Digital Commons Network^™

Responses Of Pond-Breeding Amphibians To Wildfire: Short-Term Patterns In Occupancy And Colonization, Blake R. Hossack, Paul Stephen Corn

United States Geological Survey: Staff Publications

Wildland fires are expected to become more frequent and severe in many ecosystems, potentially posing a threat to many sensitive species. We evaluated the effects of a large, stand-replacement wildfire on three species of pond-breeding amphibians by estimating changes in occupancy of breeding sites during the three years before and after the fire burned 42 of 83 previously surveyed wetlands. Annual occupancy and colonization for each species was estimated using recently developed models that incorporate detection probabilities to provide unbiased parameter estimates. We did not find negative effects of the fire on the occupancy or colonization rates of the long-toed …

Fate Of Fish Production In A Seasonally Flooded Saltmarsh, Philip W. Stevens, Clay L. Montague, Kenneth J. Sulak

United States Geological Survey: Staff Publications

Although saltmarshes are thought to enhance the productivity of open estuarine water, the mechanism by which energy transfer occurs has been debated for decades. One possible mechanism is the transfer of saltmarsh production to estuarine waters by vagile fishes and invertebrates. Monthly estimates of fish standing stock, net fish ingress, and predation were used to develop a bio-mass budget to estimates annual production of fishes and the relative yield to predatory fish, birds, and direct migration to the estuary. Annual production of saltmarsh fishes was estimated to 31.0 gm^-2 saltmarsh, which falls within the range of previously reported values …

Spatial And Temporal Variation In Cores From Lake Titicaca, Bolivia/Peru During The Last 13,000 Years, Sherilyn C. Fritz, P. A. Baker, P. Tapia, J. Garland

Department of Earth and Atmospheric Sciences: Faculty Publications

We compared the stratigraphy of sediment cores that span the last 13,000 yrs from three sites in the main basin of Lake Titicaca, Boliva/Peru as indicators of regional paleoclimate. The cores show similar patterns of change after ~6,400 calendar yrs before present (cal yr BP) but differ before that time. Site NE98-PC2, which is near the Rio Illave and its delta, shows differences in diatom species composition and in calcium carbonate concentrations relative to cores from the other two sites, particularly during times of inferred high precipitation. In contrast, the carbon isotopic stratigraphy of the three sites is relatively similar. …

Water Resources And Geologic Field Trip In York And Seward Counties, Nebraska, Michael J. Jess, Mark Burbach

Conservation and Survey Division

No abstract provided.

The Legacy Of Leaded Gasoline In Bottom Sediment Of Small Rural Reservoirs, Kyle E. Juracek, Andrew C. Ziegler

United States Geological Survey: Staff Publications

The historical and ongoing lead (Pb) contamination caused by the 20th-century use of leaded gasoline was investigated by an analysis of bottom sediment in eight small rural reservoirs in eastern Kansas, USA. For the reservoirs that were completed before or during the period of maximum Pb emissions from vehicles (i.e., the 1940s through the early 1980s) and that had a major highway in the basin, increased Pb concentrations reflected the pattern of historical leaded gasoline use. For at least some of these reservoirs, residual Pb is still being delivered from the basins. There was no evidence of increased Pb deposition …

Deep-Water Antipatharians: Proxies Of Environmental Change, B. Williams, M.J. Risk, S.W. Ross, K.J. Sulak

United States Geological Survey: Staff Publications

Deep-water (307–697 m) antipatharian (black coral) specimens were collected from the southeastern continental slope of the United States and the north-central Gulf of Mexico. The sclerochronology of the specimens indicates that skeletal growth takes place by formation of concentric coeval layers. We used 210Pb to estimate radial growth rate of two specimens, and to establish that they were several centuries old. Bands were delaminated in KOH and analyzed for carbon and nitrogen stable isotopes. Carbon values ranged from _16.4‰ to _15.7‰; the oldest specimen displayed the largest range in values. Nitrogen values ranged from 7.7‰ to 8.6‰. …

Cold Climate In The Eastern Australian Mid To Late Permian May Reflect Cold Upwelling Waters, Andrew T. Jones, Tracy D. Frank, Christopher R. Fielding

Department of Earth and Atmospheric Sciences: Faculty Publications

A suite of ice-rafted dropstones and glendonites throughout the Permian succession of eastern Australia indicates the cold climate associated with the late Paleozoic ice age persisted longest in this part of Gondwana. Paradoxically, these cold climate indicators are preserved in transgressive and highstand facies and formed at mid to high latitudes at a time when paleofloral and sedimentological data suggest equable onshore environments during the intervening lowstands and temperate conditions at the pole. These apparent inconsistencies suggest that eastern Australia was anomalously cold in the context of post-Sakmarian Gondwanan climates, and the distribution of sedimentary indicators could indicate localized cooling …

Major Land Resource Areas Of Montana, Natural Resources Conservation Service

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Major Land Resource Areas 32, Northern Intermountain Desertic Basins 43A, Northern Rocky Mountains 43B, Central Rocky Mountains 44A, Northern Rocky Mountain Valleys 44B, Central Rocky Mountain Valleys 46, Northern Rocky Mountain Foothills 52, Brown Glaciated Plains 53A, Northern Dark Brown Glaciated Plains 54, Soft Shale Plains 58A, Northern Rolling Plains, Northern Part 58B, Northern Rolling Plains, Southern Part 58C, Northern Rolling Plains, Northeastern Part 58D, Northern Rolling Plains, Eastern Part 60A, Pierre Shale Plains and Badlands 60B, Pierre Shale Plains and Badlands, Northern Part

Upper Flow Regime Sheets, Lenses And Scour Fills: Extending The Range Of Architectural Elements For Fluvial Sediment Bodies, Christopher R. Fielding

Department of Earth and Atmospheric Sciences: Faculty Publications

Fluvial strata dominated internally by sedimentary structures of interpreted upper flow regime origin are moderately common in the rock record, yet their abundance is not appreciated and many examples may go unnoticed. A spectrum of sedimentary structures is recognised, all of which occur over a wide range of scale: 1. cross-bedding with humpback, sigmoidal and ultimately low-angle cross-sectional foreset geometries (interpreted as recording the transition from dune to upper plane bed bedform stability field), 2. planar/flat lamination with parting lineation, characteristic of the upper plane bed phase, 3. flat and low-angle lamination with minor convex-upward elements, characteristic of the transition …

Large Wind Shift On The Great Plains During The Medieval Warm Period, Venkataramana Sridhar, David B. Loope, James B. Swinehart, Joseph A. Mason, Robert J. Oglesby, Clinton M. Rowe

Department of Earth and Atmospheric Sciences: Faculty Publications

Spring-summer winds from the south move moist air from the Gulf of Mexico to the Great Plains. Rainfall in the growing season sustains prairie grasses that keep large dunes in the Nebraska Sand Hills immobile. Longitudinal dunes built during the Medieval Warm Period (800 to 1000 years before the present) record the last major period of sand mobility. These dunes are oriented NW-SE and are composed of cross-strata with bipolar dip directions. The trend and structure of the dunes record a drought that was initiated and sustained by a historically unprecedented shift of spring-summer atmospheric circulation over the Plains: Moist …

Ground-Water Quality Of The Northern High Plains Aquifer, 1997, 2002–04, Jennifer S. Stanton, Sharon L. Qi

Publications of the US Geological Survey

An assessment of ground-water quality in the northern High Plains aquifer was completed during 1997 and 2002–04. Ground-water samples were collected at 192 low-capacity, primarily domestic wells in four major hydrogeologic units of the northern High Plains aquifer—Ogallala Formation, Eastern Nebraska, Sand Hills, and Platte River Valley. Each well was sampled once, and water samples were analyzed for physical properties and concentrations of nitrogen and phosphorus compounds, pesticides and pesticide degradates, dissolved solids, major ions, trace elements, dissolved organic carbon (DOC), radon, and volatile organic compounds (VOCs). Tritium and microbiology were analyzed at selected sites. The results of this assessment …

Ground-Water Quality Beneath Irrigated Cropland Of The Northern And Southern High Plains Aquifer, Nebraska And Texas, 2003–04, Jennifer S. Stanton, Lynne Fahlquist

Publications of the US Geological Survey

A study of the quality of ground water beneath irrigated cropland was completed for the northern and southern High Plains aquifer. Ground-water samples were collected from 30 water-table monitoring wells in the northern agricultural land-use (NAL) study area in Nebraska in 2004 and 29 water-table monitoring wells in the southern agricultural land-use (SAL) study area in Texas in 2003. The two study areas represented different agricultural and hydrogeologic settings. The primary crops grown in the NAL study area were corn and soybeans, and the primary crop in the SAL study area was cotton. Overall, pesticide and fertilizer application rates were …

Anguilliform Larvae Collected Off North Carolina, Steve W. Ross, Tara L. Casazza, Andrea M. Quattrini, Kenneth J. Sulak

United States Geological Survey: Staff Publications

The distinctive larval stage of eels (leptocephalus) facilitates dispersal through prolonged life in the open ocean. Leptocephali are abundant and diverse off North Carolina, yet data on distributions and biology are lacking. The water column (from surface to 1,293 m) was sampled in or near the Gulf Stream off Cape Hatteras, Cape Lookout, and Cape Fear, North Carolina during summer through fall of 1999–2005, and leptocephali were collected by neuston net, plankton net, Tucker trawl, and dip net. Additional samples were collected nearly monthly from a transect across southern Onslow Bay, North Carolina (from surface to 91 m) from April …

Geomorphic Impact And Rapid Subsequent Recovery From The 1996 Skeióarársandur Jökulhlaup, Iceland, Measured With Multi-Year Airborne Lidar, Laurence C. Smith, Yongwei Sheng, Francis J. Magilligan, Norman D. Smith, Basil Gomez, Leal A. K. Mertes, William B. Krabill, James B. Garvin

Department of Earth and Atmospheric Sciences: Faculty Publications

The November 1996 jökulhlaup that burst from the Vatnajökull ice cap onto Skeiðarársandur was the highest-magnitude flood ever measured on the largest active glacial outwash plain (sandur). Centimeter-scale elevation transects, measured from repeat-pass airborne laser altimetry missions flown in 1996 (pre-flood), 1997, and 2001, show that sediment deposition exceeded erosion across the central Skeiðarársandur and established an average net elevation gain of +22 cm for the event. Net elevation gains of +29 and +24 cm occurred in braided channels of the Gígjukvísl and Skeiðará rivers, respectively. Nearly half of these gains, however, were removed within 4 years, and the two …

Sprawl And The Resilience Of Humans And Nature: An Introduction To The Special Feature, Craig R. Allen

United States Geological Survey: Staff Publications

Human-driven change in land use and land cover is an accelerating global phenomenon with far-reaching implications for food production, forest and water resources, the climate, and biogeochemical cycles (Foley et al. 2005). It affects the amount and configuration of habitat available for animals ranging from soil nematodes to elephants. It affects the provision of ecological goods and services for human beings. It affects the processes and function of ecosystems.

On The Spatial Nature Of The Groundwater Pumping Externality, Nicholas Brozovic, David L. Sunding, David Zilberman

Daugherty Water for Food Global Institute: Faculty Publications

Most existing economic analyses of optimal groundwater management use single-cell aquifer models, which assume that an aquifer responds uniformly and instantly to ground- water pumping. This paper demonstrates how spatially explicit aquifer response equations from the water resources engineering literature may be embedded in a general economic framework. Calibration of our theoretical model to published economic studies of spe- cific aquifers demonstrates that, by averaging basin drawdown across the entire resource, existing studies generally understate the magnitude of the groundwater pumping external- ity relative to spatially explicit models. For the aquifers studied, the drawdown predicted by single- cell models may …

Coupling Between Primary Terrestrial Succession And The Trophic Development Of Lakes At Glacier Bay, D. R. Engstrom, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

We use sediment cores from lakes in Glacier Bay National Park to examine the relationship between successional changes in catchment vegetation and trends in water-column nitrogen (a limiting nutrient) and lake primary production. Terrestrial succession at Glacier Bay follows several different pathways, with older sites in the lower bay being colonized directly by spruce (Picea) and by-passing a prolonged alder (Alnus) stage that characterizes younger upper-bay sites. Sediment cores from three sites spanning this successional gradient demonstrate that the variability in trophic development among lakes is a consequence of the establishment and duration of N-fixing alder …

Discontinuities In Ecological Data, Craig R. Allen

United States Geological Survey: Staff Publications

Historically, ecology has focused on continuous distributions and smooth transitions. Only recently have discontinuities and thresholds become an explicit focus in some areas of ecology, especially in the realm of complex systems. The study of animal body mass distributions has been recognized for its potential to provide insight into the underlying processes shaping animal communities. Hutchinson (1) formalized the understanding of species niches and the potential for competition to shape body mass distributions. However, despite a long history of theoretical and empirical pursuit, the mechanisms driving patterns in body mass distributions remain poorly understood. The work of Scheffer and van …

Physical And Chemical Predictors Of Diatom Dissolution In Freshwater And Saline Lake Sediments In North America And West Greenland, David B. Ryves, Richard W. Battarbee, Stephen Juggins, Sherilyn C. Fritz, N. John Anderson

Department of Earth and Atmospheric Sciences: Faculty Publications

Diatom dissolution in surface sediment samples from two regional lake datasets in the Northern Great Plains (NGP; n = 64) and West Greenland (n = 40) is assessed using a morphological approach categorizing valves during routine diatom analysis. Two dissolution indices are derived to parameterize diatom dissolution, and, when compared between two analysts in a blind test, show good correspondence and are closely correlated to diatom fragmentation. We explore the relationships between hydrochemical and physical lake parameters (including meromixis) on dissolution within both lake regions using multivariate methods and modeled with logistic regression. Salinity is the sole significant predictor …

Modeling The Evolution Of Natural Organic Matter In The Environment With An Agent-Based Stochastic Approach, Xiaorong Xiang, Yingping Huang, Gregory Madey, Steve Cabaniss, Leilani Arthurs, Patricia Maurice

Department of Earth and Atmospheric Sciences: Faculty Publications

Natural organic matter (NOM) is ubiquitous in terrestrial and aquatic ecosystems, and it plays a crucial role in the evolution of soils, the transport of pollutants, and the global carbon cycle. NOM is a complex mixture of molecules and is thus heterogeneous in structure and composition. As NOM passes through an ecosystem, it is acted upon by a variety of processes, such as microbial degradation, adsorption to mineral surfaces, and photochemical reactions that can change its properties and reactivity. The evolution of NOM in space and time thus is an important research area in biology, geochemistry, ecology, soil science, and …

Hydrological Effects And Groundwater Fluctuations In Interdunal Environments In The Nebraska Sandhills, David Gosselin, Venkataramana Sridhar, F. Edwin Harvey, James Goeke

Great Plains Research: A Journal of Natural and Social Sciences

Nine years of groundwater monitoring data has documented the important influence that topographic relief and location in the groundwater flow system have on the hydrologic function of interdunal valleys. The western "wet" valley at the Gudmundsen Sandhills Laboratory in central Nebraska, which is a net discharge area, is more strongly buffered from the effects of annual-scale climatic variability than the eastern "dry" valley. The east valley is generally an area of net recharge and as such is more responsive to climatic variability. This study employed a simple water balance approach to estimate evapotranspiration (ET) from water level measurements in the …

Geochronology And Mammalian Biostratigraphy Of Middle And Upper Paleocene Continental Strata, Bighorn Basin, Wyoming, Ross Secord, Philip D. Gingerich, M. Elliot Smith, William C. Clyde, Peter Wilf, Brad S. Singer

Department of Earth and Atmospheric Sciences: Faculty Publications

The Bighorn Basin of northwestern Wyoming preserves one of the most complete records of middle Paleocene to lower Eocene continental biota. The geochronology of this important interval depends partly on numerical calibration of the geomagnetic polarity time scale (GPTS), but the middle and late Paleocene parts of the GPTS have been poorly constrained radioisotopically. A new volcanic ash from the northern Bighorn Basin provides the first radioisotopic age for upper middle Paleocene strata (upper Selandian) and is an important calibration point for the base of polarity Chron C26n and the Selandian-Thanetian stage boundary in the GPTS. Sanidine from the ash …

A 2200-Year Record Of Hydrologic Variability From Foy Lake, Montana, Usa, Inferred From Diatom And Geochemical Data, Lora R. Stevens, Jeffery R. Stone, Josh Campbell, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

A 2200-yr long, high-resolution (~5 yr) record of drought variability in northwest Montana is inferred from diatoms and δ¹⁸O values of bio-induced carbonate preserved in a varved lacustrine core from Foy Lake. A previously developed model of the diatom response to lake-level fluctuations is used to constrain estimates of paleolake levels derived from the diatom data. High-frequency (decadal) fluctuations in the de-trended δ¹⁸O record mirror variations in wet/dry cycles inferred from Banff tree-rings, demonstrating the sensitivity of the oxygen-isotope values to changes in regional moisture balance. Low frequency (multi-centennial) isotopic changes may be associated with shifts …

The Earth All Around Us Selected Building Stone In Lincoln, Nebraska, William J. Wayne

Conservation and Survey Division

No abstract provided.

The Last 2000 Years In Northern Yellowstone National Park Based On Multiproxy Data From Crevice Lake, Cathy Whitlock, Sherilyn C. Fritz, Brandi Bracht, Lora Stevens, Mitchell Power

Department of Earth and Atmospheric Sciences: Faculty Publications

Pollen, charcoal, diatoms, stable-isotope, and geochemical records were analyzed in high-resolution in cores obtained from Crevice Lake, a varved-sediment lake in northern Yellowstone National Park. The objective was to reconstruct the vegetation, fire, and ecohydrologic history of the watershed for the period from AD 0-1917 and compare the results with the PDSI reconstructions of Cook et al. (2004). Pollen percentages and accumulation rates provide information on vegetation and flowering season conditions. Charcoal accumulation rates (CHAR) provide information on fire activity, including fire size or intensity and fire frequency. Diatoms disclose the nature of spring nutrient status, time of ice off, …

The Late Paleozoic Ice Age Revisited, Christopher R. Fielding, Tracy D. Frank, John L. Isbell

Department of Earth and Atmospheric Sciences: Faculty Publications

The late Paleozoic Gondwanan ice age (LPGIA), which spans the late Carboniferous through early Permian, marks Earth's last complete transition into, and out of,'icehouse' conditions, and corresponds to peaks in the diversity and extent of paleotropical 'wet' forests [Gastaldo et al, 1996].Studying the LPGIA therefore has the potential to provide valuable information for understanding the Earth's transition out of the current Cenozoic ice age.

A recent two-day workshop brought together about 40 researchers from the various subdisciplines of the geosciences to (1) assess the current understanding of the timing, duration, and character of the LPGIA and how it influenced Earth's …

Burrows Dug By Large Vertebrates Into Rain-Moistened Middle Jurassic Sand Dunes, David B. Loope

Department of Earth and Atmospheric Sciences: Faculty Publications

In south-central Utah, eolian cross-strata of the Escalante Member of the Entrada Sandstone contain inclined, cylindrical burrows up to 63 cm in diameter and 305 cm long. Of the 14 large tunnels located during this study, 12 descend from second- and third-order bounding surfaces that formed on the lee slopes of large dune ridges, well above the water table. The tunnels are inclined 15°–22°; one tunnel ends in an expanded chamber. Eolian cross-strata fill proximal portions of four of the tunnels and indicate that after abandonment, sand drifts migrated as much as a meter into the open shafts. Structureless sand …

Pumping-Induced Drawdown And Stream Depletion In A Leaky Aquifer System, James J. Butler Jr., Xiaoyong Zhan, Vitaly A. Zlotnik

Department of Earth and Atmospheric Sciences: Faculty Publications

The impact of ground water pumping on nearby streams is often estimated using analytic models of the interconnected stream-aquifer system. A common assumption of these models is that the pumped aquifer is underlain by an impermeable formation. A new semianalytic solution for drawdown and stream depletion has been developed that does not require this assumption. This solution shows that pumping-induced flow (leakage) through an underlying aquitard can be an important recharge mechanism in many stream-aquifer systems. The relative importance of this source of recharge increases with the distance between the pumping well and the stream. The distance at which leakage …

Understanding Farmers’ Forecast Use From Their Beliefs, Values, Social Norms, And Perceived Obstacles*, Q. Steven Hu, Lisa M. Pytlikzillig, Gary D. Lynne, Alan Tomkins, William J. Waltman, Michael J. Hayes, Kenneth Hubbard, Ikrom Artikov, Stacey Hoffman, Donald A. Wilhite

Department of Earth and Atmospheric Sciences: Faculty Publications

Although the accuracy of weather and climate forecasts is continuously improving and new information retrieved from climate data is adding to the understanding of climate variation, use of the forecasts and climate information by farmers in farming decisions has changed little. This lack of change may result from knowledge barriers and psychological, social, and economic factors that undermine farmer motivation to use forecasts and climate information. According to the theory of planned behavior (TPB), the motivation to use forecasts may arise from personal attitudes, social norms, and perceived control or ability to use forecasts in specific decisions. These attributes are …

Coupling Between Primary Terrestrial Succession And The Trophic Development Of Lakes At Glacier Bay, Alaska, D. R. Engstrom, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

The natural eutrophication of lakes is still an accepted concept in limnology, arising as it does from the earliest efforts to classify lakes and place them in an evolutionary sequence. Recent studies of newly formed lakes at Glacier Bay, Alaska, only partially support this idea, and suggest more variable trends in lake trophic development which are under local (catchment-level) control. Here we use sediment cores from several lakes in Glacier Bay National Park to examine the relationship between successional changes in catchment vegetation and trends in water-column nitrogen (a limiting nutrient) and lake primary production. Terrestrial succession at Glacier Bay …