Publications
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Soil surface disturbances in cold deserts: Effects on nitrogenase activity in cyanobacterial-lichen soil crusts
CyanobacteriaMichen soil crusts can be a dominant
source of nitrogen for cold-desert ecosystems. Effects
of surface disturbance from footprints, bike and vehicle
tracks on the nitrogenase activity in these crusts was investigated.
Surface disturbances reduced nitrogenase activity
by 30-100%. Crusts dominated by the cyanobacterium
Microcoleus vaginatus on sandy soils were the most susceptible
Authors
Jayne Belnap
Indicators of red squirrel (Tamiasciurus hudonicus) abundance in the whitebark pine zone
We investigated occupied squirrel middens and squirrel sightings and vocalizations as indicators of red squirrel (Tamiasciurus hudsonicus) abundance in the high-elevation whitebark pine (Pinus albicaulis) zone. Data were collected 1984-1989 from line transects located on 2 study sites in the Yellowstone ecosystem. We evaluated the performance of each measure on the basis of precision and biologica
Authors
D.J. Mattson, Daniel P. Reinhart
Ecology of kokanee salmon (Oncorhynchus nerka) and rainbow trout (Oncorhynchus mykiss) in Crater Lake, Oregon
No abstract available.
Authors
M. W. Buktenica, Gary L. Larson
Zooplankton assemblages in Crater Lake, Oregon, USA
The zooplankton community in Crater Lake was comprised of 11 rotifer species and 2 species of cladocerans. Most zooplankton taxa were distributed in winter and spring from the lake surface to a depth of about 200 m, the maximum depth of mixing of lake waters by wind energy. The distribution of zooplankton species was partitioned in the water column to a depth of 200 m during summer and fall, which
Authors
Gary L. Larson, C. D. McIntire, R.E. Truitt, M. W. Buktenica, E. Karnaugh-Thomas
Taxonomic structure and productivity of phytoplankton assemblages in Crater Lake, Oregon
Interactions among physical, chemical, and biological components and processes in Crater Lake result in a complex and dynamic ecosystem. In winter and spring, wind energy mixes the lake to a depth of about 200 m. During this period, episodic sinking of cold water below the depth of 200 m produces an upwelling of nutrient-rich water from the deep lake, a process that has a strong influence on the c
Authors
C. D. McIntire, Gary L. Larson, R.E. Truitt, M.K. Debacon
Temperature, water chemistry, and optical properties of Crater Lake
Water temperature, water chemistry, and optical properties of Crater Lake were studied from 1983 to 1991. In winter and spring, wind energy and convection mixed the water column to a depth of 200 to 250 m. The lake was thermally stratified in summer and early fall; however, the epilimnion was only 5 to 20 m thick, and most of the 589 m deep water column was a cold hypolimnion. The lake was slightl
Authors
Gary L. Larson, C. D. McIntire, M. W. Buktenica
Development of a 10-year limnological study of Crater Lake, Crater Lake National Park, Oregon, USA
This paper summarizes the development of a limnological study of Crater Lake conducted between 1983 and 1992. The program was mandated by Congress in the fall of 1982 after a panel of limnologists found the lake data base (1896–1981) to be inadequate to determine if the phytoplankton community had changed and if the lake was decreasing in clarity as suggested from independent studies between 1978
Authors
Gary L. Larson
Factors leading to different viability predictions for a grizzly bear data set
Population viability analysis programs are being used increasingly in research and management applications, but there has not been a systematic study of the congruence of different program predictions based on a single data set. We performed such an analysis using four population viability analysis computer programs: GAPPS, INMAT, RAMAS/AGE, and VORTEX. The standardized demographic rates used in a
Authors
L. S. Mills, S.G. Hayes, M.J. Wisdom, J. Citta, D.J. Mattson, K. Murphy
Science and management of Rocky Mountain grizzly bears
The science and management of grizzly bears (Ursus arctos horribilis) in the Rocky Mountains of North America have spawned considerable conflict and controversy. Much of this can be attributed to divergent public values, but the narrow perceptions and incomplete and fragmented problem definitions of those involved have exacerbated an inherently difficult situation. We present a conceptual model th
Authors
D.J. Mattson, S. Herrero, R. G. Wright, C. M. Pease
Population structure of red-cockaded woodpeckers (Picoides borealis) in south Florida: RAPDs revisited
Six south Florida populations of the endangered red-cockaded woodpecker (Picoides borealis) were sampled to examine genetic diversity and population structure in the southernmost portion of the species' range relative to 14 previously sampled populations from throughout the species range. Random amplified polymorphic DNA (RAPD) analyses were used to evaluate the populations (n= 161 individuals, 13
Authors
Susan M. Haig, R. Bowman, Thomas D. Mullins
Crested wheatgrass-cheatgrass seedling competition in a mixed-density design
Plant competition experiments have historically used designs that are difficult to interpret due to confounding problems. Recently, designs based on a 'response function' approach have been proposed and tested in various plant mixture settings. For this study, 3 species were used that are important in current revegetation practices in the Intermountain West. 'Nordan' (Agropyron desertorum [Fish. e
Authors
Mark G. Francis, David A. Pyke
Chemical solute mass balance of Crater Lake, Oregon
Crater Lake covers the floor of the caldera at the top of Mount Mazama. Surrounded by steep walls, the water surface of the lake occupies 78 percent of the catchment basin. No major rivers empty into the lake, and there is no surface outlet Based on a chemical solute mass balance model, mass inputs of major solute chemical components (Na, Ca, K, Mg, SO4, Cl, Si, and HCO3) from atmospheric depositi
Authors
Peter O. Nelson, J.F. Reilly, Gary L. Larson