Digital Commons Network^™

Response Of Sandhill Crane (Grus Canadensis Riverine Roosting Habitat To Changes In Stage And Sandbar Morphology, Paul Kinzel, Jonathan Nelson, Ashley Heckman

United States Geological Survey: Staff Publications

Over the past century, flow regulation and vegetation encroachment have reduced active channel widths along the central Platte River, Nebraska. During the last two decades, an annual program of in-channel vegetation management has been implemented to stabilize or expand active channel widths. Vegetation management practices are intended to enhance riverine habitats which include nocturnal roosting habitat for sandhill cranes. Evaluating the success of other management treatments such as streamflow modification requires an understanding of how flow shapes the sandbars in the river and how sandbar morphology interacts with flow to create crane habitat. These linkages were investigated along a 1-km …

The Influence Of Fallback Foods On Great Ape Tooth Enamel, Paul J. Constantino, Peter W. Lucas, James J.-W. Lee, Brian R. Lawn

Biological Sciences Faculty Research

Lucas and colleagues recently proposed a model based on fracture and deformation concepts to describe how mammalian tooth enamel may be adapted to the mechanical demands of diet (Lucas et al.: Bioessays 30[2008] 374-385). Here we review the applicability of that model by examining existing data on the food mechanical properties and enamel morphology of great apes (Pan, Pongo, and Gorilla). Particular attention is paid to whether the consumption of fallback foods is likely to play a key role in influencing great ape enamel morphology. Our results suggest that this is indeed the case. We also consider the implications of …

Microbial Communities And Associated Mineral Fabrics In Altamira Cave, Spain, Soledad Cuezva, Sergio Sanchez-Moral, Cesareo Saiz-Jimenez, Juan Carlos Cañaveras

International Journal of Speleology

Evidences of microbial colonizations were observed in Altamira Cave, Spain. These consisted of distinct small coloured colonies, both on walls and ceiling, mainly located in the area near the cave entrance, which progressed until reaching the Polychromes Hall. The colonizations were characterized by a high morphological and microstructural variability and related to biomineralization processes. Two main types of CaCO₃ deposits were related to the colonies: rosette- or nest-like aggregates of rhombohedral calcite crystals, and spheroid to hemispheroid CaCO₃ elements. Colonies distribution seems to be controlled by microenvironmental conditions inside the cavity. The areas of the cave showing higher …

Measurement Of Fine Spatial Scale Ecohydrologic Gradients In A Pinyon-Juniper Ecosystem, Matthew David Madsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the dramatic expansion of pinyon-juniper woodlands over the last century, improved understanding of how these woodlands modify infiltration properties is needed, in order for land managers to make informed decisions on how to best manage their specific resources. However, current methods for measuring soil infiltration are often limited by low sample sizes and high experimental error, due to constraints associated with remote, non agricultural settings. This thesis first presents a scheme for automating and calibrating two commercially available infiltrometers, which allows collection of a large number of precise unsaturated infiltration measurements in a relatively short period of time. Secondly, …

Fish Distributions And Nutrient Cycling In Streams: Can Fish Create Biogeochemical Hotspots, Peter B. Mcintyre, Alexander S. Flecker, Michael J. Vanni, James M. Hood, Brad W. Taylor, Steven A. Thomas

Dartmouth Scholarship

Rates of biogeochemical processes often vary widely in space and time, and characterizing this variation is critical for understanding ecosystem functioning. In streams, spatial hotspots of nutrient transformations are generally attributed to physical and microbial processes. Here we examine the potential for heterogeneous distributions of fish to generate hotspots of nutrient recycling. We measured nitrogen (N) and phosphorus (P) excretion rates of 47 species of fish in an N-limited Neotropical stream, and we combined these data with population densities in each of 49 stream channel units to estimate unit- and reach-scale nutrient recycling. Species varied widely in rates of N …

The Microbial Community Structure In Petroleum-Contaminated Sediments Corresponds To Geophysical Signatures, Jonathan P. Allen, Estella A. Atekwana, Eliot A. Atekwana, Joseph W. Duris, D. Dale Werkema, Silvia Rossbach

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The interdependence between geoelectrical signatures at underground petroleum plumes and the structures of subsurface microbial communities was investigated. For sediments contaminated with light non-aqueous-phase liquids, anomalous high conductivity values have been observed. Vertical changes in the geoelectrical properties of the sediments were concomitant with significant changes in the microbial community structures as determined by the construction and evaluation of 16S rRNA gene libraries. DNA sequencing of clones from four 16S rRNA gene libraries from different depths of a contaminated field site and two libraries from an uncontaminated background site revealed spatial heterogeneity in the microbial community structures. Correspondence analysis showed …

Applications Of Trace-Element And Stable-Isotope Geochemistry To Wildlife Issues, Yellowstone National Park And Vicinity, Maurice A. Chaffee, Wayne C. Shanks Iii, Robert O. Rye, Charles C. Shwartz, Monique G. Adams, Robert R. Carlson, James G. Crock, Pamela A. Gemery-Hill, Kerry A. Gunther, Cynthia L. Kester, Harley D. King, Shannon R. Podruzny

United States Geological Survey: Publications

Reconnaissance investigations have been conducted to identify how geochemical techniques can be applied to biological studies to assist wildlife management in and near Yellowstone National Park (the Park). Many elements (for example, As, B, Be, Ce, Cl, Cs, F, Hg, K, Li, Mo, Rb, S, Sb, Si, and W) are commonly enriched in (1) thermal waters in the Yellowstone area, (2) rocks altered by these waters, (3) sinter and travertine deposits, and (4) soils and stream sediments derived from these rocks. Some of these elements, such as As, F, Hg, and Mo, may be toxic to wildlife and could be …

Airborne Dust Transport To The Eastern Pacific Ocean Off Southern California: Evidence From San Clemente Island, Daniel R. Muhs, James Budahn, Marith Reheis, Jossh Beann, Gary Skipp, Eric Fisher

United States Geological Survey: Staff Publications

Islands are natural dust traps, and San Clemente Island, California, is a good example. Soils on marine terraces cut into Miocene andesite on this island are clay-rich Vertisols or Alfisols with vertic properties. These soils are overlain by silt-rich mantles, 5–20 cm thick, that contrast sharply with the underlying clay-rich subsoils. The silt mantles have a mineralogy that is distinct from the island bedrock. Silt mantles are rich in quartz, which is rare in the island andesite. The clay fraction of the silt mantles is dominated by mica, also absent from local andesite, and contrasts with the subsoils, dominated by …

Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Final Close-Out Report, Margaret N. Rees

Oliver Ranch Project

“The mission of the Red Rock Desert Learning Center is to instill stewardship and respect by increasing knowledge and understanding of the Mojave Desert ecosystems and cultures through a unique experiential discovery program.”

Evaluating The Performance Of Leucaena Accessions For Agroforestry In Sub-Humid Environment, Southern Tanzania, A. E. Majule

Tanzania Journal of Science

The performance of Leucaena accessions on acid soils in eastern coast Tanzania for agroforestry was evaluated for three years. Plant tree parameters assessed were fodder yield and plant stem height, stem girth, the number of total branches and poles production. Also, Leucaena psyllid, a common pest threatening the plants was also counted. Soil parameters assessed were pH organic carbon, total nitrogen, exchangeable calcium and magnesium. Result showed significant difference in growth between Leucaena accessions. Leucaena leucocephal cv K8 and Leucaena diversifolia were able to grow fast reaching 4.7 and 3.3 m respectively within a period of three years. Leucaena diversifolia …

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‰. …

A Preliminary Benthic Invertebrate Study Of Jun Jaegyu Volcano : An Undersea Volcano In Antarctic Sound, Antarctica, Gina QuiñOnes

Theses, Dissertations and Culminating Projects

Jun Jaegyu volcano, an Antarctic submarine volcano, was dredged in May 2004 for sediment and marine macroinvertebrates. The objectives of this study were to examine the benthic assemblages and biodiversity present on the newly discovered volcano. The volcano is located on the continental shelf of the northeastern Antarctic Peninsula, where recent changes in surface temperature and ice shelf stability have been observed. This volcano was swath-mapped during cruise 01 -07 of the Research Vessel-Ice Breaker Nathaniel B. Palmer. The volcano was studied using a SCUD video camera and a dredge along the flanks and crest. Results indicate a seafloor surface …

Spring Census Of Mid-Continent Sandhill Cranes Using Aerial Infrared Videography, Paul Kinzel, Jonathan Nelson, Randolph Parker, Lawrence Davis

United States Geological Survey: Staff Publications

Aerial infrared videography was used to map spatial distributions of nocturnal sandhill crane (Grus canadensis) flocks and determine crane densities within roosts as an alternative to the currently used diurnal photo-corrected ocular transect method to estimate the size of the midcontinental population. The densities determined from samples taken over the course of a night show variability. Densities measured early in the night (2100 to 2300 hrs) were generally lower than those measured in the time period after midnight and up until cranes prepared to depart their roosts before sunrise. This suggests that cranes may be more active early …

Salt Ingestion Caves, Charles A. Lundquist, William W. Varnedoe Jr.

International Journal of Speleology

Large vertebrate herbivores, when they find a salt-bearing layer of rock, say in a cliff face, can produce sizable voids where, over generations, they have removed and consumed salty rock. The cavities formed by this natural animal process constitute a unique class of caves that can be called salt ingestion caves. Several examples of such caves are described in various publications. An example in Mississippi U.S.A., Rock House Cave, was visited by the authors in 2000. It seems to have been formed by deer or bison. Perhaps the most spectacular example is Kitum Cave in Kenya. This cave has been …

The Effect Of Scaling-Up On Remotely Derived Leaf Area Index Estimators In The Brazilian Amazon, John I. Menzies

All-Inclusive List of Electronic Theses and Dissertations

This research compared a traditional statistical technique with artificial neural networks to determine their effectiveness for modeling LAI in the Santarem region of the Brazilian Amazon. In addition, different satellite sensors in the form of ETM+, ASTER, MO DIS, and IKONOS were used to assess if spatial and spectral resolutions play a role in the ability to estimate LAI. This study focused on the following: (1) Determining if neural networks perform more accurately than multiple regression for LAI modeling (2) the effectiveness of different resolution satellite data including ETM+, ASTER, MODIS, and IKONOS for LAI estimation; (3) determining if spatial …

Lack Of Significant Changes In The Herpetofauna Of Theodore Roosevelt National Park, North Dakota, Since The 1920s, Blake R. Hossack, Paul Stephen Corn, David S. Pilliod

United States Geological Survey: Staff Publications

We surveyed 88 upland wetlands and 12 1-km river sections for amphibians in Theodore Roosevelt National Park, North Dakota, during 2001–2002 to gather baseline data for future monitoring efforts and to evaluate changes in the distribution of species. We compared our results to collections of herpetofauna made during 1920–1922, 1954 and 1978–1979. The boreal chorus frog (Pseudacris maculata) was the most common amphibian in upland wetlands, followed by the tiger salamander (Ambystoma tigrinum), Woodhouse’s toad (Bufo woodhousii), northern leopard frog (Rana pipiens), plains spadefoot (Spea bombifrons) and the Great Plains …

The Benthic Community Of The Eastern Us Continental Shelf: A Literature Synopsis Of Benthic Faunal Resources, R. Allen Brooks, Carla N. Purdy, Susan S. Bell, Kenneth J. Sulak

United States Geological Survey: Staff Publications

The existing scientific literature on offshore benthic assemblages (OBA) residing along the US East and Gulf of Mexico continental shelf was reviewed. Identification was made of any associations between the dominant OBA and particular sediment types and/or bathymetry. Of special interest was the evaluation of reported effects of sand dredge/mining activities on the dominant OBA and recognition of data deficiencies. One hundred and twenty-two references were selected and classified as to type of study with pertinent results extracted. Polychaetes were predominantly cited as the principal infaunal taxa present in studies from both the Gulf of Mexico and US Atlantic coast. …

Assessing Sandhill Crane Roosting Habitat Along The Platte River, Nebraska, P.J. Kinzel, J.M. Nelson, R.S. Parker

United States Geological Survey: Publications

Each spring approximately 500,000 sandhill cranes and some endangered whooping cranes use the Central Platte River Valley in Nebraska as a staging habitat during their migration north to breeding and nesting grounds in Canada, Alaska, and the Siberian Arctic. Over the last century changes in the flow of the river have altered the river channels and the distribution of roost sites. USGS researchers studied linkages between water flow, sediment supply, channel morphology, and preferred sites for crane roosting. These results are useful for estimating crane populations and for providing resource managers with techniques to understand crane habitats.

Physical And Chemical Characteristics Of Water In Selected Locations In Lake Victoria, Tanzania, M A Kishe

Tanzania Journal of Science

A study conducted during the period of March/April 2002 aimed at measuring physical and chemical parameters in Tanzanian portion of Lake Victoria. Temperature and conductivity values were homogeneous among and within the study stations. Levels of dissolved oxygen (DO) ranged from 4 - 9 mgl-1 and there was significant difference between stations (P < 0.05). Water transparency was poor (< 2 m secchi depth) and differed from one sampling station to another. Ammonium nitrogen (NH4+-N), with few exceptions, showed the highest concentrations both at the bottom and near-surface followed by total phosphates (TP), nitrate nitrogen (NO2+NO3--N), nitrite nitrogen (NO2--N) and Soluble Reactive Silicon (SRSi). Concentrations of NH4+-N, TP and SRSi were high at bottom waters and the reverse was true for NO2+NO3--N and NO2--N. Differences in nutrients and physical water parameters among sampling stations were statistically significant (P < 0.05). However, temperature and nutrient levels at studied areas were higher than that of 50 years ago and the trend reversed for DO and transparency. This indicates that Lake Victoria is receiving organic materials from the catchment area leading to the decline of water quality. Long-term efforts for rehabilitation, conservation and sustainable management of the lake are suggested.

Studies On The Fisheries And Biology Of Oreochromis Urolepsis (Pisces: Cichilidae) In The Mtera Resorvoir (Tanzania), F M M Chale

Tanzania Journal of Science

The fisheries and some aspects of the biology of Oreochromis urolepis of the Mtera Reservoir (Tanzania) were examined in August 2002. It was observed that there was no proper management of the reservoir's fisheries. Beach seine fishing dominated the fishery. Nearly all the O. urolepis caught by this type of gear were juveniles. The number of fish caught by the beach seines was very high, some times up to 4,000 fish per haul. The beach seines also destroy the spawning sites for the tilapias. Mean total lengths of O. urolepis caught in gillnets of legal mesh sizes (ranging from 88 …

The Impact Of Urbanization On Macroinvertebrate Communities Of Creeks Within Western Georgia, Jeniffer Susan Lang

Theses and Dissertations

Urbanization is a major cause of stream impairment in the United States, altering stream ecological integrity in a variety of ways. While control of point source pollution has largely improved over the last twenty years, the control of non-point source pollution has proved to be more of a challenge. Urbanization in the area surrounding streams has been linked with elevated levels of sediment, heavy metals, organic matter, and nutrients within streams, as well as with other negative effects. Examining the macroinvertebrate communities within streams has proven to be an effective indicator of the effects of urbanization on water quality. This …

Consequences Of Reservoir Drainage On Downstream Water Chemistry, Suspended Sediment, And Nutrients, Southwest Missouri, Mark W. Bowen

Graduate Theses/Dissertations

Construction and subsequent draining of reservoirs can have dramatic affects on the release of nutrients and sediments to waterways. This study describes how the temporary draining of a small reservoir for dam repair influences downstream water quality. The Valley Mill Reservoir has a surface area of 6.1 hectares and volume of 150,000 m3 when filled. Water chemistry monitoring and water sampling were performed at six sites during baseflow and ten sites during runoff events for one year. Water samples were analyzed for total nitrogen (TN), total phosphorous (TP), and total suspended sediment (TSS) concentrations. Results indicate that draining of Valley …

Great Plains Ecosystems: Past, Present, And Future, Fred B. Samson, Fritz L. Knopf, Wayne Ostlie

United States Geological Survey: Staff Publications

Little questions exists that the main bodies of North American prairie (i.e., the tall-grass, mixed, and shortgrass) are among the most endangered resources on the continent. The purpose of this paper is to provide a past and present biological base- line by which to understand North American prairies and to provide a platform for future conservation. Events both immediate to the end of the Pleistocene and historic suggest that the present grassland conditions are different from those within which most of the grassland organisms evolved. Our analysis suggests that few grassland landscapes remain adequate in area and distribution to sustain …

Differences In Habitat Use By Blanding’S Turtles, Emydoidea Blandingii, And Painted Turtles, Chysemys Picta, In The Nebraska Sandhills, R. Bruce Bury, David J. Germano

United States Geological Survey: Staff Publications

We sampled a variety of wetlands in the Nebraska sandhills at Valentine National Wildlife Refuge. Significantly more individuals of painted turtles (Chrysemys picta) occurred in lakes and open waters than in marshes or small ponds, and the opposite was true for Blanding’s turtles (Emydoidea blandingii). Besides this marked difference in habitat use, 46% of the captured E. blandingii in pond/marsh habitat were juveniles, but only 31.6% in lakes and open water. Current information suggests that marshes and small ponds are important habitat for juvenile turtles, especially Emydoidea blandingii.

Calibration Of Remotely Sensed, Coarse Resolution Ndvi To Co2 Fluxes In A Sagebrush–Steppe Ecosystem, Bruce K. Wylie, Douglas A. Johnson, Emilio Laca, Nicanor Z. Saliendra, Tagir G. Gilmanov, Bradley C. Reed, Larry L. Tieszen, Bruce B. Worstell

United States Geological Survey: Staff Publications

The net ecosystem exchange (NEE) of carbon flux can be partitioned into gross primary productivity (GPP) and respiration (R). The contribution of remote sensing and modeling holds the potential to predict these components and map them spatially and temporally. This has obvious utility to quantify carbon sink and source relationships and to identify improved land management strategies for optimizing carbon sequestration. The objective of our study was to evaluate prediction of 14-day average daytime CO₂ fluxes ( F_day) and nighttime CO₂ fluxes (R_n) using remote sensing and other data. F_{day …}

Ecoregions Of Nebraska And Kansas, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources; they are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem components. Ecoregions are directly applicable to the immediate needs of state agencies, including the development of biological criteria and water quality standards, and the establishment of management goals for nonpoint-source pollution. They are also relevant to integrated ecosystem management, an ultimate goal of most federal and state resource management agencies. The approach used to compile this map is based on the premise …

Comparison Of Tovs-Derived Land Surface Variables With Ground Observations, Venkataraman Lakshmi, Joel Susskind

Faculty Publications

The Tiros Operational Vertical Sounder (TOVS) Pathfinder Path A retrieved surface skin temperature, surface air temperatures, and surface specific humidity are compared with data obtained from three large-scale field campaigns: the First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment (FIFE), the Hydrologic Atmospheric Pilot Experiment (HAPEX) in the Sahel, and the Boreal Ecosystem-Atmosphere Study (BOREAS). The long-term estimates of surface skin temperatures, surface air temperatures, and surface vapor pressure were unbiased, and the standard deviations of the errors were about 4°C, 3.5°C, and 3.5 mbar, respectively. The monthly mean variables obtained from the TOVS data at four times …

Ecogeochemistry Of The Subsurface Food Web At Ph 0–2.5 In Iron Mountain, California, U.S.A., Eleanora I. Robbins, Teresa M. Rodgers, Charles N. Alpers, D. Kirk Nordstrom

United States Geological Survey: Staff Publications

Pyrite oxidation in the underground mining environment of Iron Mountain, California, has created the most acidic pH values ever reported in aquatic systems. Sulfate values as high as 120 000 mg 1^-1 and iron as high as 27600mg 1^-1 have been measured in the mine water, which also carries abundant other dissolved metals including Al, Zn, Cu, Cd, Mn, Sb and Pb. Extreme acidity and high metal concentrations apparently do not preclude the presence of an underground acidophilic food web, which has developed with bacterial biomass at the base and heliozoans as top predators. Slimes, oil-like films, flexible …

Earth News, Fall 1998, Department Of Earth Science, University Of Northern Iowa.

Earth News

Inside this issue:

--- Faculty Achievements and Activities
--- 1998 Earth Science Graduates
--- Student Research Presentations
--- Sigma Gamma Epsilon - Gamma Sigma Chapter
--- Earth Science Majors
--- Observatory: Room with a Stellar View
--- Gifts to the Department of Earth Science
--- 1998 Scholarship and Award Recipients
--- Earth Science Seminar Series
--- UNI Students Get Up Close and Personal with Nature
--- Earth Science Alumni Notes

Comparison Of Recent Coral Life And Death Assemblages To Pleistocene Reef Communities: Implications For Rapid Faunal Replacement On Recent Reefs, Benjamin J. Greenstein, Lora A. Harris, H. Allen Curran

Geosciences: Faculty Publications

Marine ecologists and paleoecologists are increasingly recognizing that the Pleistocene and Holocene fossil record of coral reefs is the exclusive database from which an assessment of the long-term responses of reef communities to environmental perturbations may be obtained. The apparent persistence of coral communities in the face of intense fluctuations in sea level and sea surface temperature during glacial and interglacial stages of Pleistocene time is in marked contrast to dramatic fluctuations in reef community structure documented by short-term monitoring studies. We compared the taxonomic structure of live and dead coral communities on a modem patch reef currently undergoing a …