Archives -- Research Reports

1993-1994 RESEARCH REPORTS

Animal Behavior/Physiology

Northern Flicker
Gwen Bachman, Department of Biology, UC Los Angeles  

L. Allen: UC Los Angeles

In addition to working with Mark A. Chappell (see research summary below), I conducted a pilot study on the nesting behavior of the Northern Flicker.

Ecological and Evolutionary Aspects of Physiological Performance in Belding's Ground Squirrels
Mark A. Chappell, Department of Biology, UC Riverside  

	G. C. Bachman: UC Los Angeles
	J. Odell: UC Riverside

 

In this research we measure the maximal aerobic metabolic rate during exercise and cold exposure, as well as the minimal (basal) metabolic rate. Specific questions being addressed are: 1) how repeatable are these measurements over time, and especially during maturation (i.e., is a juvenile with relatively high performance likely to mature into an adult with high performance), 2) does performance correlate with long-term survival, and, 3) does performance correlate with reproductive success in females? Funding: Intramural funds. Currently seeking NSF funds.

 

Technique Refinement for Determining Mountain Lion Densities and Habitat Use by Individual Track Recognition in the Sierra Nevada Mountains
Melissa Grigione, Department of Environmental Studies, UC Davis  

S. Smallwood: UC Davis

 

Over six weeks during this past winter track sets of 22 known and six unknown mountain lions (Felis concolor) were recorded and photographed in Round Valley and Owens Valley, California. A total of 345 slides of individual tracks were taken. Since there are only 12 radio-collared mountain lions in the study site, I have accumulated duplicate information on most of the known mountain lions. Considerable variation exists within a track set, such as different soil substrates (including snow) and slope, the time of day photographs are taken, and the age of a track set. I maximized variability for single track sets by photographing tracks under different light conditions for several days in a row enabling the track set to transform by wind and daily freezing-thawing conditions. Dr. Shawn Smallwood and I have reviewed all 345 slides and are able to use 75-80% of them. The slides are now being entered into the computer (Adobe Photoshop) and will be digitized via Arc Info GIS and analyzed. The California Department of Fish and Game, Bishop, is continuing to photograph mountain lion tracks for me to enter into this program. In the weeks ahead, we will be able to link demographic variables such as age, size, and sex to mountain lion track sets. It is hoped that the data and subsequent analysis will be able to validate or disprove the Smallwood & Fitzhugh tracking method.  

 

Two Ongoing Studies Involving Belding's Ground Squirrels at SNARL
Warren G. Holmes, Psychology Department, University of Michigan  

J. Mateo, M. Clancy, J. Osborn: University of Michigan

 

One study was aimed at explaining the development of social relationships between juveniles and the mother during the development of alarm-call response behavior in juveniles. "Alarm calls" are vocalizations produced by adults when predators appear in a colony that warn colony members of danger. In both studies, animals are observed in 10 x 10 meter outdoor enclosures designed to mimic a ground squirrel's natural environment. For the social development study, juveniles' social interactions are observed for about 10 days to determine their social preferences, which are manifested primarily through juvenile-juvenile play behavior (e.g. chasing, wrestling, mounting). For the alarm-call response study, playbacks of taped sounds arE presented to juveniles and their responses recorded on video tape and later analyzed to determine things like response times, types of responses, and durations of responses. For the social development research done during the 1993-1994 time period, we concentrated on how moms affect social development and found that when dams were absent from the enclosures juveniles did not develop preferences for their siblings like they did when dams were present. For the alarm-call response research done during the 1993-1994 time period, we worked to produce a simple descriptive picture of how juveniles' responses to different playback sounds changes with juvenile age. In our ongoing studies, we are trying to determine how juveniles learn to respond appropriately to different kinds of sounds. Funding: National Institute of Mental Health and University of Michigan.

 

Beetles
Roget Dajoz, Museum of Natural History, Paris 

Aline Dajoz, Unaffiliated

 

Roget and Aline Dajoz made their their third lengthy visit to SNARL in their ongoing study of the ecology and biodiversity of the Order Coleoptera (beetles).

Aquatic Ecology

Scale, Exchange Rates, and the Impact of Predators on Prey Populations in Streams
Scott D. Cooper, Department of Biological Sciences, UC Santa Barbara 

	C. Ouverney: California State University, Hayward (visitor)
	S. Wiseman, K. Kratz, T. Jenkins, H. Coe, C. Bartosh, N. Lackey-Schaffer, A. Cheroske, M. Embury: UC Santa Barbara

 

This research includes both theoretical and empirical examinations of the effects of scale on the responses of ecological systems to perturbation. During the summer of 1993 we ran experiments examining the effects of brown trout on invertebrate prey and algae populations at different spatial scales. We manipulated trout densities in experimental arenas at SNARL which encompassed two spatial scales, i.e. experimental channels (50 m2) and stream sections (1100 m2). Relative growth rates of trout and epibenthic densities of the dominant grazer (baetid mayfly nymphs) declined, and algal biomass increased, with increasing trout biomass. Longitudinal trends in algal biomass varied with trout treatment. Density-dependent changes in trout growth were more pronounced in the large sections than in the experimental channels. Subsidiary experiments examined the effects of prey density on the feeding rates of stonefly predators in heterogeneous environments, density-dependent emigration by mayfly prey in the presence and absence of stonefly predators, and the effects of stonefly predators on prey assemblages in simple versus complex environments. The latter project was conducted by an undergraduate researcher with support from a REU (Research Experience for Undergraduates) supplement to the NSF grant. We also mapped stonefly predator and invertebrate prey distributions in Convict Creek sections during trout manipulations by systematically sampling entire stream reaches. Funding: NSF.

Aquatic Biota in the Sierra Nevada: Current Status and Potential Effects of Acid Deposition on Populations
Scott D. Cooper, Department of Biological Sciences, UC Santa Barbara
Roland A. Knapp, Marine Science Institute, UC Santa Barbara 

T. Jenkins, K. Kratz: UC Santa Barbara

 

The goal of this research was to examine the effects of increased inputs of acid on early life history stages of golden trout (Oncorhynchus aguabonita). During the spring and summer of 1993, we conducted a dose-response experiment during snowmelt in channels lying next to the outlet stream (Mine Creek) of a representative high-altitude lake (Spuller Lake). Buried eggs of golden trout were exposed to a gradient of six pH levels ranging from 4.8 to 6.6, for a period of 40 hours, and the survivorship of eggs determined nine to ten days later. Survivorship of eggs was high at the low temperatures.

 

An Experimental Study of Stream and Riparian Recovery under Differing Grazing Management Practices
David B. Herbst and Roland A. Knapp, Marine Science Institute, UC Santa Barbara 

D. R. Dawson: SNARL

 

Livestock grazing is the most widespread land-use practice in the western United States. Sensitive riparian zones and streams are vulnerable to impacts caused by livestock and many stream miles have suffered erosion, sedimentation, and loss of riparian cover. Although physical and chemical water quality measures have been used to characterize grazing impacts on rangeland streams, effects on the ecosystem are often of greater concern. In this study we compare various biological measures of habitat quality (using aquatic invertebrates and fish) to conventional monitoring techniques. Grazing exclosures and rotation pastures represent different types of grazing practices intended to restore stream habitat condition. Our research indicates that while some effects of grazing may be detected through changes in channel and riparian conditions, others are evident only in the structure of the biological community. These are long-term studies that will require years for clear patterns to emerge. Funding: UC Water Resources Center.

Project 1: Conservation Biology of the Mountain Yellow-Legged Frog in the Sierra Nevada
Project 2: Golden Trout Ecology and the Influence of Livestock Grazing on the Golden Trout Wilderness
Roland A. Knapp, Marine Science Institute, UC Santa Barbara 

	S. D. Cooper, A. Brown, D. Herbst: UC Santa Barbara
	C. Milliron: California Department of Fish and Games, Bishop
	D. R. Dawson: SNARL
	K. Matthews, R. Osterhuber, E. Ballard, J. Muck, V. Vredenburg: USDA Pacific Southwest Research Station

Project 1: The mountain yellow-legged frog has declined precipitously throughout the Sierra Nevada during the last century. The major reason for this decline is widely believed to be the introduction of predatory non-native trout into the habitat of the mountain yellow-legged frog. To determine the feasibility of reintroducing the mountain yellow-legged frog into previously-occupied habitat, I removed all non-native trout from a lake in the Inyo National Forest and translocated frogs and tadpoles into the lake. Results to date show that translocated frogs and tadpoles have survived well, and suggest that reintroductions of mountain yellow-legged frogs are a feasible method of restoring mountain yellow-legged frog populations to formerly occupied habitat in the Sierra Nevada. Project 2: The Golden Trout Wilderness in the southern Sierra Nevada was designated largely to protect the habitat of the native golden trout. One of the largest potential impacts to the area is the grazing of livestock, a practice that has occurred for over 150 years. In the first part of this study, we compared stream and riparian conditions and golden trout populations inside and outside of a series of livestock exclosures in three meadows in the Golden Trout Wilderness. We found large differences in habitat and fish populations inside versus outside the exclosures, particularly in the oldest exclosures (11 years old), and these differences were consistent with habitat recovery inside the exclosure relative to grazed areas outside exclosures. In the second part of the study, we investigated the spawning behavior of golden trout to determine whether spawning is affected by livestock grazing. We recorded the number of trout nests built in ungrazed, lightly grazed, and heavily grazed areas, and measured a series of habitat variables at each nest to determine spawning habitat preferences of female golden trout. Our results show that nest density is highest in heavily grazed areas and lowest in ungrazed areas, and that this relationship is the result of livestock grazing resulting in stream widening. This widening increases the area of the stream composed of suitable spawning habitat. These results suggest that the high density of golden trout in grazed areas and the small size of individual fish may be a consequence of an increased amount of spawning gravel, and not an intrinsic feature of golden trout populations. Funding: Pacific Southwest Research Station, US Forest Service.

Acid Rain Research
John M. Melack, Marine Science Institute and Department of Biological Sciences, UC Santa Barbara

	D. R. Dawson: SNARL
	J. Sickman, K. Skeen, G. Spindell, S. Root, P. Kirchner, N. Fiddler, K. Leary, M. Moskowitz, D. Lucero:
	Marine Science Institute, UC Santa Barbara

 

Since 1983, high-altitude lakes of the Sierra Nevada and their watersheds have been monitored with respect to acid-deposition. Sensitive lakes and watersheds exist and undergo episodic acidification during snowmelt and during intense summer rains. Sensitive organisms have been identified in lakes. However, chronic (ie., long-term) acidification of lakes and streams is unlikely under present acid-deposition rates. Funding: California Air Resources Board.

Mono Lake Research
John M. Melack, Marine Science Institute and Department of Biological Sciences, UC Santa Barbara 

M. Gastil, D. Heil, R. Jellison, M. Embry, M. Moskowitz: Marine Science Institute, UC Santa Barbara

Mono Lake is a large, hypersaline, highly productive alkaline lake lying just east of the Sierra Nevada. In addition to its value as a recreational and scenic resource, it contains large populations of an endemic brine shrimp and the alkali fly which are an important food source for migrating birds. Although saline lakes are common throughout the world and provide important ecological resources for many species, they are much less studied than freshwater ecosystems. Limnological monitoring programs and experimental research conducted from 1982-1994 represent one of the longest continuous studies of any hypersaline ecosystem and, in addition to addressing current environmental concerns in the Mono Basin, provide insight into the functioning of saline ecosystems. Funding: Los Angeles Department of Water and Power and NASA (HIRIS).

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Geology/Geography

The Minarets Caldera
Elizabeth Warner Holt, Department of Geology, Stanford University

	J. W. Holt: Caltech
	S. Warner: Unaffiliated

 

The Minarets caldera, of mid-Cretaceous age and exposed in the Ritter Range roof pendant in the Sierra Nevada, contains a 4.5-km-thick section of caldera fill, including a caldera-collapse breccia intercalated with ignimbrite. The caldera-collapse breccia is composed of five megabreccia sections, the largest of which is >1 km thick. Sections of megabreccia are characterized by unique clast populations which consist predominantly of felsic lavas and associated pyroclastic rocks, but also include andesite, basalt, granodiorite and bedded volcanoclastic rocks. Clast populations within sections of megabreccia correspond to their hypothesized source areas along the eastern caldera margin. The presence of thick megabreccias within the caldera fill indicates that, at several times during caldera collapse, the rate of subsidence exceeded the rate of iginimbrite accumulation and allowed significant scarps to develop on the newly formed caldera wall. One particularly large subsidence event (>1.5 km) accompanied the emplacement of three massive debris avalanches from the northeastern caldera wall. Thick sections of megabreccia are clast-supported, contain large clasts (up to 800 m in length), and are underlain by more laterally extensive sections of matrix-supported breccia composed of smaller clasts. The matrix-supported breccia does not contain clasts >2 m in length, suggesting that matrix-supported breccia was deposited by debris flows in which the strength of the matrix was insufficient to support larger clasts. Clasts somewhat larger than 2 m must have been transported by a rockslide mechanism in which they were supported by grain dispersive forces and formed clast-supported deposits. Funding: NSF, Stanford School of Earth Sciences McGee Fund, and Shell Fund Grants. 

The Development of Mono Basin Shoreline Ecosystems
Deborah L. Elliott-Fisk, Geography Department, UC Davis 

C. A. Toft, J. H. Richards, J. Brown: UC Davis

 

In this long-term research project, we are investigating the interactions of the physical environment (wind, soils, geomorphology, and groundwater) with the establishment of plant communities in the process of succession on the playa and upland shoreline ecosystems (e.g., sand dunes, lagoon bottoms) along the northern shore of Mono Lake. Harsh physical conditions limit the establishment of plant species on the youngest geomorphic features, and interaction with saline groundwater, fluvial erosion with spring runoff, and aeolian transport make establishment difficult. Sarcobatus vermiculatus is the initial playa/dune colonizer, followed by other shrubs and salt grass as physical environmental conditions ameliorate through time. Funding: USDA NRI program.

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Hydrology

Monitoring of Snowmelt Solute Concentrations
Roger Bales, Department of Hydrology and Water Resources, University of Arizona 

The aim of our snowmelt research at SNARL is to determine how air pollutants and other chemicals stored in the snowpack are released into the environment when the snow melts. We collect the water issuing from the base of the snowpack in polyethylene collection pans (snowmelt lysimeters) and measure the volume of melt-water and its chemical content. We maintain eight such lysimeters at Mammoth Mountain in order to capture the temporal and spatial variability of the snowmelt process. Seasonally, the majority of the chemical load is released during the early part of the melt season because ions are rinsed off the exterior of the snow grains where they reside prior to the melting of the snowpack. This process is termed fractionation. On the time scale of a single day, the pattern of the meltwater concentration is more complicated due to the competing effects of dilution and fractionation. Funding: NSF and NASA-EOS project.

Understanding the Dynamics and Spatial Variations of Snow Properties in the Context of Applications to Remote Sensing and Hydrology
Robert E. Davis, Department of the Army  

S. Burak: Snow Survey Associates

Use of SNARL involved carrying out field and laboratory experiments to measure changes in snow properties, testing models to predict the changes in snow properties over time and developing links between these models and the electromagnetic signature of snow in the visible/near-infrared and microwave spectral regions. Investigations on the elution of chemical constituents from snow were also reported during this period. The experiments consisted of field applications of soluble tracers to the snowcover and analysis of the patterns of outflow. We observed multiple ionic pulses from the snowcover, something new not previously reported (to my knowledge). Additional work on avalanche hazard evaluated methods for analyzing weather and avalanche data sets for operation guidance on important variables. The analysis showed a surprisingly high classification accuracy, which suggests that the ranking of weather variables is robust. We have been requested to perform similar analyses for other avalanche regions.

Project 1: Hydrology and Water Resources of the Sierra Nevada
Project 2: Ripening Processes in Snowpacks of the Sierra Nevada
Rick Kattelman, Department of Biological Sciences, UC Santa Barbara 

J. Dozier, J. M. Melack: UC Santa Barbara

Project 1: Assessment of hydrologic conditions in river basins and small watersheds throughout the Sierra Nevada. Funding: USDA Forest Service and Sierra Nevada Ecosystem Project.
Project 2: The transition from dry, subfreezing snow-cover to isothermal snow freely conducting water was observed near timberline in the Sierra Nevada. Minor textural discontinuities were sufficient to both route water laterally downslope and later create ice sheets at these strata. Funding: NASA-Earth Observing System Program.

EOS NASA Project
John M. Melack, Marine Science Institute and Department of Biological Sciences, UC Santa Barbara
Jeff Dozier, Department of Geography, UC Santa Barbara

	V. B. Aizen, E. Lolctionova: Russian Academy of Sciences
	R. Kattelman: UC Santa Barbara

This is an experimental field investigation in the Sierra Nevada for developing a method of runoff calculation in mountain areas with the use of satellite information. Differences in hydrological regime of snow-cover in the Tien Shan and Sierra Nevada are being compared. Results of these field investigations are being interpreted now. Funding: EOS NASA Project.

Groundwater Hydrology of the Mono Basin
David B. Rogers, Earth Science Department, UC Santa Cruz

	D. P. Groenevel: Great Basin Unified Air Pollution Control District; Bishop, California
	F. M. Phillips: New Mexico Institute of Mining and Technology; Socorro, New Mexico
	R. S. Anderson, S. J. Dreiss (deceased): UC Santa Cruz
	N. O. Jannik: Winona State University; Winona, Minnesota

Mono Lake is a saline, closed-basin lake. Well logs show that saline groundwater of concentration >18,000 ppm extends to the bottom of 2 km of basin fill. We used numerical simulations to infer the saline ground water distribution. We re-evaluated the chloride budget of Mono Basin: 82% of the chloride inventory is in the subsurface. The low ratio of 36cl to stable chlorine for both the lake and groundwater requires that volcanic chloride inflow constitute 90% of the total, based on a mass-balance model. Model chloride accumulation time estimates range from 70 to 200 kyr, significantly shorter than the estimated 3-4 Ma basin closure age. Simulations suggest that the current high lake salinity is due to Late Quaternary lake-stage changes, a result of compression and expansion of the saline groundwater mass. Only the longer-term stage changes cause saline groundwater movement, and lake salinity equilibration requires thousands of years. Historical lake salinity data suggest a 5% loss of the lake's solutes over 50 years, consistent with a combination of diffusion into the sediments, estimated from shallow cores, and model-predicted advection into groundwater. Field results confirm that saline groundwater underlies the shoreline. Evaporation produces a salt crust, a major dust source during wind storms. Deflation removes only about 2% of the salt crust each year. Winter runoff dissolves most of the crust and carries the solutes down slope to the lake. Based on this model, the dust-producing conditions will persist indefinitely if low lake levels continue. Funding: Great Basin Unified Air Pollution Control District, using pass-through funds from the Los Angeles Department of Water and Power; Department of the Interior, U.S. Geological Survey; and grants from the Geological Society of America, the Association of Groundwater Scientists and Engineers (National Ground Water Association), and the Earth Sciences Department, UC Santa Cruz.

Satellite Determination of Snow Covered Area
Walter Rosenthal, Center for Remote Sensing and Environmental Optics, UC Santa Barbara

J. Dozier: UC Santa Barbara

Snow-covered area (SCA) is fundamental to the role of snow in hydrology and climate. Satellite derived estimates of SCA are important to snowmelt runoff models and to estimating the radiative component of the Earth's surface energy balance. The ground resolution of orbiting multi-spectral instruments varies from 20 meters to over a kilometer, so the requisite first steps in the application of remote sensing to the above problems are: 1) recognition of whether the perceived snow cover is homogeneous or mixed with other surface materials, and 2) quantifying the degree of mixing by determining the fraction of each pixel covered by snow. My research has centered on the development of algorithms that accurately map snow and estimate the fractional snow-covered area within each pixel over rugged terrain, not only in alpine basins above tree line, but beneath forest canopies and where it is interspersed with rock, soil, or vegetation. At each step quantitative estimates of SCA at sub-pixel resolution are accompanied by realistic error estimates. The tools are linked in a series of UNIX pipes and filters to produce classified images of SCA at sub-resolution scale, and binary snow and cloud masks. The accuracy of automated classification using Landsat Thematic Mapper data (30 meter ground resolution) equals that obtainable from large format aerial photographs but is faster, cheaper, and covers a much larger area. The mapping method is insensitive to surface lithology, canopy type, the water equivalent of the snow pack, snow grain size, or local illumination. This work is being extended to NOAA/AVHRR data with a ground resolution of 1.1 kilometer. Funding: NASA (EOS).

Episodic Acidification of High-Elevation Sierra Lakes
John L. Stoddard, Mantech Environmental 

	M. M. Erway: Mantech Environmental
	P. Kirchner, K. Leary, N. Fiddler, M. Moskowitz, J. Sickman, R. Erway: Marine Science Institute, UC Santa Barbara

The Sierra Episodes Study is a project to study episodic acidification of high-elevation Sierra Lakes. We collect daily snowmelt runoff samples from nine lake outlets and analyze the samples for acid/base chemistry. Funding: California Air Resources Board and the U S Environmental Protection Agency.

Studies in Snow Algae Near Tioga Pass, Sierra Nevada
William H. Thomas, Scripps Institute, UC San Diego

	T. Thomas, A. Thomas: UC San Diego
	A. Thomas: UC San Diego and UC Irvine

Three separate studies were carried out: 1) Interrelationship between snow algae and bacteria. Bacterial production rates and abundances were higher in snow patches containing algae (red snow) than in white snow. Bacteria and algae are intimately associated and the algae were probably supplying organic matter to the bacteria. 2) Snow albedo was negatively correlated with algal abundances but algae probably had little or no influence on overall snow albedo (light reflectance). 3) Green snow algal photosynthesis was inhibited strongly by ultraviolet radiation while red snow algal photosynthesis was inhibited only slightly. Green snow is found among trees and shade, while red snow is found in more open areas near timberline.

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Plant Ecology

The Effect of Herbivory on the Growth of Rabbitbrush
Heidi West, California State University at Chico

Native plant species adapted to highly alkaline and saline soils have colonized the recently exposed Mono Lake playa. These plants provide ground cover that dampens the effects of dust and sand storms. Reproduction and growth of plants on the exposed lake bed, therefore, aids in decreasing hazardous airborne material. Rabbits are one of the dominant herbivores of Chrysothamnus nauseosus (Rabbitbrush) around Mono Lake. This study examines the effects of herbivory by these animals on four juvenile populations of this plant in the Mono Dunes. Currently, little information exists on herbivory of native species around Mono Lake. In each population, thirty plants have been chosen and randomly assigned to one of three treatments. These three treatments are defined as follows: one third are fenced herbivore exclusion plots, another third are fenced herbivore exclusion plots artifically subjected to a specific amount of herbivory by the experimenter, and the last third (ie: control) are unfenced, unmanipulated plots that indicate natural levels of herbivory. Effects of herbivory will be quantified by measuring plant growth in the latter two treatments and comparing these measurements with the rabbit exclusion treatment.