T.W. "Doc" Daniel Experimental Forest

Engelmann spruce (Picea engelmannii Parry ex Engelm.) exhibits cone crop periodicity, producing seed in a cyclic pattern. Variation in seed production has been noted between individuals of a population, but synchronization on a large scale is common. The theory that ultimately these periodic large cone crops have resulted from the selective pressures of seed and cone predators, referred to as the predator satiation hypothesis, is considered. Assuming predator pressures have operated over evolutionary time to select for periodic synchrony, associations between seed and cone predators and cone crop production levels were anticipated. These potential consequences of predator satiation were examined. …


Old-Field Succession On A Minnesota Sand Plain, R S. Inouye, Nancy J. Huntly, D Tilman, J R. Tester, M Stillwell, K C. Zinnel Jan 1987

Old-Field Succession On A Minnesota Sand Plain, R S. Inouye, Nancy J. Huntly, D Tilman, J R. Tester, M Stillwell, K C. Zinnel

Biology Faculty Publications

Vegetation and soils were sampled in 22 old fields ranging in age from 1 to 56 yr since abandonment. Soil nitrogen concentration increased significantly with field age. Vegetation cover, total aboveground plant biomass, and litter cover increased significantly with soil nitrogen. Light penetration to the soil surface was negatively correlated with total plant biomass. Field age and soil nitrogen concentration were used as independent variables in simple regression and partial correlation analyses to determine the relative importance of such time—dependent processes as dispersals vs. the availability of a limiting resource (nitrogen) as predictors of patterns in species richness or the …


Influence Of Rufuging Consumers (Pikas: Ochotona Princeps) On Subalpine Meadow Vegetation, Nancy J. Huntly Jan 1987

Influence Of Rufuging Consumers (Pikas: Ochotona Princeps) On Subalpine Meadow Vegetation, Nancy J. Huntly

Biology Faculty Publications

Talus slopes in western North America frequently are bordered by vegetation that differs in biomass, cover, height, and species composition from vegetation located farther from talus. These areas are grazed by pikas (Ochotona princess, which nest in that talus. Foraging theory predicts that pikas will produce a gradient of grazing pressure, which could produce the observed vegetational zonation. In a subalpine meadow in west-central Colorado, pikas produced the predicted gradient of grazing pressure, along which plant groups varied clinally in abundance. The effects of pikas on talus-border vegetation were tested by excluding pikas from small plots at several distances from …


Aspen Sucker Damage And Defect In Colorado Clearcut Areas, Thomas E. Hinds, W.D. Shepperd Jan 1987

Aspen Sucker Damage And Defect In Colorado Clearcut Areas, Thomas E. Hinds, W.D. Shepperd

Aspen Bibliography

Substantial acreages of aspen in the Rocky Mountains are being regenerated by clearcutting; however, there is little information on the quality of the suckers that reestablish in these areas. Whether the new stands will be more or less defective than their predecessors is unknown.


Characteristics Of Successful Competitors: An Evaluation Of Potential Growth Rate In Two Cold Desert Tussock Grasses, Eissenstat D. M., Caldwell M. M. Jan 1987

Characteristics Of Successful Competitors: An Evaluation Of Potential Growth Rate In Two Cold Desert Tussock Grasses, Eissenstat D. M., Caldwell M. M.

Aspen Bibliography

Within the first few weeks after seedling emergence, Agropyron desertorum, a more competitive tussock grass, had a much higher mean relative growth rate (RGR) than Agropyron spicatum, a very similar, but less competitive species. However, beyond the early seedling stage, the two grasses had a remarkably similar whole-plant RGR in hydroponic culture and aboveground RGR in glasshouse soil, if root temperatures were above approximately 12° C. At soil temperatures between 5 and 12° C, A. desertorum exhibited a 66% greater aboveground RGR than A. spicatum (P < 0.05). Both species responded similarly to warming soil temperatures. In the field, however, tiller growth rates were generally similar. Neither species showed marked tiller elongation until a couple of weeks after snowmelt, by which time soil temperatures, at least to a depth of 10 cm, were above 12° C for a significant portion of the day. Above-ground biomass accumulation over a three-year period indicated that both grasses had similar potential growth rates whereas Artemisia tridentata ssp. vaseyana, a common neighbor planted in the same plots, had a much greater potential growth rate. The greater competitive ability of adult A. desertorum, as compared to A. spicatum, cannot be attributed to appreciable differences in potential growth rates.