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Full-Text Articles in Physical Sciences and Mathematics

The Use Of Tree Rings To Study The Impacts Of Stream Flow And Climate Variability On Native And Invasive Woody Species Along A Semi-Arid Riparian Ecosystem In The Great Plains, Usa., Kristen M. Skolaut Dec 2012

The Use Of Tree Rings To Study The Impacts Of Stream Flow And Climate Variability On Native And Invasive Woody Species Along A Semi-Arid Riparian Ecosystem In The Great Plains, Usa., Kristen M. Skolaut

School of Natural Resources: Dissertations, Theses, and Student Research

Forested riparian areas of the Northern Great Plains have historically been dominated by the native Populus deltoides L. vegetation type. Changes in climate, stream flow, groundwater, and management practices in the past few decades have promoted the expansion of the upland native woody species Juniperus virginiana L. and the invasion of the non-native Elaeagnus angustifolia L. into these riparian ecosystems. This study aims at using dendrochronology, or the study of tree rings, to assess the impacts of intra- and inter- annual climatic variability and stream flow over the past decades, on the annual tree ring growth, oxygen and carbon isotopic …


Plant Community Composition And Structure Monitoring For Scotts Bluff National Monument, 2012 Annual Report, Isabel W. Ashton, Michael Prowatzke, Stephen K. Wilson Dec 2012

Plant Community Composition And Structure Monitoring For Scotts Bluff National Monument, 2012 Annual Report, Isabel W. Ashton, Michael Prowatzke, Stephen K. Wilson

United States National Park Service: Publications

Executive Summary

the last remnants of native mixed-grass prairie in the region. The Northern Great Plains Inventory & Monitoring Network (NGPN) surveyed 8 long-term monitoring plots in Scotts Bluff National Monument in 2012 as part of an effort to better understand the condition of plant communities in the park. We measured plant diversity and cover, estimated tree and shrub density, looked for the presence of exotic species that are of concern to park management, and evaluated the amount of human and natural disturbance at all plots. This effort was the second year in a multiple-year venture to document the current …


Walleye Trophic Position Before And After A Gizzard Shad Extirpation, Bethany J. Bethke, Justin A. Vandehey, Mark J. Fincel, Brian D.S. Graeb, Mark T. Porath Dec 2012

Walleye Trophic Position Before And After A Gizzard Shad Extirpation, Bethany J. Bethke, Justin A. Vandehey, Mark J. Fincel, Brian D.S. Graeb, Mark T. Porath

The Prairie Naturalist

Walleye (Sander vitreus) are an ecologically and recreationally important sport fish species. Reduced growth and condition in walleye can occur when prey availability is limited. In two Nebraska reservoirs, walleye consumed gizzard shad (Dorosoma cepedianum) as their primary prey until a winterkill extirpated the gizzard shad in 2001. Because of the winterkill, walleye in the two reservoirs had to change to alternative prey items. Our objective was to determine if stable isotope analysis on archived walleye scales can be used to detect a known food web shift in two reservoir food webs. We quantified the changes …


Distribution And Diversity Of Ant Genera From Selected Ecoregions Across Nebraska, Jessica Jurzenski, Marc Albrecht, W. Wyatt Hoback Jun 2012

Distribution And Diversity Of Ant Genera From Selected Ecoregions Across Nebraska, Jessica Jurzenski, Marc Albrecht, W. Wyatt Hoback

The Prairie Naturalist

We documented distribution and diversity of ant genera in four of the six-level III ecoregions across Nebraska. We sampled ants using bait cards, pitfall traps, and by opportunistic sampling, including direct collection and in carrion-baited pitfall traps. We identified 22 genera from five subfamilies, which were further classified into six functional groups. In common with other Great Plains states, Formica Linnaeus and Lasius Fabricius occurred most frequently in our samples, and overall ant genus-level richness was comparable to surrounding states. We compared genera similarity using Jaccard’s similarity index within and between the High Plains (western-most) and Western Corn Belt Plains …


4th International Union Of Soil Sciences Soil Classification Conference Field Tour Guidebook Jun 2012

4th International Union Of Soil Sciences Soil Classification Conference Field Tour Guidebook

Conservation and Survey Division

No abstract provided.


North Central Region Soil Survey Conference Field Tour Jun 2012

North Central Region Soil Survey Conference Field Tour

Conservation and Survey Division

No abstract provided.


Scotts Bluff National Monument, Plant Community Resource Brief, Isabel Ashton, Mike Prowatzke Feb 2012

Scotts Bluff National Monument, Plant Community Resource Brief, Isabel Ashton, Mike Prowatzke

United States National Park Service: Publications

2011 Monitoring Status

Overview

In 2011, the first year of vegetation monitoring by the Northern Great Plains Network Inventory and Monitoring staff at Scotts Bluff National Monument, efforts resulted in the documentation of 79 plant species. This was the lowest number of species among parks sampled in 2011. Graminoid (grass and grass-like plant) species accounted for only 21 (27%) of the total species, but graminoid cover was much higher than that of any other plant type. Forbs were much more diverse, but did not provide as much foliar cover.

The 5 most abundant native non-graminoids were winterfat (Krascheninnikovia lanata …


Bats In And Around Structures, Dennis M. Ferraro, Lisa Pennisi, Scott E. Hygnstrom, Stephen M. Vantassel Jan 2012

Bats In And Around Structures, Dennis M. Ferraro, Lisa Pennisi, Scott E. Hygnstrom, Stephen M. Vantassel

School of Natural Resources: Faculty Publications

No abstract provided.


Nebraska Statewide Groundwater-Level Monitoring Report 2012, A. R. Young, M. E. Burbach, J. T. Korus, L. M. Howard Jan 2012

Nebraska Statewide Groundwater-Level Monitoring Report 2012, A. R. Young, M. E. Burbach, J. T. Korus, L. M. Howard

Conservation and Survey Division

No abstract provided.


Rinded Iron-Oxide Concretions: Hallmarks Of Altered Siderite Masses Of Both Early And Late Diagenetic Origin, David Loope, Richard Kettler, Karrie A. Weber, Nathan L. Hinrichs, Derek T. Burgess Jan 2012

Rinded Iron-Oxide Concretions: Hallmarks Of Altered Siderite Masses Of Both Early And Late Diagenetic Origin, David Loope, Richard Kettler, Karrie A. Weber, Nathan L. Hinrichs, Derek T. Burgess

Department of Earth and Atmospheric Sciences: Faculty Publications

Iron-bearing concretions are valuable records of oxidation states of subsurface waters, but the first concretions to form can be altered drastically during later diagenetic events. Distinctive concretions composed of heavy rinds of iron oxide that surround iron-poor, mud-rich cores are common along bases of fluvial cross-bed sets of the Cretaceous Dakota Formation, Nebraska, USA. Concretion rinds thicken inward and cores contain 46 to 89% void space. Millimeter-scale spherosiderites are abundant in palaeosols that developed in floodplain facies. Evolution of rinded concretions began when intraformational clasts were eroded from sideritic soils, transported, abraded and deposited in river channels. Alteration of siderite …