Tahoe Research, Scholarship & Outreach at the University of Nevada, Reno

Dissertations and Theses about the Tahoe Basin
by Students at the University of Nevada, Reno

Terrestrial Life


Author:
Ayers, Michael Benson
Year: (1997)
Title: Aerial multispectral videography for vegetation mapping and assessment of beaver distribution within selected riparian areas of the Lake Tahoe Basin (Nevada, California).
Institution: University of Nevada Reno
No. Pages: 71
Thesis Type: MS
Link: Download (UNR Only)
Keywords: AGRICULTURE, FORESTRY AND WILDLIFE (0478); PHYSICAL GEOGRAPHY (0368)
Abstract: I used multispectral videography to classify 10 streams in the Tahoe Basin, California and Nevada. I mosaicked images before georeferencing and positional accuracy did not decrease relative to a pilot study in the basin. Mosaics were manually separated into 'riparian', 'upland', and 'channel' regions and classified independently, reducing errors caused by spectral overlap among coniferous, deciduous, thick, and thin herbaceous vegetation and between water and shadow. When defining the training data, more than one spectral class defined some information classes. The videography was classified into 11 classes using a step-wise linear discriminant algorithm resulting in average accuracies of 68% and 73% when five cover classes were generalized into two classes. I compared buffer zones of 50, 100, and 200 meters centered on active dams to ones centered on random points. Area estimates of coniferous, deciduous, thick, and thin vegetation were significantly different in at least one of the three buffers. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Tueller, Paul T.
Reference: 0-591-68326-1; MAI 36/03, p. 744, Jun 1998
 

Author:
Barnes, Myra E.
Year: (1993)
Title: The Pollination Ecology and Reproductive Biology of Gentiana Newberryi (Gentianaceae) in the Eastern Sierra Nevada.
Institution: University of Nevada Reno
No. Pages: 68
Thesis Type: MS
Link:
Keywords:
Abstract: Gentiana newberryi Gray flowers at Little Valley (2000 m) and Forestdale Divide (2580 m) were significantly larger and produced more ovules than flowers at Frog Lakes (3120 m). Predation significantly reduced seed set at the higher elevation sites. Herbivores removed 37.9% of the flowers at Frog Lakes and predispersal seed predators consumed all of the seeds in 64.3% of seed capsules at Forestdale Divide and 3.0% at Frog Lakes. There was a significant relationship between the number of bees present and the number of seeds produced at Little Valley. Self fertilized seeds (autogamy) germinated at the same rate as cross pollinated seeds (allogamy). The number of seeds produced by self pollination is probably limited anatomically since flowers that were hand pollinated with pollen from a flower on the same plant (geitonogamy) did not produce significantly fewer seeds than cross pollinated flowers.
Advisor:
Reference: 1354957
 

Author:
Basey, John Martin
Year: (1987)
Title: Central-Place Foraging by Beavers in the Sierra Nevada: Tree-Size Selection and Inducible Defenses in Quaking Aspen (California).
Institution: University of Nevada Reno
No. Pages: 60
Thesis Type: MS
Link:
Keywords:
Abstract: At a newly occupied site, beavers (Castor canadensis) preferentially cut quaking aspen (Populus tremuloides) less than 8 cm in diameter. Small aspen occur in two growth forms: juvenile-form suckers abundant at sites which have received heavy prior use by beavers, and adult-form suckers, which predominate at newly occupied sites. Cafeteria-style feeding experiments in the field showed that beavers selected for branches from large trees and adult-form suckers, and against juvenile-form suckers. An unidentified compound which may be a feeding deterrent was present in juvenile-form suckers at significantly higher concentrations than in branches from mature trees or adult-form suckers. At a site with a long history of beaver use, there was a higher concentration of this compound in trees less than 10 cm in diameter than in larger trees, and the beavers at this site preferentially cut large trees, unlike beavers at the newly occupied site.
Advisor:
Reference: 1331023
 

Author:
Basey, John Martin
Year: (1992)
Title: Foraging Behavior by Beavers in Relation to Food Quality and Predation.
Institution: University of Nevada Reno
No. Pages: 207
Thesis Type: PhD
Link:
Keywords:
Abstract: Beaver foraging behavior and tree-felling behavior was examined in relation to three hypotheses: beavers select food and feeding patches and fell trees based on (1) maximizing profitability, (2) minimizing risk of predation, and (3) trade-offs between profitability maximization and predation-risk minimization. In this paper I develop two models, an energy-based foraging model and a predation-risk-based foraging model to test predictions of the three hypotheses. Predictions of tree- size and patch selection were tested with field experiments where beavers were offered a set of 1.5-cm- diameter quaking aspen stems close to water and 3.0-cm- diameter stems far from water. Selection of 1.5-cm-close and 3.0-cm-far aspen was consistent with predictions based on a trade-off strategy, but was inconsistent with predictions of both pure strategies. Predictions of tree- felling behavior were tested with data gathered at four beaver ponds in the Sierra Nevada. By cutting on the back side of aspen beavers directed them to fall more toward the pond. Beaver-tree-cutting patterns (back or front) in relation to tree-size and distance from pond were inconsistent with predictions of a profitability-based model, were consistent with predictions of a predation- risk-based model, and were consistent with a strategy of trading-off predation-risk minimization and profitability maximization. Tree-species selection by beavers in relation to the growth-rate hypothesis of investment in chemical defenses by Coley et al. (1985) was examined with cafeteria-style feeding experiments. Tree-species selection by beavers of intact stems was inconsistent with predictions of the hypothesis, but selection of aspen painted with extracts from the leaves of different species was consistent with the growth-rate hypothesis, but was also consistent with a new hypothesis outlined in this paper based on leaf-lifetime. A field experiment analyzing cost and effectiveness of using a natural chemical extract to protect trees from being cut by beavers compared to wrapping trees with chicken wire revealed that the chemical extract may be an effective deterrent.
Advisor:
Reference: 9233456
 

Author:
Beckmann, Jon Paul
Year: (2002)
Title: Changing dynamics of a population of black bears (Ursus americanus): Causes and consequences.
Institution: University of Nevada Reno
No. Pages: 126
Thesis Type: PhD
Link: Download (UNR Only)
Keywords: BIOLOGY, ECOLOGY (0329); BIOLOGY, ZOOLOGY (0472)
Abstract: Populations at the edge of their range are typically extinction-prone, and the probability of their persistence is challenged by habitat fragmentation coupled with rapid human population growth. At the interface of the Great Basin Desert and Sierra-Nevada Range including the Lake Tahoe Basin, black bears (Ursus americanus) have historically been ecologically restricted but they have recently experienced a rapid non-equilibrium response to increasing humans. To assess possible effects at contact zones, I tested predictions of resource-based models, first by contrasting biological features of individual bears between an urban-wildland interface (experimental area) and wildland areas (control area), and second by considering temporal changes in life-histories and ecology that span almost 15 years. Among the documented changes were: (i) declines of 90% and 70% in mean home range size for urban-interface males and females (respectively) relative to wildland bears (p < 0.05); (ii) body mass in which urban-interface bears averaged 30% more for both sexes relative to wildland animals (p < 0.05); (iii) alterations of denning chronology with urban-interface bears entering hibernacula later in the winter and emerging earlier than wildland conspecifics (p < 0.05); (iv) shifts in the pattern and amount of daily activity for bears in urban-interface areas relative to wildland conspecifics; and (v) bear densities which increased 3+fold in urban areas compared to baseline, historical densities. Additionally, since 1990 increases in the frequency of (i) urban-interface bears, (ii) collisions with vehicles, and (iii) citizen complaints were about 7000%, 1500%, and 1000% respectively. All mortalities (n = 59) since 1997 were due to anthropogenic causes. Finally, I examined the effectiveness of the six most common deterrents currently used by state and federal entities to alter the behavior of "nuisance" black bears using 62 individuals. My results indicate that expanding but clumped urban foods facilitated a rapid redistribution of bears across this arid landscape. The careless provisioning of food, whether deliberate or unintended, may be operating at scales substantially larger than that described here. If so, the altered distribution of populations of other species may also be compromising ecological processes, an issue that awaits further attention from conservation biologists. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Berger, Joel
Reference: 0-493-88259-6; DAI-B 63/10, p. 4459, Apr 2003
 

Author:
Bollinger, Phillip Wayne
Year: (1985)
Title: The Foraging Ecology of the Pocket Gopher Thomomys Monticola.
Institution: University of Nevada Reno
No. Pages: 71
Thesis Type: MS
Link:
Keywords:
Abstract: Abstract not available.
Advisor:
Reference: 1325138
 

Author:
Bradley, Timothy Scott
Year: (1999)
Title: Prescription fire in western ecosystems: Microsite recovery of vegetation in a pinyon juniper woodland and bark beetle response to fire-injured trees in the Lake Tahoe Basin (Nevada, California, Dendroctonus, Scolytidae).
Institution: University of Nevada Reno
No. Pages: 87
Thesis Type: MS
Link: Download (UNR Only)
Keywords: ENVIRONMENTAL SCIENCES (0768); AGRICULTURE, FORESTRY AND WILDLIFE (0478); AGRICULTURE, RANGE MANAGEMENT (0777); BIOLOGY, ENTOMOLOGY (0353); BIOLOGY, ECOLOGY (0329)
Abstract: Investigations were conducted on prescription fire effects of vegetation microsite recovery in a pinyon- juniper woodland and on bark beetle presence in fire- injured Jeffrey pines in the Lake Tahoe Basin. Analysis of variance showed significant short-term decreases in cover of perennial grasses and a general decrease in densities of all non-grass plant species. Fire effects led to highly significant microsite recovery pattern for cheatgrass. Three different plant species, absent from non-burned plots, showed significant increases in burned plots. An assessment of control and fire injured Jeffrey pines showed a significant correlation between burning and probability of bark beetle attacks. Computed odds ratio from a logistic regression model showed the probability of bark beetle attack was 24 times greater in fire plot trees. Highly significant multiple logistic regression models were developed for commonly occurring bark beetle species, showing a high positive correlation with various burn severity measures. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Tueller, Paul T.
Reference: 0-599-35465-8; MAI 37/05, p. 1422, Oct 1999
 

Author:
Brown, David L.
Year: (1987)
Title: Nitrate Cycling and Hydrologic Transport Mechanisms in a Sierra Nevada Headwaters Watershed (California; Groundwater Pollution).
Institution: University of Nevada Reno
No. Pages: 87
Thesis Type: MS
Link: UNR Life and Health Sciences Library Call Number: Thesis 2208 
Keywords: HYDROLOGY (0388)
Abstract: The primary non-point source pollutant impacting Lake Tahoe is nitrate-nitrogen. This paper presents the results of four years of research that address nitrate transport and cycling characteristics at the watershed level. Water quality was monitored in an undeveloped 79.6 ha headwaters watershed to delineate nitrate concentrations in precipitation, stream discharge, soil moisture and groundwater. The flow and storage in these systems was measured using an extensive instrumentation network. Nitrate cycling mechanisms including denitrification and uptake by periphyton, conifers and macrophytic vegetation were studied in the field, and estimates were made of nitrogen-fixation and nitrification. The results show that the study watershed removes virtually 100% of the nitrate derived from all sources. A simplified conceptual model is presented to describe the temporal interactions between removal and hydrologic transport mechanisms. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor:
Reference: MAI 26/01, p. 94, Spring 1988
 

Author:
Budy, Jerome D.
Year: (1984)
Title: Drought Avoidance in Jeffrey Pine Ecotypes from the Eastside Sierra Nevada.
Institution: University of Nevada Reno
No. Pages: 120
Thesis Type: PhD
Link:
Keywords:
Abstract: Jeffrey pine seed and seedling characteristics were evaluated in greenhouse and field trials in order to detect if any variation could be explained by the elevation, aspect, and moisture class of the parent seed trees. Single-tree cone collections were obtained from naturally occurring, wind-pollinated trees on the eastside Sierra Nevada in the fall of 1974, 1975 and 1976. For each of the 84 parent trees sampled, elevation, tree aspect, drainage aspect, watershed aspect and soil moisture class were determined. Seed and seedling characteristics used as variables included seed weight, emergence speed, seed cap persistence, cotyledon number and length, seedling heights and seedling survival after outplanting. Analyses of variance and polynomial, linear and multiple regression analyses were used to evaluate the responses as shown by seed and seedling characteristics from the 84 seed sources. Of the seed tree characteristics, elevation had the greatest effect on the characteristics and performance of the progenies. The elevation of the seed sources was significantly correlated with seven of the eleven characteristics evaluated. The tree aspect, drainage aspect, and watershed aspect of the seed sources, as well as the moisture class, had little significant effect. The lack of any significant correlations with the aspects and moisture class of the seed sources probably resulted due to cross pollination. In a given elevational zone, a seed tree could be pollinated by pollen from all possible moisture classes because the distances would not serve as a barrier. The significant correlations with elevation are probably due to the timing of pollination, the greater distances involved, the abrupt slopes on the eastside Sierra, and the discontinuous Jeffrey pine population. Pollination usually occurs two to three weeks earlier in the lowest elevational zone compared to the highest zone. Compared to the other seed tree characteristics, the elevation of the seed sources provided more of a barrier to cross pollination, and as a result, elevation significantly accounted for more of the variation detected in the seedling characteristics. The pattern of increasing dryness with decreasing elevation on the eastside Sierra Nevada suggests that the ecotypic variation detected in seedling characteristics has probably resulted due to selection favoring drought avoidance characteristics, especially in the low elevation zone. The results of this study indicate that local ecotypes have differentiated on the eastside and do not support the altitudinal variation reported on the west slope of the Sierra Nevada.
Advisor:
Reference: 8503930
 

Author:
Burcar, Scott Anthony
Year: (1992)
Title: Seasonal preferential flow and nutrient transport in selected Sierra Nevada soils.
Institution: University of Nevada Reno
No. Pages: 66
Thesis Type: MS
Link: UNR Life and Health Sciences Library Call Number:Thesis 3031   
Keywords: HYDROLOGY (0388)
Abstract: Little work has focused on groundwater, its quality, and potential affect on Lake Tahoe water quality. This study investigated seasonal infiltration, preferential water flow, and NH$/sb4/sp+$ and NO$/sb3/sp-$ transport in 2 Sierra Nevada soil types under forest and meadow conditions using rainfall simulation. Soil water repellency was clearly shown to induce preferential infiltration. The finer textured volcanic soil demonstrated continuous preferential flow with depth, whereas preferential flow rapidly dissipated in the coarser textured granitic soil. Wetting patterns showed greater instability and preferential flow in the forested areas in the late summer/early fall. Applied NH$/sb4/sp+$ was effectively adsorbed by the soil matrix suggesting that unstable wetting occurred by preferential flow in wettable portions of the soil matrix and not by macropore flow. Nitrate moved through the granitic soil at applied concentrations but was attenuated with depth in the volcanic soil as the latter demonstrated NO$/sb3/sp-$ adsorption. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Miller, W. W.
Reference: MAI 31/02, p. 737, Summer 1993
 

Author:
Caldwell, Todd Gregory
Year: (1999)
Title: Nutrient dynamics following prescription fire in Tahoe Basin forest soils (Nevada, California).
Institution: University of Nevada Reno
No. Pages: 69
Thesis Type: MS
Link: Download (UNR Only)
Keywords: HYDROLOGY (0388); AGRICULTURE, SOIL SCIENCE (0481); BIOGEOCHEMISTRY (0425); AGRICULTURE, FORESTRY AND WILDLIFE (0478)
Abstract: The effect of fire on Tahoe Basin forest soils was studied to assess the potential nutrient export from the terrestrial ecosystem via volatilization and leaching. Two field-based methods were applied to measure the amount of C and N volatilized during three prescription fires. The weight method was based on pre/post-burn forest floor measurements. The ratio method was based on the residual calcium content of the forest floor and pre- burn Ca:element regressions. Results from both methods indicate that losses ranged from 6–24 Mg C ha−1 (49–77%). Nitrogen losses ranged from 61–542 kg N ha−1 (24–55%). Both methods provided reasonable estimates, although the ratio method regressions were better correlated. Post-fire soil chemistry showed elevated pH, Ca2+, and SO 42−. Ash-derived calcium controlled post-burn soil pH. O-PO4 and pH exhibited a strong inverse linear correlation. An exponential relationship existed between pH and SO42− , resulting in high desorption or dissolution as pH increased. Results were similar on parent materials of both decomposed granite and andesite. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Johnson, Dale W.
Reference: 0-599-64868-6; MAI 38/04, p. 960, Aug 2000
 

Author:
Charlet, David Alan
Year: (1995)
Title: Great Basin Montane and Subalpine Conifer Diversity: Dispersal or Extinction Pattern?
Institution: University of Nevada Reno
No. Pages: 177
Thesis Type: PhD
Link:
Keywords:
Abstract: The patterns of conifer species diversity in the Great Basin of western North America are investigated. The sources of floristic data are 8 years of collection and observation on over 300 mountain ranges in the region, examination of herbarium material at 15 western herbaria, and extensive review of published floras and distribution maps. All isolated mountain ranges in the Great Basin with at least one montane or subalpine conifer species present were included in the data set, and all neighboring source areas in the Sierra Nevada, Rocky Mountains, Colorado Plateau, and Blue Mountains were sampled, resulting in a total of 160 montane island samples and 40 mainland samples that were used in the subsequent analyses. Physical data for each sample were compiled, as was life history data for each of the species present in the region. Classification, ordination, and regression analyses were conducted to evaluate the species diversity and occurrence patterns present in the region. Explanations for the modern distributions of conifers in the Great Basin were sought by examining four effects on species diversity (area, distance, habitat diversity, and longitude) and the effect of life history attributes (including dispersal) on the number of species occurrences. These effects were considered by testing the predictions of three idealized island biogeography theory models: (1) Immigration, (2) Extinction, and (3) Equilibrium. The Habitat Diversity Hypothesis and the Intermediate Disturbance Hypothesis were also considered, and all hypotheses were treated as alternatives to the Random Placement (null) Hypothesis. The Random Placement Hypothesis was refuted: area-species slopes generated from the data are non-random. All idealized island biogeography theory models failed because mainland slopes are within the range of island slopes. Compounding this failure, additional problems were detected in each of the models as applied to Great Basin conifers, especially the Immigration model, as it made only one correct prediction. The Habitat Diversity and Intermediate Disturbance models were not refuted as long as they were considered not mutually exclusive with the island biogeography models. If considered mutually exclusive, they fail because a significant distance effect was observed. The Great Basin conifer flora is much richer than was previously thought, particularly in terms of the number of taxa present in the region that also occur in Pacific mountains. Although not all of the predictions of either the idealized Extinction, Immigration, or Equilibrium models of island biogeography theory were observed, on balance it appears that both immigration and extinction of montane and subalpine conifers have occurred in the region since the Late Pleistocene Epoch, but extinction has been more important. The failure of all island biogeography theory models to predict the observed island-like species-area slopes of the mainlands is probably because no mainland was actually sampled. Instead, the sites considered as 'mainlands' are part of the Great Basin, which was a montane-subalpine mainland during the Tertiary. Quaternary climate changes caused widespread conifer extinctions and has resulted in a fragmented, island-like pattern of species diversity throughout the region.
Advisor:
Reference: 9614906
 

Author:
Charlet, David Alan
Year: (1991)
Title: Relationships of the Great Basin Alpine Flora: A Quantitative Analysis.
Institution: University of Nevada Reno
No. Pages: 295
Thesis Type: MS
Link:
Keywords:
Abstract: The alpine floras of the Cascade-Sierras, Rocky Mountains, and Great Basin are remarkably similar in species composition and number. Neither the Cascade- Sierra nor the Rocky Mountain flora dominates the Great Basin. Instead, florulas of Great Basin mountains express an even gradient of similarity from west to east. A central role of the Great Basin in the evolution and retention of alpine plants during glacial periods is implied. Island biogeography theory is inapplicable to the high elevation flora of the Great Basin. Long-distance Holocene immigration of taxa to Great Basin mountains is relatively unimportant. Instead, range displacement of taxa already present in extensive subalpine and alpine zones followed by extinction during the mid-Holocene warming event explains most of the modern distribution of high elevation taxa. The Cascade-Sierras and Rocky Mountains have the most recently colonized alpine areas in the North American Cordillera. Most of the alpine taxa now in these mountain systems immigrated from adjacent lowlands. Today, Great Basin mountains are important refugia for alpine taxa.
Advisor:
Reference: 1344826
 

Author:
Connell, Richard L.
Year: (1994)
Title: Improving Assessment of Old Growth Forests in the Eastern Sierra Nevada Using Geographic Information Systems.
Institution: University of Nevada Reno
No. Pages: 74
Thesis Type: MS
Link:
Keywords:
Abstract: In this thesis I present the results of an analysis utilizing Geographic Information Systems technology in conjunction with existing information to predict old growth locations along the Eastern Sierra Nevada mountain range. This analysis relied upon existing timber inventory for the vegetation layer where other similar studies utilize satellite imagery for this layer and these studies try to determine a spectral signature associated with old growth. The layers used in this analysis were known old growth, a timber inventory, slope, aspect, elevation, roads, and soils. The known old growth layer resulted from three field seasons of work by Toiyabe National Forest Wildlife Biologists. This inventory was incomplete as local knowledge indicated other stands that might meet old growth criteria exited. This analysis resulted in a prediction of 54 stands or clumps of stands that were verified via 1:12,000 aerial photography. The analysis also predicted many existing stands (31 of 54 or 57%) and one newly inventoried stand. The location of predicted stands will be turned over to Toiyabe Wildlife Biologists for further investigation and field verification.
Advisor:
Reference: 1358124
 

Author:
Cox, Steven G.
Year: (1980)
Title: Population Structure and Dynamics of Belding's Ground Squirrel, Spermophilus Beldingi Beldingi in Little Valley, Nevada.
Institution: University of Nevada Reno
No. Pages: 115
Thesis Type:
Link:
Keywords:
Abstract: Abstract not available.
Advisor:
Reference: 1316006
 

Author:
Cripps, Colleen
Year: (1984)
Title: Pollen Foraging in the Genus Osmia.
Institution: University of Nevada Reno
No. Pages: 43
Thesis Type: MS
Link:
Keywords:
Abstract: Abstract not available.
Advisor:
Reference: 1323735
 

Author:
Duncan, Richard D.
Year: (1997)
Title: The Use of Visual Foraging Cues by Belding's Ground Squirrels (Spermophilus Beldingi).
Institution: University of Nevada Reno
No. Pages: 68
Thesis Type: MS
Link:
Keywords:
Abstract: The visual capabilities of ground squirrels are fairly well known because of physiological and behavioral laboratory experiments. Whether these capabilities are used to increase foraging efficiency has apparently not been investigated. A small colony of Belding's ground squirrels (Spermophilus beldingi) was allowed to forage under natural conditions for experimental bait stations to test the hypothesis that they can learn to use visual cues to forage more efficiently. Bait stations having visual cues were more likely to be found than controls without cues. They were also found more quickly than the controls. The results support the hypothesis but also suggest that foraging using visual cues is not the only strategy utilized by ground squirrels to locate food.
Advisor:
Reference: 1384800
 

Author:
Eshelman, Bruce D.
Year: (1982)
Title: Components of Belding's Ground Squirrel Foraging Behavior.
Institution: University of Nevada Reno
No. Pages: 125
Thesis Type: MS
Link:
Keywords:
Abstract: Abstract not available.
Advisor:
Reference: 1319707
 

Author:
Finkler, Gregg John
Year: (1979)
Title: Granite Chief: Backcountry User Profile and Management Approaches for Dispersing Use, Summer 1977. (Tahoe, California).
Institution: University of Nevada Reno
No. Pages: 168
Thesis Type: MS
Link:
Keywords: AGRICULTURE, FORESTRY AND WILDLIFE (0478); RECREATION (0814)
Abstract: Abstract not available. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor:
Reference: MAI 18/03, p. 144, Fall 1980
 

Author:
Franklin, Abraham J.
Year: (1996)
Title: Riparian Vegetation Mapping in the Sierra Nevada Using Airborne Digital Multispectral Videography and Image Processing.
Institution: University of Nevada Reno
No. Pages: 164
Thesis Type: MS
Link:
Keywords:
Abstract: A multispectral videography system was used to acquire high-resolution digital imagery in four spectral bands covering 2165 ha in parts of four watersheds in Washoe County, Nevada. The imagery was georeferenced, resampled, and mosaicked, and the normalized difference vegetation index (NDVI) was used to identify riparian vegetation with an estimated accuracy of 97%. Several supervised and unsupervised algorithms were used to classify the riparian portion of one scene into six vegetation classes. The highest overall accuracy of 60% was provided by linear discriminant classification of a mean-filtered United States Geological Survey digital orthophotoquad (DOQ), a standard deviation raster derived from the DOQ, and the NDVI derived from the videography. These rasters and classification algorithm were then used to classify the riparian portion of the entire mosaic. Accuracy of the resulting map was 42% for six vegetation classes and 60% when moist and wet meadow classes were merged.
Advisor:
Reference: 1379663
 

Author:
Gorman, Kimberly P.
Year: (2003)
Title: The isolation of dissolved organic phosphorus in aqueous solutions of lake water, soil leachate, and plant extracts.
Institution: University of Nevada Reno
No. Pages: 77
Thesis Type: MS
Link: Download (UNR Only)
Keywords: ENVIRONMENTAL SCIENCES (0768); CHEMISTRY, ORGANIC (0490); AGRICULTURE, SOIL SCIENCE (0481)
Abstract: This research was designed to isolate the DOP portion of the dissolved P fraction in order to assess its bioavailability. Two different chemical treatments were performed: anion exchange utilizing a hydroxyl form resin, and chemical precipitation by addition of CaCl2, and Al2(SO 4)3. Treatments were developed to promote SRP removal while leaving DOP behind in solution. Several of the experiments performed in this study show promise with isolating DOP, however, in many cases both SRP and DOP portions of the dissolved fraction were removed from solution. Of all the experiments performed, the calcium chloride treatment seemed to be the most effective when used upon the Everglades water samples. To date, the most successful means for isolating DOP is by degassing EG water samples at ambient pH, followed by pH 10.0 adjustment and 0.01 M CaCl2 addition. DOP isolation with the Tahoe soil leachate samples seems more difficult to achieve. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Miller, W. W.
Reference: MAI 42/05, p. 1666, Oct 2004
 

Author:
Greenlee, Daniel Lloyd
Year: (1985)
Title: Denitrification Rates of a Mountain Meadow near Lake Tahoe (Acetylene, Inhibition).
Institution: University of Nevada Reno
No. Pages: 52
Thesis Type: MS
Link:
Keywords: HYDROLOGY (0388)
Abstract: Abstract not available. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor:
Reference: MAI 24/03, p. 238, Fall 1986
 

Author:
Guerrant, Douglas Gordon
Year: (1989)
Title: Evaluation of infiltration, runoff and sediment transport characteristics in Sierra Nevada watersheds through rainfall simulation.
Institution: University of Nevada Reno
No. Pages: 108
Thesis Type: MS
Link:
Keywords: GEOTECHNOLOGY (0428); ENGINEERING, AGRICULTURAL (0539)
Abstract: Quantitative erosion data for Tahoe Basin soils are lacking. Rainfall simulation was used to measured infiltration, runoff and erosion of Cagwin soil under three slope (0-15, 15-30, and $>$30%) and four plot (natural with duff, natural without duff, disturbed without duff, and disturbed with duff) condition. Simulated storms were $>$100 yr-1 hr event. Relationships were analyzed via a modified Philip's model and multiple non-linear regression (P = 0.01). All plots were significantly different. Final infiltration (i$/sb[/rm f]$) ranged from 4.6-6.1 cm hr$/sp[-1]$ and runoff from 36-59%. Natural conditions with duff demonstrated highest and without duff lowest i$/sb[/rm f]$. Runoff was reversed. Sediment discharge increased with slope, decreased with time, and was greatest for disturbed with duff (1,391-35,416 Kg Ha$/sp[-1]$) and least for natural with duff conditions (trace). Modeled cumulative sediment vs. runoff demonstrated general erosivity for each slope/plot condition. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor:
Reference: MAI 28/01, p. 158, Spring 1990
 

Author:
Hall, Gregory M.
Year: (2000)
Title: Site of Aggregation Pheromone Biosynthesis in the Pine Engraver, Ips Pini (Say), and the Jeffrey Pine Beetle, Dendroctonus Jeffreyi.
Institution: University of Nevada Reno
No. Pages: 86
Thesis Type: PhD
Link:
Keywords:
Abstract: Bark beetles (Coleoptera: Scolytidae) are responsible for the loss of billions of cubic feet of standing coniferous timber annually and are considered the most destructive insectan forest pest in the Northern Hemisphere. Unfortunately, bark beetle infestations cannot be readily controlled by the traditional spraying of insecticides because beetles remain protected beneath the bark of host trees for the majority of their life cycles. Successful colonization of a host tree by pine bark beetles is dependent on a "mass attack" where hundreds to thousands of individuals are collectively able to overcome the defenses of the tree. The key element in the orchestration of this mass attack is the release of aggregation pheromone by pioneer individuals. Disruption of aggregation pheromone biosynthesis would provide a powerful means to specifically control the damage due to bark beetle populations. Early studies suggested that bark beetles utilized host tree monoterpenes in the production of their aggregation pheromones. In the past decade, however, multiple lines of evidence concerning bark beetle pheromone production have emerged, bringing the host tree precursor modification model into serious question. Recently, the direct demonstration that unfed, juvenile hormone (JH) III-treated male I. pini and I. paraconfusus incorporated labeled acetate into ipsenol and ipsdienol has prompted the shift to a new model of de novo pheromone production via the mevalonate pathway. This discovery led to the re- emergence of a question that has lingered unanswered for over three decades: where are bark beetle pheromone components synthesized? This dissertation provides the first definitive demonstration that aggregation pheromone components are produced de novo in the anterior midgut tissue of two bark beetles, the pine engraver beetle, Ips pini (Say), and the Jeffrey pine beetle, Dendroctonus jeffreyi.
Advisor:
Reference: 9997140
 

Author:
Harlow, David Eric
Year: (1998)
Title: Nutrients in Soil Core Leachate Collected from Six Plant Communities in Incline Creek Watershed, Nevada.
Institution: University of Nevada Reno
No. Pages: 65
Thesis Type: MS
Link:
Keywords:
Abstract: The decreasing clarity of ultra-oligotrophic Lake Tahoe's waters is partly attributed to increased algal productivity resulting from enhanced nutrient loading. Soil cores were leached under saturated and unsaturated conditions to examine nutrient discharge from six common plant communities on the Incline Creek, NV, watershed. Because nitrogen fixing shrubs grow throughout the watershed, leachable nutrients from soils collected near nitrogen fixing shrubs, non-nitrogen fixing species, and non-shrub plant communities were compared. Dissolved organic/colloidal N was the dominant form of nitrogen, averaging 7.85 times the leached amount of nitrate. The magnitude and the mobility of the dissolved organic/colloidal nitrogen represents a tremendous source of potentially bioavailable nitrogen. Phosphorus was not significantly different between treatments and had a dissolved organic/colloidal to ortho-P ratio of 0.348. Limited data from unsaturated leaching experiments suggest there are few differences in nutrient transport between saturated and unsaturated leaching.
Advisor:
Reference: 1389845
 

Author:
Keaveney, Gregory J.
Year: (1999)
Title: Production of trihalomethanes and haloacetic acids from chlorinated, aqueous plant extracts.
Institution: University of Nevada Reno
No. Pages: 182
Thesis Type: MS
Link: Download (UNR Only)
Keywords: ENGINEERING, ENVIRONMENTAL (0775)
Abstract: In December 1998, the United States Environmental Protection Agency finalized the Stage 1 Disinfectant/Disinfection Byproduct (D/DBP) Rule and Interim Enhanced Surface Water Treatment Rule. USEPA's D/DBP Rule lowers the maximum contaminant level (MCL) for trihalomethanes from 100 $/mu$g/L, to 80 $/mu$g/L. If a water treatment facility cannot meet the MCL of 80 $/mu$g/L, upgrades may be required. The effect of chlorinating an aqueous leachate of six different plant types, Quaking Aspen, Fremont Cottonwood, Cheatgrass, Greenleaf Manzanita, Jeffrey Pine and Basin Big Sage was examined for trihalomethane and haloacetic acid formation potential. The various plants were collected from watersheds in the Reno-Tahoe area. Results show that the grass and coniferous trees formed less trihalomethanes and haloacetic acids than the other species. With proper watershed protection-management techniques, it may be possible to lower precursor compounds contributing to DBP formation. This would have economic benefits to treatment facilities while lowering health risks. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Adams, V. Dean
Reference: 0-599-35484-4; MAI 37/05, p. 1501, Oct 1999
 

Author:
Loehr, Karen A.
Year: (1977)
Title: Cytodifferentiation in Developing Hymenolepis Citelli.
Institution: University of Nevada Reno
No. Pages: 181
Thesis Type: PhD
Link:
Keywords:
Abstract: Abstract not available.
Advisor:
Reference: 7811019
 

Author:
Mandeno, Petronila Esther
Year: (2000)
Title: Prescribed fire effects in mixed conifer stands in the Lake Tahoe Basin (California).
Institution: University of Nevada Reno
No. Pages: 60
Thesis Type: MS
Link: Download (UNR Only)
Keywords: ENVIRONMENTAL SCIENCES (0768); AGRICULTURE, FORESTRY AND WILDLIFE (0478)
Abstract: Three years of fire effects monitoring data are analyzed to evaluate changes in forest fuel loading and vegetation characteristics on California State Park lands within the Lake Tahoe Basin. California State Parks implemented a monitoring protocol developed by the National Park Service to track vegetation changes following their prescribed fire program. This preliminary analysis of that monitoring data found that little change has occurred in herbaceous relative cover and overall overstory tree (dbh > 15.0 cm) composition, basal area and density. Whereas, significant changes occurred with fuel loading, shrub density, and pole-sized tree (dbh <= 15.0 cm) density. These results will be used to assess the achievements of the California State Parks management objectives and to determine the overall trend of these vegetation changes. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Tueller, Paul T.
Reference: 0-599-77292-1; MAI 38/06, p. 1567, Dec 2000
 

Author:
Marcus, Jonathan Allen
Year: (1995)
Title: Subsurface mobility of colloidal and inorganic nitrogen and phosphorus within a Lake Tahoe watershed (Nevada).
Institution: University of Nevada Reno
No. Pages: 72
Thesis Type: MS
Link:
Keywords: HYDROLOGY (0388); ENVIRONMENTAL SCIENCES (0768)
Abstract: Watershed disturbance has been suggested as a possible mechanism for accelerated nutrient input into Lake Tahoe. However, little is known regarding how nutrient discharge is influenced by physio-chemical watershed processes. Recent investigations in the Lake Tahoe Basin suggest that colloidal nutrient transport can play an important role in the cycling of particle-reactive materials that influence lake and tributary water quality. The objective of this study was to use tension lysimeters and constant head permeameter leaching experiments to assess the soil solution and discharge leachate for inorganic and colloid nutrient (N and P) content and evaluate possible interactions between plot condition, depth, and nutrient discharge through statistical examination. Tension lysimeters were installed under three plot conditions (riparian, non-forested, forested) at selected locations throughout the Incline Creek watershed to measure the inorganic and colloid nutrient content (N and P) of soil solution following natural precipitation and during spring melt. In addition, intact soil cores were taken from the field at two depths from each of the three plot conditions and subjected to constant head permeameter leaching experiments. Incremental leachate discharge was then analyzed for concentrations of inorganic and colloid N and P. Soil column studies showed that the riparian and non- forested areas contributed the largest total amount of nitrogen and phosphorous, respectively. The colloidal form was mobile and the most dominant form for nitrogen. Colloidal phosphorous was unable to be determined. The mobility and presence of significant amounts of colloid N indicate that this once unrecognized nutrient form is an important component of Sierra Nevada watershed processes. Further characterization and transport modeling is essential to acquiring a better understanding of nutrient cycling in pristine alpine environments. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Miller, W. W.
Reference: MAI 34/02, p. 690, Apr 1996
 

Author:
Massoth, Harry Peter, III
Year: (1978)
Title: Salt Toxicity to Conifers in the Lake Tahoe Basin.
Institution: University of Nevada Reno
No. Pages: 115
Thesis Type: MS
Link:
Keywords: AGRICULTURE, PLANT PATHOLOGY (0480)
Abstract: Abstract not available. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor:
Reference: MAI 17/03, p. 173, Fall 1979
 

Author:
Melgin, Wendy Lynn
Year: (1985)
Title: The Influence of Hillslope Hydrology on Nitrate Transport in a Forested Watershed, near Lake Tahoe.
Institution: University of Nevada Reno
No. Pages: 79
Thesis Type: MS
Link:
Keywords: HYDROLOGY (0388)
Abstract: Abstract not available. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor:
Reference: MAI 24/04, p. 370, Winter 1986
 

Author:
Morrison, Mark S.
Year: (2003)
Title: Middle Holocene vegetation change at Lake Tahoe (Nevada, California).
Institution: University of Nevada Reno
No. Pages: 52
Thesis Type: MS
Link: Download (UNR Only)
Keywords: PALEOECOLOGY (0426)
Abstract: A sediment core from Lake Tahoe, California-Nevada was analyzed for pollen to determine the nature and timing of vegetation change during the middle Holocene. Turbidite layers were found to be common in the sediments, which proved troublesome. The turbidite layers and slow deposition rate at the lake left little sediment for pollen analysis. Zone 1, between 8750 and 7280 cal yr B.P., was cool and dry with high percentages of TCT (8.7%) and  Artemisia pollen (4.9%) and relatively low percentages of pine pollen (69%) from 8090 to 7280 cal yr B.P. Zone 2, between 7060 and 4550 cal yr B.P., was relatively warmer and dry with TCT as Juniperus and  Artemisia decreasing to 7.4% and 3.1% respectively while pine increased to almost 90% from 7060 to 5510 cal yr B.P. Zone 2 concluded with wetter trend marked by an increase in TCT as Calocedrus, Abies, Typha and Isoetes. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Mensing, Scott
Reference: MAI 42/03, p. 900, Jun 2004
 

Author:
Nachlinger, Janet Lynn
Year: (1985)
Title: The Ecology of Subalpine Meadows in the Lake Tahoe Region, California and Nevada (Phytosociology, Phenology, Plant Associations, Sierra Nevada Vegetation, Snowpack Augmentation).
Institution: University of Nevada Reno
No. Pages: 166
Thesis Type: MS
Link:
Keywords: BIOLOGY, BOTANY (0309); BIOLOGY, ECOLOGY (0329)
Abstract: Abstract not available. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor:
Reference: MAI 24/04, p. 359, Winter 1986
 

Author:
Naslas, George Dimitris
Year: (1991)
Title: Infiltration, runoff, nutrient and sediment transport analysis of soils in the Lake Tahoe Basin through rainfall simulation.
Institution: University of Nevada Reno
No. Pages: 212
Thesis Type: MS
Link:
Keywords: HYDROLOGY (0388)
Abstract: Quantitative erosion, infiltration and nutrient transport data for the Lake Tahoe Basin are limited. Meeks and Umpa soils were subjected to a simulated storm event, using a modular simulator, in order to determine infiltration, runoff and sediment transport rates and runoff was analysed for soluble nutrients. Three slope gradients and four plot conditions were studied per soil type. The interaction of soil type and plot condition controlled maximum nitrate concentration, with mean maximum nitrate concentrations of 1.486 and 0.57 mg l-1 for the Umpa and Meeks respectively. The interaction between soil type, plot condition and slope significantly controlled infiltration and runoff (P = 0.0011) and erosion (P = 0.0164). Maximum 1-hr final infiltration rates of 4.5 and 6.1 cm hr-1 were measured for the Meeks and Umpa soils respectively. Wooded plots exhibited strong water repellency resulting in 75-97% of the applied water running off. Sediment and nitrate release were not related. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor:
Reference: MAI 30/01, p. 86, Spring 1992
 

Author:
Printz, Lisa A.
Year: (2000)
Title: The Genetic Variation of an Invasive Perennial, Lepidium Latifolium L. (Cruciferae), across the Western United States.
Institution: University of Nevada Reno
No. Pages: 51
Thesis Type: MS
Link:
Keywords:
Abstract: I surveyed variation in randomly amplified polymorphic DNA (RAPD) profiles to estimate the genetic diversity of Lepidium latifolium L., an aggressive, clonal, invasive plant introduced from Eurasia in the early 1900's. Samples from the Truckee River in Nevada, the Susan River in California, and 10 sites across the western United States were collected and analyzed. Significant mean within site genetic diversity for the Susan River ( HW = 0.3984 ± 0.14), Truckee River (H W = 0.4163 ± 0.12), both rivers combined (H W = 0.4082 ± 0.06), and across the west (H W = 0.3603 ± 0.09), was detected. Sufficient genetic variation was detected within sites (Susan River, HB = 0.0326 ± 0.03; Truckee River, HB = 0.0307 ± 0.02) to reveal population subdivision if it existed at this scale ( FST = 0.1053 ± 0.06 and 0.0695 ± 0.04). However, there is population subdivision between the two river systems (FST =0.1216 ± 0.06) and among the 10 western sites (FST = 0.2267 ± 0.08). The genetic variation of L. latifolium in the western United States is high, both within and between populations, indicating sexual reproduction and gene flow among riverine sites and the accumulation of site specific loci at larger geographical scales, once gene flow is limited.
Advisor:
Reference: 1401259
 

Author:
Ramsing, Frederick John
Year: (2000)
Title: Measurement of groundwater seepage into Lake Tahoe and estimation of nutrient transport from a Lake Tahoe watershed (Nevada).
Institution: University of Nevada Reno
No. Pages: 163
Thesis Type: MS
Link: Download (UNR Only)
Keywords: HYDROLOGY (0388); GEOLOGY (0372); ENVIRONMENTAL SCIENCES (0768); PHYSICAL GEOGRAPHY (0368)
Abstract: This study determined the groundwater nutrient flux into Lake Tahoe for a small watershed, Incline Creek. Seepage meters measured direct groundwater discharge from the watershed. Stable isotope analysis of deuterium and 18O from interstitial pore water in lakebed sediments validated measurements. Nutrient concentrations from nearby wells were multiplied by groundwater discharge to determine total direct groundwater nutrient flux. Calculations showed only 8 to 24 acre·ft/yr, less than 1% of the watershed budget, discharging directly as groundwater. However, 30 kg/yr of soluble inorganic nitrogen, or 14% of the watershed budget, discharged from groundwater. Groundwater contribution of soluble reactive phosphorous was insignificant. An emulated seepage run was performed by analyzing existing streamflow data to determine whether groundwater was being intercepted as seepage to streams in the lower basin. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Tyler, Scott W.
Reference: 0-599-92294-X; MAI 39/02, p. 466, Apr 2001
 

Author:
Roth, Julie K.
Year: (2001)
Title: Dispersal of Castanopsis Sempervirens by Scatter Hoarding Rodents: A Seed-Fate Model Approach.
Institution: University of Nevada Reno
No. Pages: 73
Thesis Type: MS
Link:
Keywords:
Abstract: Seed dispersal by scatter hoarding rodents was investigated for Sierra chinquapin (Castanopsis sempervirens) in 1999 and 2000 using a seed fate pathway approach. Rodents removed nearly all nuts from shrubs between mid August and early September. Rodents scatter hoarded an average of 74.3% of nuts taken from source shrubs (n = 7) within 48 hours. Most primary caches were recovered and either recached (47%), consumed (13%), or moved to locations where they could not be found (40%). Ten (7.8%) of the caches remaining by winter 1999 produced seedlings the following spring. No seedlings emerged from caches made in 2000. Chinquapin dispersal by scatter hoarding rodents is probably effective over long time intervals where successful dispersal is episodic and depends not only on rodent caching but also on climatic conditions.
Advisor:
Reference: 1408099
 

Author:
Schwaneflugel, Andrew Kidd
Year: (2002)
Title: Forms of nitrogen and phosphorous in free-draining pore water in a Lake Tahoe soil (Nevada).
Institution: University of Nevada Reno
No. Pages: 93
Thesis Type: MS
Link: Download (UNR Only)
Keywords: ENVIRONMENTAL SCIENCES (0768); HYDROLOGY (0388)
Abstract: Zero-tension lysimeters were used to collect spring snow melt from soil beneath forested, open, and grus plot conditions in the Incline Creek, NV, watershed. Snow cores and lysimeter samples were analyzed for inorganic, colloidal, and particulate forms of nitrogen and phosphorous as well as electrical conductivity, pH, Eh, and the E4/E6 ratios of the colloidal/dissolved organics. The digestible forms of nitrogen and phosphorous were greater than inorganic forms in the snowcores. Cumulative loadings for the spring run-off indicate that the colloidal and particulate forms are important components of mobile nitrogen and phosphorous within these soils. Plot condition had a significant effect on total particulate nitrogen loading but did not affect inorganic or colloidal loading. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Miller, Wally W.
Reference: MAI 42/01, p. 196, Feb 2004
 

Author:
Sullivan, Adam G.
Year: (1999)
Title: Alluvial process and geomorphic effectiveness on two Tahoe streams (California).
Institution: University of Nevada Reno
No. Pages: 100
Thesis Type: MS
Link: Download (UNR Only)
Keywords: HYDROLOGY (0388)
Abstract: Stream management and effective stream restoration require an understanding of the variables that directly influence processes that shape the channel. To understand current processes on two alluvial streams targeted for stream restoration, this study examined their geomorphic response to the January 1997 rain-on-snow flood and the 1997 and 1998 spring snowmelt runoff peaks. Sediment transport was compared among the three flow peaks in relation to patterns of exerted unit stream power. Changes in cross-sectional channel geometry were compared to patterns of stream power and channel geometry, vegetation community types, soil types, and available historical information. Stream power depends greatly on slope, and floodplain accessibility attenuates peak stream power. Neither peak nor cumulative unit stream power accurately gauged changes in channel geometry. Stream power estimated bedload transport differently than the Meyer-Peter Muller equation. Vegetation communities and soil types did not significantly correlate with changes in channel width. Spring runoff peaks dominate winter rain-on-snow peaks in cumulative sediment yield over time. The high magnitude of winter rain-on-snow runoff peaks accelerates the progression of natural recovery in incised but narrow alluvial channels. A multidisciplinary perspective on stream management and alluvial channel evolution puts channel changes into context and orients stream restoration efforts towards facilitating natural recovery. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Swanson, Sherman
Reference: 0-599-64872-4; MAI 38/04, p. 961, Aug 2000
 

Author:
Sutherland, James Colin
Year: (2001)
Title: Eighteenth century logging and the geomorphic response of a montane watershed in the Carson Range, western Nevada.
Institution: University of Nevada Reno
No. Pages: 115
Thesis Type: MS
Link: Download (UNR Only)
Keywords: HYDROLOGY (0388); AGRICULTURE, FORESTRY AND WILDLIFE (0478); ENVIRONMENTAL SCIENCES (0768)
Abstract: Vicee Canyon, a small (5.2 km2), steep watershed on the east slope of the Carson Range, contains important information on what effects large scale logging during the late 1800s had on the geomorphic stability of this drainage basin. Similarities of Vicee Canyon to drainages in the Lake Tahoe basin allow the knowledge gained through this study to be applied in watersheds that affect the fragile ecosystems of the lake. Vicee Canyon was selected both for its depositional record that spans the latest Holocene and for the wealth of historical records and human artifacts associated with this watershed. Stratigraphic analysis, radiocarbon dating, and dendrochronology were used in concert with historic records and artifacts to determine that the Comstock-era logging in fact caused an increase in the amount of sediment being delivered to the channel in Vicee Canyon. A large portion of this historic sediment has made its way out of the drainage to the alluvial fan, while a small amount remains in storage along the channel walls of the drainage basin. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Wells, Stephen G.
Reference: 0-493-36599-0; MAI 40/02, p. 420, Apr 2002
 

Author:
Tarnay, Leland William
Year: (2001)
Title: Atmospheric nitrogen deposition to the Lake Tahoe Basin, California/Nevada.
Institution: University of Nevada Reno
No. Pages: 111
Thesis Type: PhD
Link: Download (UNR Only)
Keywords: BIOGEOCHEMISTRY (0425); ENVIRONMENTAL SCIENCES (0768); BIOLOGY, ECOLOGY (0329); BIOLOGY, LIMNOLOGY (0793)
Abstract: Decreases in the clarity of Lake Tahoe have been attributed in part to atmospheric nitrogen deposition, however no estimates of dry deposition of N-containing gases to the semi-arid Lake Tahoe Basin have been performed. This research shows that the possible range of dry fluxes, calculated from preliminary nitric acid (HNO3) and ammonia (NH3) measurements, were much higher (1.2 to 8.6 kg N ha−1 yr−1 ) for Lake Tahoe's watershed than for the surface of Lake Tahoe itself (0.58 to 1.2 kg N ha−1 yr−1), largely due to the high affinity of HNO3 for the leaf surfaces to which it deposits. Laboratory gas exchange experiments on conifers native to the Lake Tahoe Basin found that accumulation of HNO3 on leaf surfaces reduces this affinity. Accounting for this phenomenon in a "bigleaf" inferential model at a representative site in the Tahoe Basin reduced estimated HNO3 flux by 30%. Scaling these improved estimates to the entire Tahoe Basin required coupling the inferential model with a GIS framework and simultaneous measurements of the major N-containing gases occurring within the Tahoe Basin. Both local and regional sources contributed to the resulting fluxes (0.7 to 2.1 kg N ha−1 yr−1), which varied nonlinearly with forest canopy cover across the landscape. Watershed retention estimates based on these inputs are as a result both lower (average = 50%) and more variable (10 to 90%) than previously considered. These results demonstrate how Tahoe's forested watersheds capture local and regional pollutants more efficiently than the lake itself and imply that watershed processes control more of the Lake Tahoe N budget than previously considered. The results also indicate that other "pristine" semi-arid forests in the West may be receiving substantial amounts of N via dry deposition from regional sources. Local-scale assessments that integrate model data and land-cover within a GIS framework will be necessary to determine the magnitude of these inputs, and their potential for causing eutrophication. Note: dissertation citations and abstracts contained here are published with permission of ProQuest Information and Learning. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by addressing your request to UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone (734) 761-7400; Web-page: wwwlib.umi.com/dissertations.
Advisor: Gertler, Alan
Reference: 0-493-56393-8; DAI-B 63/02, p. 703, Aug 2002
 

Author:
Thayer, Theodore C.
Year: (2002)
Title: Interaction between Steller's Jays (Cyanocitta Stelleri ) and Yellow Pine Chipmunks (Tamias Amoenus) and How It Affects Dispersal of Sugar Pine (Pinus Lambertiana) Seeds.
Institution: University of Nevada Reno
No. Pages: 51
Thesis Type: MS
Link:
Keywords:
Abstract: Seed dispersal allows plants to propagate in new areas and seeds to escape the typically high mortality environment under the parent plant. Animals that disperse seeds by scatter-hoarding are of different effectiveness as dispersal agents. They may differ in either the quantity or quality of dispersal. This study compares the effectiveness of Steller's jay (Cyanocitta stelleri ) and yellow pine chipmunks (Tamias amoenus) in dispersing the seeds of sugar pine (Pinus lambertiana), and explores the potential competition between these seed caching species. Aspects of the dispersal of sugar pine by jays and chipmunks, such as foraging behavior, load size, distance, cache depth and microhabitat were examined in the field. Potential cache pilfering by jays and chipmunks were examined in an aviary. The results of this study suggest that jays and chipmunks compete with each other for cached seeds, and that jays are better at long range dispersal of sugar pine, while chipmunks are responsible for local dispersal and regeneration. (Abstract shortened by UMI.)
Advisor:
Reference: 1411378
 

Author:
Vreeland, Hamilton
Year: (1980)
Title: An Analytical Approach to Interspecific Relationships of Achlorophyllous Sarcodes Sanguinea with Autotropic Flora.
Institution: University of Nevada Reno
No. Pages: 66
Thesis Type: PhD
Link:
Keywords:
Abstract: This work is a quantitative ecological study of Sarcodes sanguinea, a representative species of a group known as saprophytic achlorophyllous plants. The interspecific patterns of association are examined using regression analysis. The relationships with associated tree species are expressed as Influence Factors, considering both tree size and proximity while Consistency Factors represent the number of each species and constancy (in the classic ecological sense). It is concluded that the combination of Influence and Consistency Factors is effective in predicting the presence and number of the subject species in the ecosystem studied. It is also concluded that this is a complex relationship involving factor interaction of more than one tree species but represented by Model Choice 4 which considered both Influence and Consistency Factors. Finally, I suggest that this technique should be tested in other ecosystems on other achlorophyllous species and on this species to determine the validity or lack thereof of the model.
Advisor:
Reference: 8020951
 

Author:
Vreeland, Patricia P.
Year: (1980)
Title: Mycorrhizal Symbiosis of Sarcodes Sanguinea.
Institution: University of Nevada Reno
No. Pages: 59
Thesis Type: PhD
Link:
Keywords:
Abstract: This research studies in vivo nutrient translocation among four forest tree species and Sarcodes sanguinea, the snow plant, a mycorrhizal, achlorophyllous angiosperm. Injection of radioactive phosphorus into the tree's phloem was timed to coincide with the exponential phase of snow plant growth during which maximum nutrient mobilization is necessary. Significant isotope translocation occurred between each tree species and snow plants; other surrounding vegetation showed little uptake. Comparison of transport rates indicates that although common mycorrhizal components are shared by roots of snow plants and trees, rates supporting rapid snow plant growth occur only in Abies concolor and Pinus Jeffreyi.
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Reference: 8020950
 

Author:
Warner, Randall J.
Year: (1976)
Title: Some Environmental Effects of Beaver Activities.
Institution: University of Nevada Reno
No. Pages: 122
Thesis Type: MS
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Abstract: Abstract not available.
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Reference: 1309369
 

Author:
Yandell, Ulla Geralyn
Year: (1992)
Title: An Allozyme Analysis of Whitebark Pine (Pinus Albicaulis Engl.).
Institution: University of Nevada Reno
No. Pages: 73
Thesis Type: MS
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Abstract: Foliage samples from fourteen disjunct whitebark pine populations in the Sierra Nevada/Cascade Ranges, the Warner Mountains, the Rocky Mountains, and the Great Basin were analyzed electrophoretically at 13 loci. Whitebark pine exhibits average amounts of variability for a pine species. Across all populations the mean number of alleles/locus is 1.6, 48.8% of the loci are polymorphic, and the observed heterozygosity is 0.191. There is a moderately high amount of interpopulational differentiation (Fst = 0.088) but no distinct differentiation among geographic regions. Nei's unbiased genetic distances, the instability of the neighbor- joining dendrogram, rare allele analyses, and the sequential test procedure for heterogeneity suggest that several of the northern Nevada populations are genetically unique. Drift may be a key factor in the genetic make-up of many of the populations, although a role for differential selection cannot be ruled out. The implications for historical biogeographical reconstruction in the Great Basin and present day management of the species are discussed.
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Reference: 1351661