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Sample records for great plains usa

  1. Western Great Plains, Badlands, SD, USA

    NASA Image and Video Library

    1973-06-22

    SL2-81-162 (22 June 1973) --- The most striking feature of this scene of the western Great Plains and the Badlands of SD (43.5N, 101.0W) is the rugged topography of the landscape. Over eons of time, the White River has carved out a badlands topography of steep gullies, irregular winding ridges and isolated buttes. The barren wasteland of badlands light toned rock surfaces contrast sharply with the adjacent vegetated landscape of native grasslands and cultivated fields. Photo credit: NASA

  2. Late Pleistocene dune activity in the central Great Plains, USA

    USGS Publications Warehouse

    Mason, J.A.; Swinehart, J.B.; Hanson, P.R.; Loope, D.B.; Goble, R.J.; Miao, X.; Schmeisser, R.L.

    2011-01-01

    Stabilized dunes of the central Great Plains, especially the megabarchans and large barchanoid ridges of the Nebraska Sand Hills, provide dramatic evidence of late Quaternary environmental change. Episodic Holocene dune activity in this region is now well-documented, but Late Pleistocene dune mobility has remained poorly documented, despite early interpretations of the Sand Hills dunes as Pleistocene relicts. New optically stimulated luminescence (OSL) ages from drill cores and outcrops provide evidence of Late Pleistocene dune activity at sites distributed across the central Great Plains. In addition, Late Pleistocene eolian sands deposited at 20-25 ka are interbedded with loess south of the Sand Hills. Several of the large dunes sampled in the Sand Hills clearly contain a substantial core of Late Pleistocene sand; thus, they had developed by the Late Pleistocene and were fully mobile at that time, although substantial sand deposition and extensive longitudinal dune construction occurred during the Holocene. Many of the Late Pleistocene OSL ages fall between 17 and 14 ka, but it is likely that these ages represent only the later part of a longer period of dune construction and migration. At several sites, significant Late Pleistocene or Holocene large-dune migration also probably occurred after the time represented by the Pleistocene OSL ages. Sedimentary structures in Late Pleistocene eolian sand and the forms of large dunes potentially constructed in the Late Pleistocene both indicate sand transport dominated by northerly to westerly winds, consistent with Late Pleistocene loess transport directions. Numerical modeling of the climate of the Last Glacial Maximum has often yielded mean monthly surface winds southwest of the Laurentide Ice Sheet that are consistent with this geologic evidence, despite strengthened anticyclonic circulation over the ice sheet. Mobility of large dunes during the Late Pleistocene on the central Great Plains may have been the result of

  3. Dendroclimatic potential of plains cottonwood (Populus deltoides subsp. monilifera) from the Northern Great Plains, USA

    USGS Publications Warehouse

    Edmonson, Jesse; Friedman, Jonathan; Meko, David; Touchan, Ramzi; Scott, Julian; Edmonson, Alan

    2014-01-01

    A new 368-year tree-ring chronology (A.D. 1643–2010) has been developed in western North Dakota using plains cottonwood (Populus deltoides subsp. monilifera) growing on the relatively undisturbed floodplain of the Little Missouri River in the North Unit of Theodore Roosevelt National Park. We document many slow-growing living trees between 150–370 years old that contradict the common understanding that cottonwoods grow fast and die young. In this northern location, cottonwood produces distinct annual rings with dramatic interannual variability that strongly crossdate. The detrended tree-ring chronology is significantly positively correlated with local growing season precipitation and soil moisture conditions (r  =  0.69). This time series shows periods of prolonged low radial tree growth during the known droughts of the instrumental record (e.g. 1931–1939 and 1980–1981) and also during prehistory (e.g. 1816–1823 and 1856–1865) when other paleoclimate studies have documented droughts in this region. Tree rings of cottonwood will be a useful tool to help reconstruct climate, streamflow, and the floodplain history of the Little Missouri River and other northern river systems.

  4. Wintering Sandhill Crane exposure to wind energy development in the central and southern Great Plains, USA

    USGS Publications Warehouse

    Pearse, Aaron T.; Brandt, David; Krapu, Gary

    2016-01-01

    Numerous wind energy projects have been constructed in the central and southern Great Plains, USA, the main wintering area for midcontinental Sandhill Cranes (Grus canadensis). In an initial assessment of the potential risks of wind towers to cranes, we estimated spatial overlap, investigated potential avoidance behavior, and determined the habitat associations of cranes. We used data from cranes marked with platform transmitting terminals (PTTs) with and without global positioning system (GPS) capabilities. We estimated the wintering distributions of PTT-marked cranes prior to the construction of wind towers, which we compared with current tower locations. Based on this analysis, we found 7% spatial overlap between the distributions of cranes and towers. When we looked at individually marked cranes, we found that 52% would have occurred within 10 km of a tower at some point during winter. Using data from cranes marked after tower construction, we found a potential indication of avoidance behavior, whereby GPS-marked cranes generally used areas slightly more distant from existing wind towers than would be expected by chance. Results from a habitat selection model suggested that distances between crane locations and towers may have been driven more by habitat selection than by avoidance, as most wind towers were constructed in locations not often selected by wintering cranes. Our findings of modest regional overlap and that few towers have been placed in preferred crane habitat suggest that the current distribution of wind towers may be of low risk to the continued persistence of wintering midcontinental Sandhill Cranes in the central and southern Great Plains.

  5. Trends in nutrient and sediment retention in Great Plains reservoirs (USA).

    PubMed

    Cunha, Davi Gasparini Fernandes; do Carmo Calijuri, Maria; Dodds, Walter Kennedy

    2014-02-01

    Reservoirs are artificial ecosystems with physical, chemical, and biological transitional characteristics between rivers and lakes. Greater water retention time in reservoirs provides conditions for cycling materials inputs from upstream waters through sedimentation, biological assimilation and other biogeochemical processes. We investigated the effects of reservoirs on the water quantity and quality in the Great Plains (Kansas, USA), an area where little is known about these dominant hydrologic features. We analyzed a 30-year time-series of discharge, total phosphorus (TP), nitrate (NO3(-)), and total suspended solids (TSS) from six reservoirs and estimated overall removal efficiencies from upstream to downstream, testing correlations among retention, discharge, and time. In general, mean removal of TP (42-74%), TSS (0-93%), and NO3(-) (11-56%) from upstream to downstream did not change over 30 years. TP retention was associated with TSS removal, suggesting that nutrient substantial portion of P was adsorbed to solids. Our results indicated that reservoirs had the effect of lowering variance in the water quality parameters and that these reservoirs are not getting more or less nutrient-rich over time. We found no evidence of temporal changes in the yearly mean upstream and downstream discharges. The ratio upstream/downstream discharge was analyzed because it allowed us to assess how much contribution of additional unsampled tributaries may have biased our ability to calculate retention. Nutrient and sediment removal was less affected by hydraulic residence time than expected. Our study demonstrates that reservoirs can play a role in the removal and processing of nutrient and sediments, which has repercussions when valuing their ecological services and designing watershed management plans.

  6. Loess record of the Pleistocene-Holocene transition on the northern and central Great Plains, USA

    USGS Publications Warehouse

    Mason, J.A.; Miao, X.; Hanson, P.R.; Johnson, W.C.; Jacobs, P.M.; Goble, R.J.

    2008-01-01

    Various lines of evidence support conflicting interpretations of the timing, abruptness, and nature of climate change in the Great Plains during the Pleistocene-Holocene transition. Loess deposits and paleosols on both the central and northern Great Plains provide a valuable record that can help address these issues. A synthesis of new and previously reported optical and radiocarbon ages indicates that the Brady Soil, which marks the boundary between late Pleistocene Peoria Loess and Holocene Bignell Loess, began forming after a reduction in the rate of Peoria Loess accumulation that most likely occurred between 13.5 and 15 cal ka. Brady Soil formation spanned all or part of the B??lling-Aller??d episode (approximately 14.7-12.9 cal ka) and all of the Younger Dryas episode (12.9-11.5 cal ka) and extended at least 1000 years beyond the end of the Younger Dryas. The Brady Soil was buried by Bignell Loess sedimentation beginning around 10.5-9 cal ka, and continuing episodically through the Holocene. Evidence for a brief increase in loess influx during the Younger Dryas is noteworthy but very limited. Most late Quaternary loess accumulation in the central Great Plains was nonglacigenic and was under relatively direct climatic control. Thus, Brady Soil formation records climatic conditions that minimized eolian activity and allowed effective pedogenesis, probably through relatively high effective moisture. Optical dating of loess in North Dakota supports correlation of the Leonard Paleosol on the northern Great Plains with the Brady Soil. Thick loess in North Dakota was primarily derived from the Missouri River floodplain; thus, its stratigraphy may in part reflect glacial influence on the Missouri River. Nonetheless, the persistence of minimal loess accumulation and soil formation until 10 cal ka at our North Dakota study site is best explained by a prolonged interval of high effective moisture correlative with the conditions that favored Brady Soil formation. Burial

  7. Loess record of the Pleistocene Holocene transition on the northern and central Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Mason, Joseph A.; Miao, Xiaodong; Hanson, Paul R.; Johnson, William C.; Jacobs, Peter M.; Goble, Ronald J.

    2008-09-01

    Various lines of evidence support conflicting interpretations of the timing, abruptness, and nature of climate change in the Great Plains during the Pleistocene-Holocene transition. Loess deposits and paleosols on both the central and northern Great Plains provide a valuable record that can help address these issues. A synthesis of new and previously reported optical and radiocarbon ages indicates that the Brady Soil, which marks the boundary between late Pleistocene Peoria Loess and Holocene Bignell Loess, began forming after a reduction in the rate of Peoria Loess accumulation that most likely occurred between 13.5 and 15 cal ka. Brady Soil formation spanned all or part of the Bølling-Allerød episode (approximately 14.7-12.9 cal ka) and all of the Younger Dryas episode (12.9-11.5 cal ka) and extended at least 1000 years beyond the end of the Younger Dryas. The Brady Soil was buried by Bignell Loess sedimentation beginning around 10.5-9 cal ka, and continuing episodically through the Holocene. Evidence for a brief increase in loess influx during the Younger Dryas is noteworthy but very limited. Most late Quaternary loess accumulation in the central Great Plains was nonglacigenic and was under relatively direct climatic control. Thus, Brady Soil formation records climatic conditions that minimized eolian activity and allowed effective pedogenesis, probably through relatively high effective moisture. Optical dating of loess in North Dakota supports correlation of the Leonard Paleosol on the northern Great Plains with the Brady Soil. Thick loess in North Dakota was primarily derived from the Missouri River floodplain; thus, its stratigraphy may in part reflect glacial influence on the Missouri River. Nonetheless, the persistence of minimal loess accumulation and soil formation until 10 cal ka at our North Dakota study site is best explained by a prolonged interval of high effective moisture correlative with the conditions that favored Brady Soil formation. Burial

  8. Great plains, Chapter 11

    Treesearch

    C.M. Clark

    2011-01-01

    The North American Great Plains are the largest contiguous ecoregion in North America, covering 3.5 million square km2, or 16 percent of the continental area (CEC 1997). In the United States, the Great Plains ecoregion encompasses a roughly triangular region (Figure 2.2), bordered on the west by the Rocky Mountains and the southwestern deserts in...

  9. Sources and paleoclimatic significance of Holocene Bignell Loess, central Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Mason, Joseph A.; Jacobs, Peter M.; Hanson, Paul R.; Miao, Xiaodong; Goble, Ronald J.

    2003-11-01

    This paper reexamines the stratigraphy, sources, and paleoclimatic significance of Holocene Bignell Loess in the central Great Plains. A broadly similar sequence of loess depositional units and paleosols was observed in thick Bignell Loess sections up to 300 km apart, suggesting that these sections record major regional changes in the balance between dust deposition and pedogenesis. New optical ages, together with previously reported radiocarbon ages, indicate Bignell Loess deposition began 9000-11,000 yr ago and continued into the late Holocene; some Bignell Loess is <1000 yr old. There is little evidence that Holocene Loess was derived from flood plain sources, as previously proposed. Instead, thick Bignell Loess occurs mainly near the downwind margins of inactive dune fields, particularly atop escarpments facing the dunes. Thus, the immediate loess source was dust produced when the dunes were active. Previous work indicates that widespread episodes of dune activity are likely to have resulted from drier-than-present climatic conditions. The regionally coherent stratigraphy of Bignell Loess can be interpreted as a near-continuous record of climatically driven variation in dune field activity throughout the Holocene.

  10. Decreased runoff response to precipitation, Little Missouri River Basin, northern Great Plains, USA

    USGS Publications Warehouse

    Griffin, Eleanor R.; Friedman, Jonathan M.

    2017-01-01

    High variability in precipitation and streamflow in the semiarid northern Great Plains causes large uncertainty in water availability. This uncertainty is compounded by potential effects of future climate change. We examined historical variability in annual and growing season precipitation, temperature, and streamflow within the Little Missouri River Basin and identified differences in the runoff response to precipitation for the period 1976-2012 compared to 1939-1975 (n = 37 years in both cases). Computed mean values for the second half of the record showed little change (<5%) in annual or growing season precipitation, but average annual runoff at the basin outlet decreased by 22%, with 66% of the reduction in flow occurring during the growing season. Our results show a statistically significant (p < 0.10) 27% decrease in the annual runoff response to precipitation (runoff ratio). Surface-water withdrawals for various uses appear to account for <12% of the reduction in average annual flow volume, and we found no published or reported evidence of substantial flow reduction caused by groundwater pumping in this basin. Results of our analysis suggest that increases in monthly average maximum and minimum temperatures, including >1°C increases in January through March, are the dominant driver of the observed decrease in runoff response to precipitation in the Little Missouri River Basin.

  11. Life-cycle assessment of the beef cattle production system for the northern great plains, USA.

    PubMed

    Lupo, Christopher D; Clay, David E; Benning, Jennifer L; Stone, James J

    2013-09-01

    A life-cycle assessment (LCA) model was developed to estimate the environmental impacts associated with four different U.S. Northern Great Plains (NPG) beef production systems. The LCA model followed a "cradle-to-gate" approach and incorporated all major unit processes, including mineral supplement production. Four distinct operation scenarios were modeled based on production strategies common to the NGP, and a variety of impacts were determined. The scenarios include a normal operation, early weaning of the calf, fast-tack backgrounding, and grassfed. Enteric emissions and manure emissions and handling were consistently the largest contributors to the LCA impacts. There was little variability between production scenarios except for the grassfed, where the greenhouse gas (GHG) emissions were 37% higher due to a longer finishing time and lower finishing weight. However, reductions to GHG emissions (15-24%) were realized when soil organic carbon accrual was considered and may be a more realistic estimate for the NGP. Manure emissions and handing were primary contributors to potential eutrophication and acidification impacts. Mitigation strategies to reduce LCA impacts, including diet manipulation and management strategies (i.e., treatment of manure), were considered from a whole-systems perspective. Model results can be used for guidance by NGP producers, environmental practitioners, and policymakers. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  12. Characterizing the environmental conditions and estimating aboveground biomass productivity for switchgrass in the Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Gu, Y.; Wylie, B. K.; Howard, D. M.

    2013-12-01

    Switchgrass is being evaluated as a potential feedstock source for cellulosic biofuels and is being cultivated in several regions of the United States. The recent availability of switchgrass land cover maps derived from the National Agricultural Statistics Service cropland data layer for the conterminous United States provides an opportunity to assess the environmental conditions of switchgrass over large areas and across different geographic locations. The main goal of this study is to investigate the relationship between site environmental conditions and switchgrass productivity and identify the optimal conditions for productive switchgrass in the Great Plains (GP). Environmental and climate variables such as elevation, soil organic carbon, available water capacity, climate, and seasonal weather were used in this study. Satellite-derived growing season averaged Normalized Difference Vegetation Index was used as a proxy for switchgrass productivity. The environmental conditions for switchgrass sites of variable productivity were summarized and a data-driven multiple regression switchgrass productivity model was developed. Results show that spring precipitation has the strongest correlation with switchgrass productivity (r = 0.92, 176 samples) and spring minimum temperature has the weakest correlation with switchgrass productivity (r = 0.16). An estimated switchgrass productivity map for the entire GP based on site environmental and climate conditions was generated. The estimated switchgrass biomass productivity map indicates that highly productive switchgrass areas are mainly located in the eastern part of the GP. Results from this study provide useful information for assessing economic feasibility or optimal land use decisions regarding switchgrass development in the GP.

  13. Land cover changes associated with recent energy development in the Williston Basin; Northern Great Plains, USA.

    PubMed

    Preston, Todd M; Kim, Kevin

    2016-10-01

    The Williston Basin in the Northern Great Plains has experienced rapid energy development since 2000. To evaluate the land cover changes resulting from recent (2000-2015) development, the area and previous land cover of all well pads (pads) constructed during this time were determined, the amount of disturbed and reclaimed land adjacent to pads was estimated, land cover changes were analyzed over time for three different well types, and the effects from future development were predicted. The previous land cover of the 12,990ha converted to pads was predominately agricultural (49.5%) or prairie (47.4%) with lesser amounts of developed (2.3%), aquatic (0.5%), and forest (0.4%). Additionally, 12,121ha has likely been disturbed and reclaimed. The area required per gas well remained constant through time while the land required per oil well increased initially and then decreased as development first shifted from conventional to unconventional drilling and then to multi-bore pads. For non-oil-and-gas wells (i.e. stratigraphic test wells, water wells, and injection wells), the area per well increased through time likely due to increased produced water disposal requirements. Future land cover change is expected to be 2.7 times greater than recent development with much of the development occurring in five counties in the core Bakken development area. Direct land cover change and disturbance from recent and expected development are predicted to affect 0.4% of the landscape across the basin; however, in the core Bakken development area, 2.3% of the landscape will be affected including 2.1% of the remaining grassland. Although future development will result in significant land cover change, evolving industry practices and proactive siting decisions, such as development along energy corridors and placing pads in areas previously altered by human activity, have the potential to reduce the ecological effects of future energy development in the Williston Basin. Published by

  14. Strontium isotope geochemistry of groundwater in the central part of the Dakota (Great Plains) aquifer, USA

    USGS Publications Warehouse

    Gosselin, D.C.; Harvey, F.E.; Frost, C.; Stotler, R.; Macfarlane, P.A.

    2004-01-01

    The Dakota aquifer of the central and eastern Great Plains of the United States is an important source of water for municipal supplies, irrigation and industrial use. Although the regional flow system can be characterized generally as east to northeasterly from the Rocky Mountains towards the Missouri River, locally the flow systems are hydrologically complex. This study uses Sr isotopic data from groundwater and leached aquifer samples to document the complex subsystems within the Dakota aquifer in Nebraska and Kansas. The interaction of groundwater with the geologic material through which it flows has created spatial patterns in the isotopic measurements that are related to: long-term water-rock interaction, during which varying degrees of isotopic equilibrium between water and rock has been achieved; and the alteration of NaCl fluids by water-rock interaction. Specifically, Sr isotopic data distinguish brines from Kansas and western Nebraska from those in eastern Nebraska: the former are interpreted to reflect interaction with Permian rocks, whereas the latter record interaction with Pennsylvanian rocks. The Sr isotopic composition of groundwater from other parts of Nebraska and Kansas are a function of the dynamic interaction between groundwater and unlithified sediments (e.g., glacial till and loess), followed by interaction with oxidized and unoxidized sediments within the Dakota Formation. This study illustrates the power of combining Sr chemistry with more conventional geochemical data to obtain a more complete understanding of groundwater flow systems within regional aquifer systems where extensive monitoring networks do not exist. ?? 2003 Elsevier Ltd. All rights reserved.

  15. Land cover changes associated with recent energy development in the Williston Basin; Northern Great Plains, USA

    USGS Publications Warehouse

    Preston, Todd M.; Kim, Kevin

    2016-01-01

    The Williston Basin in the Northern Great Plains has experienced rapid energy development since 2000. To evaluate the land cover changes resulting from recent (2000 – 2015) development, the area and previous land cover of all well pads (pads) constructed during this time was determined, the amount of disturbed and reclaimed land adjacent to pads was estimated, land cover changes were analyzed over time for three different well types, and the effects from future development were predicted. The previous land cover of the 12,990 ha converted to pads was predominately agricultural (49.5%) or prairie (47.4%) with lesser amounts of developed (2.3%), aquatic (0.5%), and forest (0.4%). Additionally, 12,121 ha have likely been disturbed and reclaimed. The area required per gas well remained constant through time while the land required per oil well increased initially and then decreased as development first shifted from conventional to unconventional drilling and then to multi-bore pads. For non-oil-and- gas wells (i.e. stratigraphic test wells, water wells, injection wells, etc.), the area per well increased through time likely due to increased produced water disposal requirements. Future land cover change is expected to be 2.7 times greater than recent development with much of the development occurring in five counties in the core Bakken development area. Direct land cover change and disturbance from recent and expected development are predicted to affect 0.4% of the landscape across the basin; however, in the core Bakken development area, 2.3% of the landscape will be affected including 2.1% of the remaining grassland. Although future development will result in significant land cover change, evolving industry practices and proactive siting decisions, such as development along energy corridors and placing pads in areas previously altered by human activity, have the potential to reduce the ecological effects of future energy development in the Williston Basin.

  16. Using stable isotopes to understand hydrochemical processes in and around a Prairie Pothole wetland in the Northern Great Plains, USA

    USGS Publications Warehouse

    Mills, Christopher T.; Goldhaber, Martin B.; Stricker, Craig A.; Holloway, JoAnn M.; Morrison, Jean M.; Ellefsen, Karl J.; Rosenberry, Donald O.; Thurston, Roland S.

    2011-01-01

    Millions of internally drained wetland systems in the Prairie Potholes region of the northern Great Plains (USA and Canada) provide indispensable habitat for waterfowl and a host of other ecosystem services. The hydrochemistry of these systems is complex and a crucial control on wetland function, flora and fauna. Wetland waters can have high concentrations of SO2-4 due to the oxidation of large amounts of pyrite in glacial till that is in part derived from the Pierre shale. Water chemistry including δ18OH2O, δ2HH2O, and δ34SSO4 values, was determined for groundwater, soil pore water, and wetland surface water in and around a discharge wetland in North Dakota. The isotopic data for the first time trace the interaction of processes that affect wetland chemistry, including open water evaporation, plant transpiration, and microbial SO4 reduction.

  17. Net global warming potential and greenhouse gas intensity under dryland cropping systems in the northern Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Sainju, U. M.; Usda-Ars-Gracenet

    2013-05-01

    Dryland cropping systems constitute a major farming system globally but little is known about management practices effect on net global warming potential (GWP) and greenhouse gas intensity (GHGI). We evaluated the effects of cropping sequences {conventional-tilled malt barley (Hordeum vulgaris L.)-fallow [CTB-F], no-tilled malt barley-pea (Pisum sativum L.) rotation [NTB-P], and no-tilled continuous malt barley [NTCB]} and N fertilization rates (0 and 80 kg N ha-1) on dryland soil greenhouse gas (GHG) emissions, GWP, and GHGI from 2008 to 2011 in eastern Montana, USA. The CO2 and N2O fluxes and CH4 uptake from spring to autumn were greater in NTB-P and NTCB with 80 kg N ha-1 than in other treatments. Net GWP and GHGI based on soil respiration and GHGI based on soil organic C (SOC) were greater in NTCB with 0 kg N ha-1 but GWP based on SOC was greater in CTB-F with 0 kg N ha-1 than in NTB-P with 0 and 80 kg N ha-1. Because of increased grain yield but reduced GWP and GHGI, NTB-P with 80 kg N ha-1 may be used as a management option to reduce dryland GWP and GHGI while sustaining crop yields in the northern Great Plains, USA.

  18. Extent of Kentucky bluegrass and its effect on native plant species diversity and ecosystem services in the Northern Great Plains of the USA

    USDA-ARS?s Scientific Manuscript database

    The geographic spread of Kentucky bluegrass in rangelands of the USA has increased significantly over the past decades. Preliminary analysis of National Resources Inventory data indicates that Kentucky bluegrass occupies a majority of ecological sites across the Northern Great Plains. Despite its fa...

  19. Self-seeding warm-season legumes for low-input forage production in the southern Great Plains of the USA

    USDA-ARS?s Scientific Manuscript database

    In the southern Great Plains (SGP) of the USA warm-season legumes can improve the quality of available forage in pasture systems based on perennial warm-season grasses. Legumes that persist through self-seeding may be especially useful in low-input systems where resources for annual replanting are l...

  20. Patterns of seasonal phytoplankton distribution in prairie saline lakes of the northern Great Plains (U.S.A.)

    PubMed Central

    Salm, Courtney R; Saros, Jasmine E; Martin, Callie S; Erickson, Jarvis M

    2009-01-01

    Seasonal changes in freshwater phytoplankton communities have been extensively studied, but key drivers of phytoplankton in saline lakes are currently not well understood. Comparative lake studies of 19 prairie saline lakes in the northern Great Plains (USA) were conducted in spring and summer of 2004, with data gathered for a suite of limnological parameters. Nutrient enrichment assays for natural phytoplankton assemblages were also performed in spring and summer of 2006. Canonical correspondence analysis of 2004 data showed salinity (logCl), nitrogen, and phosphorus (N:P ratios) to be the main drivers of phytoplankton distribution in the spring, and phosphorus (C:P ratios), iron (logTFe), and nitrogen (logTN) as important factors in the summer. Despite major differences in nutrient limitation patterns (P-limitation in freshwater systems, N-limitation in saline systems), seasonal patterns of phytoplankton phyla changes in these saline lakes were similar to those of freshwater systems. Dominance shifted from diatoms in the spring to cyanobacteria in the summer. Nutrient enrichment assays (control, +Fe, +N, +P, +N+P) in 2006 indicated that nutrient limitation is generally more consistent within lakes than for individual taxa across systems, with widespread nitrogen and secondary phosphorus limitation. Understanding phytoplankton community structure provides insight into the overall ecology of saline lakes, and will assist in the future conservation and management of these valuable and climatically-sensitive systems. PMID:19123939

  1. Spatial differences in hydrologic characteristics and water chemistry of a temperate coastal plain peatland: The Great Dismal Swamp, USA

    USGS Publications Warehouse

    Speiran, Gary K.; Wurster, Frederick C.

    2016-01-01

    Spatial differences in hydrologic processes and geochemistry across forested peatlands control the response of the wetland-community species and resiliency to natural and anthropogenic disturbances. Knowing these controls is essential to effectively managing peatlands as resilient wetland habitats. The Great Dismal Swamp is a 45,325 hectare peatland in the Atlantic Coastal Plain of Virginia and North Carolina, USA, managed by the U.S. Fish and Wildlife Service. The existing forest-species distribution is a product of timber harvesting, hydrologic alteration by canal and road construction, and wildfires. Since 2009, studies of hydrologic and geochemical controls have expanded knowledge of groundwater flow paths, water chemistry, response to precipitation events, and characteristics of the peat. Dominant hydrologic and geochemical controls include (1) the gradual slope in land surface, (2) vertical differences in the hydraulic characteristics of the peat, (3) the proximity of lateral groundwater and small stream inflows from uplands, (4) the presence of an extensive canal and road network, and (5) small, adjustable-height dams on the canals. Although upland sources provide some surface water and lateral groundwater inflow to western parts of the swamp, direct groundwater recharge by precipitation is the major source of water throughout the swamp and the only source in many areas. Additionally, the proximity and type of upland water sources affect water levels and nutrient concentrations in canal water and groundwater. Where streams are a dominant upland source, variations in groundwater levels and nutrient concentrations are greater than where recharge by precipitation is the primary water source. Where upland groundwater is a dominant source, water levels are more stable. Because the species distribution of forest communities in the Swamp is strongly influenced by these controls, swamp managers are beginning to incorporate this knowledge into forest, water, and fire

  2. 'Billings' wheat combines early maturity, disease resistance, and desirable grain quality for the Southern Great Plains of the USA

    USDA-ARS?s Scientific Manuscript database

    Selection pressure for earliness, resistance to multiple pathogens, and quality attributes consistent with the hard red winter (HRW) wheat (Triticum aestivum L.) market class is tantamount to, or can obscure, selection for yield potential in lower elevations of the U.S. southern Great Plains. The de...

  3. 'Duster' wheat: A durable, dual-purpose cultivar adapted to the southern great plains of the USA

    USDA-ARS?s Scientific Manuscript database

    Winter wheat (Triticum aestivum L.) cultivars which gain broad commercial acceptance in Oklahoma and surrounding states of the U.S. southern Great Plains must produce a definitive grain yield advantage, and they must demonstrate season-long dependability in dual purpose management systems, effective...

  4. Provenance of loess in the central Great Plains, U.S.A. based on Nd-Sr isotopic composition, and paleoenvironmental implications

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Mason, Joseph A.; Zhang, Hanzhi; Lu, Huayu; Ji, Junfeng; Chen, Jun; Liu, Lianwen

    2017-10-01

    Loess of the central Great Plains, U.S.A., records intervals of Quaternary aeolian dust accumulation at rates among the highest known worldwide. This study used Nd-Sr isotopic analysis to investigate the provenance of Middle Pleistocene to Holocene loess in western and central Nebraska, U.S.A., essential information for understanding the paleoenvironmental conditions that allowed such rapid accumulation to occur at some times and not others. Nd-Sr isotopic data suggest that dust from unglaciated Great Plains landscapes has been the primary component of loess accumulated at both very high and low rates since the Middle Pleistocene. However, loess isotopic compositions all require an additional minor source with higher 87Sr/86Sr and lower εNd, most likely debris from Precambrian rocks in the Rocky Mountains, carried to the Great Plains by the Platte River system. The contribution from this secondary source-probably including glacially eroded sediment-was greater in Marine Isotope Stage (MIS) 3 and early MIS 2, but decreased somewhat just after the last glacial maximum (LGM) at the Bignell Hill section. Earlier research showed that the highest accumulation rates in that section also occurred after the LGM; thus our results likely indicate increased dust emission from unglaciated landscapes at that time. Greater plant moisture stress in a warming climate with still-low CO2 could have played a role in that increased dust production, along with lagged vegetation response; however, a strengthened westerly component of surface winds is the most straightforward explanation.

  5. Centennial Drought Cyclicity in the Great Plains, USA: A Dominant Climate Pattern over the Past 4000 Years

    NASA Astrophysics Data System (ADS)

    Schwalb, A.; Dean, W. E.; Kromer, B.

    2003-04-01

    A 17-m long sediment core from Pickerel Lake, northeastern South Dakota, provides a continuous record of climatic and environmental change for the last 12,000 years. The upper 6 m of sediment, representing the past 4000 years, are marked by distinct 1-m cycles in magnetic susceptibility, contents of carbonates, organic carbon and major elements, ostracode species assemblages, as well as stable oxygen- and carbon-isotopes in ostracodes and authigenic carbonates. Proxies indicate that there were cyclic changes in effective moisture, temperature and wind activity. Maxima in magnetic susceptibility are accompanied by maxima in abundances of the ostracode Candona rawsoni, indicating windy and dry conditions. Proxies between these aridity maxima indicate calmer and wetter periods with increased lake productivity. Our age model, based on 6 bulk sediment and 4 charcoal 14CAMS dates and the timing of the historical settlement (ca. AD 1880), indicates that the 1-m cycles have an average periodicity of 700 years and large amplitudes. In addition, there are 200-year cycles with lower amplitudes. The 700-year cycles are best preserved in magnetic susceptibility, whereas the 200-year cycles are particularly well documented by major-element percentages. The 200-year cycles in the Pickerel Lake record suggest that solar activity contributes significantly to climate variability in the Great Plains of the United States. The prominent 700-year cycles, however, suggest that longer-term oceanic/atmospheric forcing cannot be excluded. Our data are consistent with century-scale cyclic variations in various proxy variables for aridity and eolian activity recorded in sediments deposited over the past 2000 years in other lakes in the northern Great Plains, as well as in sand dune activity. The onset of these drought cycles at around 4000 yr BP is consistent with transformations in human societies in Europe and the Near East and suggests that there were major changes in global atmospheric

  6. Architecture, heterogeneity, and origin of late Miocene fluvial deposits hosting the most important aquifer in the Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Joeckel, R. M.; Wooden, S. R.; Korus, J. T.; Garbisch, J. O.

    2014-08-01

    The Ash Hollow Formation (AHF) of the Ogallala Group is an important sedimentary archive of the emergence of the Great Plains and it contains major groundwater resources. Stratal patterns of constituent alluvial lithofacies demonstrate that the AHF is much more heterogeneous than is commonly assumed. Very fine- to fine-grained sandstone dominate overall, chiefly lithofacies Sm (massive to locally stratified sandstone). Stacked, thin sheets of Sm with accretionary macroform surfaces are common, indicating that many sandstone architectural elements originated as compound-bar deposits in dominantly sand-bed streams. Channel forms are difficult to identify and steep cutbanks are absent. Multiple units of lithofacies Sm show dense, and sometimes deep, burrowing by insects well above water tables under ancient floodplains. Massive, pedogenically modified siltstones (Fm), which compose floodplain fine architectural elements, are subsidiary in volumetric abundance to sandstones. Paleosols in these siltstones lack evidence for well-developed B horizons and advanced stages of maturity. Thin lenses of impure carbonate and laminated mud (lithofacies association Fl + C), which appear in most exposures, are deposits of ponded water in abandoned channels. Paleosols, ponded-water elements, and large vertebrate burrows in both Sm and Fm indicate that episodes of floodplain deposition, bar accretion, and channel filling were regularly followed by intervals of nondeposition on floodplains and by channel migration and abandonment. This study documents a major downdip change in the Ogallala Group overall, from source-proximal gravelly successions in the Wyoming Gangplank and deep, narrow paleovalley fills extending eastward into the Nebraska Panhandle. The lithofacies composition, stratigraphic architecture, and stratal dimensions of the AHF in the present study area are compatible with the planform geometries and floodplain soils of modestly-sized, sandy, low-sinuosity braided streams

  7. Centennial eolian cyclicity in the Great Plains, USA: A dominant pattern of wind transport over the past 4000 years?

    USGS Publications Warehouse

    Schwalb, Antje; Dean, Walter E.; Fritz, C. Sherilyn; Geiss, Christoph E.; Kromer, Bernd

    2010-01-01

    Proxy evidence at decadal resolution from Late Holocene sediments from Pickerel Lake, northeastern South Dakota, shows distinct centennial cycles (400-700 years) in magnetic susceptibility; contents of carbonate, organic carbon, and major elements; abundance in ostracodes; and delta18O and delta13C values in calcite. Proxies indicate cyclic changes in eolian input, productivity, and temperature. Maxima in magnetic susceptibility are accompanied by maxima in aluminum and iron mass accumulation rates (MARs), and in abundances of the ostracode Fabaeformiscandona rawsoni. This indicates variable windy, and dry conditions with westerly wind dominance, including during the Medieval Climate Anomaly. Maxima in carbonates, organic carbon, phosphorous, and high delta13C values of endogenic calcite indicate moister and less windy periods with increased lake productivity, including during the Little Ice Age, and alternate with maxima of eolian transport. Times of the Maunder, Sporer and Wolf sunspot minima are characterized by maxima in delta18O values and aluminum MARs, and minima in delta13C values and organic carbon content. We interpret these lake conditions during sunspot minima to indicate decreases in lake surface water temperatures of up to 4-5 degrees C associated with decreases in epilimnetic productivity during summer. We propose that the centennial cycles are triggered by solar activity, originate in the tropical Pacific, and their onset during the Late Holocene is associated with insolation conditions driven by precession. The cyclic pattern is transmitted from the tropical Pacific into the atmosphere and transported by westerly winds into the North Atlantic realm where they strengthen the Atlantic Meridional Overturning Circulation during periods of northern Great Plains wind maxima. This consequently leads to moister climates in Central and Northern Europe. Thus, Pickerel Lake provides evidence for mechanisms of teleconnections including an atmospheric link

  8. Southern Great Plains Safety Orientation

    SciTech Connect

    Schatz, John

    2014-05-01

    Welcome to the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ARM) Southern Great Plains (SGP) site. This U.S. Department of Energy (DOE) site is managed by Argonne National Laboratory (ANL). It is very important that all visitors comply with all DOE and ANL safety requirements, as well as those of the Occupational Safety and Health Administration (OSHA), the National Fire Protection Association, and the U.S. Environmental Protection Agency, and with other requirements as applicable.

  9. Using a network modularity analysis to inform management of a rare endemic plant in the northern Great Plains, USA

    USGS Publications Warehouse

    Larson, Diane L.; Droege, Sam; Rabie, Paul A.; Larson, Jennifer L.; Devalez, Jelle; Haar, Milton; McDermott-Kubeczko, Margaret

    2014-01-01

    1. Analyses of flower-visitor interaction networks allow application of community-level information to conservation problems, but management recommendations that ensue from such analyses are not well characterized. Results of modularity analyses, which detect groups of species (modules) that interact more with each other than with species outside their module, may be particularly applicable to management concerns. 2. We conducted modularity analyses of networks surrounding a rare endemic annual plant, Eriogonum visheri, at Badlands National Park, USA, in 2010 and 2011. Plant species visited were determined by pollen on insect bodies and by flower species upon which insects were captured. Roles within modules (network hub, module hub, connector and peripheral, in decreasing order of network structural importance) were determined for each species. 3. Relationships demonstrated by the modularity analysis, in concert with knowledge of pollen species carried by insects, allowed us to infer effects of two invasive species on E. visheri. Sharing a module increased risk of interspecific pollen transfer to E. visheri. Control of invasive Salsola tragus, which shared a module with E. visheri, is therefore a prudent management objective, but lack of control of invasive Melilotus officinalis, which occupied a different module, is unlikely to negatively affect pollination of E. visheri. Eriogonum pauciflorum may occupy a key position in this network, supporting insects from the E. visheri module when E. visheri is less abundant. 4. Year-to-year variation in species' roles suggests management decisions must be based on observations over several years. Information on pollen deposition on stigmas would greatly strengthen inferences made from the modularity analysis. 5. Synthesis and applications: Assessing the consequences of pollination, whether at the community or individual level, is inherently time-consuming. A trade-off exists: rather than an estimate of fitness effects, the

  10. Genetic variation in Great Plains Juniperus

    Treesearch

    David F. Van Haverbeke; Rudy M. King

    1990-01-01

    Fifth-year analyses of Great Plains Juniperus seed sources indicate eastern redcedar should be collected in east-central Nebraska for use throughout the Great Plains; Rocky Mountain juniper seed should be collected from northwest Nebraska, or central Montana, for planting southward through the Great Plains into west-central Kansas west of the 100th meridian.

  11. The potential response of eolian sands to greenhouse warming and precipitation reduction on the Great Plains of the U.S.A.

    USGS Publications Warehouse

    Muhs, D.R.; Maat, P.B.

    1993-01-01

    Sand dunes and sand sheets are extensive on the semi-arid GreatPlains but are at present stabilized by a sparse vegetation cover. Use of a dune mobility index, which incorporates wind strength and the ratio of mean annual precipitation to potential evapotranspiration, shows that under predicted greenhouse climate effects of increased temperature and reduced precipitation, sand dunes and sand sheets on the GreatPlains are likely to become reactivated over a significant part of the region.

  12. Long-term patterns of air temperatures, daily temperature range, precipitation, grass-reference evapotranspiration and aridity index in the USA Great Plains: Part I. Spatial trends

    NASA Astrophysics Data System (ADS)

    Kukal, M.; Irmak, S.

    2016-11-01

    Due to their substantial spatio-temporal behavior, long-term quantification and analyses of important hydrological variables are essential for practical applications in water resources planning, evaluating the water use of agricultural crop production and quantifying crop evapotranspiration patterns and irrigation management vs. hydrologic balance relationships. Observed data at over 800 sites across the Great Plains of USA, comprising of 9 states and 2,307,410 km2 of surface area, which is about 30% of the terrestrial area of the USA, were used to quantify and map large-scale and long-term (1968-2013) spatial trends of air temperatures, daily temperature range (DTR), precipitation, grass-reference evapotranspiration (ETo) and aridity index (AI) at monthly, growing season and annual time steps. Air temperatures had a strong north to south increasing trend, with annual average varying from -1 to 24 °C, and growing season average temperature varying from 8 to 30 °C. DTR gradually decreased from western to eastern parts of the region, with a regional annual and growing season averages of 14.25 °C and 14.79 °C, respectively. Precipitation had a gradual shift towards higher magnitudes from west to east, with the average annual and growing season (May-September) precipitation ranging from 163 to 1486 mm and from 98 to 746 mm, respectively. ETo had a southwest-northeast decreasing trend, with regional annual and growing season averages of 1297 mm and 823 mm, respectively. AI increased from west to east, indicating higher humidity (less arid) towards the east, with regional annual and growing season averages of 0.49 and 0.44, respectively. The spatial datasets and maps for these important climate variables can serve as valuable background for climate change and hydrologic studies in the Great Plains region. Through identification of priority areas from the developed maps, efforts of the concerned personnel and agencies and resources can be diverted towards development

  13. Estimation of potential evapotranspiration from extraterrestrial radiation, air temperature and humidity to assess future climate change effects on the vegetation of the Northern Great Plains, USA

    USGS Publications Warehouse

    King, David A.; Bachelet, Dominique M.; Symstad, Amy J.; Ferschweiler, Ken; Hobbins, Michael

    2014-01-01

    The potential evapotranspiration (PET) that would occur with unlimited plant access to water is a central driver of simulated plant growth in many ecological models. PET is influenced by solar and longwave radiation, temperature, wind speed, and humidity, but it is often modeled as a function of temperature alone. This approach can cause biases in projections of future climate impacts in part because it confounds the effects of warming due to increased greenhouse gases with that which would be caused by increased radiation from the sun. We developed an algorithm for linking PET to extraterrestrial solar radiation (incoming top-of atmosphere solar radiation), as well as temperature and atmospheric water vapor pressure, and incorporated this algorithm into the dynamic global vegetation model MC1. We tested the new algorithm for the Northern Great Plains, USA, whose remaining grasslands are threatened by continuing woody encroachment. Both the new and the standard temperature-dependent MC1 algorithm adequately simulated current PET, as compared to the more rigorous PenPan model of Rotstayn et al. (2006). However, compared to the standard algorithm, the new algorithm projected a much more gradual increase in PET over the 21st century for three contrasting future climates. This difference led to lower simulated drought effects and hence greater woody encroachment with the new algorithm, illustrating the importance of more rigorous calculations of PET in ecological models dealing with climate change.

  14. Precipitation induced stream flow: An event based chemical and isotopic study of a small stream in the Great Plains region of the USA

    USGS Publications Warehouse

    Machavaram, M.V.; Whittemore, D.O.; Conrad, M.E.; Miller, N.L.

    2006-01-01

    A small stream in the Great Plains of USA was sampled to understand the streamflow components following intense precipitation and the influence of water storage structures in the drainage basin. Precipitation, stream, ponds, ground-water and soil moisture were sampled for determination of isotopic (D, 18O) and chemical (Cl, SO4) composition before and after two intense rain events. Following the first storm event, flow at the downstream locations was generated primarily through shallow subsurface flow and runoff whereas in the headwaters region - where a pond is located in the stream channel - shallow ground-water and pond outflow contributed to the flow. The distinct isotopic signatures of precipitation and the evaporated pond water allowed separation of the event water from the other sources that contributed to the flow. Similarly, variations in the Cl and SO4 concentrations helped identify the relative contributions of ground-water and soil moisture to the streamflow. The relationship between deuterium excess and Cl or SO4 content reveals that the early contributions from a rain event to streamflow depend upon the antecedent climatic conditions and the position along the stream channel within the watershed. The design of this study, in which data from several locations within a watershed were collected, shows that in small streams changes in relative contributions from ground water and soil moisture complicate hydrograph separation, with surface-water bodies providing additional complexity. It also demonstrates the usefulness of combined chemical and isotopic methods in hydrologic investigations, especially the utility of the deuterium excess parameter in quantifying the relative contributions of various source components to the stream flow. ?? 2006 Elsevier B.V. All rights reserved.

  15. Great Plains Synfuels` hidden treasures

    SciTech Connect

    Kuhn, A.K.; Duncan, D.H.

    1996-12-31

    The Great Plains Synfuels Project was commissioned 12 years ago. While demonstrating success regarding SNG production, DGC quietly started development of chemical products derived from the liquid by-product streams of Lurgi moving bed gasifiers. Naphtha, crude phenol, and tar oil are the primary by-products, and these contain valuable compounds such as phenol, cresylic acid, catechols, naphthols, fluorene, and BTX. Process technologies have been developed for (1) separation of various impurities from cresylic acid distillate fractions or from whole cresylic acid; (2) extracting cresylic acid from tar oil; (3) conversion of tar pitch to a blend stock used in making anode binder pitch; and (4) separating high purity catechol and methyl catechols. As a result of this work, DGC built a phenol/cresylic acid facility. The cresylic acid side supplies over 10 percent of the world market. The achievement with the catechols is presently leading to bench scale routes for synthesis of chemical intermediates which ultimately may include compounds such as vanillin, pyrogallol, sesamol, homoveratrylamine, and many others, penetrating the fields of flavors and fragrances, pharmaceuticals, pesticides, photographic chemicals, dyes, etc. These efforts stimulate DGC`s growth and will provide an economic uplift. By-products already contribute more than 10% of revenues and are destined to rival natural gas in importance.

  16. Life on the Great Plains. [Lesson Plan].

    ERIC Educational Resources Information Center

    2000

    In this four-part lesson, students examine the concept of geographic region by exploring the history of the United States Great Plains. In Part I, students gather information about the location and environment of the Great Plains in order to produce a map outlining the region in formal terms. In Part II, students examine how the region has been…

  17. a New High-Resolution Chronology of Megadrought Following the Medieval Climatic Anomaly and Little Ice Age in the Central Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Halfen, A. F.; Johnson, W. C.; Hanson, P. R.; Spencer, J. Q.; Woodburn, T.; Young, A. R.

    2010-12-01

    Recent research has emphasized using eolian sediments for reconstructing late Holocene megadroughts, especially in the Great Plains where other drought proxies are scarce. Eolian dune fields can serve as proxy sources for megadroughts because, during prolonged drought conditions, vegetation cover is diminished and eolian sedimentation ensues. In an effort to better characterize late-Holocene megadroughts, two dune fields spanning a 400 km east-west transect of the central Great Plains have been investigated, resulting thus far in over 110 optically stimulated luminescence ages. Ages from the Hutchinson and Arkansas River dune fields have provided a new, high-resolution chronology of dune activity that spans much of the past 2000 years. Both dune fields were stable prior to the Medieval Climatic Anomaly (MCA) but started to activate towards the height of the warming around 1.0 ka. Activity continued throughout the MCA but intensified as climate shifted towards cooler conditions between 0.8 and 0.7 ka. Around the onset of the Little Ice Age (LIA) dune activity decreased, but did not cease, and, by the end of the LIA, activity again intensified between 0.3 and 0.2 ka. Dune activity continued into historical times (e.g., 1930’s Dust Bowl drought), and today the dune fields are stable with only small areas of anthropogenically-triggered activity. A clustering of ages defines two periods of megadrought, at 0.8 to 0.7 and 0.3 to 0.2 ka. Dune activity between 0.8 and 0.7 ka correlates well with Palmer Drought Severity Index data constructed from tree-rings and regional dune activity; this suggests that one or more megadroughts occurred within much of the Great Plains during the MCA. The period of dune activity between 0.3 and 0.2 ka correlate with activity in the Great Bend Sand Prairie and southwestern Nebraska, but is not coeval with activation records from the Nebraska Sand Hills, or those from the Duncan and Abilene dune fields of the eastern Great Plains. This

  18. Long-term patterns of air temperatures, daily temperature range, precipitation, grass-reference evapotranspiration and aridity index in the USA great plains: Part II. Temporal trends

    NASA Astrophysics Data System (ADS)

    Kukal, M.; Irmak, S.

    2016-11-01

    Detection of long-term changes in climate variables over large spatial scales is a very important prerequisite to the development of effective mitigation and adaptation measures for the future potential climate change and for developing strategies for future hydrologic balance analyses under changing climate. Moreover, there is a need for effective approaches of providing information about these changes to decision makers, water managers and stakeholders to aid in efficient implementation of the developed strategies. This study involves computation, mapping and analyses of long-term (1968-2013) county-specific trends in annual, growing-season (1st May-30th September) and monthly air temperatures [(maximum (Tmax), minimum (Tmin) and average (Tavg)], daily temperature range (DTR), precipitation, grass reference evapotranspiration (ETo) and aridity index (AI) over the USA Great Plains region using datasets from over 800 weather station sites. Positive trends in annual Tavg, Tmax and Tmin, DTR, precipitation, ETo and AI were observed in 71%, 89%, 85%, 31%, 61%, 38% and 66% of the counties in the region, respectively, whereas these proportions were 48%, 89%, 62%, 20%, 57%, 28%, and 63%, respectively, for the growing-season averages of the same variables. On a regional average basis, the positive trends in growing-season Tavg, Tmax and Tmin, DTR, precipitation, ETo and AI were 0.18 °C decade-1, 0.19 °C decade-1, 0.17 °C decade-1, 0.09 °C decade-1, 1.12 mm yr-1, 0.4 mm yr-1 and 0.02 decade-1, respectively, and the negative trends were 0.21 °C decade-1, 0.06 °C decade-1, 0.09 °C decade-1, 0.22 °C decade-1, 1.16 mm yr-1, 0.76 mm yr-1 and 0.02 decade-1, respectively. The temporal trends were highly variable in space and were appropriately represented using monthly, annual and growing-season maps developed using Geographic Information System (GIS) techniques. The long-term and spatial and temporal information and data for a large region provided in this study can be

  19. The geologic story of the Great Plains

    USGS Publications Warehouse

    Trimble, Donald E.

    1980-01-01

    For more than half a century after Lewis and Clark crossed the country in 1805-6, the Great Plains was the testing ground of frontier America here America grew to maturity (fig. 1). In 1805-7, explorer Zebulon Pike crossed the southcentral Great Plains, following the Arkansas River from near Great Bend, Kans., to the Rocky Mountains. In later years, Santa Fe traders, lured by the wealth of New Mexican trade, followed Pike's path as far as Bents Fort, Colo., where they turned southwestward away from the river route. Those pioneers who later crossed the plains on the Oregon Trail reached the Platte River near the place that would become Kearney, Nebr., by a nearly direct route from Independence, Mo., and followed the Platte across the central part of the Great Plains.

  20. Reading for Young People: The Great Plains.

    ERIC Educational Resources Information Center

    Laughlin, Mildred

    One of five annotated bibliographies that describe books about certain regions of the United States, this compilation focuses on books about the Great Plains. The stated purposes of these regional bibliographies are: (1) to introduce young people living in the subject region to books dealing with their cultural heritage, (2) to help young people…

  1. Juniper seed sources in the Great Plains

    Treesearch

    Richard A. Cunningham; Rudy M. King

    2000-01-01

    At age 10, 100% of eastern redcedar ( L.) and Rocky Mountain juniper ( Sarg.) trees from several seed sources throughout the Great Plains had survived. Seed sources from southeastern Texas had the poorest survival. Eastern redcedar trees from Kansas seed sources grew tallest, and trees from Montana and southeastern Texas seed sources were the shortest. Rocky Mountain...

  2. Reading for Young People: The Great Plains.

    ERIC Educational Resources Information Center

    Laughlin, Mildred

    One of five annotated bibliographies that describe books about certain regions of the United States, this compilation focuses on books about the Great Plains. The stated purposes of these regional bibliographies are: (1) to introduce young people living in the subject region to books dealing with their cultural heritage, (2) to help young people…

  3. Great plains regional climate assessment technical report

    USDA-ARS?s Scientific Manuscript database

    The Great Plains region (GP) plays important role in providing food and energy to the economy of the United States. Multiple climatic and non-climatic stressors put multiple sectors, livelihoods and communities at risk, including agriculture, water, ecosystems and rural and tribal communities. The G...

  4. Great Salt Lake, Utah, USA

    NASA Technical Reports Server (NTRS)

    1990-01-01

    As seen from space, the Great Salt Lake, Utah, USA (41.5N, 112.5W) appears as two separate bodies of water with a narrow divider in the middle. At the turn of the century, a railroad bridge without culverts, was built across the lake and ever since, the water and salinity levels have been uneqal on either side. Fed by snowmelt from the nearby Wasatch Mountains, the lake in recent years has had record high water levels, threatening to flood the local areas.

  5. Great Salt Lake, Utah, USA

    NASA Image and Video Library

    1990-03-04

    As seen from space, the Great Salt Lake, Utah, USA (41.5N, 112.5W) appears as two separate bodies of water with a narrow divider in the middle. At the turn of the century, a railroad bridge without culverts, was built across the lake and ever since, the water and salinity levels have been uneqal on either side. Fed by snowmelt from the nearby Wasatch Mountains, the lake in recent years has had record high water levels, threatening to flood the local areas.

  6. Isolation and characterization of a bacteriophage with an unusually large genome from the Great Salt Plains National Wildlife Refuge, Oklahoma, USA.

    PubMed

    Seaman, Paul F; Day, Martin J

    2007-04-01

    In this study we present a bacteriophage isolated from the Great Salt Plains National Wildlife Refuge (GSP) that is shown to have a genome size of 340 kb, unusually large for a bacterial virus. Transmission electron microscopy analysis of the virion showed this to be a Myoviridae, the first reported to infect the genus Halomonas. This temperate phage, PhigspC, exhibits a broad host range, displaying the ability to infect two different Halomonas spp. also isolated from the GSP. The phage infection process demonstrates a high level of tolerance towards temperature, pH and salinity; however, free virions are rapidly inactivated in water unless supplemented with salt. We show that susceptibility to osmotic shock is correlated with the density of the packaged DNA (rho(pack)). Lysogens of Halomonas salina GSP21 were detrimental to host fitness at 10% salinity, but the lysogen was able to grow faster than the wild type at 20% salinity. From these results we propose that the extensive genome of PhigspC may encode environmentally relevant genes (ERGs); genes that are perhaps not essential for the phage life cycle but increase host and phage fitness in some environmental conditions.

  7. Close evolutionary affinities between freshwater corbulid bivalves from the Neogene of western Amazonia and Paleogene of the northern Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Anderson, Laurie C.; Hartman, Joseph H.; Wesselingh, Frank

    2006-03-01

    Freshwater corbulid bivalves found in Miocene deposits of western Amazonia have been considered products of an endemic radiation of a marine clade within the large lacustrine system occupying the region at that time. Our reexamination of Paleocene freshwater corbulids of the Tongue River Formation of western North Dakota and eastern Montana, however, extends the stratigraphic and geographic range of three Amazonian taxa— Pachydon, Ostomya, and Anticorbula—to the Paleocene of the northern Great Plains of the United States. Both Paleocene and Miocene freshwater corbulid taxa occur in large freshwater systems with an intermittent marine connection. To test the phylogenetic relationships of one particularly widespread Paleocene species ( Pachydon mactriformis), we conducted cladistic analyses using maximum parsimony and heuristic searches of matrices of conchologic characters. Seven species of Pachydon and Pebasia dispar from the western Amazonian Neogene, Pachydon mactriformis from the Paleocene of North Dakota, representative species of eight neotropical marine corbulid genera, and three additional corbulid taxa were included. Corbula was the outgroup. All analyses produced similar regions of stability within trees. One such area is a Pachydon crown group that includes P. mactriformis, indicating that Paleocene and Miocene Pachydon are not convergent. Our results also indicate that Pachydon does not represent a separate basal radiation within the family. However, we have not resolved a robust sister clade relationship for the Pachydon crown group. Two Amazonian Neogene taxa do not fall within the Pachydon crown group, and their phylogenetic position is not resolved. At this time, we do not have sufficient evidence to refine the definitions of Pachydon and Pachydontinae as monophyletic clades. Although we have evidence that three genera of corbulid bivalves ( Pachydon, Ostomya, and Anticorbula) in the Pebas Formation are not endemic and have long geologic

  8. Late Quaternary environmental change inferred from phytoliths and other soil-related proxies: Case studies from the central and southern Great Plains, USA

    USGS Publications Warehouse

    Cordova, C.E.; Johnson, W.C.; Mandel, R.D.; Palmer, M.W.

    2011-01-01

    This study investigates stable carbon isotopes (??13C), opal phytolith assemblages, burnt phytoliths, microscopic charcoal and Sporormiella spores from modern soils and paleosols in Kansas and Oklahoma. Grass and dicot phytoliths in combination with ??13C are used as proxies for reconstructing the structure of grasslands and woodlands. Burnt grass phytoliths and microscopic charcoal are evaluated as proxies for reconstructing paleofire incidence. Concentrations of the fungal spore Sporormiella are used as a proxy for assessing large herbivore activity. These proxies were tested on various modern grassland communities of the central and southern Great Plains, including areas with bison, cattle, and small herbivores, and areas under different fire frequencies.Opal phytolith assemblages and ??13C values show that before cal 11ka, C3 grasses and woody plants predominated in areas that today are dominated by C4 grasses. The origin of the shortgrass prairie dates back to about cal 10ka. The origin of the tallgrass prairie, however, is not clear as phytolith data show variable assemblages throughout the Holocene (mixed-grass, tallgrass, and tallgrass-woodland mosaic). Different proxies (burnt phytoliths vs. charcoal) reveal different fire frequencies, but it is apparent that microfossil evidence for fire incidence is closely related to the abundance of woody plants in the landscape.Before cal 12. ka, soils show somewhat elevated concentration of Sporormiella, but lower concentrations than the modern high-density bison and cattle grazing areas. Throughout the Holocene, Sporormiella frequencies are low, which suggests lower large ungulate densities and perhaps high mobility. ?? 2010 Elsevier B.V.

  9. Impacts of stream flow and climate variability on native and invasive woody species in a riparian ecosystem of a semi-arid region of the Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Skolaut, K.; Awada, T.; Cherubini, P.; Schapaugh, A.; Huddle, J.

    2012-04-01

    Riparian ecosystems support diverse plant communities that exert direct and indirect biological, physical and chemical influence on, and are influenced by, adjacent water through both above and below-ground interactions. Historically, riparian areas of the northern Great Plains (United States) have been dominated by the native Populus deltoides (eastern cottonwood). This species relies on regular floods for regeneration and groundwater access for success. Over the past sixty years, changes in flow management and agricultural practices, coupled with climate variability and drought, have altered stream flow and caused a dramatic decline in stream water yields and levels of groundwater. These and other biotic factors have promoted the expansion of the upland native woody species Juniperus virginiana (eastern redcedar), and the invasion of the non-native (introduced) Elaeagnus angustifolia (Russian olive) into riparian ecosystems. This invasion has further altered the water balance in the system and exasperated the problem of water scarcity with negative feedback on ecosystem services and growth of native woody species. The ability of P. deltoides to re-establish and grow is of concern for natural resource managers. The study utilizes tree ring analysis of annual growth rates and stable isotope ratios of 13C and 18O to determine 1) the response P. deltoides and invasive J. virginiana and E. angustifulia have to climate variation and stream flow regulation, and 2) the impacts of the two invasive species on the growth of native P. deltoides. Preliminary results have shown that P. deltoids annual growth rate (using basal area increment growth) continually declined over the last 40 yrs, while that of E. angustifolia steadily increased. Growth of both P. deltoides and J. virginiana displayed greater dependence on climatic factors than E. angustifolia. Ecological and hydrological significance of the results will be presented.

  10. Stable carbon and oxygen isotopic variations in modern Rabdotus land snail shells in the southern Great Plains, USA, and their relation to environment

    NASA Astrophysics Data System (ADS)

    Goodfriend, Glenn A.; Ellis, G. Lain

    2002-06-01

    Variations of stable isotopic ratios of carbon (13C/12C) and oxygen (18O/16O) were investigated in modern shells of two species of Rabdotus land snails (R. dealbatus and R. alternatus) in the southern Great Plains. Geographic variation in relation to climate and vegetation, microgeographic variation, variability among individuals, and detailed records of seasonal variations within individual shells were studied. Stable carbon isotopic ratios in shell carbonate are primarily a function of the isotopic composition of the diet of the snails, as represented by the isotopic composition of shell organic matter. This in turn reflects the presence or absence of CAM (Crassulacean Acid Metabolism) or C4 plants. Vegetation density may have a small effect on the carbon isotope ratios. Microgeographic variation (samples within 25 to 300 m) is greater than that seen across different climatic regions and points to very local control of isotopic variations, predominantly related to vegetation. Seasonal variations, as assessed through serial analysis of individual shells (up to 35 samples per shell), may provide a means for distinguishing between isotopic influences of perennial CAM vs. annual C4 plants. Carbon isotopic variations in time-series of shells from a site provide a means of reconstructing temporal changes in environment and climate. Oxygen isotopic values of shell carbonate are uniform across the region and also show no significant microgeographic variation. The oxygen isotopic composition appears to be mainly a function of the rainwater isotopic composition, with no direct influence of rainfall amount or evaporative effects. The δ18O values are only 2‰ enriched relative to estimated equilibrium with rainwater. Variability is low (SD of 0.8‰ among sites), so the isotopic composition of fossil Rabdotus shells can provide a precise record of changes in the isotopic composition of rain over time.

  11. Great Plains makes 100 billion cubic feet

    SciTech Connect

    Not Available

    1987-03-01

    The Great Plains coal gasification plant on January 18, 1987 produced its 100 billionth cubic foot of gas since start-up July 28, 1984. Owned by the Department of Energy and operated by ANG Coal Gasification Company, the plant uses the Lurgi process to produce about 50 billion cubic feet per year of gas from five million tons per year of lignite. The plant has been performing at well above design capacity.

  12. Impacts of Stream Flow and Climate Variability on Native and Invasive Woody Species in a Riparian Ecosystem of a Semi-Arid Region of the Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Skolaut, K.; Awada, T.; Cherubini, P.; Schapaugh, A.

    2012-12-01

    Riparian ecosystems support diverse plant communities that exert direct and indirect biological, physical and chemical influence on, and are influenced by, adjacent water through both above and below-ground interactions. Historically, riparian areas of the northern Great Plains, US have been dominated by the native Populus deltoides (eastern cottonwood). This species relies on regular floods for regeneration and groundwater access for success. Over the past sixty years, changes in flow management and agricultural practices, coupled with climate variability and drought have altered stream flow and caused a dramatic decline in stream water yields and levels of groundwater. These and other biotic and biotic factors have promoted the expansion of the upland native woody species Juniperus virginiana (eastern redcedar), and the invasion of the non-native (introduced) Elaeagnus angustifolia (Russian olive) into riparian ecosystems. This invasion has further altered the water balance in the system and exasperated the problem of water scarcity with negative feedback on ecosystem services and growth of native woody species. The ability of P. deltoides to re-establish and grow is of concern for natural resource managers. Tree ring analysis of annual growth rates were used to determine 1) the responses P. deltoides and invasive J. virginiana and E. angustifulia to climate variability and stream flow regulation, and 2) the impacts of the two invasive species on the growth of native P. deltoides. Results show a dependency of growth for P. deltoides on the previous year summer temperature, and a less significant correlation to annual stream flow. J. virginiana showed the highest correlation to annual stream flow, as well as some dependency on the previous growing season precipitation. While the growth of both P. deltoides and J. virginiana displayed greater dependence on climatic factors, E. angustifolia displayed the lowest mean basal area growth and deviation from the growth. E

  13. Medicine Wheels of the Great Plains

    NASA Astrophysics Data System (ADS)

    Vogt, David

    Medicine Wheels are unexplained aboriginal boulder configurations found primarily on hilltops and river valley vistas across the northwest Great Plains of North America. Their varied, complex designs have inspired diverse hypotheses concerning their meaning and purpose, including astronomical ones. While initial "observatory" speculations were unfounded, and quests to "decode" these structures remain unfulfilled and possibly misguided, the Medicine Wheels nevertheless represent a uniquely worthwhile case study in archaeoastronomical theory and method. In addition, emerging technologies for data acquisition and analysis pertinent to Medicine Wheels offer prospectively important new sight lines for the future of archaeoastronomy.

  14. Dust storms - Great Plains, Africa, and Mars

    NASA Technical Reports Server (NTRS)

    Woiceshyn, P. M.; Krauss, R.; Minzner, R.; Shenk, W.

    1977-01-01

    Dust storms in the Great Plains of North America and in the Sahara Desert are analyzed on the basis of imagery from the geostationary Synchronous Meteorological Satellite. The onset time, location and areal extent of the dust storms are studied. Over land surfaces, contrast enhancement techniques are needed to obtain an adequate picture of dust storm development. In addition, infrared imagery may provide a means of monitoring the strong horizontal temperature gradients characteristic of dust cloud boundaries. Analogies between terrestrial dust storms and the airborne rivers of dust created by major Martian dust storms are also drawn.

  15. Great Plains Gasification Project status report

    SciTech Connect

    Pollock, D.C.

    1985-08-01

    The Great Plains Gasification Project is the first commercial synthetic fuels project based on coal conversion in the US. The goal is to convert North Dakota lignite into pipeline quality synthetic natural gas (SNG). The project consists of an open pit coal mine, a gasification plant, and an SNG pipeline in Mercer County, North Dakota. The project took 12 years from its conception to the production in 1984 of SNG for users. The author describes the plant's basic processes, the start-up activities and schedule, and some of the more interesting start-up problems.

  16. DOE receives title to Great Plains plant

    SciTech Connect

    Not Available

    1986-09-01

    On June 30, 1986 the Great Plains Coal Gasification Project was sold at a foreclosure sale at the Mercer County courthouse in North Dakota. The US Department of Energy was the only bidder at the sale. DOE's bid for the plant was $1 billion DOE-secured loan that the five sponsor companies defaulted on when they withdrew from the project in August 1985. DOE did not receive title to the plant until a lawsuit filed by American Natural Resources (ANR) was settled on July 14, 1986. DOE has vowed to keep the plant running as long as it does not cost the taxpayers any money. Eventually DOE wishes to dispose of the plant. Therefore, in February 1986 DOE requested that interested organizations submit expressions of interest in the Great Plains plant. This paper, after discussing the lawsuit, summarizes the nine responses received by DOE. Some companies were willing for it to remain a coal gasification facility; other submitted plans for modifications to produce methanol.

  17. Nest sites and conservation of endangered Interior Least Terns Sterna antillarum athalassos on an alkaline flat in the south-central Great Plains (USA)

    USGS Publications Warehouse

    Winton, Brian R.; Leslie, David M.

    2003-01-01

    We monitored nest sites of endangered Interior Least Terns on a 5 095 ha alkaline flat in north-central Oklahoma, USA. After nest loss, Least Terns commonly renested and experienced 30% apparent nest success in 1995-1996 (n = 233 nests). Nest success and predation differed by location on the alkaline flat in 1995 and overall, but nest success and flooding did not differ by microhabitat type. Predation was highest at nests ??? 5 cm from debris (driftwood/hay) in 1995. No differences in nesting success, flooding, or predation were observed on comparing nests inside and outside electrified enclosures. Coyotes and Striped Skunks were confirmed nest predators, and Ring-billed Gulls were suspected nest predators. We identified one location on the alkaline flat of about 1 000 ha with consistently lower nest losses attributable to flooding and predation and the highest hatching success compared with other parts of the alkaline flat; it was typified by open ground and bisected by several creeks. Management activities that minimize flooding and predation in this area could further enhance nest success and theoretically increase overall productivity of this population of Least Terns. However, the efficacy of electrified enclosures and nest-site enhancements, as currently undertaken, is questionable because of considerable annual variation in use by and protection of Least Terns.

  18. Novel Insect Leaf-Mining after the End-Cretaceous Extinction and the Demise of Cretaceous Leaf Miners, Great Plains, USA

    PubMed Central

    Donovan, Michael P.; Wilf, Peter; Labandeira, Conrad C.; Johnson, Kirk R.; Peppe, Daniel J.

    2014-01-01

    Plant and associated insect-damage diversity in the western U.S.A. decreased significantly at the Cretaceous-Paleogene (K-Pg) boundary and remained low until the late Paleocene. However, the Mexican Hat locality (ca. 65 Ma) in southeastern Montana, with a typical, low-diversity flora, uniquely exhibits high damage diversity on nearly all its host plants, when compared to all known local and regional early Paleocene sites. The same plant species show minimal damage elsewhere during the early Paleocene. We asked whether the high insect damage diversity at Mexican Hat was more likely related to the survival of Cretaceous insects from refugia or to an influx of novel Paleocene taxa. We compared damage on 1073 leaf fossils from Mexican Hat to over 9000 terminal Cretaceous leaf fossils from the Hell Creek Formation of nearby southwestern North Dakota and to over 9000 Paleocene leaf fossils from the Fort Union Formation in North Dakota, Montana, and Wyoming. We described the entire insect-feeding ichnofauna at Mexican Hat and focused our analysis on leaf mines because they are typically host-specialized and preserve a number of diagnostic morphological characters. Nine mine damage types attributable to three of the four orders of leaf-mining insects are found at Mexican Hat, six of them so far unique to the site. We found no evidence linking any of the diverse Hell Creek mines with those found at Mexican Hat, nor for the survival of any Cretaceous leaf miners over the K-Pg boundary regionally, even on well-sampled, surviving plant families. Overall, our results strongly relate the high damage diversity on the depauperate Mexican Hat flora to an influx of novel insect herbivores during the early Paleocene, possibly caused by a transient warming event and range expansion, and indicate drastic extinction rather than survivorship of Cretaceous insect taxa from refugia. PMID:25058404

  19. Novel insect leaf-mining after the end-Cretaceous extinction and the demise of cretaceous leaf miners, Great Plains, USA.

    PubMed

    Donovan, Michael P; Wilf, Peter; Labandeira, Conrad C; Johnson, Kirk R; Peppe, Daniel J

    2014-01-01

    Plant and associated insect-damage diversity in the western U.S.A. decreased significantly at the Cretaceous-Paleogene (K-Pg) boundary and remained low until the late Paleocene. However, the Mexican Hat locality (ca. 65 Ma) in southeastern Montana, with a typical, low-diversity flora, uniquely exhibits high damage diversity on nearly all its host plants, when compared to all known local and regional early Paleocene sites. The same plant species show minimal damage elsewhere during the early Paleocene. We asked whether the high insect damage diversity at Mexican Hat was more likely related to the survival of Cretaceous insects from refugia or to an influx of novel Paleocene taxa. We compared damage on 1073 leaf fossils from Mexican Hat to over 9000 terminal Cretaceous leaf fossils from the Hell Creek Formation of nearby southwestern North Dakota and to over 9000 Paleocene leaf fossils from the Fort Union Formation in North Dakota, Montana, and Wyoming. We described the entire insect-feeding ichnofauna at Mexican Hat and focused our analysis on leaf mines because they are typically host-specialized and preserve a number of diagnostic morphological characters. Nine mine damage types attributable to three of the four orders of leaf-mining insects are found at Mexican Hat, six of them so far unique to the site. We found no evidence linking any of the diverse Hell Creek mines with those found at Mexican Hat, nor for the survival of any Cretaceous leaf miners over the K-Pg boundary regionally, even on well-sampled, surviving plant families. Overall, our results strongly relate the high damage diversity on the depauperate Mexican Hat flora to an influx of novel insect herbivores during the early Paleocene, possibly caused by a transient warming event and range expansion, and indicate drastic extinction rather than survivorship of Cretaceous insect taxa from refugia.

  20. Great Plains Wind Energy Transmission Development Project

    SciTech Connect

    Brad G. Stevens, P.E.; Troy K. Simonsen; Kerryanne M. Leroux

    2012-06-09

    In fiscal year 2005, the Energy & Environmental Research Center (EERC) received funding from the U.S. Department of Energy (DOE) to undertake a broad array of tasks to either directly or indirectly address the barriers that faced much of the Great Plains states and their efforts to produce and transmit wind energy at the time. This program, entitled Great Plains Wind Energy Transmission Development Project, was focused on the central goal of stimulating wind energy development through expansion of new transmission capacity or development of new wind energy capacity through alternative market development. The original task structure was as follows: Task 1 - Regional Renewable Credit Tracking System (later rescoped to Small Wind Turbine Training Center); Task 2 - Multistate Transmission Collaborative; Task 3 - Wind Energy Forecasting System; and Task 4 - Analysis of the Long-Term Role of Hydrogen in the Region. As carried out, Task 1 involved the creation of the Small Wind Turbine Training Center (SWTTC). The SWTTC, located Grand Forks, North Dakota, consists of a single wind turbine, the Endurance S-250, on a 105-foot tilt-up guyed tower. The S-250 is connected to the electrical grid on the 'load side' of the electric meter, and the power produced by the wind turbine is consumed locally on the property. Establishment of the SWTTC will allow EERC personnel to provide educational opportunities to a wide range of participants, including grade school through college-level students and the general public. In addition, the facility will allow the EERC to provide technical training workshops related to the installation, operation, and maintenance of small wind turbines. In addition, under Task 1, the EERC hosted two small wind turbine workshops on May 18, 2010, and March 8, 2011, at the EERC in Grand Forks, North Dakota. Task 2 involved the EERC cosponsoring and aiding in the planning of three transmission workshops in the midwest and western regions. Under Task 3, the

  1. Middle Holocene Bison diet and mobility in the eastern Great Plains (USA) based on δ13C, δ18O, and 87Sr/ 86Sr analyses of tooth enamel carbonate

    NASA Astrophysics Data System (ADS)

    Widga, Chris; Walker, J. Douglas; Stockli, Lisa D.

    2010-05-01

    During the Holocene, bison ( Bison bison) were key components of the Great Plains landscape. This study utilizes serial stable isotope analyses (tooth enamel carbonate) of 29 individuals from five middle Holocene (˜ 7-8.5 ka) archaeological sites to address seasonal variability in movement patterns and grazing behavior of bison populations in the eastern Great Plains. Stable carbon isotopes ( δ13C) indicate a bison diet that is similar to the C3/C4 composition of modern tallgrass prairies, while 87Sr/ 86Sr values generally indicate very little seasonal movement (< 50 km) and relatively limited inter-annual movement (< 500 km) over the course of 4-5 yr. Analyses of variability in serial stable oxygen isotope samples ( δ18O) further substantiate a model of localized bison herds that adhered to upland areas of the eastern Plains and prairie-forest border.

  2. Statistical Downscaling for the Northern Great Plains

    NASA Astrophysics Data System (ADS)

    Coburn, J.

    2014-12-01

    The need for detailed, local scale information about the warming climate has led to the use of ever more complex and geographically realistic computer models as well as the use of regional models capable of capturing much finer details. Another class of methods for ascertaining localized data is known as statistical downscaling, which offers some advantages over regional models, especially in the realm of computational efficiency. Statistical downscaling can be described as the process of linking coarse resolution climate model output to that of fine resolution or even station-level data via statistical relationships with the purpose of correcting model biases at the local scale. The development and application of downscaling has given rise to a plethora of techniques which have been applied to many spatial scales and multiple climate variables. In this study two downscaling processes, bias-corrected statistical downscaling (BCSD) and canonical correlation analysis (CCA), are applied to minimum and maximum temperatures and precipitation for the Northern Great Plains (NGP, 40 - 53°N and 95 - 120°W) region at both daily and monthly time steps. The abilities of the methods were tested by assessing their ability to recreate local variations in a set of both spatial and temporal climate metrics obtained through the analysis of 1/16 degree station data for the period 1950 to 2000. Model data for temperature, precipitation and a set of predictor variables were obtained from CMIP5 for 15 models. BCSD was applied using direct comparison and correction of the variable distributions via quadrant mapping. CCA was calibrated on the data for the period 1950 to 1980 using a series of model-based predictor variables screened for increasing skill, with the derived model being applied to the period 1980 to 2000 so as to verify that it could recreate the overall climate patterns and trends. As in previous studies done on other regions, it was found that the CCA method recreated

  3. Particulate Loads Caused by Wind Erosion in the Great Plains

    ERIC Educational Resources Information Center

    Hagen, Lawrence J.; Woodruff, Neil P.

    1975-01-01

    In this paper the annual flux of suspended particulates caused by wind erosion in the Great Plains is estimated. This study demonstrated that climate causes wide variations in air pollution from wind erosion. (BT)

  4. Great Plains Drought in Simulations of Twentieth Century

    NASA Astrophysics Data System (ADS)

    McCrary, R. R.; Randall, D. A.

    2008-12-01

    The Great Plains region of the United States was influenced by a number of multi-year droughts during the twentieth century. Most notable were the "Dust Bowl" drought of the 1930s and the 1950s Great Plains drought. In this study we evaluate the ability of three of the Coupled Global Climate Models (CGCMs) used in the Fourth Assessment Report (AR4) of the IPCC to simulate Great Plains drought with the same frequency and intensity as was observed during the twentieth century. The models chosen for this study are: GFDL CM 2.0, NCAR CCSM3, and UKMO HadCM3. We find that the models accurately capture the climatology of the hydrologic cycle of the Great Plains, but that they tend to overestimate the variability in Great Plains precipitation. We also find that in each model simulation at least one long-term drought occurs over the Great Plains region during their representations 20th Century Climate. The multi-year droughts produced by the models exhibit similar magnitudes and spatial scales as was observed during the twentieth century. This study also investigates the relative roles that external forcing from the tropical Pacific and local feedbacks between the land surface and the atmosphere have in the initiation and perpetuation of Great Plains drought in each model. We find that cool, La Nina-like conditions in the tropical pacific are often associated with long-term drought conditions over the Great Plains in GFDL CM 2.0 and UKMO HadCM3, but there appears to be no systematic relationship between tropical Pacific SST variability and Great Plains drought in CCSM3. It is possible the strong coupling between the land surface and the atmosphere in the NCAR model causes precipitation anomalies to lock into phase over the Great Plains thereby perpetuating drought conditions. Results from this study are intended to help assess whether or not these climate models are credible for use in the assessment of future drought over the Great Plains region of the United States.

  5. Rural School District Reorganization on the Great Plains.

    ERIC Educational Resources Information Center

    Bryant, Miles

    2002-01-01

    Rural school district reorganization and school consolidation are put into perspective by reviewing the large population increases that fueled small-school growth in the Great Plains, 1870-1930. Since the Dust Bowl and Great Depression, population losses, improvements in transportation, and arguments advocating economies of scale and increased…

  6. Soil and Water Conservation Advances in the Northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Great American Desert” is what many maps often call the Great Plains of North America. This is where dryland agriculture practices for North America have their roots. The purpose of this part of the book was to determine the advances in soil and water conservation technology over the past century a...

  7. Rural School District Reorganization on the Great Plains.

    ERIC Educational Resources Information Center

    Bryant, Miles

    2002-01-01

    Rural school district reorganization and school consolidation are put into perspective by reviewing the large population increases that fueled small-school growth in the Great Plains, 1870-1930. Since the Dust Bowl and Great Depression, population losses, improvements in transportation, and arguments advocating economies of scale and increased…

  8. Causes and Predictability of the 2012 Great Plains Drought

    NASA Technical Reports Server (NTRS)

    Hoerling, M.; Eischeid, J.; Kumar, A.; Leung, R.; Mariotti, A.; Mo, K.; Schubert, S.; Seager, R.

    2013-01-01

    Central Great Plains precipitation deficits during May-August 2012 were the most severe since at least 1895, eclipsing the Dust Bowl summers of 1934 and 1936. Drought developed suddenly in May, following near-normal precipitation during winter and early spring. Its proximate causes were a reduction in atmospheric moisture transport into the Great Plains from the Gulf of Mexico. Processes that generally provide air mass lift and condensation were mostly absent, including a lack of frontal cyclones in late spring followed by suppressed deep convection in summer owing to large-scale subsidence and atmospheric stabilization. Seasonal forecasts did not predict the summer 2012 central Great Plains drought development, which therefore arrived without early warning. Climate simulations and empirical analysis suggest that ocean surface temperatures together with changes in greenhouse gases did not induce a substantial reduction in summertime precipitation over the central Great Plains during 2012. Yet, diagnosis of the retrospective climate simulations also reveals a regime shift toward warmer and drier summertime Great Plains conditions during the recent decade, most probably due to natural decadal variability. As a consequence, the probability for severe summer Great Plains drought may have increased in the last decade compared to the 1980s and 1990s, and the so-called tail-risk for severe drought may have been heightened in summer 2012. Such an extreme drought event was nonetheless still found to be a rare occurrence within the spread of 2012 climate model simulations. Implications of this study's findings for U.S. seasonal drought forecasting are discussed.

  9. Heat flow in the Great Plains of the United States

    NASA Astrophysics Data System (ADS)

    Gosnold, William D.

    1990-01-01

    Anomalous high heat flow previously reported for the Great Plains is inconsistent with the tectonic setting and requires reexamination. Forty-six new heat flow measurements, 12 revised heat flow values, and several hundred geothermal gradient measurements indicate extensive geothermal anomalies with heat flows ranging from 80 to 140 mW m-2 in the northern and central Great Plains. Heat flow in the Great Plains outside the geothermally anomalous regions ranges from 40 - 60 mW m-2. The heat flow anomalies result from the thermal effects of regional groundwater flow where it moves upward either within a dipping aquifer or by cross-formational flow through fractures. The gravitational driving force for the groundwater flow derives from the eastward sloping surface of the Great Plains, and the locations of the geothermal amonalies are determined by the structures of the aquifers and the crystalline basement rocks. The most widespread and largest-amplitude geothermal anomaly occurs in southern South Dakota and northern Nebraska. Another large anomaly occurs on the eastern flank of the Denver Basin, and small anomalies occur on structures such as the Billings and Nesson anticlines in the Williston Basin. Previous reports of high heat flow in the Great Plains generally are supported by the results of this study. However, the source of anomalous heat is shown to be nontectonic, and theoretical arguments for normal continental heat flow in the Great Plains are supported. Another difference from the results of previous heat flow studies is that the thermal conductivities of shales in the Mesozoic strata in the Great Plains are about 40% lower than the conductivities that commonly have been used for shales. This observation and recent studies which have suggested lower thermal conductivities for shales in the Great Plains are the reasons for revision of some previous heat flow calculations. A significant result of revising some of the previous heat flow values is that the high

  10. The Great Plains IDEA Gerontology Program: An Online, Interinstitutional Graduate Degree

    ERIC Educational Resources Information Center

    Sanders, Gregory F.

    2011-01-01

    The Great-Plains IDEA Gerontology Program is a graduate program developed and implemented by the Great Plains Interactive Distance Education Alliance (Great Plains IDEA). The Great Plains IDEA (Alliance) originated as a consortium of Colleges of Human Sciences ranging across the central United States. This Alliance's accomplishments have included…

  11. The Great Plains IDEA Gerontology Program: An Online, Interinstitutional Graduate Degree

    ERIC Educational Resources Information Center

    Sanders, Gregory F.

    2011-01-01

    The Great-Plains IDEA Gerontology Program is a graduate program developed and implemented by the Great Plains Interactive Distance Education Alliance (Great Plains IDEA). The Great Plains IDEA (Alliance) originated as a consortium of Colleges of Human Sciences ranging across the central United States. This Alliance's accomplishments have included…

  12. The Renewal of Population Loss in the Nonmetropolitan Great Plains.

    ERIC Educational Resources Information Center

    Albrecht, Don E.

    1993-01-01

    Analysis of population trends in 293 nonmetropolitan counties in the Great Plains, 1950-90, reveals that the rural population turnaround of the 1970s has indeed ended. During the 1980s, 84% of these counties had total population declines, and 96% had net outmigration. The most important variable in producing positive trends was inmigration of…

  13. MANAGING ANNUAL BROMES IN THE NORTHERN GREAT PLAINS

    USDA-ARS?s Scientific Manuscript database

    Annual bromes periodically have substantial impact on rangelands in the northern Great Plains. The often rapid increases in annual brome populations and there negative effects on forage and animal production are justified cause for concern. However, population increases are predictable and managem...

  14. Aquatic and wetland vascular plants of the northern Great Plains

    Treesearch

    Gary E. Larson

    1993-01-01

    A taxonomic treatment of aquatic and wetland vascular plants has been developed as a tool for identifying over 500 plant species inhabiting wetlands of the northern Great Plains region. The treatment provides dichotomous keys and botanical descriptions to facilitate identification of all included taxa. Illustrations are also provided for selected species. Geographical...

  15. Crop diversity on traditional great plains wheat farms

    USDA-ARS?s Scientific Manuscript database

    Historically, the vast majority of cropland in the western Great Plains was either seeded to continuous monoculture wheat or was in a wheat-fallow rotation. The objective of this paper is to determine the combined effects of crop diversity and tillage systems on wheat grain yield and net returns fo...

  16. Producing and Marketing Proso Millet in the Great Plains

    USDA-ARS?s Scientific Manuscript database

    Proso millet is a short-season summer crop that produces well in the semi-arid western Great Plains and is suitable for diversifying and intensifying dryland production systems. Proso allows transition back to winter wheat in cropping rotations. No-till methods work well with proso establishment. Pr...

  17. Wooded draws in rangelands of the northern Great Plains

    Treesearch

    Ardell J. Bjugstad; Michele M. Girard

    1985-01-01

    Wooded draws and natural prairie woodlands occupy about 1.1 percent of the northern Great Plains. While the extent of wooded draws is extremely limited, their importance and value is much greater. These unique communities are important for wildlife and livestock habitats, soil stabilization, watershed maintenance, firewood, esthetics, and species diversity (Fig. 1). An...

  18. A Socioeconomic Profile of the Northern Great Plains Coal Region.

    ERIC Educational Resources Information Center

    Myers, Paul R.; And Others

    When historic (1940-70) and recent (1970-74) trends in population, income, and employment for the Northern Great Plains coal region are compared with that for the entire U.S. and all U.S. nonmetro counties, data reveal a minimal population increase from 1940 to 1970, a period of declining agricultural employment and high outmigration rates. In…

  19. The Renewal of Population Loss in the Nonmetropolitan Great Plains.

    ERIC Educational Resources Information Center

    Albrecht, Don E.

    1993-01-01

    Analysis of population trends in 293 nonmetropolitan counties in the Great Plains, 1950-90, reveals that the rural population turnaround of the 1970s has indeed ended. During the 1980s, 84% of these counties had total population declines, and 96% had net outmigration. The most important variable in producing positive trends was inmigration of…

  20. Walking the Sky: Visionary Traditions of the Great Plains.

    ERIC Educational Resources Information Center

    Irwin, Lee

    1994-01-01

    Uses ethnographic materials of the past 150 years to examine the visionary traditions of Native Americans of the Great Plains. Presents a Native American worldview in which dreams and visions represent contacts with primordial sources of empowerment and knowledge and play a creative role in the formation and maintenance of cultural values. (SV)

  1. Regional dynamics of grassland change in the western Great Plains

    USGS Publications Warehouse

    Drummond, M.A.

    2007-01-01

    This paper examines the contemporary land-cover changes in two western Great Plains ecoregions between 1973 and 2000. Agriculture and other land uses can have a substantial effect on grassland cover that varies regionally depending on the primary driving forces of change. In order to better understand change, the rates, types, and causes of land conversion were examined for 1973, 1980, 1986, 1992, and 2000 using Landsat satellite data and a statistical sampling strategy. The overall estimated rate of land-cover change between 1973 and 2000 was 7.4% in the Northwestern Great Plains and 11.5% in the Western High Plains. Trends in both ecoregions have similarities, although the dynamics of change differ temporally depending on driving forces. Between 1973 and 1986, grassland cover declined when economic opportunity drove an expansion of agriculture. Between 1986 and 2000, grassland expanded as public policy and a combination of socioeconomic factors drove a conversion from agriculture to grassland. ?? 2007 Copyright by the Center for Great Plains Studies, University of Nebraska-Lincoln.

  2. Long-term Agroecosystem Research in the Northern Great Plains.

    NASA Astrophysics Data System (ADS)

    Schmer, M.; Sanderson, M.; Liebig, M. A.; Wienhold, B.; Awada, T.; Papiernik, S.; Osborne, S.; Kemp, W.; Okalebo, J. A.; Riedall, W.

    2015-12-01

    The Northern Great Plains is the bread basket of the United States, accounting for a substantial portion of U.S. agricultural production. This region faces critical challenges regarding balancing food needs, resource conservation (e.g Ogallala aquifer), environmental concerns, and rural economy development. Developing transformative, multifunctional systems will require equally imaginative and efficient tools to help farmers manage complex agroecosystems in a rapidly changing climate. The Northern Plains long-term agroecosystem research (LTAR) site at Mandan, ND and the Platte River High Plains LTAR (ARS/University of Nebraska-Lincoln) at Lincoln, NE in collaboration with USDA-ARS research units in Brookings, SD and Fargo, ND are collaborating to address the grand challenge of providing and sustaining multiple service provisions from Northern Great Plains agroecosystems. We propose to attain these goals through sustainable intensification based on the adoption of conservation agriculture principles including reduced soil disturbance, livestock integration, and greater complexity and diversity in the cropping system. Here, we summarize new concepts these locations have pioneered in dynamic cropping systems, resource use efficiency, and agricultural management technologies. As part of the LTAR network, we will conduct long-term cross-site research to design and assess new agricultural practices and systems aimed at improving our understanding of decision making processes and outcomes across an array of agricultural systems.

  3. Distribution and nesting success of ferruginous hawks and Swainson's hawks on an agricultural landscape in the Great Plains

    USDA-ARS?s Scientific Manuscript database

    We studied nest site land cover associations, and reproductive success of two Buteo species of conservation concern on the southern Great Plains, USA. The study area was in Cimarron County, Oklahoma, where land use is dominated by row crop agriculture, livestock grazing, and Conservation Reserve Pro...

  4. Early weaning in Northern Great Plains beef cattle production systems: III. Steer weaning, finishing and carcass characteristics

    USDA-ARS?s Scientific Manuscript database

    Studies were conducted to evaluate the effect of weaning of steer calves on BW gain, feedlot performance, and carcass characteristics in two herds located in the Northern Great Plains, USA. Steer calves from predominantly Angus × Hereford dams were stratified within dam age and calving date (Fort K...

  5. Downstream effects of dams on channel geometry and bottomland vegetation: Regional patterns in the Great Plains

    USGS Publications Warehouse

    Friedman, J.M.; Osterkamp, W.R.; Scott, M.L.; Auble, G.T.

    1998-01-01

    The response of rivers and riparian forests to upstream dams shows a regional pattern related to physiographic and climatic factors that influence channel geometry. We carried out a spatial analysis of the response of channel geometry to 35 dams in the Great Plains and Central Lowlands, USA. The principal response of a braided channel to an upstream dam is channel-narrowing, and the principal response of a meandering channel is a reduction in channel migration rate. Prior to water management, braided channels were most common in the southwestern Plains where sand is abundant, whereas meandering channels were most common in the northern and eastern Plains. The dominant response to upstream dams has been channel-narrowing in the southwestern Plains (e.g., six of nine cases in the High Plains) and reduction in migration rate in the north and east (e.g., all of twelve cases in the Missouri Plateau and Western Lake Regions). Channel-narrowing is associated with a burst of establishment of native and exotic woody riparian pioneer species on the former channel bed. In contrast, reduction in channel migration rate is associated with a decrease in reproduction of woody riparian pioneers. Thus, riparian pioneer forests along large rivers in the southwestern Plains have temporarily increased following dam construction while such forests in the north and east have decreased. These patterns explain apparent contradictions in conclusions of studies that focused on single rivers or small regions and provide a framework for predicting effects of dams on large rivers in the Great Plains and elsewhere. These conclusions are valid only for large rivers. A spatial analysis of channel width along 286 streams ranging in mean annual discharge from 0.004 to 1370 cubic meters per second did not produce the same clear regional pattern, in part because the channel geometries of small and large streams are affected differently by a sandy watershed.

  6. Update on the Great Plains Coal Gasification Project

    SciTech Connect

    Imler, D.L.

    1985-12-01

    The Great Plains Gasification Plant is the US's first commercial synthetic fuels project based on coal conversion. The ANG Coal Gasification Company is the administer of the Great Plains Coal Gasification Project for the United States Department of Energy. The Project is designed to convert 14 M TPD of North Dakota of lignite into 137.5 MM SCFD of pipeline quality synthetic natural gas (SNG). Located in Mercer County, North Dakota, the gasification plant, and an SNG pipeline. Some 12 years passed from the time the project was conceived unit it became a reality by producing SNG into the Northern Border pipeline in 1984 for use by millions of residential, commercial, and industrial consumers. In this paper, the basic processes utilized in the plant are presented. This is followed by a discussion of the start-up activities and schedule. Finally, some of the more interesting start-up problems are described.

  7. Monitoring vegetation systems in the Great Plains with ERTS

    NASA Technical Reports Server (NTRS)

    Rouse, J. W., Jr.; Haas, R. H.; Schell, J. A.; Deering, D. W.

    1974-01-01

    The Great Plains Corridor rangeland project utilizes natural vegetation systems as phenological indicators of seasonal development and climatic effects upon regional growth conditions. A method has been developed for quantitative measurement of vegetation conditions over broad regions using ERTS-1 MSS data. Radiance values recorded in ERTS-1 spectral bands 5 and 7, corrected for sun angle, are used to compute a band ratio parameter which is shown to be correlated with aboveground green biomass on rangelands.

  8. Saline lakes of the glaciated Northern Great Plains

    USGS Publications Warehouse

    Mushet, David M.

    2011-01-01

    Unless you have flown over the region or seen aerial photographs, it is hard to grasp the scale of the millions of lakes and wetlands that dot the prairie landscape of the glaciated Northern Great Plains (Figure 1). This region of abundant aquatic habitats within a grassland matrix provides for the needs of a wide diversity of wildlife species and has appropriately been deemed the "duck factory of North America." While the sheer number of lakes and wetlands within this area of the Northern Great Plains can be truly awe-inspiring, their diversity in terms of the chemical composition of their water adds an equally important component supporting biotic diversity and productivity. Water within these lakes and wetlands can range from extremely fresh with salinities approaching that of rainwater to hypersaline with salinity ten times greater than that of seawater. Additionally, while variation in salinity among these water bodies can be great, the ionic composition of lakes and wetlands with similar salinities can vary markedly, influencing the overall spatial and temporal diversity of the region's biota.

  9. Whooping crane stopover site use intensity within the Great Plains

    USGS Publications Warehouse

    Pearse, Aaron T.; Brandt, David A.; Harrell, Wade C.; Metzger, Kristine L.; Baasch, David M.; Hefley, Trevor J.

    2015-09-23

    Whooping cranes (Grus americana) of the Aransas-Wood Buffalo population migrate twice each year through the Great Plains in North America. Recovery activities for this endangered species include providing adequate places to stop and rest during migration, which are generally referred to as stopover sites. To assist in recovery efforts, initial estimates of stopover site use intensity are presented, which provide opportunity to identify areas across the migration range used more intensively by whooping cranes. We used location data acquired from 58 unique individuals fitted with platform transmitting terminals that collected global position system locations. Radio-tagged birds provided 2,158 stopover sites over 10 migrations and 5 years (2010–14). Using a grid-based approach, we identified 1,095 20-square-kilometer grid cells that contained stopover sites. We categorized occupied grid cells based on density of stopover sites and the amount of time cranes spent in the area. This assessment resulted in four categories of stopover site use: unoccupied, low intensity, core intensity, and extended-use core intensity. Although provisional, this evaluation of stopover site use intensity offers the U.S. Fish and Wildlife Service and partners a tool to identify landscapes that may be of greater conservation significance to migrating whooping cranes. Initially, the tool will be used by the U.S. Fish and Wildlife Service and other interested parties in evaluating the Great Plains Wind Energy Habitat Conservation Plan.

  10. Effects of fire in the Northern Great Plains

    USGS Publications Warehouse

    Higgins, Kenneth F.; Kruse, Arnold D.; Piehl, James L.

    1989-01-01

    This publication is a review of selected literature about prescribed burning in the Northern Great Plains (NGP) for management of wildlife. It also will be useful to other resource managers and researchers and to persons interested in the NGP. It is more 'descriptive' than 'interpretative.'The publication is a joint effort of the South Dakota State Cooperative Fish and Wildlife Research Unit (SDCFWRU), South Dakota State University, Brookings; the Northern Prairie Wildlife Research Center (NPWRC), Jamestown, N.D.; and the U.S. Fish and Wildlife Service (USFWS), Fergus Falls, Minn. Manuscript typing and library services were shared between SDCFWRU and NPWRC.This publication (EC 761) is the second of three SDSU Extension circulars on grassland fires. EC 760 is Prescribed burning guidelines in the Northern Great Plains; EC 762 is Annotated bibliography of fire literature relative to northern grasslands in South-Central Canada and North-Central United States and contains many more citations than presented in this publication. All three circulars may be obtained from either the Wildlife and Fisheries Sciences Department; SDSU Box 2206; ph (605) 688-6121; or from the Ag Communications Bulletin Room; SDSU Box 2231; ph (605) 688-5628; both in Brookings, S.D. 57007.

  11. Great Plains ASPEN model development: Phosam section. Final topical report

    SciTech Connect

    Stern, S S; Kirman, J J

    1985-02-01

    An ASPEN model has been developed of the PHOSAM Section, Section 4600, of the Great Plains Gasification Plant. The bases for this model are the process description given in Section 6.18 of the Great Plains Project Management Plan and the Lummus Phosam Schematic Process Flow Diagram, Dwg. No. SKD-7102-IM-O. The ASPEN model that has been developed contains the complete set of components that are assumed to be in the gasifier effluent. The model is primarily a flowsheet simulation that will give the material and energy balance and equipment duties for a given set of process conditions. The model is unable to predict fully changes in process conditions that would result from load changes on equipment of fixed sizes, such as a rating model would predict. The model can be used to simulate the steady-state operation of the plant at or near design conditions or to design other PHOSAM units. Because of the limited amount of process information that was available, several major process assumptions had to be made in the development of the flowsheet model. Patent literature was consulted to establish the ammonia concentration in the circulating fluid. Case studies were made with the ammonia content of the feed 25% higher and 25% lower than the base feed. Results of these runs show slightly lower recoveries of ammonia with less ammonia in the feed. As expected, the duties of the Stripper and Fractionator reboilers were higher with more ammonia in the feed. 63 references.

  12. Empirically Modeling Carbon Fluxes over the Northern Great Plains Grasslands

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Wylie, B. K.; Ji, L.; Gilmanov, T.; Tieszen, L. L.

    2007-12-01

    Grasslands cover nearly one-fifth of the global terrestrial surface and store most of their carbon below ground. The grassland ecosystem in the Great Plains occupies over 1.5 million km2 of land area and is the primary resource for livestock production in North America. However, the contributions of grasslands to local and regional carbon budgets remain uncertain due to the lack of carbon flux data for the expansive grassland ecosystems under various managements, land uses, and climate variability. A quantitative understanding of carbon fluxes across these systems is essential for developing regional, national, and global carbon budgets and providing guidance to policy makers and managers when substantial conversion to biofuels are implemented. Additionally, these estimates will provide insights into how the grassland ecosystem will respond to future climate and what systems are sustainable and offer net carbon sinks. This knowledge base and decisions support tools are needed for developing land management strategies for the region under a variety of environmental conditions and land use options. In the past, we used a remote sensing-based piecewise regression (PWR) model to estimate the grassland carbon fluxes in the northern Great Plains using the 1-km SPOT VEGETATION normalized difference vegetation index (NDVI) data. We estimated the carbon fluxes through integrated spatial databases and remotely sensed extrapolations of flux tower data to regional scales. The PWR model was applied to derive an empirical relationship between environmental variables and tower-based measurements. The PWR equations were then applied through time and space to estimate carbon fluxes across the study area at 1-km resolution. We now improve this modeling approach by 1) using Moderate Resolution Imaging Spectroradiometer (MODIS) data with higher temporal, spatial, and spectral resolutions (8-day, 500-m, and 7-band) as input; 2) incorporating the actual vegetation evapotranspiration

  13. The 16 May 1909 northern Great Plains earthquake

    USGS Publications Warehouse

    Bakun, W.H.; Stickney, M.C.; Rogers, Gary C.

    2011-01-01

    The largest historical earthquake in the northern Great Plains occurred on 16 May 1909. Our analysis of intensity assignments places the earthquake location (48.81° N, 105.38° W) close to the Montana–Saskatchewan border with an intensity magnitude MI of 5.3–5.4. Observations from two seismic observatories in Europe give an average Ms value of 5.3. The 1909 earthquake is near an alignment of epicenters of small earthquakes in Montana and Saskatchewan and on strike with the mapped Hinsdale fault in Montana. Thus, the 1909 earthquake may have occurred on a 300-km-long seismically active fault, which could have seismic-hazard implications for the region, particularly for the hydraulically emplaced earth-filled Fort Peck Dam, constructed in the 1930s on the Missouri River in northeast Montana.

  14. ESTAR Measurements During the Southern Great Plains Experiment (SGP99)

    NASA Technical Reports Server (NTRS)

    LeVine, D. M.; Jackson, T. J.; Swift, C. T.; Haken, M.; Bidwell, S.; Zukor, Dorothy J. (Technical Monitor)

    2001-01-01

    During the Southern Great Plains experiment, the synthetic aperture radiometer, ESTAR, mapped L-band brightness temperature over a swath about 50 km wide and about 300 km long extending west from Oklahoma City to El Reno and north from the Little Washita River watershed to the Kansas border. ESTAR flew on the NASA P-3B Orion aircraft at an altitude of 7.6 km and maps were made on 7 days between July 8-20, 1999. The brightness temperature maps reflect the patterns of soil moisture expected from rainfall and are consistent with values of soil moisture observed at the research sites within the SGP99 study area and with previous measurements in this area. The data add to the resources for hydrologic modeling in this area and are further validation of the technology represented by ESTAR as a potential path to a future mission to map soil moisture globally from space.

  15. Summertime Low-Level Jets over the Great Plains

    SciTech Connect

    Stensrud, D.J.

    1996-04-01

    The sky over the southern Great Plains Cloud and Atmospheric Radiation Testbed (CART) site of the Atmospheric Radiation Measurement (ARM) Program during the predawn and early morning hours often is partially obstructed by stratocumulus, stratus fractus, or cumulus fractus that are moving rapidly to the north, even through the surface winds are weak. This cloud movement is evidence of the low-level jet (LLJ), a wind speed maximum that occurs in the lowest few kilometers of the atmosphere. Owing to the wide spacing between upper-air sounding sites and the relatively infrequent sounding launches, LLJ evolution has been difficult to observe adequately, even though the effects of LLJs on moisture flux into North America are large. Model simulation of the LLJ is described.

  16. A Sustainable Biomass Industry for the North American Great Plains

    SciTech Connect

    Rosenberg, Norman J.; Smith, Steven J.

    2009-12-01

    The North American Great Plains (hereafter NAGP) region is economically distressed and prone to severe ecological disruptions such as soil erosion. Its water resources are over-used and subject to pollution from agricultural fertilizers and chemicals, issues common to agricultural lands globally. On the other hand, the region is well suited to the production of herbaceous biomass that can be combusted directly for power or converted to liquid transportation fuels. This paper reviews the geography, history and current condition of the NAGP and offers suggestions about how the agriculture, economy and environment of this and similar regions around the world can be made more sustainable and able to contribute to a reduction in CO2 emissions and consequent global warming.

  17. Building Indigenous Community Resilience in the Great Plains

    NASA Astrophysics Data System (ADS)

    Gough, B.

    2014-12-01

    Indigenous community resilience is rooted in the seasoned lifeways, developed over generations, incorporated into systems of knowledge, and realized in artifacts of infrastructure through keen observations of the truth and consequences of their interactions with the environment found in place over time. Their value lies, not in their nature as artifacts, but in the underlying patterns and processes of culture: how previous adaptations were derived and evolved, and how the principles and processes of detailed observation may inform future adaptations. This presentation examines how such holistic community approaches, reflected in design and practice, can be applied to contemporary issues of energy and housing in a rapidly changing climate. The Indigenous Peoples of the Great Plains seek to utilize the latest scientific climate modeling to support the development of large, utility scale distributed renewable energy projects and to re-invigorate an indigenous housing concept of straw bale construction, originating in this region. In the energy context, we explore the potential for the development of an intertribal wind energy dynamo on the Great Plains, utilizing elements of existing federal policies for Indian energy development and existing federal infrastructure initially created to serve hydropower resources, which may be significantly altered under current and prospective drought scenarios. For housing, we consider the opportunity to address the built environment in Indian Country, where Tribes have greater control as it consists largely of residences needed for their growing populations. Straw bale construction allows for greater use of local natural and renewable materials in a strategy for preparedness for the weather extremes and insurance perils already common to the region, provides solutions to chronic unemployment and increasing energy costs, while offering greater affordable comfort in both low and high temperature extremes. The development of large

  18. Solar Radiation and Climate Change in the Great Plains

    NASA Astrophysics Data System (ADS)

    Popham, J. L.; Dong, X.

    2004-05-01

    The global average air surface temperature has increased about 0.6° C over the 20th century (Houghton et al. 2001). This warming has resulted in a 10% decrease in the extent of snow cover observed from satellite, and about two weeks reduction in the annual duration of lake and river ice cover in the mid- and high latitudes of the Northern Hemisphere from ground-based observations (Houghton et al. 2001). In the Great Plains, we found ground-surface warming increases systematically with latitude from 0.4° C per century at 41.1° N to 2.0° C per century at 49.4° N (Gosnold et al. 1997). This project expands our study to investigate coherence between ground-surface temperatures, solar radiation, and all other relevant meteorological data. We have collected more than 20 years of surface meteorological data, such as soil temperatures, surface air temperatures (SAT), precipitation, and downward solar radiation, from the High Plains Regional Climate Center (HPRCC) in Lincoln, Nebraska since 1981. The daily mean values of meteorological data within the states of Kansas, Nebraska, South Dakota, and North Dakota have been binned and averaged to 0.5-degree latitude intervals to study temporal and latitudinal variations of soil temperatures, SAT, and solar radiation as well as their coherences. This area covers the latitudes of 37° N to 49° N, and the longitudes of 95° W to 104° W. Through this study, we are attempting to answer the following questions: (1) How does this warming trend relate to solar radiation? (2) How does this warming trend relate to the satellite-measured 10% decrease in the extent of snow cover since late 1960's and the ground-based observed 2-week reduction in the annual duration of lake and river ice over the Great Plains? (3) What is the coherence between the SAT and soil temperature during the study period? (4) What are the causes of this observed warming trend?

  19. Potential nitrogen critical loads for northern Great Plains grassland vegetation

    USGS Publications Warehouse

    Symstad, Amy J.; Smith, Anine T.; Newton, Wesley E.; Knapp, Alan K.

    2015-01-01

    The National Park Service is concerned that increasing atmospheric nitrogen deposition caused by fossil fuel combustion and agricultural activities could adversely affect the northern Great Plains (NGP) ecosystems in its trust. The critical load concept facilitates communication between scientists and policy makers or land managers by translating the complex effects of air pollution on ecosystems into concrete numbers that can be used to inform air quality targets. A critical load is the exposure level below which significant harmful effects on sensitive elements of the environment do not occur. A recent review of the literature suggested that the nitrogen critical load for Great Plains vegetation is 10-25 kg N/ha/yr. For comparison, current atmospheric nitrogen deposition in NGP National Park Service (NPS) units ranges from ~4 kg N/ha/yr in the west to ~13 kg N/ha/yr in the east. The suggested critical load, however, was derived from studies far outside of the NGP, and from experiments investigating nitrogen loads substantially higher than current atmospheric deposition in the region.Therefore, to better determine the nitrogen critical load for sensitive elements in NGP parks, we conducted a four-year field experiment in three northern Great Plains vegetation types at Badlands and Wind Cave National Parks. The vegetation types were chosen because of their importance in NGP parks, their expected sensitivity to nitrogen addition, and to span a range of natural fertility. In the experiment, we added nitrogen at rates ranging from below current atmospheric deposition (2.5 kg N/ha/yr) to far above those levels but commensurate with earlier experiments (100 kg N/ha/yr). We measured the response of a variety of vegetation and soil characteristics shown to be sensitive to nitrogen addition in other studies, including plant biomass production, plant tissue nitrogen concentration, plant species richness and composition, non-native species abundance, and soil inorganic

  20. Land surface process and radiobrightness modeling of the Great Plains

    NASA Astrophysics Data System (ADS)

    Judge, Jasmeet

    Accurate estimation of stored water by Land Surface Process (LSP) models is crucial to the prediction of continental weather and near-term climate by General Circulation Models (GCMs). This dissertation represents an important step toward assimilating the satellite radiometric observations to improve the soil moisture estimates. It consists of "forward" modeling of terrain brightnesses through a biophysically-based Land Surface Process/Radiobrightness (LSP/R) model, and correlating ground-based brightnesses with those from the Special Sensor Microwave/Imager (SSM/I). The LSP/R model was modified and calibrated for representative terrain in the Great Plains during summertime, when the surface processes are dominant and strongly coupled. The calibration used data from two collaborative field investigations, the fourth and the fifth Radiobrightness Energy Balance Experiments (REBEX-4 and REBEX-5). REBEX-4 was a collaboration with the Atmospheric Environment Service (AES), Canada, at the USGS EROS Data Center near Sioux Falls, SD. During the experiment, we observed microwave emission and concurrent micro-meteorological parameters at a bare soil and a nearby grass site from June-September in 1996. REBEX-5 was the University of Michigan's contribution to an extensive field investigation, Southern Great Plains Hydrology Experiment (SGP'97), conducted in north central Oklahoma from June 18--July 17 in 1997. During REBEX-5, we measured brightnesses of senescent winter wheat and after harvest wheat-stubble. In general, the calibrated LSP model predicted realistic surface processes that compared well with the field observations. The model predictions were most sensitive to shortwave albedo of the terrain and soil thermal and hydraulic conductivities. The Radiobrightness module captured the mean diurnal variations in brightnesses. The H-pol terrain brightnesses at 19 GHz were more sensitive to soil moisture and roughness than the V-pol brightnesses. The comparison of the EASE

  1. Evidence of Oxyspirura petrowi in migratory songbirds found in the rolling plains of West Texas, USA.

    PubMed

    Dunham, Nicholas R; Kendall, Ronald J

    2014-07-01

    Three Northern Mockingbirds (Mimus polyglottos) and one Curve-billed Thrasher (Toxostoma curvirostre) from the Rolling Plains of Texas, USA were sampled for eyeworms in September 2013. All four birds were infected with the eyeworm Oxyspirura petrowi.

  2. Fire Cycles on the Northern Great Plains and Their Relation to Prairie Drought

    NASA Astrophysics Data System (ADS)

    Brown, K. J.; Clark, J. S.; Grimm, E. C.; Donovan, J. J.; Mueller, P.

    2004-12-01

    Drought is a naturally occurring, recurrent phenomenon that has historically gripped large regions of the United States, often with catastrophic consequences. Human insight into the duration, frequency, and dynamics of drought is largely limited to short-term observation. For example, the "Dust Bowl" of the 1930's in the central plains is one of the most vivid cases of prolonged drought in the USA and yet it persisted for less than a decade. To circumnavigate this limited perspective, we employed a paleoenvironmental approach to better characterize landscape response to prairie droughts and specifically document fire response to droughts. Two long sediment cores were collected from Kettle and Brush lakes in the Northern Great Plains (NGP) and age-depth models were developed for the cores by fitting locally weighted loess curves to AMS radiocarbon dates. The cores were continuously sub-sampled at high resolution (1 cm) for particulate charcoal, pollen, sediment mineralogy, and loss-on-ignition. In contrast to recent human observation, spectral and wavelet analyses reveal that multi-decadal to centennial drought cycles have persisted on the northern plains for much of the last ca. 10,000 years, though there were intervals where the cycles were muted, further compounding the dynamics of climate on the plains. In the latest Holocene interval, 160-year fire and drought cycles are clearly denoted. Fires are more common during the wet phases of the drought cycles because moist conditions foster increased grass productivity, resulting in greater fuel loads. In contrast, forbs expanded during the drier periods, limiting fuel loads which resulted in less fire. The charcoal data reveal three general Holocene fire intervals on the NGP associated with millennial-scale changes in climate. In general, the incidence of fire was greater in the early- and late-Holocene with less fire during the warm dry mid-Holocene.

  3. Preliminary Report of NRC Twin Otter Operations in the 1997 Southern Great Plains Experiment

    NASA Technical Reports Server (NTRS)

    MacPherson, J. Ian

    1997-01-01

    From June 18 to July 17, 1997, the NRC Twin Otter atmospheric research aircraft was operated from Oklahoma City, U.S.A., in the Southern Great Plains 1997 (SGP97) Hydrology Experiment. The primary role of the aircraft was to measure the vertical fluxes of sensible and latent heat, CO2, ozone and momentum in the atmospheric boundary layer, along with supporting meteorological and radiometric data. Approximately 400 flux runs and 100 soundings were flown in 27 project flights over rural areas near Oklahoma City. This preliminary report documents the flight program, lists the instrumentation aboard the aircraft, and presents a summary of run-averaged data from each flux run. These data are from the in-field analysis and must be considered preliminary. A re-analysis incorporating updated calibrations is planned for the fall of 1997 followed by a more comprehensive technical report.

  4. Great Sand Dune National Monument, CO, USA

    NASA Image and Video Library

    1991-06-14

    STS040-151-126 (5-14 June 1991) --- Croplands of the San Luis Valley stand out exceptionally clearly from low Earth orbit. The Rio Grande flows through the valley. Circular center pivot irrigation patterns have almost completely replaced the earlier rectangular grid pattern. Pinto beans are the specialty of the area. The Great Sand Dunes National Monument appears in fine detail near the center of the picture. The sands of these dunes have been blown from the valley floor by westerly winds in the course of the last few tens of thousands of years, now banked up against the foot of the Sangre de Christo Mountains (snowcapped peaks reach over 14000 feet). The town of Alamosa lies on the Rio Grande. The San Juan Mountains appear at the bottom left.

  5. Net Ecosystem Production (NEP) of the Great Plains, United States

    USGS Publications Warehouse

    Howard, Daniel; Gilmanov, Tagir; Gu, Yingxin; Wylie, Bruce; Zhang, Li

    2012-01-01

    Flux tower networks, such as AmeriFlux and FLUXNET, consist of a growing number of eddy covariance flux tower sites that provide a synoptic record of the exchange of carbon, water, and energy between the ecosystem and atmosphere at various temporal frequencies. These towers also detect and measure certain site characteristics, such as wind, temperature, precipitation, humidity, atmospheric pressure, soil features, and phenological progressions. Efforts are continuous to combine flux tower network data with remote sensing data to upscale the conditions observed at specific sites to a regional and, ultimately, worldwide scale. Data-driven regression tree models have the ability to incorporate flux tower records and remote sensing data to quantify exchanges of carbon with the atmosphere (Wylie and others, 2007; Xiao and others, 2010; Zhang and others, 2010; Zhang and others, 2011). Previous study results demonstrated the dramatic effect weather has on NEP and revealed specific ecoregions and times acting as carbon sinks or sources. As of 2012, more than 100 site-years of flux tower measurements, represented by more than 50 individual cropland or grassland sites throughout the Great Plains and surrounding area, have been acquired, quality controlled, and partitioned into gross photosynthesis (Pg) and ecosystem Re using detailed light-response, soil temperature, and vapor pressure deficit (VPD) based analysis.

  6. Mid-Wisconsinan environments on the eastern Great Plains

    NASA Astrophysics Data System (ADS)

    Baker, R. G.; Bettis, E. A., III; Mandel, R. D.; Dorale, J. A.; Fredlund, G. G.

    2009-05-01

    Few sites on the eastern Great Plains contain paleobotanical records for the mid-Wisconsin. We report on four sites, two stream cutbanks and two quarry exposures, ranging in age from >50 to ˜23.4 ka. The oldest site at >50 ka contains a suite of macrofossils from prairie and disturbed ground habitats, with no representation of trees, indicating an open prairie. By ˜38 ka the assemblages include aquatic, wetland, mudflat, and prairie elements with rare specimens of Populus, Betula cf. papyrifera, Salix and at the most northerly site, Picea. This assemblage suggests a prairie/parkland with interspersed marshes, cooler temperatures and increased moisture. Populus and Salix continued to be represented from ˜36 to ˜29 ka, but the only other taxon was Carex. A hiatus may be present at some time during this interval. After ˜29 ka, Picea became dominant on the uplands and it was joined by sedges in local wetlands. At sites near riverine loess sources, loess accumulation began to fill in the wetlands and organic deposition ceased some time after 29 ka.

  7. Quantifying Russian wheat aphid pest intensity across the Great Plains.

    PubMed

    Merrill, Scott C; Peairs, Frank B

    2012-12-01

    Wheat, the most important cereal crop in the Northern Hemisphere, is at-risk for an approximate 10% reduction in worldwide production because of animal pests. The potential economic impact of cereal crop pests has resulted in substantial research efforts into the understanding of pest agroecosystems and development of pest management strategy. Management strategy is informed frequently by models that describe the population dynamics of important crop pests and because of the economic impact of these pests, many models have been developed. Yet, limited effort has ensued to compare and contrast models for their strategic applicability and quality. One of the most damaging pests of wheat in North America is the Russian wheat aphid, Diuraphis noxia (Kurdjumov). Eighteen D. noxia population dynamic models were developed from the literature to describe pest intensity. The strongest models quantified the negative effects of fall and spring precipitation on aphid intensity, and the positive effects associated with alternate food source availability. Population dynamic models were transformed into spatially explicit models and combined to form a spatially explicit, model-averaged result. Our findings were used to delineate pest intensity on winter wheat across much of the Great Plains and will help improve D. noxia management strategy.

  8. Mid-Wisconsinan environments on the eastern Great Plains

    USGS Publications Warehouse

    Baker, R.G.; Bettis, E. Arthur; Mandel, R.D.; Dorale, J.A.; Fredlund, G.G.

    2009-01-01

    Few sites on the eastern Great Plains contain paleobotanical records for the mid-Wisconsin. We report on four sites, two stream cutbanks and two quarry exposures, ranging in age from >50 to ???23.4 ka. The oldest site at >50 ka contains a suite of macrofossils from prairie and disturbed ground habitats, with no representation of trees, indicating an open prairie. By ???38 ka the assemblages include aquatic, wetland, mudflat, and prairie elements with rare specimens of Populus, Betula cf. papyrifera, Salix and at the most northerly site, Picea. This assemblage suggests a prairie/parkland with interspersed marshes, cooler temperatures and increased moisture. Populus and Salix continued to be represented from ???36 to ???29 ka, but the only other taxon was Carex. A hiatus may be present at some time during this interval. After ???29 ka, Picea became dominant on the uplands and it was joined by sedges in local wetlands. At sites near riverine loess sources, loess accumulation began to fill in the wetlands and organic deposition ceased some time after 29 ka. ?? 2009 Elsevier Ltd. All rights reserved.

  9. Regional setting of Niobrara Formation in Northern Great Plains

    SciTech Connect

    Shurr, G.W.

    1984-05-01

    Natural gas is currently produced from the Upper Cretaceous Niobrara Formation in northeastern Colorado, northwestern Kansas, and several small fields in Nebraska. As a part of studies of low-permeability gas reservoirs in the northern Great Plains, the regional geologic setting of the Niobrara has been investigated in North Dakota, South Dakota, and Nebraska. Structural contours of the Ardmore Bentonite Bed suggest that the area of thin Niobrara strata presently approximates the south flank of the Williston basin and north flank of the Denver and Kennedy basins. Chalk tongues are interpreted as low-angle shelf surfaces, known as carbonate ramps, which sloped gently to the northwest and southeast off a paleotectonic high. The paleotectonic high cut obliquely across the seaway and was close to the position of the Transcontinental arch that influenced Paleozoic sedimentation. As a result, the present-day stratigraphy and structural setting of the Niobrara are different north and south of the arch crest. 58 references, 13 figures, 1 table.

  10. A Cloud Climatology of the Southern Great Plains ARM CART.

    NASA Astrophysics Data System (ADS)

    Lazarus, Steven M.; Krueger, Steven K.; Mace, Gerald G.

    2000-05-01

    Cloud amount statistics from three different sources were processed and compared. Surface observations from a National Centers for Environmental Prediction dataset were used. The data (Edited Cloud Report; ECR) consist of synoptic weather reports that have been edited to facilitate cloud analysis. Two stations near the Southern Great Plains (SGP) Cloud and Radiation Test Bed (CART) in north-central Oklahoma (Oklahoma City, Oklahoma and Wichita, Kansas) were selected. The ECR data span a 10-yr period from December 1981 to November 1991. The International Satellite Cloud Climatology Project (ISCCP) provided cloud amounts over the SGP CART for an 8-yr period (1983-91). Cloud amounts were also obtained from Micro Pulse Lidar (MPL) and Belfort Ceilometer (BLC) cloud-base height measurements made at the SGP CART over a 1-yr period. The annual and diurnal cycles of cloud amount as a function of cloud height and type were analyzed. The three datasets closely agree for total cloud amount. Good agreement was found in the ECR and MPL-BLC monthly low cloud amounts. With the exception of summer and midday in other seasons, the ISCCP low cloud amount estimates are generally 5%-10% less than the others. The ECR high cloud amount estimates are typically 10%-15% greater than those obtained from either the ISCCP or MPL-BLC datasets. The observed diurnal variations of altocumulus support the authors' model results of radiatively induced circulations.

  11. A cloud climatology of the Southern Great Plains ARM CART

    SciTech Connect

    Lazarus, S.M.; Krueger, S.K.; Mace, G.G.

    2000-05-15

    Cloud amount statistics from three different sources were processed and compared. Surface observations from a National Centers for Environmental Prediction dataset were used. The data (Edited Cloud Report; ECR) consist of synoptic weather reports that have been edited to facilitate cloud analysis. Two stations near the Southern Great Plains (SGP) Cloud and Radiation Test Bed (CART) in north-central Oklahoma (Oklahoma City, Oklahoma and Wichita, Kansas) were selected. The ECR data span a 10-yr period from December 1981 to November 1991. The International Satellite Cloud Climatology Project (ISCCP) provided cloud amounts over the SGP CART for an 8-yr period (1983--91). Cloud amounts were also obtained from Micro Pulse Lidar (MPL) and Belfort Ceilometer (BLC) cloud-base height measurements made at the SGP CART over a 1-yr period. The annual and diurnal cycles of cloud amount as a function of cloud height and type were analyzed. The three datasets closely agree for total cloud amount. Good agreement was found in the ECR and MPL-BLC monthly low cloud amounts. With the exception of summer and midday in other seasons, the ISCCP low cloud amount estimates are generally 5%--10% less than the others. The ECR high cloud amount estimates are typically 10%--15% greater than those obtained from either the ISCCP or MPL-BLC datasets. The observed diurnal variations of altocumulus support the authors' model results of radiatively induced circulations.

  12. Great Lakes Region, State of Michigan, USA

    NASA Image and Video Library

    1991-06-14

    STS040-77-045 (6 June 1991) --- This image, photographed on June 6, 1991, is an oblique view looking north-northeast and shows most of the Great Lakes region. Part of Columbia's cargo bay and the Spacelab Life Sciences (SLS-1) module are in the foreground. In the center of the image is Lake Michigan with Chicago clearly visible along the southwest shore. According to NASA photo experts studying the STS-40 imagery, this image shows several interesting meteorological phenomena. The difference in temperature between the warming land and the cold lake waters is illustrated by the low level clouds. The warming land surface results in rising air and the formation of clouds, while the lake waters are cold and result in the lakes remaining cloud free. Also visible is evidence of lake breezes developing around several of the lakes. This phenomena is also driven by the difference in temperature between the land and the water. Winds blowing off the lakes must travel 25 - 30 miles inland before it warms sufficiently to create clouds.

  13. Backcasting the decline of a vulnerable Great Plains reproductive ecotype: identifying threats and conservation priorities.

    PubMed

    Worthington, Thomas A; Brewer, Shannon K; Grabowski, Timothy B; Mueller, Julia

    2014-01-01

    Conservation efforts for threatened or endangered species are challenging because the multi-scale factors that relate to their decline or inhibit their recovery are often unknown. To further exacerbate matters, the perceptions associated with the mechanisms of species decline are often viewed myopically rather than across the entire species range. We used over 80 years of fish presence data collected from the Great Plains and associated ecoregions of the United States, to investigate the relative influence of changing environmental factors on the historic and current truncated distributions of the Arkansas River shiner Notropis girardi. Arkansas River shiner represent a threatened reproductive ecotype considered especially well adapted to the harsh environmental extremes of the Great Plains. Historic (n = 163 records) and current (n = 47 records) species distribution models were constructed using a vector-based approach in MaxEnt by splitting the available data at a time when Arkansas River shiner dramatically declined. Discharge and stream order were significant predictors in both models; however, the shape of the relationship between the predictors and species presence varied between time periods. Drift distance (river fragment length available for ichthyoplankton downstream drift before meeting a barrier) was a more important predictor in the current model and indicated river segments 375-780 km had the highest probability of species presence. Performance for the historic and current models was high (area under the curve; AUC > 0.95); however, forecasting and backcasting to alternative time periods suggested less predictive power. Our results identify fragments that could be considered refuges for endemic plains fish species and we highlight significant environmental factors (e.g., discharge) that could be manipulated to aid recovery. Published 2013. This article is a U.S. Government work and is in the public domain in the U.S.A.

  14. DEVELOPMENT AND EVALUATION OF A FISH ASSEMBLAGE INDEX OF BIOTIC INTEGRITY FOR NORTHWESTERN GREAT PLAINS STREAMS

    EPA Science Inventory

    Quantitative indicators of biological integrity are needed for streams in the Great Plains of North America, but it was not known if the Index of Biotic Integrity (IBI) approach would be effective in this semi-arid region. Great Plains streams have a depauperate and tolerant i...

  15. Recent Trends in Soil Science and Agronomy Research in the Northern Great Plains of North America

    USDA-ARS?s Scientific Manuscript database

    The book “Recent Trends in Soil Science and Agronomy Research in the Northern Great Plains of North America” summarizes published research in soil science and agronomy from various field experiments conducted in the soil-climatic/agro-ecological regions of the Northern Great Plains of North America....

  16. DEVELOPMENT AND EVALUATION OF A FISH ASSEMBLAGE INDEX OF BIOTIC INTEGRITY FOR NORTHWESTERN GREAT PLAINS STREAMS

    EPA Science Inventory

    Quantitative indicators of biological integrity are needed for streams in the Great Plains of North America, but it was not known if the Index of Biotic Integrity (IBI) approach would be effective in this semi-arid region. Great Plains streams have a depauperate and tolerant i...

  17. Agroecosystem diversity and pollinator ecosystem services on the northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    The northern Great Plains provide critical habitat to pollinators. In 2012, North and South Dakota produced one-third of the total honey in the U.S. According to large scale analyses, crop diversity in the northern Great Plains has increased during the past 35 years. Increased diversity, greater com...

  18. Determinants of fish assemblage structure in Northwestern Great Plains streams

    USGS Publications Warehouse

    Mullen, J.A.; Bramblett, R.G.; Guy, C.S.; Zale, A.V.; Roberts, D.W.

    2011-01-01

    Prairie streams are known for their harsh and stochastic physical conditions, and the fish assemblages therein have been shown to be temporally variable. We assessed the spatial and temporal variation in fish assemblage structure in five intermittent, adventitious northwestern Great Plains streams representing a gradient of watershed areas. Fish assemblages and abiotic conditions varied more spatially than temporally. The most important variables explaining fish assemblage structure were longitudinal position and the proportion of fine substrates. The proportion of fine substrates increased proceeding upstream, approaching 100% in all five streams, and species richness declined upstream with increasing fine substrates. High levels of fine substrate in the upper reaches appeared to limit the distribution of obligate lithophilic fish species to reaches further downstream. Species richness and substrates were similar among all five streams at the lowermost and uppermost sites. However, in the middle reaches, species richness increased, the amount of fine substrate decreased, and connectivity increased as watershed area increased. Season and some dimensions of habitat (including thalweg depth, absolute distance to the main-stem river, and watershed size) were not essential in explaining the variation in fish assemblages. Fish species richness varied more temporally than overall fish assemblage structure did because common species were consistently abundant across seasons, whereas rare species were sometimes absent or perhaps not detected by sampling. The similarity in our results among five streams varying in watershed size and those from other studies supports the generalization that spatial variation exceeds temporal variation in the fish assemblages of prairie and warmwater streams. Furthermore, given longitudinal position, substrate, and stream size, general predictions regarding fish assemblage structure and function in prairie streams are possible. ?? American

  19. View east over the Rocky Mountains and Great Plains

    NASA Image and Video Library

    1974-02-01

    SL4-138-3875 (February 1974) --- A color oblique photograph looking east over the Rocky Mountains and Great Plains. This view covers a portion of the States of Colorado, Wyoming, and Nebraska. A Skylab 4 crewmen took this picture with a hand-held 70mm Hasselblad camera. This entire region, covered with a blanket of snow, depicts much of the structural and topographic features of the Rocky Mountain chain. Man's only apparent change to the snow pattern seen here is the (right center) metropolitan areas of Denver and Colorado Springs, Colorado, which can be observed along the eastern edge of the mountain front. Grand Junction, Colorado on the western slope of the Rocky Mountains is just off the photograph at left center bottom. The major inter-montane valleys of South Park (right center), Middle Park (center), and North Park (left center) are clearly visible and separate the Colorado Rockies Front Range from the high rugged mountains can be discovered such as Pikes Peak near right border (center), Mt. Cunnison region, circular feature accentuated by the Cunnison River (dark) in the right center (bottom) of the photograph. The snow covered peaks of Mts. Harvard, Princeton and Yale form the high region of the Collegiate Range which is the pronounced mountain area in the right center. Snow cover not only enhances mountain features but also the drainage patterns. East of Denver (right corner) the sinuous trace of the South Platte River (center) and its junction with the North Platte River near North Platte, Nebraska. Lake McConaughy in Nebraska is the body of water (black) near the river intersection. The trace of the Republic River in southern Nebraska is visible near the right corner of the photography. Geologic and hydro logic studies using this photograph will be conducted by Dr. Roger Morrison, U.S. Geological Survey. Photo credit: NASA

  20. Catastrophic failure of the Northern Great Plains: A unifying hypothesis

    SciTech Connect

    Clausen, E.N. . Science Div.)

    1992-01-01

    The Northern Great Plains, at peak Laurentide glaciation, was a 1,600 km thick barrier between meltwater sources and the lower Missouri Valley. Meltwater and floodwaters flowed along the ice margin, moved between the Black Hills and Laurentide ice. Water was trapped between ice to the N and E and mountains to the W and S. The Pine Ridge Escarpment began as the S wall of a W-trending headcut while other headcuts eroded N, parallel to the ice margin. Sheetflow from the west and northwest stripped the easily-eroded surface between major headcuts. The Cheyenne Valley headcut then captured sheetflow from the eastern Powder River Basin, both N and S of the Black Hills. Sheetflow moving through the western Powder River Basin, however, continued to spill over the southern wall of the initial headcut, carving the upper White River Valley. These floodwaters filled the lower White River Valley, including the Scenic and Sage Creek Basins, and breached divides by spilling over into the newly formed Cheyenne Valley. Another W-trending headcut next initiated the upper Little Missouri Valley by diverting sheetflow from the northeastern Powder River Basin. The Little Missouri Valley was extended northward by diversion of flow to a fourth major headcut and then again by diversion to the Missouri Valley headcut. Sheetflow, moving SE into the Powder River Basin, was progressively captured and diverted as SW-trending headcuts formed the Yellowstone-Powder, Yellowstone-Tongue, and Yellowstone-Bighorn valleys. At the same time sheetflow was progressively captured and diverted by a northerly set of SW-trending headcuts which eroded the Redwater, Big Dry, and Musselshell valleys. Major spillways finally breached the 1,600 km thick barrier by cutting between the Highwood and Bearpaw Mountains and between Milk River Ridge and the Cypress Hills.

  1. Dunes Reveal Unprecedented Circulation Patterns During Great Plains Droughts

    NASA Astrophysics Data System (ADS)

    Oglesby, R. J.; Rowe, C. M.; Loope, D. B.; Sridhar, V.; Swinehart, J. B.; Mason, J. A.

    2006-12-01

    The Nebraska Sand Hills consist of sand dunes that currently are immobile, because growing season rainfall is sufficient for prairie grass growth, which in turn stabilizes the dunes. These dunes have undergone numerous periods of activation and mobility in the past, presumably because prolonged drought conditions removed the vegetation cover. In particular, dune reactivation occurred during the Medieval Warm Period (MWP) 800-1000 years ago. Analysis of dune morphology also provides one of the very few means of directly determining wind direction for pre-instrumental periods. Modern day winds over the Sand Hills (and central Great Plains as a whole) are dominantly from the northwest in winter, and from the southeast in late spring and summer. These southeast winds transport considerable moisture from the Gulf of Mexico and Caribbean, and hence play a key role in the May through July rainy season that occurs at present. Analysis of the dunes that activated during the MWP shows that the dominant winds must have been from the northwest and from the southwest. Assuming that the northwest winds reflected a winter pattern similar to that at present, the spring and summer wind regime and associated circulation patterns must have been very different. Southwesterly winds do occur at present, but only aloft, where they transport hot dry air from the Mexican plateau. We infer that during the MWP these southwesterlies must have reached the surface, sharply reducing moisture transport and yielding hot dry conditions relative to the present. Analysis of NCEP reanalyses from 1949-2002, as well as daily wind data from selected weather stations in and around the Sand Hills, yields no present-day analog, not even individual years, during which southwesterlies dominated during May through June. This implies that circulation patterns responsible for inducing and/or enhancing long-term drought over the central US may be very different than anything experienced during the recent times of

  2. Vulnerability of grazing and confined livestock in the Northern Great Plains to projected mid- and late-twenty-first century climate

    Treesearch

    Justin Derner; David Briske; Matt Reeves; Tami Brown-Brandl; Miranda Meehan; Dana Blumenthal; William Travis; David Augustine; Hailey Wilmer; Derek Scasta; John Hendrickson; Jerry Volesky; Laura Edwards; Dannele Peck

    2017-01-01

    The Northern Great Plains (NGP) region of the USA - which comprises Montana, Wyoming, Colorado, North Dakota, South Dakota, and Nebraska - is a largely rural area that provides numerous ecosystem services, including livestock products, cultural services, and conservation of biological diversity. The region contains 25% of the Nation's beef cattle and approximately...

  3. Global warming likely reduces crop yield and water availability of the dryland cropping systems in the U.S. central Great Plains

    USDA-ARS?s Scientific Manuscript database

    We investigated impacts of GCM-projected climate change on dryland crop rotations of wheat-fallow and wheat-corn-fallow in the Central Great Plains (Akron in Colorado, USA) using the CERES 4.0 crop modules in RZWQM2. The climate change scenarios for CO2, temperature, and precipitation were produced ...

  4. Southern Great Plains Ice Nuclei Characterization Experiment Final Campaign Summary

    SciTech Connect

    DeMott, PJ; Suski, KJ; Hill, TCJ; Levin, EJT

    2015-03-01

    The first ever ice nucleating particle (INP) measurements to be collected at the Southern Great Plains site were made during a period from late April to June 2014, as a trial for possible longer-term measurements at the site. These measurements will also be used to lay the foundation for understanding and parameterizing (for cloud resolving modeling) the sources of these climatically important aerosols as well as to augment the existing database containing this knowledge. Siting the measurements during the spring was intended to capture INP sources in or to this region from plant, soil, dust transported over long distances, biomass burning, and pollution aerosols at a time when they may influence warm-season convective clouds and precipitation. Data have been archived of real-time measurements of INP number concentrations as a function of processing conditions (temperature and relative humidity) during 18 days of sampling that spanned two distinctly different weather situations: a warm, dry and windy period with regional dust and biomass burning influences in early May, and a cooler period of frequent precipitation during early June. Precipitation delayed winter wheat harvesting, preventing intended sampling during that perturbation on atmospheric aerosols. INP concentrations were highest and most variable at all temperatures in the dry period, where we attribute the INP activity primarily to soil dust emissions. Additional offline INP analyses are underway to extend the characterization of INP to cover the entire mixed phase cloud regime from -5°C to -35°C during the full study. Initial comparisons between methods on four days show good agreement and excellent future promise. The additional offline immersion freezing data will be archived as soon as completed under separate funding. Analyses of additional specialized studies for specific attribution of INP to biological and smoke sources are continuing via the National Science Foundation and National Aeronautics

  5. Soil salinity study in Northern Great Plains sodium affected soil

    NASA Astrophysics Data System (ADS)

    Kharel, Tulsi P.

    Climate and land-use changes when combined with the marine sediments that underlay portions of the Northern Great Plains have increased the salinization and sodification risks. The objectives of this dissertation were to compare three chemical amendments (calcium chloride, sulfuric acid and gypsum) remediation strategies on water permeability and sodium (Na) transport in undisturbed soil columns and to develop a remote sensing technique to characterize salinization in South Dakota soils. Forty-eight undisturbed soil columns (30 cm x 15 cm) collected from White Lake, Redfield, and Pierpont were used to assess the chemical remediation strategies. In this study the experimental design was a completely randomized design and each treatment was replicated four times. Following the application of chemical remediation strategies, 45.2 cm of water was leached through these columns. The leachate was separated into 120- ml increments and analyzed for Na and electrical conductivity (EC). Sulfuric acid increased Na leaching, whereas gypsum and CaCl2 increased water permeability. Our results further indicate that to maintain effective water permeability, ratio between soil EC and sodium absorption ratio (SAR) should be considered. In the second study, soil samples from 0-15 cm depth in 62 x 62 m grid spacing were taken from the South Dakota Pierpont (65 ha) and Redfield (17 ha) sites. Saturated paste EC was measured on each soil sample. At each sampling points reflectance and derived indices (Landsat 5, 7, 8 images), elevation, slope and aspect (LiDAR) were extracted. Regression models based on multiple linear regression, classification and regression tree, cubist, and random forest techniques were developed and their ability to predict soil EC were compared. Results showed that: 1) Random forest method was found to be the most effective method because of its ability to capture spatially correlated variation, 2) the short wave infrared (1.5 -2.29 mum) and near infrared (0

  6. The Buffalo Commons: Great Plains Residents' Responses to a Radical Vision

    ERIC Educational Resources Information Center

    Rees, Amanda

    2005-01-01

    The American Great Plains has gained and shed various regional meanings since Euro-American exploration began. From a desert to a garden to a dust bowl to a breadbasket, this region's identity has shifted radically and dramatically over the last 200 years. In the mid-1980s unusual things were happening on the Plains that suggested yet another…

  7. Genetic variation in ponderosa pine: A 15-year test of provenances in the Great Plains

    Treesearch

    David F. Van Haverbeke

    1986-01-01

    Survival was highest and height growth greatest in ponderosa pine provenances from northcentral Nebraska, southwest South Dakota, and the High Plains region. Genotype x environment interaction was minimal in central and northern Great Plains plantations. Age/age correlations indicate provenances expressing superior height growth can be identified after 5 or 10 years....

  8. The Buffalo Commons: Great Plains Residents' Responses to a Radical Vision

    ERIC Educational Resources Information Center

    Rees, Amanda

    2005-01-01

    The American Great Plains has gained and shed various regional meanings since Euro-American exploration began. From a desert to a garden to a dust bowl to a breadbasket, this region's identity has shifted radically and dramatically over the last 200 years. In the mid-1980s unusual things were happening on the Plains that suggested yet another…

  9. Dynamical connection between Great Plains low-level winds and variability of central Gulf States precipitation

    NASA Astrophysics Data System (ADS)

    Pu, Bing; Dickinson, Robert E.; Fu, Rong

    2016-04-01

    The Great Plains low-level jet has been related to summer precipitation over the northern Great Plains and Midwest through its moisture transport and convergence at the jet exit area. Much less studied has been its negative relationship with precipitation over the southern Great Plains and the Gulf coastal area. This work shows that the southerly low-level winds at 30°-40°N over the southern Great Plains are significantly correlated with anticyclonic vorticity to its east over the central Gulf States (30°-35°N, 85°-95°W) from May to July. When the low-level jet is strong in June and July, anomalous anticyclonic vorticity over the central Gulf States leads to divergence and consequent subsidence suppressing precipitation over that region. In contrast, an enhanced southerly flow at the entrance region of the jet over the Gulf of Mexico, largely uncorrelated with the meridional wind over the southern Great Plains, is correlated with increased precipitation over the central Gulf States. Precipitation is large over the central Gulf States when the meridional wind over the southern Great Plains is weakest and over the Gulf of Mexico is strongest. This increase is consistent with the increased moisture transport and dynamic balance between loss of vorticity by advection and friction and gain by convergence.

  10. A proxy, instrumental, and model analysis of spring and summer moisture over the Great Plains

    NASA Astrophysics Data System (ADS)

    Howard, I.; Stahle, D. W.; Feng, S.

    2016-12-01

    A number of sustained sub-decadal to decadal drought and wetness regimes have impacted the Great Plains. Here, we examine the seasonal and spatial characteristics of these regimes using a combination of gridded tree ring reconstructions, gridded instrumental climate data, output from the Community Climate System Model, and new reconstructions of the spring and summer moisture balance for the southern and northern Plains. Many of the decadal drought and pluvials in the tree-ring and instrumental record encompassed large areas of the continent, but the most severe conditions often intersected over the Great Plains. Twentieth century moisture regimes, most notably the 1930s Dust Bowl Drought and the 1950s Drought, had distinct seasonal and spatial impacts. The 1930s Dust Bowl Drought was severe in the spring but especially summer over the central and northern Plains, while the 1950s Drought was more of a summertime phenomenon that impacted the southern Plains and southeastern U.S. Instrumental data and climate model output suggest that decadal anomalies of sea-surface temperatures in the tropical and extratropical Pacific are related to decadal moisture variability in the southern Plains, but the signal is weak for the northern Plains. This teleconnection at decadal timescales is strongest over the southern Plains during the spring season. Using new chronologies of earlywood and latewood width from drought sensitive conifers, we demonstrate the ability to separately and skillfully model the spring and summer moisture balance over the northern and southern Plains. The new reconstructions highlight interesting seasonal moisture anomalies previously undocumented over the Great Plains.

  11. Influence of riparian and watershed alterations on sandbars in a Great Plains river

    USGS Publications Warehouse

    Fischer, Jeffrey M.; Paukert, Craig P.; Daniels, M.L.

    2014-01-01

    Anthropogenic alterations have caused sandbar habitats in rivers and the biota dependent on them to decline. Restoring large river sandbars may be needed as these habitats are important components of river ecosystems and provide essential habitat to terrestrial and aquatic organisms. We quantified factors within the riparian zone of the Kansas River, USA, and within its tributaries that influenced sandbar size and density using aerial photographs and land use/land cover (LULC) data. We developed, a priori, 16 linear regression models focused on LULC at the local, adjacent upstream river bend, and the segment (18–44 km upstream) scales and used an information theoretic approach to determine what alterations best predicted the size and density of sandbars. Variation in sandbar density was best explained by the LULC within contributing tributaries at the segment scale, which indicated reduced sandbar density with increased forest cover within tributary watersheds. Similarly, LULC within contributing tributary watersheds at the segment scale best explained variation in sandbar size. These models indicated that sandbar size increased with agriculture and forest and decreased with urban cover within tributary watersheds. Our findings suggest that sediment supply and delivery from upstream tributary watersheds may be influential on sandbars within the Kansas River and that preserving natural grassland and reducing woody encroachment within tributary watersheds in Great Plains rivers may help improve sediment delivery to help restore natural river function.

  12. Projected climate change for the coastal plain region of Georgia, USA

    USDA-ARS?s Scientific Manuscript database

    Climatic patterns for the Coastal Plain region of Georgia, USA, centered on Tifton, Georgia (31 28 30N, 83 31 54W) were examined for long term patterns in precipitation and air temperature. Climate projections based upon output from seven Global Circulation Models (GCMs) and three future Green Hous...

  13. Dissolved phosphorus retention and release from southeastern USA Coastal Plain in-stream wetlands

    USDA-ARS?s Scientific Manuscript database

    In the southeastern USA Coastal Plain region, many inland surface water systems will meander through flat or depressional landscape areas prior to discharge into coastal estuaries. Slow water flow through these areas often causes flooding that promotes formation of in-stream wetlands with dense vege...

  14. The High Plains Aquifer, USA: Groundwater development and sustainability

    USGS Publications Warehouse

    Dennehy, K.F.; Litke, D.W.; McMahon, P.B.

    2002-01-01

    The High Plains Aquifer, located in the United States, is one of the largest freshwater aquifers in the world and is threatened by continued decline in water levels and deteriorating water quality. Understanding the physical and cultural features of this area is essential to assessing the factors that affect this groundwater resource. About 27% of the irrigated land in the United States overlies this aquifer, which yields about 30% of the nation's groundwater used for irrigation of crops including wheat, corn, sorghum, cotton and alfalfa. In addition, the aquifer provides drinking water to 82% of the 2.3 million people who live within the aquifer boundary. The High Plains Aquifer has been significantly impacted by human activities. Groundwater withdrawals from the aquifer exceed recharge in many areas, resulting in substantial declines in groundwater level. Residents once believed that the aquifer was an unlimited resource of high-quality water, but they now face the prospect that much of the water may be gone in the near future. Also, agricultural chemicals are affecting the groundwater quality. Increasing concentrations of nitrate and salinity can first impair the use of the water for public supply and then affect its suitability for irrigation. A variety of technical and institutional measures are currently being planned and implemented across the aquifer area in an attempt to sustain this groundwater resource for future generations. However, because groundwater withdrawals remain high and water quality impairments are becoming more commonplace, the sustainability of the High Plains Aquifer is uncertain.

  15. Estimated historical distribution of grassland communities of the Southern Great Plains

    USGS Publications Warehouse

    Reese, Gordon C.; Manier, Daniel J.; Carr, Natasha B.; Callan, Ramana; Leinwand, Ian I.F.; Assal, Timothy J.; Burris, Lucy; Ignizio, Drew A.

    2016-12-07

    The purpose of this project was to map the estimated distribution of grassland communities of the Southern Great Plains prior to Euro-American settlement. The Southern Great Plains Rapid Ecoregional Assessment (REA), under the direction of the Bureau of Land Management and the Great Plains Landscape Conservation Cooperative, includes four ecoregions: the High Plains, Central Great Plains, Southwestern Tablelands, and the Nebraska Sand Hills. The REA advisors and stakeholders determined that the mapping accuracy of available national land-cover maps was insufficient in many areas to adequately address management questions for the REA. Based on the recommendation of the REA stakeholders, we estimated the potential historical distribution of 10 grassland communities within the Southern Great Plains project area using data on soils, climate, and vegetation from the Natural Resources Conservation Service (NRCS) including the Soil Survey Geographic Database (SSURGO) and Ecological Site Information System (ESIS). The dominant grassland communities of the Southern Great Plains addressed as conservation elements for the REA area are shortgrass, mixed-grass, and sand prairies. We also mapped tall-grass, mid-grass, northwest mixed-grass, and cool season bunchgrass prairies, saline and foothill grasslands, and semi-desert grassland and steppe. Grassland communities were primarily defined using the annual productivity of dominant species in the ESIS data. The historical grassland community classification was linked to the SSURGO data using vegetation types associated with the predominant component of mapped soil units as defined in the ESIS data. We augmented NRCS data with Landscape Fire and Resource Management Planning Tools (LANDFIRE) Biophysical Settings classifications 1) where NRCS data were unavailable and 2) where fifth-level watersheds intersected the boundary of the High Plains ecoregion in Wyoming. Spatial data representing the estimated historical distribution of

  16. Alfalfa production with subsurface drip irrigation in the Central Great Plains

    USDA-ARS?s Scientific Manuscript database

    Irrigated alfalfa production is gaining interest because of the growing number of dairies in the semi-arid U.S. Central Great Plains and its longstanding superior profitability compared to other alternative crops grown in the region. Irrigation requirements for alfalfa are great because of alfalfa's...

  17. Seasonal weather-related decision making for cattle production in the Northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    High inter-annual variability of seasonal weather patterns can greatly affect forage and therefore livestock production in the Northern Great Plains. This variability can make it difficult for ranchers to set yearly stocking rates, particularly in advance of the grazing season. To better understand ...

  18. Impacts of irrigation on 20th century temperature in the northern Great Plains

    NASA Astrophysics Data System (ADS)

    Mahmood, Rezaul; Foster, Stuart A.; Keeling, Travis; Hubbard, Kenneth G.; Carlson, Christy; Leeper, Ronnie

    2006-11-01

    Land use change can modify root zone moisture distribution, energy partitioning and subsequently, near surface energy balance. Various modeling studies provided evidence of these changes. For example, land use change from natural grass land to irrigated land use would significantly increase and decrease latent and sensible energy flux, respectively. This type of long-term modification of energy balance would in turn change near surface temperatures. The Great Plains of North America experienced significant overturning of land from natural grass land to irrigated land use during the 20th century. This study provides assessment on the changes in the historical near surface temperature records in Nebraska, USA. Long-term mean monthly maximum, minimum, and monthly mean air temperature data from 5 irrigated and 5 non-irrigated sites were analyzed. Length and homogeneity of time series and stability of stations were primary determinants in selection of these stations. The time series include Cooperative Weather Observation Network (COOP) and Historical Climate Network (HCN) data sets. Pairwise comparisons of temperatures between irrigated and non-irrigated locations for pre- and post-1945, -1950, and -1955 periods were completed for both data sets. These breakdowns of time series helped to identify periods of widespread land use change. Results show notably cooler temperatures over irrigated areas. For example, mean maximum growing season temperature at irrigated Alliance was 0.64 °C and 1.65 °C cooler compared to non-irrigated Halsey during pre- and post-1945 period, respectively. Hence, there was a 1.01 °C cooling during post-1945 years. Moreover, there has been a greater cooling during the second half of 20th century. The bootstrap re-sampling method was applied and trend analyses were completed for further verification of results. These assessments largely show a decreasing trend in mean maximum growing season temperatures over irrigated areas. To further verify

  19. Hidden in Plain Sight: Signs of Great Power War

    DTIC Science & Technology

    2016-06-01

    great power war more likely during the 1914 July Crisis. Nuclear weapons, a different international order, and geography are clear differences in... July Crisis of 1914 is similar to today, there are three glaring differences between the two time periods: one, nuclear weapons have brought...interactions with a potential hegemon, they are more likely to harbor fear over their rival’s intentions. The fourth variable, entangling alliances, stems

  20. An analysis of drought in the Northern Great Plains: Summary of progress

    SciTech Connect

    Sieg, C.H.; Meko, D.M.; Ni, W.; DeGaetano, A.T.; Miller, J.R. Jr.; Bunkers, M.J.

    1995-12-31

    The purpose of this research is to increase the understanding of the magnitude, recurrence interval and periodicity of drought in the Northern Great Plains both from dendrochronological reconstructions and from analyses of available climate data. The objectives are to: (1) develop a network of climatically sensitive tree-ring chronologies to fill a void in the Northern Great Plains; (2) isolate climate variables most highly correlated with tree-growth; (3) reconstruct the drought history for the past 100 to 300 years; (4) identify regions which are climatically similar with respect to drought; (5) isolate patterns of drought persistence or recurrence; and (6) determine if drought recurrence is related to southern oscillation events. This paper summarizes progress on development of tree-ring chronologies in the Northern Great Plains preliminary analyses on the relationship between annual tree-ring widths and both precipitation and soil moisture and efforts to identify climatic regions and drought patterns in this region from climatic records.

  1. A conceptual model to facilitate amphibian conservation in the northern Great Plains

    USGS Publications Warehouse

    Mushnet, David M.; Euliss, Ned H.; Stockwell, Craig A.

    2012-01-01

    As pressures on agricultural landscapes to meet worldwide resource needs increase, amphibian populations face numerous threats including habitat destruction, chemical contaminants, disease outbreaks, wetland sedimentation, and synergistic effects of these perturbations. To facilitate conservation planning, we developed a conceptual model depicting elements critical for amphibian conservation in the northern Great Plains. First, we linked upland, wetland, and landscape features to specific ecological attributes. Ecological attributes included adult survival; reproduction and survival to metamorphosis; and successful dispersal and recolonization. Second, we linked ecosystem drivers, ecosystem stressors, and ecological effects of the region to each ecological attribute. Lastly, we summarized information on these ecological attributes and the drivers, stressors, and effects that work in concert to influence the maintenance of viable and genetically diverse amphibian populations in the northern Great Plains. While our focus was on the northern Great Plains, our conceptual model can be tailored to other geographic regions and taxa.

  2. Modelling dust-drought interactions in the U.S Great Plains

    NASA Astrophysics Data System (ADS)

    Koven, C. D.; Fung, I.

    2006-12-01

    We examine the possible role of mineral dust in amplifying summertime drought over the US Great Plains, specifically addressing the question of whether dust released during the 1930s drought could have acted as a drought feedback. We use the NCAR CAM3.0 atmospheric GCM, forced with drought-inducing SSTs as boundary conditions. We compare model runs with and without specified monthly-mean dust forcings centered over the southern US Great Plains, which was the center of the 1930s "dust-bowl". We specify multiple dust single-scattering albedos to explore the relative roles of scattering and absorption in enhancing drought. We also compare the role of dust in amplifying drought with the role of land surface perturbation, by running the GCM with climatological and desert vegetation over the Great Plains region. We find that all dust and land surface modification scenarios lead to decreased precipitation over the region, on top of the SST- induced precipitation reduction.

  3. Upscaling carbon fluxes over the Great Plains grasslands: Sinks and sources

    USGS Publications Warehouse

    Zhang, Li; Wylie, Bruce K.; Ji, Lei; Gilmanov, Tagir G.; Tieszen, Larry L.; Howar, Daniel M.

    2011-01-01

    Previous studies suggested that the grasslands may be carbon sinks or near equilibrium, and they often shift between carbon sources in drought years and carbon sinks in other years. It is important to understand the responses of net ecosystem production (NEP) to various climatic conditions across the U.S. Great Plains grasslands. Based on 15 grassland flux towers, we developed a piecewise regression model and mapped the grassland NEP at 250 m spatial resolution over the Great Plains from 2000 to 2008. The results showed that the Great Plains was a net sink with an averaged annual NEP of 24 ± 14 g C m−2 yr−1, ranging from a low value of 0.3 g C m−2 yr−1 in 2002 to a high value of 47.7 g C m−2 yr−1 in 2005. The regional averaged NEP for the entire Great Plains grasslands was estimated to be 336 Tg C yr−1 from 2000 to 2008. In the 9 year period including 4 dry years, the annual NEP was very variable in both space and time. It appeared that the carbon gains for the Great Plains were more sensitive to droughts in the west than the east. The droughts in 2000, 2002, 2006, and 2008 resulted in increased carbon losses over drought-affected areas, and the Great Plains grasslands turned into a relatively low sink with NEP values of 15.8, 0.3, 20.1, and 10.2 g C m−2 yr−1 for the 4 years, respectively.

  4. Modeling the Impact of Irrigation on Precipitation over the Great Plains

    NASA Astrophysics Data System (ADS)

    Harding, Keith John Iliff

    2011-12-01

    Since World War II, the rapid expansion of irrigation throughout the Great Plains has threatened the sustainability of the Ogallala Aquifer. Irrigation has been shown to modify the surface energy and water budgets over the Great Plains by altering the partitioning of latent and sensible heating. An increase in latent heating from irrigation contributes to a cooler and more humid surface, which has competing impacts on convection. In this study, the Weather Research and Forecasting model was modified to simulate the effects of irrigation at sub-grid scales. Nine April-October simulations were completed for different hydrologic conditions over the Great Plains. Data from these simulations was assimilated into a back-trajectory analysis to identify where evapotranspired moisture from irrigated fields predominantly falls out as precipitation. May through September precipitation increased on average over the Great Plains by 4.97 mm (0.91%), with the largest increases during wet years (6.14 mm; 0.98%) and the smallest increases during drought years (2.85 mm; 0.63%). Large precipitation increases occurred over irrigated areas during normal and wet years, with decreases during drought years. On average, only 15.8% of evapotranspired moisture from irrigated fields fell out as precipitation over the Great Plains, resulting in 5.11 mm of May-September irrigation-induced precipitation. The heaviest irrigation-induced precipitation occurred over north-central Nebraska, coincident with simulated and observed precipitation increases. While irrigation resulted in localized and region-wide increases in precipitation, large evapotranspiration increases suggest that irrigation contributes to a net loss of water in the Great Plains.

  5. Characterizing isotopic variability of primary production and consumers in Great Plains ecosystems during protracted regional drought

    NASA Astrophysics Data System (ADS)

    Haveles, A. W.; Fox-Dobbs, K.; Talmadge, K. A.; Fetrow, A.; Fox, D. L.

    2012-12-01

    Over the last few years (2010-2012), the Great Plains of the central USA experienced protracted drought conditions, including historically severe drought during Summer, 2011. Drought severity in the region generally decreases with increasing latitude, but episodic drought is a fundamental trait of grassland ecosystems. Documenting above ground energy and nutrient flow with current drought is critical to understanding responses of grassland ecosystems in the region to predicted increased episodicity of rainfall and recurrence of drought due to anthropogenic climate change. Characterization of biogeochemical variability of modern ecosystems at the microhabitat, local landscape, and regional scales is also necessary to interpret biogeochemical records of ancient grasslands based on paleosols and fossil mammals. Here, we characterize three grassland ecosystems that span the drought gradient in the Great Plains (sites in the Texas panhandle, southwest Kansas, and northwest Nebraska). We measured δ13C and δ15N values of plants and consumers to characterize the biogeochemical variability within each ecosystem. Vegetation at each site is a mix of trees, shrubs, herbs, and cool- and warm-growing season grasses (C3 and C4, respectively). Thus, consumers have access to isotopically distinct sources of forage that vary in abundance with microhabitat (e.g., open grassland, shrub thicket, riparian woodland). Observations indicate herbivorous arthropod (grasshoppers and crickets) abundance follows drought severity, with high abundance of many species in Texas, and low abundance of few species in Nebraska. Small mammal (rodents) abundance follows the inverse pattern with 0.8%, 3.2% and 17.2% capture success in Texas, Kansas and Nebraska, respectively. The inverse abundance patterns of consumer groups may result from greater sensitivity of small mammal consumers with high metabolic needs to lower local net primary productivity and forage quality under drought conditions. As a

  6. Late Pleistocene braided rivers of the Atlantic Coastal Plain, USA

    NASA Astrophysics Data System (ADS)

    Leigh, David S.; Srivastava, Pradeep; Brook, George A.

    2004-01-01

    Infrared Landsat imagery (band 4) clearly reveals braided river patterns on late Pleistocene terraces of unglaciated rivers in the Atlantic Coastal Plain of the southeastern United States, a region that presently exhibits meandering patterns that have existed throughout the Holocene. These Pleistocene braided patterns provide a unique global example of river responses to late Quaternary climate changes in an unglaciated humid subtropical region at 30-35° north latitude. Detailed morphological and chronological results are given for the Oconee-Altamaha River valley in Georgia and for the Pee Dee River valley in South Carolina, including 15 optically stimulated luminescence (OSL) dates and four radiocarbon dates. Correlative examples are drawn from additional small to large rivers in South- and North Carolina. OSL and radiocarbon ( 14C) dates indicate distinct braiding at 17-30 ka, within oxygen isotope stage 2 (OIS 2), and braiding probably existed at least during parts of OIS 3 and possibly OIS 4 back to ca 70 ka. The chronology suggests that braiding is the more common pattern for the late Quaternary in the southeastern United States. Braided terraces appear to have been graded to lower sea-levels and are onlapped by Holocene floodplain deposits up to 10-60 km from the coast. The braiding probably reflects the response of discharge and sediment yield to generally cooler and drier paleoclimates, which may have had a pronounced runoff season. Sedimentation of eolian dunes on the braid plains is coeval with braiding and supports the conclusion of dry soils and thin vegetation cover during the late Pleistocene. Our chronological data contribute to a body of literature indicating that reliable OSL age estimates can be obtained from quartz-rich bed load sand from braided rivers, based on good correlations with both radiocarbon dates from braided fluvial sediment and OSL dates from stratigraphically correlative eolian sand.

  7. Grassland Vegetation in the Southern Great Plains during the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Hall, Stephen A.; Valastro, Salvatore

    1995-09-01

    New pollen records from White Lake in the Southern High Plains and from Friesenhahn Cave on the southeastern Edwards Plateau of Texas indicate that the glacial-age vegetation of the southern Great Plains was a grassland. The High Plains was a treeless Artemisia grassland and the Edwards Plateau, at the south edge of the Great Plains, was a grassland with pinyon pines and deciduous trees in canyons and riparian habitats. The glacial-age grasslands differ from modern shortgrass and tallgrass prairies and may have no modern analog. The dominance of prairie vegetation during the last glacial maximum is compatible with late Pleistocene mammalian faunas and late-glacial grassland pollen records from the region. Earlier interpretations of a pine-spruce forest on the High Plains were based on pollen assemblages that are here shown to have been altered by postdepositional deterioration, resulting in differential preservation of conifer pollen grains. Accordingly, the "Tahoka Pluvial" and other "climatic episodes" defined by High Plains pollen records are abandoned.

  8. Channel narrowing and vegetation development following a great plains flood

    USGS Publications Warehouse

    Friedman, J.M.; Osterkamp, W.R.; Lewis, W.M.

    1996-01-01

    Streams in the plains of eastern Colorado are prone to intense floods following summer thunderstorms. Here, and in other semiarid and arid regions, channel recovery after a flood may take several decades. As a result, flood history strongly influences spatial and temporal variability in bottomland vegetation. Interpretation of these patterns must be based on understanding the long-term response of bottomland morphology and vegetation to specific floods. A major flood in 1965 on Plum Creek, a perennial sandbed stream, removed most of the bottomland vegetatiqn and transformed the single-thread stream into a wider, braided channel. Channel narrowing began in 1973 and continues today. In 1991, we determined occurrences of 150 vascular plant species in 341 plots (0.5 m2) along a 7-km reach of Plum Creek near Louviers, Colorado. We related patterns of vegetation to elevation, litter cover, vegetative cover, sediment particle size, shade, and year of formation of the underlying surface (based on age of the excavated root flare of the oldest woody plants). Geomorphic investigation determined that Plum Creek fluvial surfaces sort into five groups by year of formation: terraces of fine sand formed before 1965; terraces of coarse sand deposited by the 1965 flood; stable bars formed by channel narrowing during periods of relatively high bed level (1973-1986); stable bars similarly formed during a recent period of low bed level (1987-1990); and the present channel bed (1991). Canonical correspondence analysis indicates a strong influence of elevation and litter cover, and lesser effects of vegetative cover, shade, and sediment particle size. However, the sum of all canonical eigenvalues explained by these factors is less than that explained by an analysis including only the dummy variables that define the five geomorphically determined age groups. The effect of age group is significant even when all five other environmental variables are specified as covariables. Therefore, the

  9. Atmosphere-Land-Surface Interaction over the Southern Great Plains: Diagnosis of Mechanisms from SGP ARM Data

    SciTech Connect

    Sumant Nigam

    2013-02-01

    Work reported included analysis of pentad (5 day) averaged data, proposal of a hypothesis concerning the key role of the Atlantic Multi-decadal Oscillation in 20th century drought and wet periods over the Great Plains, analysis of recurrent super-synoptic evolution of the Great Plains low-level jet, and study of pentad evolution of the 1988 drought and 1993 flood over the Great Plains from a NARR perspective on the atmospheric and terrestrial water balance.

  10. New Chronologies of Dune Activation Extracted from the Central Great Plains

    NASA Astrophysics Data System (ADS)

    Johnson, W. C.; Halfen, A. F.

    2011-12-01

    Recent investigations of dunefield activation histories in the Great Plains of North America have documented many long-duration, spatially-extensive, Holocene droughts. These "megadroughts" have been documented mostly in the larger dunefields of the Great Plains, e.g., the Nebraska Sand Hills, making it difficult for researchers to characterize these events region-wide. Several studies being conducted by the authors aim to extract a better spatial and temporal representation of megadroughts across the region by investigating smaller, less known dunefields of the Central Great Plains. Thus far, these studies have yielded new activation histories from three dunefields, the Kansas River, Hutchinson, and Arkansas Valley dunefields, which together span the precipitation gradient from eastern Kansas to eastern Colorado. While each of these dunefields have a unique history, collectively their activation chronologies yield new and important information on Holocene megadrought activity in the Great Plains, which may have been more spatially diverse and complex than previously thought. The Kansas River dunefield mantles a remnant high terrace of the lower Kansas River valley in the east-Central Great Plains and is one of the most easterly dunefields in the Great Plains. Optically stimulated luminescence (OSL) ages indicate dune activation last occurred ~36-31 ka, i.e., during MIS 3 between Heinrich Events 4 and 3 and was coincidental with loess deposition (Gillman Canyon Formation). The Kansas River dunefield also shows some evidence of minor activation during the middle Holocene, however this activity was likely limited to erosion of the dune surface and not full activation. About 200 km southwest of the Kansas River dunefield is the Hutchinson dunefield (HD), located immediately northeast of the Big Bend of the Arkansas River. OSL ages document dunefield-wide activity in the HD between ~1200 and 120 years ago, with peaks of activity centered after the Medieval Climatic

  11. Great Plains Coal Gasification Project: Quarterly technical progress report, April-June 1988 (Fourth fiscal quarter, 1987-1988)

    SciTech Connect

    Not Available

    1988-07-29

    This progress report describes the operation of the Great Plains Gasification Plant, including lignite coal production, SNG production, gas quality, by-products, and certain problems encountered. (LTN)

  12. Colonization and extinction in dynamic habitats: an occupancy approach for a Great Plains stream fish assemblage.

    PubMed

    Falke, Jeffrey A; Bailey, Larissa L; Fausch, Kurt D; Bestgen, Kevin R

    2012-04-01

    Despite the importance of habitat in determining species distribution and persistence, habitat dynamics are rarely modeled in studies of metapopulations. We used an integrated habitat-occupancy model to simultaneously quantify habitat change, site fidelity, and local colonization and extinction rates for larvae of a suite of Great Plains stream fishes in the Arikaree River, eastern Colorado, USA, across three years. Sites were located along a gradient of flow intermittency and groundwater connectivity. Hydrology varied across years: the first and third being relatively wet and the second dry. Despite hydrologic variation, our results indicated that site suitability was random from one year to the next. Occupancy probabilities were also independent of previous habitat and occupancy state for most species, indicating little site fidelity. Climate and groundwater connectivity were important drivers of local extinction and colonization, but the importance of groundwater differed between periods. Across species, site extinction probabilities were highest during the transition from wet to dry conditions (range: 0.52-0.98), and the effect of groundwater was apparent with higher extinction probabilities for sites not fed by groundwater. Colonization probabilities during this period were relatively low for both previously dry sites (range: 0.02-0.38) and previously wet sites (range: 0.02-0.43). In contrast, no sites dried or remained dry during the transition from dry to wet conditions, yielding lower but still substantial extinction probabilities (range: 0.16-0.63) and higher colonization probabilities (range: 0.06-0.86), with little difference among sites with and without groundwater. This approach of jointly modeling both habitat change and species occupancy will likely be useful to incorporate effects of dynamic habitat on metapopulation processes and to better inform appropriate conservation actions.

  13. Bed site selection by neonate deer in grassland habitats on the northern Great Plains

    USGS Publications Warehouse

    Grovenburg, T.W.; Jacques, C.N.; Klaver, R.W.; Jenks, J.A.

    2010-01-01

    Bed site selection is an important behavioral trait influencing neonate survival. Vegetation characteristics of bed sites influence thermal protection of neonates and concealment from predators. Although previous studies describe bed site selection of neonatal white-tailed deer (Odocoileus virginianus) in regions of forested cover, none determined microhabitat effects on neonate bed site selection in the Northern Great Plains, an area of limited forest cover. During summers 2007–2009, we investigated bed site selection (n  =  152) by 81 radiocollared neonate white-tailed deer in north-central South Dakota, USA. We documented 80 (52.6%) bed sites in tallgrass–Conservation Reserve Program lands, 35 (23.0%) bed sites in forested cover, and 37 (24.3%) in other habitats (e.g., pasture, alfalfa, wheat). Bed site selection varied with age and sex of neonate. Tree canopy cover (P < 0.001) and tree basal area (P < 0.001) decreased with age of neonates, with no bed sites observed in forested cover after 18 days of age. Male neonates selected sites with less grass cover (P < 0.001), vertical height of understory vegetation (P < 0.001), and density of understory vegetation (P < 0.001) but greater bare ground (P  =  0.047), litter (P  =  0.028), and wheat (P  =  0.044) than did females. Odds of bed site selection increased 3.5% (odds ratio  =  1.035, 95% CI  =  1.008–1.062) for every 1-cm increase in vertical height of understory vegetation. Management for habitat throughout the grasslands of South Dakota that maximizes vertical height of understory vegetation would enhance cover characteristics selected by neonates.

  14. Multiple watershed alterations influence fish community structure in Great Plains prairie streams

    SciTech Connect

    Perkin, Joshuah S.; Troia, Matthew J.; Shaw, Dustin C. R.; Gerken, Joseph E.; Gido, Keith B.

    2014-10-26

    Stream fish distributions are commonly linked to environmental disturbances affecting terrestrial landscapes. In Great Plains prairie streams, the independent and interactive effects of watershed impoundments and land cover changes remain poorly understood despite their prevalence and assumed contribution to declining stream fish diversity. We used structural equation models and fish community samples from third-order streams in the Kansas River and Arkansas River basins of Kansas, USA to test the simultaneous effects of geographic location, terrestrial landscape alteration, watershed impoundments and local habitat on species richness for stream-associated and impoundment-associated habitat guilds. Watershed impoundment density increased from west to east in both basins, while per cent altered terrestrial landscape (urbanisation + row-crop agriculture) averaged ~50% in the west, declined throughout the Flint Hills ecoregion and increased (Kansas River basin ~80%) or decreased (Arkansas River basin ~30%) to the east. Geographic location had the strongest effect on richness for both guilds across basins, supporting known zoogeography patterns. In addition to location, impoundment species richness was positively correlated with local habitat in both basins; whereas stream-species richness was negatively correlated with landscape alterations (Kansas River basin) or landscape alterations and watershed impoundments (Arkansas River basin). These findings suggest that convergences in the relative proportions of impoundment and stream species (i.e., community structure) in the eastern extent of both basins are related to positive effects of increased habitat opportunities for impoundment species and negative effects caused by landscape alterations (Kansas River basin) or landscape alterations plus watershed impoundments (Arkansas River basin) for stream species.

  15. Effects of Grazing Pressure on Efficiency of Grazing on North American Great Plains Rangelands

    USDA-ARS?s Scientific Manuscript database

    Robust prediction models describing vegetation and animal responses to stocking rate in North American Great Plains rangelands are lacking as across site comparisons are limited by different qualitative designations of light, moderate and heavy stocking. Comparisons of stocking rates across sites ca...

  16. Wildlife associations in Rocky Mountain juniper in the northern Great Plains, South Dakota

    Treesearch

    Mark A. Rumble; John E. Gobeille

    1995-01-01

    Rocky Mountain juniper is an important habitat component in the northern Great Plains. These woodlands provide vertical and horizontal vegetative structure that enhances wildlife use. Ecological approaches to managing habitats require understanding relationships between wildlife species and succession in plant communities. We determined bird, small mammals and large...

  17. Circular buffer strips in center pivot irrigation for multiple benefits in the Southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    The Ogallala Aquifer has converted the Southern Great Plains from a dust bowl to a highly productive agricultural region in the US. However, over exploitation of the aquifer is threatening sustainability of irrigated agriculture in the region. Partial pivots, where high water using conventional crop...

  18. Greenhouse gas mitigation potential of dryland cropping systems in the U.S. Great Plains

    USDA-ARS?s Scientific Manuscript database

    The U.S. Great Plains contain significant expanses of agricultural land dedicated to dryland cropping. Dryland cropping systems in the region that sequester soil organic carbon (SOC) and minimize nitrous oxide (N2O) emissions can serve to reduce the greenhouse gas (GHG) balance of U.S. agriculture....

  19. Recent biodiversity patterns in the Great Plains: Implications for restoration and management

    Treesearch

    Carolyn Hull Sieg; Curtis H. Flather; Stephen McCanny

    1999-01-01

    Ecosystem, species and genetic dimensions of biodiversity have eroded since widespread settlement of the Great Plains. Conversion of native vegetation in the region followed the precipitation gradient, with the greatest conversion in the eastern tallgrass prairie and eastern mixed-grass types. Areas now dominated by intensive land uses are "hot spots" for...

  20. Growth and Quality of Cool-Season Perennial Grass Species in the Southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Annually planted winter wheat is the major cool-season livestock forage enterprise in a large part of the southern Great Plains and is a good complement to warm-season perennials. However, gaps in both fall and spring exist in the system. Cool-season perennial grasses that have origins in the Nort...

  1. Growth and Quality of Perennial C3 Grasses in the Southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Spring and fall gaps in forage production for systems utilizing winter wheat forage in the Southern Great Plains have led to an interest in additional resources such as C3 perennial grasses. We evaluated the potential of nine cool-season grass entries for forage production and quality through the fa...

  2. Particulate matter concentrations for mono-slope beef cattle facilities in the Northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Confined cattle facilities are an increasingly common housing system in the Northern Great Plains region of the United States. Producers may maintain a deep-bedded manure pack (Pack), they may remove all bedding/manure material from the pens weekly (Scrape), or use a combination of management styles...

  3. But What Is There to See? An Exploration of a Great Plains Aesthetic

    ERIC Educational Resources Information Center

    Tangney, ShaunAnne

    2004-01-01

    In the fall of 2001 I taught a beginning college composition course at Minot State University, a small state university located in the northwestern quadrant of North Dakota. It is typical of such courses to include a fair amount of reading, and one of the texts I assigned was Ian Frazier's "Great Plains". The book is a travelogue that…

  4. Developing the 18th indicator for interpreting indicators of rangeland health on Northern Great Plains rangelands

    USDA-ARS?s Scientific Manuscript database

    National Resources Inventory (NRI) resource assessment report shows little to no departure on Rangeland Health for most Northern Great Plains Rangelands. This information is supported by Interpreting Indicators of Rangeland Health (IIRH) data collected at local to regional scales. There is however a...

  5. Soil erosion and organic matter variations for central Great Plains cropping systems under residue removal

    USDA-ARS?s Scientific Manuscript database

    The diversity of geo-climatic land bases and potential feedstocks within the United States Central Great Plains (CGP) requires sustainable production that provides optimal resource utilization while maintaining or enhancing localized soil and environmental quality as much as possible. This study exa...

  6. Dataset: Soil erosion and organic matter for central Great Plains cropping systems under residue removal

    USDA-ARS?s Scientific Manuscript database

    The diversity of geo-climatic land bases and potential feedstocks within the United States Central Great Plains (CGP) requires sustainable production that provides optimal resource utilization while maintaining or enhancing localized soil and environmental quality as much as possible. This study exa...

  7. Low-dose glyphosate does not control annual bromes in the northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Annual bromes (downy brome and Japanese brome) have been shown to decrease perennial grass forage production and alter ecosystem functions in northern Great Plains rangelands. Large-scale chemical control might be a method for increasing rangeland forage production if low application rates confer co...

  8. Immigration to the Great Plains, 1865-1914: War, Politics, Technology, and Economic Development

    ERIC Educational Resources Information Center

    Garver, Bruce

    2011-01-01

    The advent and vast extent of immigration to the Great Plains states during the years 1865 to 1914 is perhaps best understood in light of the new international context that emerged during the 1860s in the aftermath of six large wars whose consequences included the enlargement of civil liberties, an acceleration of economic growth and technological…

  9. Application of pheromone traps for managing Hessian fly, (Diptera: Cecidomyiidae) in the Southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    The Hessian fly, Mayetiola destructor Say, is an important pest of winter wheat in the Southern Great Plains of the U.S. As larvae feed behind the leaf sheath, infestations often go undetected until crop damage is evident and there are no remedial actions that can prevent economic loss once a field...

  10. Developing wind and/or solar powered crop irrigation systems for the Great Plains

    USDA-ARS?s Scientific Manuscript database

    Some small scale, off-grid irrigation systems (less than 2.5 ha) that are powered by wind or solar energy are cost effective, but this paper discusses ways to achieve an economical renewable energy powered center pivot irrigation system for crops in the Great Plains. It was found that partitioning t...

  11. Cover crop effect on subsequent wheat yield and water use efficiency in the central great plains

    USDA-ARS?s Scientific Manuscript database

    Crop production systems in the water-limited environment of the semi-arid central Great Plains may not have potential to profitably use cover crops because of lowered subsequent wheat (Triticum asestivum L.) yields following the cover crop. Cover crop mixtures have reportedly shown less yield-reduci...

  12. Cover crops can affect subsequent wheat yield in the central great plains

    USDA-ARS?s Scientific Manuscript database

    Crop production systems in the water-limited environment of the semi-arid central Great Plains may not have potential to profitably use cover crops because of lowered subsequent wheat (Triticum asestivum L.) yields following the cover crop. Cover crop mixtures have reportedly shown less yield-reduci...

  13. Adaptation of Pulse Crops to the Changing Climate of the Northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Climate over the northern Great Plains has generally warmed over the last 60 yr. The rate of warming has varied temporally and spatially, confounding trend analysis for climate indicators such as increased length of the growing season. Change in precipitation has been even more variable. Despite thi...

  14. Internet Usage by Native Americans with Disabilities Living on American Indian Reservations in the Great Plains

    ERIC Educational Resources Information Center

    De Mars, AnnMaria

    2010-01-01

    It has been assumed that, due to limited Internet access, electronic media is an ineffective means for information dissemination to Native Americans with disabilities. In this investigation, we surveyed a sample of 467 households of Native Americans with disabilities living on Great Plains reservations regarding access to electronic resources. Of…

  15. Evapotranspiration in winter wheat under different grazing and tillage practices in the southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Precipitation in the Southern Great Plains (SGP) is highly variable both spatially and temporally with recurring periods of severe drought. Winter wheat (Triticum aestivum L.) – summer fallow system with conventional tillage is the principal dryland cropping system in this region for both grazing an...

  16. Weather pattern climatology of the Great Plains and the related wind regime

    SciTech Connect

    Barchet, W.R.

    1982-11-01

    The meteorology of the Great Plains can be described as a constant progression of air masses, fronts and cyclonic storm systems. Each of these meteorological conditions can be characterized by identifiable isobaric and related weather parameter patterns. Nine such patterns have been defined to type the weather patterns in the Great Plains. Time series of weather pattern types were produced for 62 stations on the Great Plains. Statistical analyses of these time series produced annual and seasonal frequencies of occurrence of the weather pattern types. Maps of the annual and seasonal frequency of occurrence of weather pattern type are presented for the Great Plains. Persistence and alternation frequencies match what is expected for traveling temperate latitude cyclones, anticyclones and fronts. The wind regime for stations at which the anemometer height and location was constant (and known) for a minimum of three consecutive years was stratified by weather pattern type. Statistical analyses were made to show the response of the wind to the large-scale distribution of air pressure associated with a weather pattern type. The response of the wind to the weather pattern is a site-specific result of the interaction of the large-scale meteorology with local terrain, surface roughness and atmospheric stability. Mean wind speed discriminates between pairs of weather pattern types with better than 75% confidence for more than two-thirds of the possible pairs of weather pattern types.

  17. Cover crop biomass production and water use in the Central Great Plains

    USDA-ARS?s Scientific Manuscript database

    The water-limited environment of the semi-arid central Great Plains may not have potential to produce enough cover crop biomass to generate benefits associated with cover crop use in more humid regions. There have been reports that cover crops grown in mixtures produce more biomass with greater wate...

  18. Cover crop biomass production and water use in the central great plains under varying water availability

    USDA-ARS?s Scientific Manuscript database

    The water-limited environment of the semi-arid central Great Plains may not have potential to produce enough cover crop biomass to generate benefits associated with cover crop use in more humid regions. There have been reports that cover crops grown in mixtures produce more biomass with greater wate...

  19. Immigration to the Great Plains, 1865-1914: War, Politics, Technology, and Economic Development

    ERIC Educational Resources Information Center

    Garver, Bruce

    2011-01-01

    The advent and vast extent of immigration to the Great Plains states during the years 1865 to 1914 is perhaps best understood in light of the new international context that emerged during the 1860s in the aftermath of six large wars whose consequences included the enlargement of civil liberties, an acceleration of economic growth and technological…

  20. Pigeon pea potential for summer grazing in the Southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Stocker cattle production in the southern Great Plains (SGP) faces forage quality gaps during July through September. A study was conducted in 2008 through 2010 to determine if pigeon pea [Cajanus cajan (L.) Millsp.] could fill this deficit period. Six, 0.41 ha experimental paddocks were randomly ...

  1. Integrated Migratory Bird Planning in the Lower Great Lakes/St. Lawrence Plain Bird Conservation Region

    Treesearch

    Chuck Hayes; Andrew Milliken; Randy Dettmers; Kevin Loftus; Brigitte Collins; Isabelle Ringuet

    2005-01-01

    The Atlantic Coast and Eastern Habitat Joint Ventures hosted two international planning workshops to begin the process of integrating bird conservation strategies under the North American Bird Conservation Initiative in the Lower Great Lakes/St. Lawrence Plain Bird Conservation Region. The workshops identified priority species and habitats, delineated focus areas,...

  2. IMPLICATIONS OF INVASION BY JUNIPERUS VIRGINIANA ON SMALL MAMMALS IN THE SOUTHERN GREAT PLAINS

    EPA Science Inventory

    Changes in landscape cover in the Great Plains are resulting from the range expansion and invasion of eastern red cedar (Juniperus virginiana). By altering the landscape and local vegetation, red cedar is changing the structure and function of habitat for small mammals. We exam...

  3. But What Is There to See? An Exploration of a Great Plains Aesthetic

    ERIC Educational Resources Information Center

    Tangney, ShaunAnne

    2004-01-01

    In the fall of 2001 I taught a beginning college composition course at Minot State University, a small state university located in the northwestern quadrant of North Dakota. It is typical of such courses to include a fair amount of reading, and one of the texts I assigned was Ian Frazier's "Great Plains". The book is a travelogue that…

  4. A landscape inventory framework: scenic analyses of the Northern Great Plains

    Treesearch

    Litton R. Burton Jr.; Robert J. Tetlow

    1978-01-01

    A set of four visual inventories are proposed. They are designed to document scenic resources for varied scales of application, from regional and general to local and specific. The Northern Great Plains is used as a case study. Scenic analysis and identification of criteria extend earlier work. The inventory is based on (1) study of previously developed landscape...

  5. Potential Climate Change Effects on Warm-Season Livestock Production in the Great Plains

    USDA-ARS?s Scientific Manuscript database

    Climate changes suggested by some global circulation models (GCM) will impact livestock production systems in the Great Plains region of the United States. Production/response models for growing swine and beef cattle, and milk-producing dairy cattle, were developed based on summary information conta...

  6. Agricultural Producer Perceptions of Climate Change and Climate Education Needs for the Central Great Plains

    ERIC Educational Resources Information Center

    Hibbs, Amber Campbell; Kahl, Daniel; PytlikZillig, Lisa; Champion, Ben; Abdel-Monem, Tarik; Steffensmeier, Timothy; Rice, Charles W.; Hubbard, Kenneth

    2014-01-01

    The Central Great Plains Climate Education Partnership conducted focus groups throughout Kansas to gain a better understanding of farmer perceptions and attitudes towards climate change education. Results indicate concern about climatic changes, even if producers are unsure that "human caused climate change" is occurring. Participants…

  7. Child Labor in the Early Sugar Beet Industry in the Great Plains, 1890-1920

    ERIC Educational Resources Information Center

    Lyons-Barrett, Mary

    2005-01-01

    Children working in agriculture have always been a part of the rural culture and work ethos of the United States, especially on the Great Plains. Many teenagers still detassel corn or walk the beans in the summer months to earn spending money or money for college. But what about the children who work as migrant laborers in commercialized…

  8. Assessing urban forest effects and values of the Great Plains: Kansas, Nebraska, North Dakota, South Dakota

    Treesearch

    David J. Nowak; Robert E. III Hoehn; Daniel E. Crane; Allison R. Bodine

    2012-01-01

    This report details the evaluation of the urban tree resources of the north-central Great Plains region of the United States. Specifically this report provides a more comprehensive understanding of the species composition and structural and functional benefits of the urban forests in the states of Kansas (33.1 million urban trees), Nebraska (13.3 million urban trees),...

  9. Grasshopper responses to fire and postfire grazing in the northern Great Plains vary among species

    USDA-ARS?s Scientific Manuscript database

    Rangeland management practices such as burning and grazing management may affect grasshopper populations by impacting development, survival and reproduction. Experiments are lacking in the northern Great Plains examining the effects of fire and grazing intensity on grasshoppers. As part of a larger ...

  10. Ecology of fire in shortgrass prairie of the southern Great Plains

    Treesearch

    Paulette L. Ford; Guy R. McPherson

    1996-01-01

    The ecology of fire in shortgrass prairie of the southern Great Plains includes a complex interaction between the shortgrass prairie ecosystem and its inhabitants, all inextricably linked to land-use patterns. The history of the relationship between man and fire has been filled with ambivalence and mistrust, along with an appreciation of the power of fire as a...

  11. Cropping Intensity Impacts on Soil Aggregation and Carbon Sequestration in the Central Great Plains

    USDA-ARS?s Scientific Manuscript database

    The predominant cropping system in the Central Great Plains is conventional tillage (CT) winter wheat–summer fallow. We investigated the effect 15 yrs of variable cropping intensity, fallow frequency, and tillage (CT and no-till [NT]) had on soil organic C (SOC) sequestration, particulate organic ma...

  12. Black Enclaves of Violence: Race and Homicide in Great Plains Cities, 1890-1920

    ERIC Educational Resources Information Center

    McKanna, Clare V., Jr.

    2003-01-01

    The author examines interracial homicides in the early twentieth century in three Great Plains cities: Coffeyville, Kansas; Topeka, Kansas; and Omaha, Nebraska. Railroads attracted hundreds of young blacks searching for steady employment. Alcohol played an important role in violence levels as did the availability of cheap and handguns, and certain…

  13. Low-rank coal research: Volume 3, Combustion research: Final report. [Great Plains

    SciTech Connect

    Mann, M. D.; Hajicek, D. R.; Zobeck, B. J.; Kalmanovitch, D. P.; Potas, T. A.; Maas, D. J.; Malterer, T. J.; DeWall, R. A.; Miller, B. G.; Johnson, M. D.

    1987-04-01

    Volume III, Combustion Research, contains articles on fluidized bed combustion, advanced processes for low-rank coal slurry production, low-rank coal slurry combustion, heat engine utilization of low-rank coals, and Great Plains Gasification Plant. These articles have been entered individually into EDB and ERA. (LTN)

  14. The future of irrigation on the U.S. Great Plains

    USDA-ARS?s Scientific Manuscript database

    In the Great Plains, soil and water conservation is being achieved in both dryland and irrigated agricultural systems, and increasingly in combinations of these systems. Limiting tillage has increased the retention of crop residues on the surface and has reduced the evaporative loss of water, making...

  15. Black Enclaves of Violence: Race and Homicide in Great Plains Cities, 1890-1920

    ERIC Educational Resources Information Center

    McKanna, Clare V., Jr.

    2003-01-01

    The author examines interracial homicides in the early twentieth century in three Great Plains cities: Coffeyville, Kansas; Topeka, Kansas; and Omaha, Nebraska. Railroads attracted hundreds of young blacks searching for steady employment. Alcohol played an important role in violence levels as did the availability of cheap and handguns, and certain…

  16. IIMPLICATIONS OF INVASION BY JUNIPERUS VIRGINIANA ON SMALL MAMMALS IN THE SOUTHERN GREAT PLAINS

    EPA Science Inventory

    Changes in landscape cover in the Great Plains are resulting from the range expansion and invasion of eastern red cedar (Juniperus virginiana). By altering the landscape and local vegetation, red cedar is changing the structure and function of habitat for small mammals. We examin...

  17. Child Labor in the Early Sugar Beet Industry in the Great Plains, 1890-1920

    ERIC Educational Resources Information Center

    Lyons-Barrett, Mary

    2005-01-01

    Children working in agriculture have always been a part of the rural culture and work ethos of the United States, especially on the Great Plains. Many teenagers still detassel corn or walk the beans in the summer months to earn spending money or money for college. But what about the children who work as migrant laborers in commercialized…

  18. Understanding Great Plains Urbanization through the Lens of South Dakota Townscapes

    ERIC Educational Resources Information Center

    Conzen, Michael P.

    2010-01-01

    Most towns were crucial to the initial colonization and economic development of the Great Plains. Many were, directly or indirectly, creatures of railroad corporate planning, owing their location as well as their physical layout to the townsite companies controlled by railroad officials. This article examines how these facts shaped the fundamental…

  19. Great Plains climate and land-use effects on soil organic carbon

    USDA-ARS?s Scientific Manuscript database

    Soil organic carbon (SOC) is essential to agricultural productivity and sustainability in response to climate and land-use change. Here, we examine 14 sites across the US Great Plains to determine the sensitivity of important SOC fractions to climatic gradients (temperature and precipitation) and l...

  20. Evaluating potential dryland cropping systems adapted to climate change in the Central Great Plains

    USDA-ARS?s Scientific Manuscript database

    Climate in the semi-arid Central Great Plains is expected to become warmer and drier in coming decades, with potentially greater variability in precipitation and temperature. Cropping systems that include forages and allow flexibility for determining if a crop should be planted and which crop to pla...

  1. Agricultural Producer Perceptions of Climate Change and Climate Education Needs for the Central Great Plains

    ERIC Educational Resources Information Center

    Hibbs, Amber Campbell; Kahl, Daniel; PytlikZillig, Lisa; Champion, Ben; Abdel-Monem, Tarik; Steffensmeier, Timothy; Rice, Charles W.; Hubbard, Kenneth

    2014-01-01

    The Central Great Plains Climate Education Partnership conducted focus groups throughout Kansas to gain a better understanding of farmer perceptions and attitudes towards climate change education. Results indicate concern about climatic changes, even if producers are unsure that "human caused climate change" is occurring. Participants…

  2. Understanding Great Plains Urbanization through the Lens of South Dakota Townscapes

    ERIC Educational Resources Information Center

    Conzen, Michael P.

    2010-01-01

    Most towns were crucial to the initial colonization and economic development of the Great Plains. Many were, directly or indirectly, creatures of railroad corporate planning, owing their location as well as their physical layout to the townsite companies controlled by railroad officials. This article examines how these facts shaped the fundamental…

  3. Reflectance based characterization of wheat cultivars for identifying drought tolerance in the Southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    In the U.S. Southern Great Plains (SGP), drought stress is the single most important factor for reducing yield in winter wheat. Selection of drought tolerant wheat cultivars has been and will continue to be a critical strategy for wheat management under limited water conditions. Currently, yield is ...

  4. Developing a hybrid solar/wind powered irrigation system for crops in the Great Plains

    USDA-ARS?s Scientific Manuscript database

    Some small scale irrigation systems (< 2 ha) powered by wind or solar do not require subsidies, but this paper discusses ways to achieve an economical renewable energy powered center pivot irrigation system for crops in the Great Plains. By adding a solar-photovoltaic (PV) array together with a wind...

  5. Simulating the dynamics of linear forests in great plains agroecosystems under changing climates

    Treesearch

    Qinfeng Guo; J. Brandle; Michele Schoeneberger; D. Buettner

    2004-01-01

    Most forest growth models are not suitable for the highly fragmented, linear (or linearly shaped) forests in the Great Plains agroecosystems (e.g., windbreaks, riparian forest buffers), where such forests are a minor but ecologically important component of the land mosaics. This study used SEEI)SCAPE, a recently modified gap model designed for cultivated land mosaics...

  6. IMPLICATIONS OF INVASION BY JUNIPERUS VIRGINIANA ON SMALL MAMMALS IN THE SOUTHERN GREAT PLAINS

    EPA Science Inventory

    Changes in landscape cover in the Great Plains are resulting from the range expansion and invasion of eastern red cedar (Juniperus virginiana). By altering the landscape and local vegetation, red cedar is changing the structure and function of habitat for small mammals. We exam...

  7. IIMPLICATIONS OF INVASION BY JUNIPERUS VIRGINIANA ON SMALL MAMMALS IN THE SOUTHERN GREAT PLAINS

    EPA Science Inventory

    Changes in landscape cover in the Great Plains are resulting from the range expansion and invasion of eastern red cedar (Juniperus virginiana). By altering the landscape and local vegetation, red cedar is changing the structure and function of habitat for small mammals. We examin...

  8. Small mammals in successional prairie woodlands of the northern Great Plains

    Treesearch

    Mark A. Rumble; John E. Gobeille

    2001-01-01

    Prairie woodlands comprise about 1 percent of the landscape in the northern Great Plains. However, prairie woodlands provide habitat for far more than 1 percent of the wildlife species that occur in the prairie region. With increasing pressures on natural resources, managers need methods for managing wildlife habitat and biodiversity that are based on ecological...

  9. Defining a dryland grain sorghum production function for the Central Great Plains

    USDA-ARS?s Scientific Manuscript database

    Grain sorghum (Sorghum bicolor L. Moench) is a drought tolerant C4 species capable of making use of limited available water supplies and is suitable for dryland crop rotations in the central Great Plains. In order for farmers to assess the production risk encountered when utilizing sorghum in rotati...

  10. Microbial mat mineralization in Great Salt Lake (Utah, USA)

    NASA Astrophysics Data System (ADS)

    PACE, Aurélie; Bouton, Anthony; Bourillot, Raphaël; Vennin, Emmanuelle; Visscher, Pieter; Dupraz, Christophe; Thomazo, Christophe; Serge, Galaup; Sophie, Leleu; Anna, Kwasniewski; Léa, Pigot; Michel, Franceschi

    2015-04-01

    Great Salt Lake is located in the Basin and Range province of Utah (USA). Its average surface is 4480 Km2 and its maximum depth is of about 15m. It is a partly rainfed endorheic hypersaline lake (average salinity: 140g/L). Due to the high salinity, little or no grazing organisms are present, favoring the development of microbialites that cover the margin of the lake. This work aims to understand the products and processes of mineralization in recent and modern microbialites on the western margin of Antelope Island. The distribution of microbialites and their morphology has been studied along lakeshore to center transects, showing a contrasting spatial distribution in bay versus headland. Fossil microbialites show a great diversity of macro- and microfabrics, some microbialites being essentially built by microbial-mediated carbonate precipitation, while other show the predominance of trapping and binding processes. The nature and composition of the microbial carbonates have been determined through polarizing, cathodoluminescence, reflected fluorescence microscopy, X-Ray diffractometry and isotope geochemistry (δ 18O and δ13C) in order to investigate the preservation of environmental signals in microbialites. Petrophysics analysis such as permeability and porosimetry, have been done to observe the structure of the microbialite. Microprobe and silver foils method have been used respectively to characterize oxygen production and sulfate reduction in living microbial mats. Mineralization zones seem to coincide with sulfate reduction hotspots. This mineralization results in mixed clotted-laminated fabric at the macro- and microscale. Several analysis such as Cryo-SEM, environmental SEM and raman spectroscopy three phases of mineralization allowed us to distinguish three type of minerals inside the mat: (1) a Mg and Si-rich clay developing on the organic matrix; (2) an intracellular Al-rich clay. (3) aragonite clots replacing the organic matrixes and embedding bacteria

  11. 78 FR 17653 - Upper Great Plains Wind Energy Draft Programmatic Environmental Impact Statement (DOE/EIS-0408)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ... Wind Energy Draft Programmatic Environmental Impact Statement (DOE/EIS-0408) AGENCIES: Western Area... Service (Service), have, as joint lead agencies, prepared the Upper Great Plains Wind Energy Draft... wind energy development within Western's Upper Great Plains Customer Service Region (UGP Region), which...

  12. Spatial and Temporal Complexities of Current Great Plains Dunefield Chronological Data

    NASA Astrophysics Data System (ADS)

    Halfen, A. F.; Johnson, W. C.

    2012-12-01

    The North American Great Plains span nearly 2.8 million km2, of which nearly half is mantled by aeolian sediments (loess deposits, sand sheets, and dunefields). Stratigraphies of these sediments contain a rich history of late-Quaternary climate change, in particular aeolian dunefields, which provide a record of drought. During arid conditions in the Great Plains, stabilizing vegetation is diminished, leaving dunefields susceptible to aeolian erosion; during periods of increased moisture, conversely, vegetation re-establishes and dunefields stabilize. Using radiometric dating techniques, researchers can extract from the stratigraphy of dunefields the timing of past activity, and, therefore, periods of past drought. To date, more than 50 chronologies, comprised of over 700 ages, have established a detailed record of past dunefield activity in the Great Plains. Despite this extensive dataset, correlating periods of past droughts across the region remains problematic, in large part due to the spatial and temporal limitations in the data. In this poster, we present a spatial and temporal synthesis of current Great Plains dunefield chronologies, followed by an analysis of the complexities of these data, in particular when used to determine periods of past drought. To illustrate these complexities, we present a bicentennial, 1 x 1 degree gridded model of dune activity (e.g., active, stable, no data) spanning the last 2000 years. Our model clearly illustrates gaps in spatial coverage and temporal biases of chronologies. To further highlight the complexities of using current Great Plains datasets as proxies for prehistoric drought, we compare a 2.5 x 2.5 degree gridded model of dune activity during the Medieval Climatic Anomaly (A.D. 1000-1400) and historic time (A.D. 1800-2000) to Palmer Drought Severity Index (PDSI)-reconstructed droughts for the same time intervals. In general, dunefield activity is in good agreement with PDSI-reconstructed drought, however, unlike tree

  13. Dynamics of cultural transmission in Native Americans of the high Great Plains.

    PubMed

    Lycett, Stephen J

    2014-01-01

    Culture is a phenomenon shared by all humans. Attempts to understand how dynamic factors affect the origin and distribution of cultural elements are, therefore, of interest to all humanity. As case studies go, understanding the distribution of cultural elements in Native American communities during the historical period of the Great Plains would seem a most challenging one. Famously, there is a mixture of powerful internal and external factors, creating-for a relatively brief period in time-a seemingly distinctive set of shared elements from a linguistically diverse set of peoples. This is known across the world as the "Great Plains culture." Here, quantitative analyses show how different processes operated on two sets of cultural traits among nine High Plains groups. Moccasin decorations exhibit a pattern consistent with geographically-mediated between-group interaction. However, group variations in the religious ceremony of the Sun Dance also reveal evidence of purifying cultural selection associated with historical biases, dividing down ancient linguistic lines. The latter shows that while the conglomeration of "Plains culture" may have been a product of merging new ideas with old, combined with cultural interchange between groups, the details of what was accepted, rejected or elaborated in each case reflected preexisting ideological biases. Although culture may sometimes be a "melting pot," the analyses show that even in highly fluid situations, cultural mosaics may be indirectly shaped by historical factors that are not always obvious.

  14. Dynamics of Cultural Transmission in Native Americans of the High Great Plains

    PubMed Central

    Lycett, Stephen J.

    2014-01-01

    Culture is a phenomenon shared by all humans. Attempts to understand how dynamic factors affect the origin and distribution of cultural elements are, therefore, of interest to all humanity. As case studies go, understanding the distribution of cultural elements in Native American communities during the historical period of the Great Plains would seem a most challenging one. Famously, there is a mixture of powerful internal and external factors, creating-for a relatively brief period in time-a seemingly distinctive set of shared elements from a linguistically diverse set of peoples. This is known across the world as the “Great Plains culture.” Here, quantitative analyses show how different processes operated on two sets of cultural traits among nine High Plains groups. Moccasin decorations exhibit a pattern consistent with geographically-mediated between-group interaction. However, group variations in the religious ceremony of the Sun Dance also reveal evidence of purifying cultural selection associated with historical biases, dividing down ancient linguistic lines. The latter shows that while the conglomeration of “Plains culture” may have been a product of merging new ideas with old, combined with cultural interchange between groups, the details of what was accepted, rejected or elaborated in each case reflected preexisting ideological biases. Although culture may sometimes be a “melting pot,” the analyses show that even in highly fluid situations, cultural mosaics may be indirectly shaped by historical factors that are not always obvious. PMID:25372277

  15. Monitoring the vernal advancement and retrogradation (green wave effect) of natural vegetation. [Great Plains Corridor

    NASA Technical Reports Server (NTRS)

    Rouse, J. W., Jr. (Principal Investigator); Haas, R. H.; Deering, D. W.; Schell, J. A.

    1973-01-01

    The author has identified the following significant results. The Great Plains Corridor rangeland project utilizes natural vegetation systems as phenological indicators of seasonal development and climatic effects upon regional growth conditions. A method has been developed for quantitative measurement of vegetation conditions over broad regions using ERTS-1 MSS data. Radiance values recorded in ERTS-1 spectral bands 5 and 7, corrected for sun angle, are used to compute a band ratio parameter which is shown to be correlated with green biomass and vegetation moisture content. This report details the progress being made toward determining factors associated with the transformed vegetation index (TVI) and limitations on the method. During the first year of ERTS-1 operation (cycles 1-20), an average of 50% usable ERTS-1 data was obtained for the ten Great Plains Corridor test sites.

  16. Factors Affecting Public Preferences for Grassland Landscape Heterogeneity in the Great Plains.

    PubMed

    Joshi, Omkar; Becerra, Terrie A; Engle, David M; Fuhlendorf, Samuel D; Elmore, R Dwayne

    2017-08-22

    Agricultural intensification has fragmented rangelands in the Great Plains, which has contributed to uniform and homogeneous landscapes and decreased biodiversity. Alternative land management practices involving fire-grazing interactions can help maintain biodiversity without affecting livestock productivity. A survey was designed to understand the factors that influence preferences among the general population towards grassland landscape heterogeneity. Given the ordinal nature of survey responses, requisite data were analyzed using a generalized ordinal logit model. Results suggested that respondents who valued open space and those who recognized a need for a varying mix of uniform grasses and grasslands preferred landscape heterogeneity. Female respondents were about two times as likely to prefer heterogeneous landscapes compared to male respondents. In contrast, population groups that preferred wildlife habitat did not desire heterogeneous landscapes. Results suggest the need for extension and outreach activities to educate certain segments of the general population regarding benefits of alternative management practices that support landscape heterogeneity in the Great Plains.

  17. Annual crop type classification of the U.S. Great Plains for 2000 to 2011

    USGS Publications Warehouse

    Howard, Daniel M.; Wylie, Bruce K.

    2014-01-01

    The purpose of this study was to increase the spatial and temporal availability of crop classification data. In this study, nearly 16.2 million crop observation points were used in the training of the US Great Plains classification tree crop type model (CTM). Each observation point was further defined by weekly Normalized Difference Vegetation Index, annual climate, and a number of other biogeophysical environmental characteristics. This study accounted for the most prevalent crop types in the region, including, corn, soybeans, winter wheat, spring wheat, cotton, sorghum, and alfalfa. Annual CTM crop maps of the US Great Plains were created for 2000 to 2011 at a spatial resolution of 250 meters. The CTM achieved an 87 percent classification success rate on 1.8 million observation points that were withheld from model training. Product validation was performed on greater than 15,000 county records with a coefficient of determination of R2 = 0.76.

  18. Habitat relationships with fish assemblages in minimally disturbed Great Plains regions

    USGS Publications Warehouse

    Fischer, John R.; Paukert, C.P.

    2008-01-01

    Effects of local environmental influences on the structure of fish assemblages were evaluated from 159 sites in two regions of the Great Plains with limited anthropogenic disturbance. These regions offered an opportunity to evaluate the structure and variation of streams and fish assemblages within the Great Plains. We used canonical correspondence analyses to determine the influence of environmental conditions on species abundances, species occurrences and assemblage characteristics. Analysis of regions separately indicated that similar environmental factors structured streams and fish assemblages, despite differences in environmental conditions and species composition between regions. Variance in fish abundance and assemblage characteristics from both regions was best explained by metrics of stream size and associated metrics (width, depth, conductivity and instream cover). Our results provide a framework and reference for conditions and assemblage structure in North American prairie streams.

  19. Simulation of the great plains low-level jet and associated clouds by general circulation models

    SciTech Connect

    Ghan, S.J.; Bian, X.; Corsetti, L.

    1996-07-01

    The low-level jet frequently observed in the Great Plains of the United States forms preferentially at night and apparently influences the timing of the thunderstorms in the region. The authors have found that both the European Centre for Medium-Range Weather Forecasts general circulation model and the National Center for Atmospheric Research Community Climate Model simulate the low-level jet rather well, although the spatial distribution of the jet frequency simulated by the two GCM`s differ considerably. Sensitivity experiments have demonstrated that the simulated low-level jet is surprisingly robust, with similar simulations at much coarser horizontal and vertical resolutions. However, both GCM`s fail to simulate the observed relationship between clouds and the low-level jet. The pronounced nocturnal maximum in thunderstorm frequency associated with the low-level jet is not simulated well by either GCM, with only weak evidence of a nocturnal maximum in the Great Plains. 36 refs., 20 figs.

  20. Geochemical evolution of Great Salt Lake, Utah, USA

    USGS Publications Warehouse

    Jones, B.F.; Naftz, D.L.; Spencer, R.J.; Oviatt, Charles G.

    2009-01-01

    The Great Salt Lake (GSL) of Utah, USA, is the largest saline lake in North America, and its brines are some of the most concentrated anywhere in the world. The lake occupies a closed basin system whose chemistry reflects solute inputs from the weathering of a diverse suite of rocks in its drainage basin. GSL is the remnant of a much larger lacustrine body, Lake Bonneville, and it has a long history of carbonate deposition. Inflow to the lake is from three major rivers that drain mountain ranges to the east and empty into the southern arm of the lake, from precipitation directly on the lake, and from minor groundwater inflow. Outflow is by evaporation. The greatest solute inputs are from calcium bicarbonate river waters mixed with sodium chloride-type springs and groundwaters. Prior to 1930 the lake concentration inversely tracked lake volume, which reflected climatic variation in the drainage, but since then salt precipitation and re-solution, primarily halite and mirabilite, have periodically modified lake-brine chemistry through density stratification and compositional differentiation. In addition, construction of a railway causeway has restricted circulation, nearly isolating the northern from the southern part of the lake, leading to halite precipitation in the north. These and other conditions have created brine differentiation, mixing, and fractional precipitation of salts as major factors in solute evolution. Pore fluids and diagenetic reactions have been identified as important sources and especially sinks for CaCO3, Mg, and K in the lake, depending on the concentration gradient and clays. ?? U.S. Geological Survey 2008.

  1. Correlation of spacecraft passive microwave system data with soil moisture indices (API). [great plains corridor

    NASA Technical Reports Server (NTRS)

    Blanchard, B. J.; Mcfarland, M. J.; Theis, S.; Richter, J. G.

    1981-01-01

    Electrical scanning microwave radiometer brightness temperature, meteorological data, climatological data, and winter wheat crop information were used to estimate that soil moisture content in the Great Plains region. Results over the predominant winter wheat areas indicate that the best potential to infer soil moisture occurs during fall and spring. These periods encompass the growth stages when soil moisture is most important to winter wheat yield. Other significant results are reported.

  2. Aerosol measurements at the Southern Great Plains Site: Design and surface installation

    SciTech Connect

    Leifer, R.; Knuth, R.H.; Guggenheim, S.F.; Albert, B.

    1996-04-01

    To impropve the predictive capabilities of the Atmospheric Radiation Measurements (ARM) program radiation models, measurements of awserosol size distributions, condensation particle concentrations, aerosol scattering coefficients at a number of wavelenghts, and the aerosol absorption coefficients are needed at the Southern Great Plains (SGP) site. Alos, continuous measurements of ozone concnetrations are needed for model validation. The environmental Measuremenr Laboratory (EMK) has the responsibility to establish the surface aerosol measurements program at the SGP site. EML has designed a special sampling manifold.

  3. Population change in the Great Plains since 1950 and the consequences of selective migration.

    PubMed

    Rathge, R; Highman, P

    1998-01-01

    This "study was initiated to explore the causes and consequences of persistent population loss in the Great Plains region [of the United States]. After classifying all counties by their growth patterns over the past five decades, we developed a typology that categorized counties based on the direction and magnitude of their population change.... We use this typology to explore the correlates of residential population change, and to examine the explanatory power of the variables found to be statistically significant."

  4. Are Droughts in the United States Great Plains Predictable on Seasonal and Longer Time Scales?

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried D.; Suarez, M.; Pegion, P.; Kistler, M.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The United States Great Plains has experienced numerous episodes of unusually dry conditions lasting anywhere from months to several years, In this presentation, we will examine the predictability of such episodes and the physical mechanisms controlling the variability of the summer climate of the continental United States. The analysis is based on ensembles of multi-year simulations and seasonal hindcasts generated with the NASA Seasonal to-Interannual Prediction Project (NSIPP-1) General Circulation Model.

  5. Kansas environmental and resource study: A Great Plains model, tasks 1-6

    NASA Technical Reports Server (NTRS)

    Haralick, R. M.; Kanemasu, E. T.; Morain, S. A.; Yarger, H. L. (Principal Investigator); Ulaby, F. T.; Shanmugam, K. S.; Williams, D. L.; Mccauley, J. R.; Mcnaughton, J. L.

    1972-01-01

    There are no author identified significant results in this report. Environmental and resources investigations in Kansas utilizing ERTS-1 imagery are summarized for the following areas: (1) use of feature extraction techniqued for texture context information in ERTS imagery; (2) interpretation and automatic image enhancement; (3) water use, production, and disease detection and predictions for wheat; (4) ERTS-1 agricultural statistics; (5) monitoring fresh water resources; and (6) ground pattern analysis in the Great Plains.

  6. Stratigraphy of the Younger Dryas Chronozone and paleoenvironmental implications: Central and Southern Great Plains

    USGS Publications Warehouse

    Holliday, V.T.; Meltzer, D.J.; Mandel, R.

    2011-01-01

    The Great Plains of the United States was the setting for some of the earliest research in North America into patterns and changes in the character of late Pleistocene environments and their effects on contemporary human populations. Many localities in the region have well-stratified records of terminal Pleistocene and early Holocene human (Paleoindian) activity and past environments. These have proven important in debates over the character of the Younger Dryas Chronozone (YDC; 11,000-10,000 14C BP; 12,900-11,700 cal BP) in the continental interior. This paper reviews the lithostratigraphic record of the YDC on the Central and Southern Great Plains and summarizes paleobiological records (largely isotopic). The goal is to determine if there is any uniformity in the timing, character, direction and/or magnitude of changes in depositional environments or broader geomorphic systems before, during or after the YDC in order to address the question of the character of environments through this time. The stratigraphic records of the late Pleistocene to early Holocene transition, and in particular, the stratigraphic records of the YDC vary through time and space. The data clearly show that a host of geomorphic processes produced the terminal Pleistocene and early Holocene stratigraphic records of the Great Plains. Moreover, the YDC is not necessarily manifest as a distinct lithostratigraphic or biostratigraphic entity in these different types of deposits and soils. The various geomorphic systems of the Great Plains did not behave synchronously in response to any common climate driver. These stratigraphic records reflect local environmental conditions and probably a complex response to the reorganization of mid-latitude climates in the terminal Pleistocene and early Holocene. ?? 2011 Elsevier Ltd and INQUA.

  7. Are Droughts in the United States Great Plains Predictable on Seasonal and Longer Time Scales?

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried D.; Suarez, M.; Pegion, P.; Kistler, M.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The United States Great Plains has experienced numerous episodes of unusually dry conditions lasting anywhere from months to several years, In this presentation, we will examine the predictability of such episodes and the physical mechanisms controlling the variability of the summer climate of the continental United States. The analysis is based on ensembles of multi-year simulations and seasonal hindcasts generated with the NASA Seasonal to-Interannual Prediction Project (NSIPP-1) General Circulation Model.

  8. On the Micrometeorology of the Southern Great Plains 1: Legacy Relationships Revisited

    NASA Astrophysics Data System (ADS)

    Hicks, B. B.; Pendergrass, W. R.; Vogel, C. A.; Keener, R. N.; Leyton, S. M.

    2014-06-01

    Data from a 32-m tower located near Ocotillo, Texas (N; W), provide an opportunity to examine the relevance of standard micrometeorological flux-gradient formulations to observations made in an area characteristic of a large portion of the central USA, within the Southern Great Plains. Comparison with data obtained at a greater height (80 m) reveals that the velocity distributions change substantially between the lower set of observations and the upper, with the former being constrained at the low wind-speed end. In the early morning, sensible heat-flux divergence correlates well with the measured rate of change of temperature with time within the surface layer of air sampled by the tower, but this association disappears when the depth of the mixed layer extends beyond the reach of the tower. As in the case of all previous examinations of flux-gradient relationships, the overall dependence of the dimensionless wind and temperature gradients and on stability is characterized by considerable scatter, with the familiar relationships best describing the average. For conditions of stable stratification, there is indeed the expected close proximity of and , however, describing either or in terms of the classical stability index (where is the height above the zero plane and L is the Obukhov length scale of turbulence) then appears questionable because the dependence of on the measured sensible heat flux is not always single-valued, especially near the surface. For unstable stratification, support is found for the conclusions of early workers that free convection initiates at about , and that the general behaviour is then compatible with the concept of a moving air mass from which momentum is continuously extracted, embedded within freely convective cells. It is concluded that legacy descriptions of the relationships between fluxes and gradients apply to averages that might occur rarely, that a dominant factor is likely the chaotic nature of the processes that control the

  9. Estimated areal extent of colonies of black-tailed prairie dogs in the northern Great Plains

    USGS Publications Warehouse

    Sidle, John G.; Johnson, Douglas H.; Euliss, Betty R.

    2001-01-01

    During 1997–1998, we undertook an aerial survey, with an aerial line-intercept technique, to estimate the extent of colonies of black-tailed prairie dogs (Cynomys ludovicianus) in the northern Great Plains states of Nebraska, North Dakota, South Dakota, and Wyoming. We stratified the survey based on knowledge of colony locations, computed 2 types of estimates for each stratum, and combined ratio estimates for high-density strata with average density estimates for low-density strata. Estimates of colony areas for black-tailed prairie dogs were derived from the average percentages of lines intercepting prairie dog colonies and ratio estimators. We selected the best estimator based on the correlation between length of transect line and length of intercepted colonies. Active colonies of black-tailed prairie dogs occupied 2,377.8 km2 ± 186.4 SE, whereas inactive colonies occupied 560.4 ± 89.2 km2. These data represent the 1st quantitative assessment of black-tailed prairie dog colonies in the northern Great Plains. The survey dispels popular notions that millions of hectares of colonies of black-tailed prairie dogs exist in the northern Great Plains and can form the basis for future survey efforts.

  10. Land change variability and human-environment dynamics in the United States Great Plains

    USGS Publications Warehouse

    Drummond, Mark A.; Auch, Roger F.; Karstensen, Krista A.; Sayler, Kristi L.; Taylor, Janis L.; Loveland, Thomas R.

    2012-01-01

    Land use and land cover changes have complex linkages to climate variability and change, biophysical resources, and socioeconomic driving forces. To assess these land change dynamics and their causes in the Great Plains, we compare and contrast contemporary changes across 16 ecoregions using Landsat satellite data and statistical analysis. Large-area change analysis of agricultural regions is often hampered by change detection error and the tendency for land conversions to occur at the local-scale. To facilitate a regional-scale analysis, a statistical sampling design of randomly selected 10 km x 10 km blocks is used to efficiently identify the types and rates of land conversions for four time intervals between 1973 and 2000, stratified by relatively homogenous ecoregions. Nearly 8% of the overall Great Plains region underwent land-use and land-cover change during the study period, with a substantial amount of ecoregion variability that ranged from less than 2% to greater than 13%. Agricultural land cover declined by more than 2% overall, with variability contingent on the differential characteristics of regional human–environment systems. A large part of the Great Plains is in relatively stable land cover. However, other land systems with significant biophysical and climate limitations for agriculture have high rates of land change when pushed by economic, policy, technology, or climate forcing factors. The results indicate the regionally based potential for land cover to persist or fluctuate as land uses are adapted to spatially and temporally variable forcing factors.

  11. Land change variability and human-environment dynamics in the United States Great Plains

    USGS Publications Warehouse

    Drummond, M.A.; Auch, R.F.; Karstensen, K.A.; Sayler, K.L.; Taylor, J.L.; Loveland, T.R.

    2012-01-01

    Land use and land cover changes have complex linkages to climate variability and change, biophysical resources, and socioeconomic driving forces. To assess these land change dynamics and their causes in the Great Plains, we compare and contrast contemporary changes across 16 ecoregions using Landsat satellite data and statistical analysis. Large-area change analysis of agricultural regions is often hampered by change detection error and the tendency for land conversions to occur at the local-scale. To facilitate a regional-scale analysis, a statistical sampling design of randomly selected 10 km ?? 10 km blocks is used to efficiently identify the types and rates of land conversions for four time intervals between 1973 and 2000, stratified by relatively homogenous ecoregions. Nearly 8% of the overall Great Plains region underwent land-use and land-cover change during the study period, with a substantial amount of ecoregion variability that ranged from less than 2% to greater than 13%. Agricultural land cover declined by more than 2% overall, with variability contingent on the differential characteristics of regional human-environment systems. A large part of the Great Plains is in relatively stable land cover. However, other land systems with significant biophysical and climate limitations for agriculture have high rates of land change when pushed by economic, policy, technology, or climate forcing factors. The results indicate the regionally based potential for land cover to persist or fluctuate as land uses are adapted to spatially and temporally variable forcing factors. ?? 2011.

  12. Land change variability and human-environment dynamics in the United States Great Plains

    USGS Publications Warehouse

    Drummond, Mark A.; Auch, Roger F.; Karstensen, Krista A.; Sayler, Kristi L.; Taylor, Janis L.; Loveland, Thomas R.

    2012-01-01

    Land use and land cover changes have complex linkages to climate variability and change, biophysical resources, and socioeconomic driving forces. To assess these land change dynamics and their causes in the Great Plains, we compare and contrast contemporary changes across 16 ecoregions using Landsat satellite data and statistical analysis. Large-area change analysis of agricultural regions is often hampered by change detection error and the tendency for land conversions to occur at the local-scale. To facilitate a regional-scale analysis, a statistical sampling design of randomly selected 10 km × 10 km blocks is used to efficiently identify the types and rates of land conversions for four time intervals between 1973 and 2000, stratified by relatively homogenous ecoregions. Nearly 8% of the overall Great Plains region underwent land-use and land-cover change during the study period, with a substantial amount of ecoregion variability that ranged from less than 2% to greater than 13%. Agricultural land cover declined by more than 2% overall, with variability contingent on the differential characteristics of regional human–environment systems. A large part of the Great Plains is in relatively stable land cover. However, other land systems with significant biophysical and climate limitations for agriculture have high rates of land change when pushed by economic, policy, technology, or climate forcing factors. The results indicate the regionally based potential for land cover to persist or fluctuate as land uses are adapted to spatially and temporally variable forcing factors.

  13. Great Plains Coal Gasification Project, Mercer County, North Dakota. Quarterly technical and environmental report, fourth quarter, 1983. [Great Plains, Mercer County, North Dakota

    SciTech Connect

    Not Available

    1983-01-01

    Activities remain on schedule to meet Great Plains Gasification Associates' full gas production date. Gasification Plant: detailed engineering in the Contractors' home office was completed in the fourth quarter. The remaining engineering tasks, which include field support activities and special projects, will be performed by the Contractors' Field Engineering Group. A substantial amount of construction progress was achieved during the fourth quarter. Although the Plant's construction activities are still slightly behind schedule, it is currently forecasted that the construction schedule will be regained by the end of June 1984. Start-Up operations are continuing at a rapid pace. The current emphasis is on system turnover and commissioning activities. The environmental permitting for the construction phase is complete. Freedom Mine: mine development activities remain on schedule.

  14. SuomiNet efforts in the U. S. Southern Great Plains.

    SciTech Connect

    Peppler, R. A.; Carr, F. H.; Ahern, J. L.; Liljegren, J. C.; Eagan, R. C.; Smith, J. J.

    2000-10-10

    SuomiNet provides great promise for advancing research at the University of Oklahoma in numerical weather prediction and plate tectonics studies, and will further help the U.S. DOE ARM (Atmospheric Radiation Measurement) Program better specify the measurement of water vapor over the Southern Great Plains. The SuomiNet program is also allowing ARM to upgrade its data collection infrastructure to provide more reliable and near real-time observations not only to SuomiNet but also to other researchers.

  15. Human Responses to Middle Holocene (Altithermal) Climates on the North American Great Plains

    NASA Astrophysics Data System (ADS)

    Meltzer, David J.

    1999-11-01

    The climate of the Great Plains during the middle Holocene varied considerably, but overall it was marked by a north-south gradient of increasingly warmer and drier conditions, with a reduction in effective moisture, surface water, and resource abundance, and an increase in resource patchiness, sediment weathering, erosion, and aeolian activity. Pronounced drought conditions were most evident on the Southern High Plains. Understanding the human responses to middle Holocene climates is complicated by a lack of archaeological data, which is partly a result of geomorphic processes that removed or deeply buried sites of this age, and by the varying adaptive responses of hunter-gatherers during this period. On the Southern High Plains, where drought was most severe, surface and groundwater sources dried and bison populations were diminished, prompting substantial adaptive changes, including local abandonment, well-digging to tap underground water, and a widening of the diet breadth to incorporate higher-cost, lower-return seed and plant resources. Sites of this age on the Central and Northern Plains also show a possible increase in diet breadth (with the incorporation of plant foods in the diet), and perhaps changes in settlement mobility (including possible shift into higher elevation areas, or mapping-on to extant rivers and springs). But linking those changes to middle Holocene drought is less straightforward.

  16. Hydrologic characteristics of soils in the High Plains, northern Great Plains, and Central Texas Carbonates Regional Aquifer Systems

    USGS Publications Warehouse

    Dugan, Jack T.; Hobbs, Ryne D.; Ihm, Laurie A.

    1990-01-01

    Certain physical characteristics of soils, including permeability, available water capacity, thickness, and topographic position, have a measurable effect on the hydrology of an area. These characteristics control the rate at which precipitation infiltrates or is transmitted through the soil, and thus they have an important role in determining the rates of actual evapotranspiration (consumptive water use), groundwater recharge, and surface runoff. In studies of groundwater hydrology, it is useful to differentiate soils spatially according to their physical characteristics and to assign values that indicate their hydrologic responses.The principal purpose of this report is to describe the relation between the hydrologic characteristics of the soils in the study area and those environmental factors that affect the development and distribution of the soils. This objective will be achieved by (1) defining both qualitatively and quantitatively those soil characteristics that affect hydrology, and (2) classifying and delineating the boundaries of the soils in the study area according to these hydrologic characteristics.The study area includes the High Plains, Northern Great Plains, the Central Texas Carbonates, and parts of the Central Midwest Regional Aquifer Systems as described by the U.S. Geological Survey Regional Aquifer-System Analysis (RASA) Program (Sun, 1986, p.5and Sun, personal commun., June 1985) and shown in figures 1 through 5. The spatial patterns of the soils classified according to their quantifiable hydrologic characteristics will subsequently serve as an integral component in the analysis of actual evapotranspiration (consumptive water use), consumptive irrigation requirements, and potential ground-water recharge of the study area.The classification system used to describe the soils in this report is compatible with that of Dugan (1986). Dugan described the same characteristics of soils that are immediately underlain by principal aquifers of

  17. Farmers, Ranchers, and the Railroad: The Evolution of Fence Law in the Great Plains, 1865-1900

    ERIC Educational Resources Information Center

    Kawashima, Yasuhide

    2010-01-01

    This article is divided into three parts. The first examines specific fencing policies in Kansas, Nebraska, and other Plains states, highlighting the transformation from the "fence-out" to "fence-in" (herd laws) policies. The second part discusses the coming of the railroads to the Great Plains and the farmers and the ranchers…

  18. Farmers, Ranchers, and the Railroad: The Evolution of Fence Law in the Great Plains, 1865-1900

    ERIC Educational Resources Information Center

    Kawashima, Yasuhide

    2010-01-01

    This article is divided into three parts. The first examines specific fencing policies in Kansas, Nebraska, and other Plains states, highlighting the transformation from the "fence-out" to "fence-in" (herd laws) policies. The second part discusses the coming of the railroads to the Great Plains and the farmers and the ranchers…

  19. Transmission of biology and culture among post-contact Native Americans on the western Great Plains

    PubMed Central

    Lycett, Stephen J.; von Cramon-Taubadel, Noreen

    2016-01-01

    The transmission of genes and culture between human populations has major implications for understanding potential correlations between history, biological, and cultural variation. Understanding such dynamics in 19th century, post-contact Native Americans on the western Great Plains is especially challenging given passage of time, complexity of known dynamics, and difficulties of determining genetic patterns in historical populations for whom, even today, genetic data for their descendants are rare. Here, biometric data collected under the direction of Franz Boas from communities penecontemporaneous with the classic bison-hunting societies, were used as a proxy for genetic variation and analyzed together with cultural data. We show that both gene flow and “culture flow” among populations on the High Plains were mediated by geography, fitting a model of isolation-by-distance. Moreover, demographic and cultural exchange among these communities largely overrode the visible signal of the prior millennia of cultural and genetic histories of these populations. PMID:27514818

  20. Application of wheat yield model to United States and India. [Great Plains

    NASA Technical Reports Server (NTRS)

    Feyerherm, A. M. (Principal Investigator)

    1977-01-01

    The author has identified the following significant results. The wheat yield model was applied to the major wheat-growing areas of the US and India. In the US Great Plains, estimates from the winter and spring wheat models agreed closely with USDA-SRS values in years with the lowest yields, but underestimated in years with the highest yields. Application to the Eastern Plains and Northwest indicated the importance of cultural factors, as well as meteorological ones in the model. It also demonstrated that the model could be used, in conjunction with USDA-SRRS estimates, to estimate yield losses due to factors not included in the model, particularly diseases and freezes. A fixed crop calendar for India was built from a limited amount of available plot data from that country. Application of the yield model gave measurable evidence that yield variation from state to state was due to different mixes of levels of meteorological and cultural factors.

  1. Transmission of biology and culture among post-contact Native Americans on the western Great Plains.

    PubMed

    Lycett, Stephen J; von Cramon-Taubadel, Noreen

    2016-08-12

    The transmission of genes and culture between human populations has major implications for understanding potential correlations between history, biological, and cultural variation. Understanding such dynamics in 19th century, post-contact Native Americans on the western Great Plains is especially challenging given passage of time, complexity of known dynamics, and difficulties of determining genetic patterns in historical populations for whom, even today, genetic data for their descendants are rare. Here, biometric data collected under the direction of Franz Boas from communities penecontemporaneous with the classic bison-hunting societies, were used as a proxy for genetic variation and analyzed together with cultural data. We show that both gene flow and "culture flow" among populations on the High Plains were mediated by geography, fitting a model of isolation-by-distance. Moreover, demographic and cultural exchange among these communities largely overrode the visible signal of the prior millennia of cultural and genetic histories of these populations.

  2. Role of ground water in geomorphology, geology, and paleoclimate of the Southern High Plains, USA.

    PubMed

    Wood, Warren W

    2002-01-01

    Study of ground water in the Southern High Plains is central to an understanding of the geomorphology, deposition of economic minerals, and climate change record in the area. Ground water has controlled the course of the Canadian and Pecos rivers that isolated the Southern High Plains from the Great Plains and has contributed significantly to the continuing retreat of the westward escarpment. Evaporative and dissolution processes are responsible for current plateau topography and the development of the signature 20,000 small playa basins and 40 to 50 large saline lake basins in the area. In conjunction with eolian processes, ground water transport controls the mineralogy of commercially valuable mineral deposits and sets up the distribution of fine efflorescent salts that adversely affect water quality. As the water table rises and retreats, lunette and tufa formation provides valuable paleoclimate data for the Southern High Plains. In all these cases, an understanding of ground water processes contributes valuable information to a broad range of geological topics, well beyond traditional interest in water supply and environmental issues.

  3. Role of ground water in geomorphology, geology, and paleoclimate of the southern High Plains, USA

    USGS Publications Warehouse

    Wood, Warren W.

    2002-01-01

    Study of ground water in the Southern High Plains is central to an understanding of the geomorphology, deposition of economic minerals, and climate change record in the area. Ground water has controlled the course of the Canadian and Pecos rivers that isolated the Southern High Plains from the Great Plains and has contributed significantly to the continuing retreat of the westward escarpment. Evaporative and dissolution processes are responsible for current plateau topography and the development of the signature 20,000 small playa basins and 40 to 50 large saline lake basins in the area. In conjunction with eolian processes, ground water transport controls the mineralogy of commercially valuable mineral deposits and sets up the distribution of fine efflorescent salts that adversely affect water quality. As the water table rises and retreats, lunette and tufa formation provides valuable paleoclimate data for the Southern High Plains. In all these cases, an understanding of ground water processes contributes valuable information to a broad range of geological topics, well beyond traditional interest in water supply and environmental issues.

  4. USGS Historical, Current, and Projected Future Land Cover Mapping for the Northern Great Plains

    NASA Astrophysics Data System (ADS)

    Sohl, T. L.; Gallant, A.; Sayler, K. L.

    2008-12-01

    Land cover in the Northern Great Plains has changed considerably in the last several decades. While a significant proportion of the landscape has been cultivated for over one hundred years, the intensity of cultivation, crop type, and management practices have changed in response to shifts in government policy, commodity prices, access to water, and technological advances. Changes in land cover impact a wide variety of ecosystem processes and services, including carbon balances, climate, hydrology and water quality, and biodiversity. A consistent record of historical land cover is required to understand relations between land- cover change and these ecological processes, while projections of future land cover are needed for planning and potential mitigation efforts. Several U.S. Geological Survey efforts have been completed or are ongoing in the Northern Great Plains, resulting in the compilation of an unmatched record of historical, current, and future land-cover information for the region. The USGS Land Cover Trends project is using the historical record of Landsat imagery and a robust sampling approach to examine the rates, causes, and consequences of contemporary (1973-2000) land-cover change on an ecoregional basis for the conterminous United States. Results from completed Trends analyses for Great Plains ecoregions revealed changes in the proportion and distribution of grassland/shrubland and agricultural uses during the study period; Some areas exhibited considerable loss in cultivated land after initiation of the Conservation Reserve Program (CRP) in the mid 1980s. In recent years (post-2000), agricultural commodity prices have skyrocketed as food and energy compete for use of agricultural products, which in conjunction with the expiration of many CRP contracts, has led to expansion of cultivated land. In the coming decades, calls for U.S. energy independence and the development of biofuels from cellulosic stock could result in a transformation of the Great

  5. Modeling the Current and Future Impacts of Irrigation on Great Plains Precipitation

    NASA Astrophysics Data System (ADS)

    Harding, K. J.; Snyder, P. K.

    2011-12-01

    Since World War II, the rapid expansion of irrigation throughout the Great Plains has threatened the sustainability of the Ogallala Aquifer as evidenced by a dramatic decline in the water table of more than 40 m. Irrigation has been shown to modify the surface energy and water budgets by altering the partitioning of latent and sensible heating. An increase in latent heating from irrigation contributes to a cooler and more humid surface, which has competing impacts on convection. The Weather Research and Forecasting (WRF) model was modified to simulate the effects of irrigation at sub-grid scales. Two sets of simulations forced with observational data and global climate model output from the IPCC Fourth Assessment Report (AR4) were completed to assess the current and future impact of irrigation on precipitation. In nine simulations using observational data, May through September precipitation increased on average over the Great Plains by 4.97 mm (0.91%), with localized increases of up to 20%. The largest increases in precipitation occurred during wet years (6.14 mm; 0.98%) and the smallest increases occurred during drought years (2.85 mm; 0.63%). Over irrigated areas, precipitation increased by 7.86 mm (1.61%). Large precipitation increases occurred over irrigated areas during normal and pluvial years, while decreases occurred during drought years. Evapotranspiration increases were significantly larger than precipitation increases, suggesting that irrigation results in a large net export of water. During drought years, the greatest increase in evapotranspiration combined with the smallest increase in precipitation to produce the largest loss of water from irrigation. Because drought prevalence and severity are expected to increase over the Great Plains with climate change, irrigation is expected to result in increased future water losses and accelerated depletion of the Ogallala Aquifer. Simulations of WRF using future climate data suggest that irrigation will

  6. An Innovative Approach to Effective Climate Science Application through Stakeholder Participation in Great Plains Grasslands

    NASA Astrophysics Data System (ADS)

    Athearn, N.; Broska, J.

    2015-12-01

    For natural resource managers and other Great Plains stakeholders, climate uncertainties further confound decision-making on a highly altered landscape. Partner organizations comprising the Great Plains Landscape Conservation Cooperative (GPLCC) acknowledge climate change as a high-priority threat to grasslands and associated habitats, affecting water availability, species composition, and other factors. Despite its importance, incorporation of climate change impacts into planning is hindered by high uncertainty and lack of translation to a tangible outcome: effects on species and their habitats. In 2014, the GPLCC initiated a Landscape Conservation Design (LCD) process to ultimately improve the size and connectivity of grasslands - informing land managers of the landscape-scale impacts of local decisions about where to restore, enhance, protect, and develop lands. Defining this goal helped stakeholders envision a tangible product. High resolution land cover data recently completed for Texas and Oklahoma represent current grassland locations. By focusing climate change models to project changes in these land cover datasets, resulting land cover projections can be directly incorporated into LCD-based models to focus restoration where future climates will support grasslands. Broad organizational cooperation has been critical for this USGS-led project, which uses downscaled climate data and other support from the South Central Climate Science Center Consortium and builds on existing work including LCD efforts of the Playa Lakes Joint Venture and the Bureau of Land Management's Southern Great Plains Rapid Ecological Assessment. Ongoing stakeholder guidance through an advisory team ensures effective application of a product that will be both relevant to and understood by decision makers, for whom the primary role of research is to reduce uncertainties and clear the path for more efficient decision-making in the face of climatic uncertainty.

  7. Evidence of Late-Holocene floods in the central Great Plains

    SciTech Connect

    May, D.W. . Dept. of Geography)

    1992-01-01

    From southwestern Kansas to northeastern Nebraska alluvial studies are revealing stratigraphic and morphological evidence of two brief periods of large-magnitude floods in the central Great Plains during the past 2,500 years. Evidence for these floods consists of deeply-scoured paleochannels, coarse-textured point-bar deposits overlying fine-grained deposits, soils on former floodplains that are buried by alluvium, and fluvial terraces. Wood and bone collagen in several deeply-scoured paleochannels date to about 2,300--2,000 yr B.P. Modest incision and floodplain reconstruction at this time is evident from both maps of fluvial landforms and C-14-dated stratigraphic sections in both large and small basins. Sediments near the base and top of inset gully fills in both trenched and untrenched tributary valleys to Great Plains rivers date to about 2,000 yr B.P. A second episode of large floods in the central Great Plains occurred about 1,300--850 yr B.P. Throughout most valleys a buried soil that developed in alluvium occurs from 50 cm to 1.0 m below terraces. Recently, stratified point-bar deposits beneath a low terrace in a small (9.6 km[sup 2]) basin in east-central Nebraska were exposed and studied. Crossbedded, gravelly sand strata alternative with massive, dark, silty strata. The C-14-dated section indicates that multiple floods occurred between 1,250 and 850 yr B.P. Such widespread evidence of flooding about 2,300--2,000 yr B.P. and again 1,250--850 yr B.P. attests to regional, and probably, global climate changes at these times. Discontinuities in the alluvial record have previously been recognized at 2,000 and 1,200 yr B.P. Furthermore, a discontinuity in the pollen record at 850 yr B.P. has long been recognized.

  8. Using natural range of variation to set decision thresholds: a case study for great plains grasslands

    USGS Publications Warehouse

    Symstad, Amy J.; Jonas, Jayne L.; Edited by Guntenspergen, Glenn R.

    2014-01-01

    Natural range of variation (NRV) may be used to establish decision thresholds or action assessment points when ecological thresholds are either unknown or do not exist for attributes of interest in a managed ecosystem. The process for estimating NRV involves identifying spatial and temporal scales that adequately capture the heterogeneity of the ecosystem; compiling data for the attributes of interest via study of historic records, analysis and interpretation of proxy records, modeling, space-for-time substitutions, or analysis of long-term monitoring data; and quantifying the NRV from those data. At least 19 National Park Service (NPS) units in North America’s Great Plains are monitoring plant species richness and evenness as indicators of vegetation integrity in native grasslands, but little information on natural, temporal variability of these indicators is available. In this case study, we use six long-term vegetation monitoring datasets to quantify the temporal variability of these attributes in reference conditions for a variety of Great Plains grassland types, and then illustrate the implications of using different NRVs based on these quantities for setting management decision thresholds. Temporal variability of richness (as measured by the coefficient of variation, CV) is fairly consistent across the wide variety of conditions occurring in Colorado shortgrass prairie to Minnesota tallgrass sand savanna (CV 0.20–0.45) and generally less than that of production at the same sites. Temporal variability of evenness spans a greater range of CV than richness, and it is greater than that of production in some sites but less in other sites. This natural temporal variability may mask undesirable changes in Great Plains grasslands vegetation. Consequently, we suggest that managers consider using a relatively narrow NRV (interquartile range of all richness or evenness values observed in reference conditions) for designating a surveillance threshold, at which

  9. Expansion of Juniperus virginiana L. in the Great Plains: Changes in soil organic carbon dynamics

    NASA Astrophysics Data System (ADS)

    Smith, Dixie L.; Johnson, Loretta C.

    2003-06-01

    Woody encroachment by Juniperus virginiana into Great Plains grasslands allowed us to answer: Does changing the type of plant input to soils alter soil organic carbon (SOC) distribution or soil carbon (C) storage? The answer is critical because woody encroachment may alter C cycling over millions of hectares in the Great Plains and Midwest. We predicted that (1) forest SOC would become concentrated in shallow soil layers compared to SOC distribution in grassland, (2) woody expansion would increase soil C storage, and (3) forest C would be apparent in the larger soil organic matter fractions. Using δ13C signatures of SOC, 1/5 of the C from 0 to 25 cm in juniper forest soils was derived from C3 juniper trees. Forest C3 input occurred primarily in shallow surface layers: Forest soils developed over former C4 prairie contained 42% C3-SOC from 0 to 2.5 cm depth, and decreased to 6% at 25 cm. Isotopic analysis of SOC size fractions revealed that at 0-2.5 cm, the forest soil fraction >212 μm was -25.7‰. The fraction <2 μm had a 13C isotope ratio of -17.0‰ at the same depth, reflecting the predominance of residual prairie C in the smallest fraction. In spite of fast dynamics of soil C turnover, there was no net change in SOC amounts over 40-60 years (cumulative mineral and organic SOC in forest, 8782 g C/m2 ± 810; in grassland, 7699 ± 1004). Thus as junipers expand into mesic areas of the Great Plains, juniper forests will provide little additional soil C storage.

  10. Climate change impacts on hillslope runoff on the northern Great Plains, 1962-2013

    NASA Astrophysics Data System (ADS)

    Coles, A. E.; McConkey, B. G.; McDonnell, J. J.

    2017-07-01

    On the Great Plains of North America, water resources are being threatened by climatic shifts. However, a lack of hillslope-scale climate-runoff observations is limiting our ability to understand these impacts. Here, we present a 52-year (1962-2013) dataset (precipitation, temperature, snow cover, soil water content, and runoff) from three 5 ha hillslopes on the seasonally-frozen northern Great Plains. In this region, snowmelt-runoff drives c. 80% of annual runoff and is potentially vulnerable to warming temperatures and changes in precipitation amount and phase. We assessed trends in these climatological and hydrological variables using time series analysis. We found that spring snowmelt-runoff has decreased (on average by 59%) in response to a reduction in winter snowfall (by 18%), but that rainfall-runoff has shown no significant response to a 51% increase in rainfall or shifts to more multi-day rain events. In summer, unfrozen, deep, high-infiltrability soils act as a 'shock absorber' to rainfall, buffering the long-term runoff response to rainfall. Meanwhile, during winter and spring freshet, frozen ground limits soil infiltrability and results in runoff responses that more closely mirror the snowfall and snowmelt trends. These findings are counter to climate-runoff relationships observed at the catchment scale on the northern Great Plains where land drainage alterations dominate. At the hillslope scale, decreasing snowfall, snowmelt-runoff, and spring soil water content is causing agricultural productivity to be increasingly dependent on growing season precipitation, and will likely accentuate the impact of droughts.

  11. Cowbird parasitism in grassland and cropland in the northern Great Plains: Chapter 27

    USGS Publications Warehouse

    Koford, Rolf R.; Bowen, B.S.; Lokemoen, John T.; Kruse, Arnold D.; Smith, James N.M.; Cook, T.L.; Rothstein, S. IU.; Robinson, S.K.; Sealy, S.G.

    2000-01-01

    The landscape of the Great Plains has been greatly altered by human activities in the past century, and several grassland passerines have experienced significant population declines in recent decades. We explore here whether brood parasitism by Brown-headed Cowbirds, which are abundant in the Great Plains, has contributed to these declines. We measured the frequency of cowbird parasitism of passerine species in seeded grassland, natural grassland, and cropland in studies conducted in North Dakota during 1981-1993. The proportions of parasitized nests were 25%, 34%, and 39% in seeded grassland, natural grassland, and cropland, respectively. We speculate that much of the variation in parasitism rate among these habitats is related to the local abundance of cowbirds, to nest visibility, and to the presence of suitable perches for female cowbirds. Local abundance of cowbirds may be high in areas with cattle pastures. Nests and nesting behavior are probably more visible to female cowbirds in cropland than in grassland. Female cowbirds may use shrubs as perches while searching for host nests, and shrubs are more common in natural grasslands than in the other habitats we examined. Experimental work on the determinants of cowbird abundance in grasslands is needed.

  12. AmeriFlux US-ARb ARM Southern Great Plains burn site- Lamont

    DOE Data Explorer

    Torn, Margaret [Lawrence Berkeley National Laboratory

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-ARb ARM Southern Great Plains burn site- Lamont. Site Description - The ARM SGP Burn site is located in the native tallgrass prairies of the USDA Grazinglands Research Laboratory near El Reno, OK. One of two adjacent 35 ha plots, the US-ARb plot was burned on 2005/03/08. The second plot, US-ARc, was left unburned as the control for experimental purposes. Aside from 2005, the region evaded burning activities for at least 15 years. Current disturbances consist of only light grazing activities.

  13. Hydrogeologic considerations for an interstate ground-water compact on the Madison aquifer, northern Great Plains

    USGS Publications Warehouse

    Konikow, Leonard F.

    1978-01-01

    The development of an interstate ground-water compact for the Madison aquifer in the Northern Great Plains may provide a framework to allocate equitably this large ground-water resource while avoiding possible future interstate legal conflicts. However, some technical problems will have to be resolved first. A compact designed to regulate or to allocate the available ground water will have to be written in very precise, legally acceptable definitions. The required definitions may infer a degree of measurement accuracy that cannot be technically or economically provided. Therefore, a trade off may be required between preserving natural conditions and allowing beneficial use of the ground-water resource.

  14. Monitoring the Vernal Advancement and Retrogradation (Green Wave Effect) of Natural Vegetation. [Great Plains Corridor

    NASA Technical Reports Server (NTRS)

    Rouse, J. W., Jr. (Principal Investigator); Haas, R. H.; Deering, D. W.; Schell, J. A.; Harlan, J. C.

    1974-01-01

    The author has identified the following significant results. The Great Plains Corridor rangeland project successfully utilized natural vegetation systems as phenological indicators of seasonal development and climatic effects upon regional growth conditions. An effective method was developed for quantitative measurement of vegetation conditions, including green biomass estimates, recorded in bands 5 and 6, corrected for sun angle, were used to compute a ratio parameter (TV16) which is shown to be highly correlated with green biomass and vegatation moisture content. Analyses results of ERTS-1 digital data and correlated ground data are summarized. Attention was given to analyzing weather influences and test site variables on vegetation condition measurements with ERTS-1 data.

  15. Stratigraphic evidence of desertification in the west-central Great Plains within the past 1000 yr

    USGS Publications Warehouse

    Madole, R.F.

    1994-01-01

    Stratigraphic and geomorphic relations, archaeological data, and eight radiocarbon ages at five widely scattered localities in northeastern Colorado indicate that eolian sand was mobilized over broad areas within the past 1000 yr. The mobilization began after 1 ka, was episodic, and ended at some as yet undetermined time prior to the latter part of the 19th century. Given that climate-model simulations suggest only slight variation in average surface temperature and annual precipitation in this region during the past 1000 yr, this part of the Great Plains evidently is near the threshold of widespread eolian sand transport under the present climate. -Author

  16. Stratigraphic evidence of desertification in the west-central Great Plains within the past 1000 yr

    NASA Astrophysics Data System (ADS)

    Madole, Richard F.

    1994-06-01

    Stratigraphic and geomorphic relations, archeological data, and eight radiocarbon ages at five widely scattered localities in northeastern Colorado indicate that eolian sand was mobilized over broad areas within the past 1000 yr. The mobilization began after 1 ka, was episodic, and ended at some as yet undetermined time prior to the latter part of the nineteenth century. Given that climate-model simulations suggest only slight variation in average surface temperature and annual precipitation in this region during the past 1000 yr, this part of the Great Plains evidently is near the threshold of widespread eolian sand transport under the present climate.

  17. Groundwater recharge and chemical evolution in the southern High Plains of Texas, USA

    NASA Astrophysics Data System (ADS)

    Fryar, Alan; Mullican, William; Macko, Stephen

    2001-11-01

    The unconfined High Plains (Ogallala) aquifer is the largest aquifer in the USA and the primary water supply for the semiarid southern High Plains of Texas and New Mexico. Analyses of water and soils northeast of Amarillo, Texas, together with data from other regional studies, indicate that processes during recharge control the composition of unconfined groundwater in the northern half of the southern High Plains. Solute and isotopic data are consistent with a sequence of episodic precipitation, concentration of solutes in upland soils by evapotranspiration, runoff, and infiltration beneath playas and ditches (modified locally by return flow of wastewater and irrigation tailwater). Plausible reactions during recharge include oxidation of organic matter, dissolution and exsolution of CO2, dissolution of CaCO3, silicate weathering, and cation exchange. Si and 14C data suggest leakage from perched aquifers to the High Plains aquifer. Plausible mass-balance models for the High Plains aquifer include scenarios of flow with leakage but not reactions, flow with reactions but not leakage, and flow with neither reactions nor leakage. Mechanisms of recharge and chemical evolution delineated in this study agree with those noted for other aquifers in the south-central and southwestern USA. Résumé. L'aquifère libre des Hautes Plaines (Ogallala) est le plus vaste aquifère des états-Unis et la ressource de base pour l'eau potable de la région semi-aride du sud des Hautes Plaines du Texas et du Nouveau-Mexique. Des analyses de l'eau et des sols prélevés au nord-est d'Amarillo (Texas), associées à des données provenant d'autres études dans cette région, indiquent que des processus intervenant au cours de l'infiltration contrôlent la composition de l'eau de la nappe libre dans la moitié septentrionale du sud des Hautes Plaines. Les données chimiques et isotopiques sont compatibles avec une séquence de précipitation épisodique, avec la reconcentration en solut

  18. Multimetric Fish Indices for Midcontinent (USA) Great Rivers

    EPA Science Inventory

    As part of the Environmental Monitoring and Assessment Program for Great River Ecosystems we developed a fish-assemblage based multimetric index (Great River Fish Index,GRFIn) as an indicator of ecological conditions in the Lower Missouri, impounded Upper Mississippi, unimpounded...

  19. Interpretation and compendium of historical fire accounts in the Northern Great Plains

    USGS Publications Warehouse

    Higgins, K.F.

    1986-01-01

    This interpretation and compendium of historical fire accounts in the northern Great Plains provides resource managers with background information to justify the study or use of fire in management and provides a reference of historic fire accounts for those without ready access to major library collections. Historical accounts of fire are critiqued to aid interpreting the compendium accounts. An interpretation is included by the author.Lightning-set fires were recorded in the literature far less frequently than were Indian-set fires. The kinds of fire most frequently reported were scattered, single events of short duration and small extent. Although fires occurred in wetlands, wetlands as well as sandy soil sites usually were good areas for escape from the effects of fire. Both Indians and wild animals were reportedly injured or killed during prairie fires. The frequency of historic fires was less evident in the literature than the descriptions of fire distribution in time and space. Indian-set fires were reported in every month except January. Fires occurred mainly in two periods, March through May with a peak in April, and July to early November with a peak in October. Grassland fuels burned readily within a few hours or days after rain and even during light snowfall.I agree with arguments that support the concept that Indians of the northern Great Plains generally did not subscribe to annual wholesale or promiscuous burning practices, but that they did purposely use fire as a tool to aid hunting and gathering of food and materials. Apparently, the northern plains Indians did not pattern their use of fire with the seasonal patterns of lightning fires. More likely they developed seasonal patterns of burning the prairies in harmony with bison (Bison bison) herd movements because the hunter-gatherer economy of these nomadic tribes was centrally focused and largely dependent on bison and bison ecology.

  20. A Baroclinic Nocturnal Low-Level Jet over the Great Plains

    NASA Astrophysics Data System (ADS)

    Shapiro, A.; Gebauer, J.; Fedorovich, E.

    2016-12-01

    The nocturnal low-level jet (LLJ) is a warm-season atmospheric boundary layer phenomenon common to the Great Plains of the United States and other places worldwide. Low-level jets develop around sunset in fair weather conditions conducive to strong radiative cooling and reach peak intensity in the pre-dawn hours. Key precursors to their formation are the establishment of a strongly turbulent dry convective boundary layer during the afternoon and a rapid cessation of the turbulence during the early evening transition. The two main physical mechanisms underpinning the generation of nocturnal low-level jets over the Great Plains are associated with diurnal variations in turbulent mixing (Blackadar mechanism) and in heating/cooling of the gently sloping terrain (Holton mechanism). These two mechanisms were recently combined within a single unified theory (Shapiro et al. 2016) in which analytical solutions of the Boussinesq equations of motion and thermal energy were obtained. In the present study we apply the unified theory to the case where the free-atmosphere geostrophic wind is zero, and there is strong daytime heating of the slope. When appropriately tuned, the analytical model predicts the low elevation (jet nose within 250 m of the ground) and strong wind maximum (> 15 m/s) characteristic of the strongly baroclinic jet observed over northern Kansas on 10 June 2015 during Intensive Observing Period 7 of the Plains Elevated Convection at Night (PECAN) field experiment. Although there is generally good agreement between the tuned model and observations (including soundings and aircraft data), our main interest is in investigating the profound roles of the free-atmosphere stratification, daytime heating, and daytime/nighttime mixing on jet strength and structure.

  1. The Impact of Cloud and Radiation on the Great Plains Climate Change During 1981-2003

    NASA Astrophysics Data System (ADS)

    Popham, J. L.; Dong, X.

    2005-05-01

    Relationships of surface air and soil temperature changes have been compared to downward solar radiation and cloud fraction over the Great Plains (latitudes of 37°N to 49°N, and longitudes of 95°W to 104°W). Twenty-three years of surface meteorological data have been collected, including surface air and 10 cm soil temperatures and downward solar flux from the High Plains Regional Climate Center (HPRCC) since 1981. The daily mean values of meteorological data within the states of Kansas, Nebraska, South Dakota, and North Dakota have been binned and averaged to 0.5-degree latitude intervals to study temporal and latitudinal variations of surface air and soil temperatures, as well as their correlations with downward solar flux. Preliminary results from this project have demonstrated that the surface air and soil temperatures have increased during the 1981-2003 period over the Great Plains. When broken down by latitude, the air temperature change has increased from nearly 0°C at 37°N to 1.7°C at 49°N, and the soil temperature change increased about 2.7°C. The downward solar flux has generally decreased during the 23-year period, but the downward solar flux change increases with latitude: -38 Wm-2 at 37°N and 18 Wm-2 at 49°N which is positively correlated to the air and soil temperature changes. The cloud fractions from International Satellite Cloud Climatology Project (ISCCP) during the 1983-2001 period have been used to study the impact of clouds on the surface radiation and temperatures. The Department of Energy Atmospheric Radiation Measurement (DOE ARM) downward solar fluxes over southern Kansas have been used to determine the overall quality of the results.

  2. Backcasting the decline of a vulnerable Great Plains reproductive ecotype: identifying threats and conservation priorities

    USGS Publications Warehouse

    Worthington, Thomas A.; Brewer, Shannon K.; Grabowski, Timothy B.; Mueller, Julia

    2014-01-01

    Conservation efforts for threatened or endangered species are challenging because the multi-scale factors that relate to their decline or inhibit their recovery are often unknown. To further exacerbate matters, the perceptions associated with the mechanisms of species decline are often viewed myopically rather than across the entire species range. We used over 80 years of fish presence data collected from the Great Plains and associated ecoregions of the United States, to investigate the relative influence of changing environmental factors on the historic and current truncated distributions of the Arkansas River shiner Notropis girardi. Arkansas River shiner represent a threatened reproductive ecotype considered especially well adapted to the harsh environmental extremes of the Great Plains. Historic (n = 163 records) and current (n = 47 records) species distribution models were constructed using a vector-based approach in MaxEnt by splitting the available data at a time when Arkansas River shiner dramatically declined. Discharge and stream order were significant predictors in both models; however, the shape of the relationship between the predictors and species presence varied between time periods. Drift distance (river fragment length available for ichthyoplankton downstream drift before meeting a barrier) was a more important predictor in the current model and indicated river segments 375–780 km had the highest probability of species presence. Performance for the historic and current models was high (area under the curve; AUC > 0.95); however, forecasting and backcasting to alternative time periods suggested less predictive power. Our results identify fragments that could be considered refuges for endemic plains fish species and we highlight significant environmental factors (e.g., discharge) that could be manipulated to aid recovery.

  3. Inorganic nitrogen supply and dissolved organic nitrogen abundance across the US Great Plains.

    PubMed

    Mobley, Megan L; Cleary, Matthew J; Burke, Ingrid C

    2014-01-01

    Across US Great Plains grasslands, a gradient of increasing mean annual precipitation from west to east corresponds to increasing aboveground net primary productivity (ANPP) and increasing N-limitation. Previous work has shown that there is no increase in net N mineralization rates across this gradient, leading to the question of where eastern prairie grasses obtain the nitrogen to support production. One as-yet unexamined source is soil organic N, despite abundant literature from other ecosystems showing that plants take up dissolved soil organic N. This study measured KCl-extractable dissolved organic N (DON) in surface soils across the grassland productivity gradient. We found that KCl-extractable DON pools increased from west to east. If available to and used by plants, this DON may help explain the high ANPP in the eastern Great Plains. These results suggest a need for future research to determine whether, in what quantities, and in what forms prairie grasses use organic N to support primary production.

  4. Potential effects of anthropogenic greenhouse gases on avian habitas and populations in the northern Great Plains

    SciTech Connect

    Larson, D.L. )

    1994-04-01

    Biotic response to the buildup of greenhouse gases in Earth's atmosphere is considerably more complex than an adjustment to changing temperature and precipitation. The fertilization effect CO[sub 2] has on some plants, the impact UVB radiation has on health and productivity of organisms, and the resulting changes in competitive balance and trophic structure must also be considered. The intent of this paper is to review direct and indirect effects of anthropogenic greenhouse gases on wildlife, and to explore possible effects on populations of birds and their habitats in the northern Great Plains. Many of the potential effects of increasing greenhouse gases, such as declining plant nutritional value, changes in timing of insect emergence, and fewer and saltier wetlands, foreshadow a decline in avian populations on the Great Plains. However, other possible effects such as increased drought resistance and water use efficiency of vegetation, longer growing seasons, and greater overall plant biomass promise at least some mitigation. Effects of multiple simultaneous perturbations such as can be expected under doubled CO[sub 2] scenarios will require substantial basic research to clarify. 113 refs., 1 fig.

  5. Potential effects of anthropogenic greenhouse gases on avian habitats and populations in the northern Great Plains

    USGS Publications Warehouse

    Larson, Diane L.

    1994-01-01

    Biotic response to the buildup of greenhouse gases in Earth's atmosphere is considerably more complex than an adjustment to changing temperature and precipitation. The fertilization effect carbon dioxide has on some plants, the impact UVB radiation has on health and productivity of organisms, and the resulting changes in competitive balance and trophic structure must also be considered. The intent of this paper is to review direct and indirect effects of anthropogenic greenhouse gases on wildlife, and to explore possible effects on populations of birds and their habitats in the northern Great Plains.Many of the potential effects of increasing greenhouse gases, such as declining plant nutritional value, changes in timing of insect emergence, and fewer and saltier wetlands, foreshadow a decline in avian populations on the Great Plains. However, other possible effects such as increased drought resistance and water use efficiency of vegetation, longer growing seasons, and greater overall plant biomass promise at least some mitigation. Effects of multiple simultaneous perturbations such as can be expected under doubled carbon dioxide scenarios will require substantial basic research to clarify.

  6. Measuring and mitigating agricultural greenhouse gas production in the US Great Plains, 1870-2000.

    PubMed

    Parton, William J; Gutmann, Myron P; Merchant, Emily R; Hartman, Melannie D; Adler, Paul R; McNeal, Frederick M; Lutz, Susan M

    2015-08-25

    The Great Plains region of the United States is an agricultural production center for the global market and, as such, an important source of greenhouse gas (GHG) emissions. This article uses historical agricultural census data and ecosystem models to estimate the magnitude of annual GHG fluxes from all agricultural sources (e.g., cropping, livestock raising, irrigation, fertilizer production, tractor use) in the Great Plains from 1870 to 2000. Here, we show that carbon (C) released during the plow-out of native grasslands was the largest source of GHG emissions before 1930, whereas livestock production, direct energy use, and soil nitrous oxide emissions are currently the largest sources. Climatic factors mediate these emissions, with cool and wet weather promoting C sequestration and hot and dry weather increasing GHG release. This analysis demonstrates the long-term ecosystem consequences of both historical and current agricultural activities, but also indicates that adoption of available alternative management practices could substantially mitigate agricultural GHG fluxes, ranging from a 34% reduction with a 25% adoption rate to as much as complete elimination with possible net sequestration of C when a greater proportion of farmers adopt new agricultural practices.

  7. Land Use and Family Formation in the Settlement of the U.S. Great Plains

    PubMed Central

    Gutmann, Myron P.; Pullum-Piñón, Sara M.; Witkowski, Kristine; Deane, Glenn D.; Merchant, Emily

    2014-01-01

    In agricultural settings, environment shapes patterns of settlement and land use. Using the Great Plains of the United States during the period of its initial Euro-American settlement (1880–1940) as an analytical lens, this article explores whether the same environmental factors that determine settlement timing and land use—those that indicate suitability for crop-based agriculture—also shape initial family formation, resulting in fewer and smaller families in areas that are more conducive to livestock raising than to cropping. The connection between family size and agricultural land availability is now well known, but the role of the environment has not previously been explicitly tested. Descriptive analysis offers initial support for a distinctive pattern of family formation in the western Great Plains, where precipitation is too low to support intensive cropping. However, multivariate analysis using county-level data at 10-year intervals offers only partial support to the hypothesis that environmental characteristics produce these differences. Rather, this analysis has found that the region was also subject to the same long-term social and demographic changes sweeping the rest of the country during this period. PMID:24634550

  8. Projected intensification of subseasonal temperature variability and heat waves in the Great Plains

    NASA Astrophysics Data System (ADS)

    Teng, Haiyan; Branstator, Grant; Meehl, Gerald A.; Washington, Warren M.

    2016-03-01

    Compared to changes in the climatological mean temperature, we have less confidence in how much and by what mechanisms temperature variability may be affected by anthropogenic climate change. Here based on a 30-member climate change projection from an earth system model, we find that summertime subseasonal temperature variability in the U.S. Great Plains is enhanced by approximately 20% in 2070-2100 relative to 1980-2010. In particular, daily temperature departures from the new climatologies during future heat waves are on average 0.6°C warmer than are the corresponding departures under present-day conditions. Although in both periods heat waves in the Great Plains tend to be associated with planetary wave events, the amplification of future heat waves does not appear to be induced by changes in planetary wave variability in the midlatitudes. Instead, in this experiment the strengthening appears to be primarily caused by enhanced local land-atmosphere feedbacks resulting from a warmer/drier future climate.

  9. Measuring and mitigating agricultural greenhouse gas production in the US Great Plains, 1870–2000

    PubMed Central

    Parton, William J.; Gutmann, Myron P.; Merchant, Emily R.; Hartman, Melannie D.; Adler, Paul R.; McNeal, Frederick M.; Lutz, Susan M.

    2015-01-01

    The Great Plains region of the United States is an agricultural production center for the global market and, as such, an important source of greenhouse gas (GHG) emissions. This article uses historical agricultural census data and ecosystem models to estimate the magnitude of annual GHG fluxes from all agricultural sources (e.g., cropping, livestock raising, irrigation, fertilizer production, tractor use) in the Great Plains from 1870 to 2000. Here, we show that carbon (C) released during the plow-out of native grasslands was the largest source of GHG emissions before 1930, whereas livestock production, direct energy use, and soil nitrous oxide emissions are currently the largest sources. Climatic factors mediate these emissions, with cool and wet weather promoting C sequestration and hot and dry weather increasing GHG release. This analysis demonstrates the long-term ecosystem consequences of both historical and current agricultural activities, but also indicates that adoption of available alternative management practices could substantially mitigate agricultural GHG fluxes, ranging from a 34% reduction with a 25% adoption rate to as much as complete elimination with possible net sequestration of C when a greater proportion of farmers adopt new agricultural practices. PMID:26240366

  10. Magnitude, Duration, and Geographic Coherence of Interannual Anomalies of the Great Plains Low-Level Jet

    NASA Technical Reports Server (NTRS)

    Helfand, H. Mark; Schubert, Siegfried D.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The Great Plains region of the United States is characterized by some of the world's most frequent and regular occurrences of a nocturnal low-level jet (LLJ). While this southerly jet is generally confined to the lowest kilometer of the atmosphere, it may cover a substantial region of the Great Plains and reach wind speed maxima of 20 m/s or more. The temporal and spatial structure of this jet has been well captured by the GEOS-1 15-year reanalysis. The jet is most evident during the warm season, May through August. The year-to-year variability of the seasonally-averaged jet structure is small relative to its diurnal or its intraseasonal variability and is comparable in magnitude to the seasonal variability for the mean climatology. The interannual variance maximum is located to the east of both the jet maximum and the seasonal variance maximum and seems to be related to a biennial oscillation which occurs for the first six years of the reanalysis period. There is a second maximum which is free of this oscillation, which is located at the same latitude but further south in the Gulf of Mexico. Interannual anomalies seem to have a duration of about three weeks and spatial coherences about ten degrees wide. Meridional velocity anomalies for the drought year 1988 and the flood year 1993 are large, but their impacts on the hydrological cycle may be as sensitive to their eastward location as to their magnitudes.

  11. Evaluation of herbacceous biomass crops in the northern Great Plains. Final report

    SciTech Connect

    Meyer, D.W.; Norby, W.E.; Erickson, D.O.; Johnson, R.G.

    1994-08-01

    Herbaceous lignocellulose crops are a potential renewable feedstock for biochemical conversion systems second in size to wood products. Several herbaceous crops are utilized as forage crops in the northern Great Plains, but forage quality considerations usually dictates a early harvest. Biomass cropping does not have this constraint; therefore, little information was available on herbaceous crops utilized as energy crops prior to this project. Our primary objectives were to evaluate the biomass yield and select chemical components of several herbaceous crops for energy crops in the northern Great Plains, compare the economic feasibility of energy crops with common competing crops, and evaluate biomass cropping on summer fallow lands. Three good, two marginal, and one irrigated sites were used during 1988 to 1992 for the first component. At least six perennial and four annual biomass species were included at all sites. Three to four nitrogen (N) levels and a crop-recrop comparison (annuals only) were management intensities included. Biomass cropping on idled lands was performed on dryland at Carrington and evaluated the effects of removing leguminous biomass on fallowed lands. This report summarizes results from the 5-year project.

  12. Detection of nocturnal coherent turbulence in the US Great Plains and effects on wind turbine fatigue

    NASA Astrophysics Data System (ADS)

    Dvorak, M. J.; Wiersema, D. J.; Zhou, B.; Chow, F. K.

    2012-12-01

    Strong low-level jet winds that develop in the nocturnal stable boundary layer (SBL) create some of the most energetic wind energy resources in Great Plains of North America. These stratified flows, however, can cause strong wind shear and veer across wind turbine rotors. Additionally, turbulent bursting events triggered by strong vertical wind shear can lead to fatigue and damage of wind turbine blades and components, increasing maintenance costs and reducing wind turbine power production. Coherent structures which are the signature of turbulent bursting events can be observed in heavily instrumented wind farms and in high-resolution simulations. Large-scale adoption of wind energy will benefit from the ability to predict these turbulence events with limited in-situ data. By identifying signatures of these bursting events, new turbine control technologies could be used to reduce wind turbine damage and increase overall wind farm energy yield (for example using algorithms with the ability to proactively and independently pitch blades). This research analyzes SBL turbulence in the Great Plains to develop methods to identify these structures at wind farms. Nested large-eddy simulations down to about 20m horizontal resolution are performed and compared to high-resolution Doppler wind LIDAR data (1 Hz) to determine if the model is able to create similar wind and turbulence conditions. Wavelet analysis of the LIDAR and model wind fields is used to detect coherent turbulent structures at frequencies that could be potentially damaging for wind turbines and provide guidance for design of turbine control technologies.

  13. Statistical Methods for Quantifying Uncertainty in ENSO on Wind Power in the Northern Great Plains

    NASA Astrophysics Data System (ADS)

    Harper, B. R.

    2006-12-01

    The El Nino Southern Oscillation (ENSO) is a well-known source of inter-annual climate variability for both precipitation and temperature in the northern Great Plains. The northern Great Plains also have the largest wind resource in the United States. With the continued growth of wind energy, ENSO's effect on wind speed needs to be examined because of our current lack of understanding about how wind speeds are affected by inter-annual variability. After having previously established that a teleconnection to ENSO exists, we set out to quantify the uncertainty in this relationship with this study. Our method uses the sign test and resampling of hourly airport wind speed measurements for the past half-century at 4 airports in both North Dakota and South Dakota. Airport data are useful in this case because they have very long and continuous measurement of hourly wind speed. With this data, we were able to show that ENSO did have an effect on wind speeds as well as on wind power. The warm phase of El Nino, in particular, was correlated with the largest reductions in wind speed in South Dakota. In North Dakota, it was the cold phase that produced the largest reduction in wind power. The largest differences occurred in April, while the smallest differences occurred in July. It is our hope that this method will also be a useful tool for wind farm developers across the country to more accurately assess the value of their site based on limited in-situ data.

  14. Woody encroachment in northern Great Plains grasslands: Perceptions, actions, and needs

    USGS Publications Warehouse

    Symstad, Amy; Leis, Sherry A.

    2017-01-01

    The United States Northern Great Plains (NGP) has a high potential for landscape-scale conservation, but this grassland landscape is threatened by encroachment of woody species. We surveyed NGP land managers to identify patterns in, and illustrate a broad range of, individual managers' perceptions on (1) the threat of woody encroachment to grasslands they manage, and (2) what management practices they use that may influence woody encroachment in this region. In the 34 surveys returned, which came from predominantly public lands in the study area, 79% of responses reported moderate or substantial woody encroachment. Eastern redcedar (Juniperus virginiana) and Rocky Mountain juniper (Juniperus scopulorum) were the most problematic encroachers. Thirty-one survey respondents said that prescribed fire was used on the lands they manage, and 64% of these responses reported that controlling woody encroachment was a fire management objective. However, only 18% of survey respondents using prescribed fire were achieving their desired fire return interval. Most respondents reported using mechanical and/or chemical methods to control woody species. In contrast to evidence from the central and southern Great Plains, few survey respondents viewed grazing as affecting encroachment. Although the NGP public land managers we surveyed clearly recognize woody encroachment as a problem and are taking steps to address it, many feel that the rate of their management is not keeping pace with the rate of encroachment. Developing strategies for effective woody plant control in a variety of NGP management contexts requires filling ecological science gaps and overcoming societal barriers to using prescribed fire.

  15. Comparative riverscape genetics reveals reservoirs of genetic diversity for conservation and restoration of Great Plains fishes

    PubMed Central

    Osborne, Megan J; Perkin, Joshuah S.; Gido, Keith B.; Turner, Thomas F.

    2014-01-01

    We used comparative landscape genetics to examine the relative roles of historical events, intrinsic traits, and landscape factors in determining the distribution of genetic diversity of river fishes across the North American Great Plains. Spatial patterns of diversity were overlaid on a patch-based graphical model, and then compared within and among three species that co-occurred across five Great Plains watersheds. Species differing in reproductive strategy (benthic vs. pelagic spawning) were hypothesized to have different patterns of genetic diversity, but the overriding factor shaping contemporary patterns of diversity was the signature of past climates and geological history. Allelic diversity was significantly higher at southern latitudes for Cyprinella lutrensis and Hybognathus placitus, consistent with northward expansion from southern Pleistocene refugia. Within the historical context, all species exhibited lowered occupancy and abundance in heavily fragmented and drier upstream reaches, particularly H. placitus; a pelagic-spawning species, suggesting rates of extirpation have outpaced losses of genetic diversity in this species. Within most basins, genetically diverse populations of each species persisted. Hence, reconnecting genetically diverse populations with those characterized by reduced diversity (regardless of their position within the riverine network) would provide populations with greater genetic and demographic resilience. We discuss cases where cross-basin transfer may be appropriate to enhance genetic diversity and mitigate negative effects of climate change. Overall, striking similarities in genetic patterns and response to fragmentation and dewatering suggest a common strategy for genetic resource management in this unique riverine fish assemblage. PMID:25327780

  16. Synchrony of Piping Plover breeding populations in the U.S. Northern Great Plains

    USGS Publications Warehouse

    Roche, Erin A.; Shaffer, Terry L.; Dovichin, Colin M.; Sherfy, Mark H.; Anteau, Michael J.; Wiltermuth, Mark T.

    2016-01-01

    Local populations that fluctuate synchronously are at a greater risk of extinction than those that do not. The closer the geographic proximity of populations, the more prone they are to synchronizing. Shorebird species select habitat broadly, and many breed across regions with diverse nesting habitat types. Under these conditions, nearby populations may experience conditions sufficiently different to prevent population synchrony, despite dispersal. In the U.S. Northern Great Plains, the Piping Plover (Charadrius melodus), federally listed as Threatened, is a migratory shorebird species that nests on the shorelines of rivers, reservoirs, and alkaline lakes. We assessed the degree to which local plover breeding population abundances were correlated (population synchrony), changed over time (population stability), and were influenced by environmental factors such as available habitat, precipitation, and within-season reservoir level rise. We found that the abundances of breeding populations nesting in riverine and reservoir habitats were the most synchronous, while populations nesting in alkaline lake habitats exhibited the greatest stability. Changes in local breeding population abundances were not explained by a single factor across habitat types. However, the abundances of local populations nesting in alkaline lake and river shoreline habitats were positively correlated with changes in nesting habitat availability. Our results suggest that dispersal among populations nesting in either river or reservoir and alkaline lake shoreline habitat may have an overall stabilizing effect on the persistence of the Great Plains Piping Plover metapopulation.

  17. Simulating the dynamics of linear forests in Great Plains agroecosystems under changing climates

    USGS Publications Warehouse

    Guo, Q.; Brandle, J.R.; Schoeneberger, M.M.; Buettner, D.

    2004-01-01

    Most forest growth models are not suitable for the highly fragmented, linear (or linearly shaped) forests in the Great Plains agroecosystems (e.g., windbreaks, riparian forest buffers) where such forests are a minor but ecologically important component of the land mosaics. This study used SEEDSCAPE, a recently modified gap model designed for cultivated land mosaics in the Great Plains, to simulate the effects of climate change on the dynamics of such linear forests. We simulated the dynamics of windbreaks with different initial planting species richness and widths (light changes as the selected resulting factor) using current climate data and nested regional circulation models (RegCMs). Results indicated that (1) it took 70-80 simulation years for the linear forests to reach a steady state under both normal (present-day) and warming climates; (2) warming climates would reduce total aboveground tree biomass and the spatial variation in biomass but increase dominance in the linear forests, especially in the upland forests; (3) linear forests with higher planting species richness and smaller width produced higher aboveground tree biomass per unit area; and (4) same species performed very differently with different climate scenarios, initial planting diversity, and forest widths. Although the model still needs further improvements (e.g., the effects of understory species should be included), the model can serve as a useful tool in modeling the succession of linear forests in human-dominated land mosaics under changing climates and may also have significant practical implications in other systems.

  18. Simulating the dynamics of linear forests in Great Plains agroecosystems under changing climates

    USGS Publications Warehouse

    Guo, Q.; Brandle, J.; Schoeneberger, M.; Buettner, D.

    2004-01-01

    Most forest growth models are not suitable for the highly fragmented, linear (or linearly shaped) forests in the Great Plains agroecosystems (e.g., windbreaks, riparian forest buffers), where such forests are a minor but ecologically important component of the land mosaics. This study used SEEDSCAPE, a recently modified gap model designed for cultivated land mosaics in the Great Plains, to simulate the effects of climate change on the dynamics of such linear forests. We simulated the dynamics of windbreaks with different initial planting species richness and widths (light changes as the selected resulting factor) using current climate data and nested regional circulation models (RegCMs). Results indicated that (i) it took 70-80 simulation years for the linear forests to reach a steady state under both normal (present-day) and warming climates; (ii) warming climates would reduce total aboveground tree biomass and the spatial variation in biomass, but increase dominance in the linear forests, especially in the upland forests; (iii) linear forests with higher planting species richness and smaller width produced higher aboveground tree biomass per unit area; and (iv) the same species performed very differently with different climate scenarios, initial planting diversity, and forest widths. Although the model still needs further improvements (e.g., the effects of understory species should be included), the model can serve as a useful tool in modeling the succession of linear forests in human-dominated land mosaics under changing climates and may also have significant practical implications in other systems. ?? 2004 NRC Canada.

  19. Resistance among cultivated sunflower germplasm to stem-infesting pests in the central Great Plains.

    PubMed

    Charlet, Laurence D; Aiken, Robert M; Miller, Jerry F; Seiler, Gerald J

    2009-06-01

    A 7-yr field study evaluated 61 oilseed sunflower, Helianthus annuus L., accessions and 31 interspecific crosses for resistance to attack by naturally occurring populations of three stem-infesting pests, the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae); a longhorned beetle, Dectes texanus LeConte (Coleoptera: Cerambycidae); and a root boring moth, Pelochrista womonana (Kearfott) (Lepidoptera: Tortricidae), at two locations in the central Great Plains. Germplasm with potential sources of resistance to attack from all three stem-infesting species were revealed. Accessions PI 650558, PI 386230, and PI 431516 were consistent in averaging low densities of stem weevil larvae per stalk among lines tested, and PI 497939 exceeded 25 weevil larvae per stalk in only 1 yr of 5 yr of trials. Several interspecific crosses also had consistently low densities of C. adspersus larvae per stalk. Populations of both D. texanus and P. womonana were variable over years, but differences among the lines tested were evident in many trials, revealing potential for developing resistant germplasm. Four accessions (PI 386230, PI 431542, PI 650497, and PI 650558) had low larval densities of C. adspersus and P. womonana in addition to reduced percentage infestation by D. texanus. Results showed potential for developing resistant genotypes for these pests. The prospect of adding host plant resistance as an integrated pest management (IPM) tactic would provide another tool for reducing economic losses from stem-infesting insect pests of sunflower in the central Great Plains.

  20. Comparative riverscape genetics reveals reservoirs of genetic diversity for conservation and restoration of Great Plains fishes.

    PubMed

    Osborne, Megan J; Perkin, Joshuah S; Gido, Keith B; Turner, Thomas F

    2014-12-01

    We used comparative landscape genetics to examine the relative roles of historical events, intrinsic traits and landscape factors in determining the distribution of genetic diversity of river fishes across the North American Great Plains. Spatial patterns of diversity were overlaid on a patch-based graphical model and then compared within and among three species that co-occurred across five Great Plains watersheds. Species differing in reproductive strategy (benthic vs. pelagic-spawning) were hypothesized to have different patterns of genetic diversity, but the overriding factor shaping contemporary patterns of diversity was the signature of past climates and geological history. Allelic diversity was significantly higher at southern latitudes for Cyprinella lutrensis and Hybognathus placitus, consistent with northward expansion from southern Pleistocene refugia. Within the historical context, all species exhibited lowered occupancy and abundance in heavily fragmented and drier upstream reaches, particularly H. placitus; a pelagic-spawning species, suggesting rates of extirpation have outpaced losses of genetic diversity in this species. Within most tributary basins, genetically diverse populations of each species persisted. Hence, reconnecting genetically diverse populations with those characterized by reduced diversity (regardless of their position within the riverine network) would provide populations with greater genetic and demographic resilience. We discuss cases where cross-basin transfer may be appropriate to enhance genetic diversity and mitigate negative effects of climate change. Overall, striking similarities in genetic patterns and in response to fragmentation and dewatering suggest a common strategy for genetic resource management in this unique riverine fish assemblage. © 2014 John Wiley & Sons Ltd.

  1. Saline systems of the Great Plains of western Canada: an overview of the limnogeology and paleolimnology.

    PubMed

    Last, William M; Ginn, Fawn M

    2005-11-18

    In much of the northern Great Plains, saline and hypersaline lacustrine brines are the only surface waters present. As a group, the lakes of this region are unique: there is no other area in the world that can match the concentration and diversity of saline lake environments exhibited in the prairie region of Canada and northern United States. The immense number of individual salt lakes and saline wetlands in this region of North America is staggering. Estimates vary from about one million to greater than 10 million, with densities in some areas being as high as 120 lakes/km2. Despite over a century of scientific investigation of these salt lakes, we have only in the last twenty years advanced far enough to appreciate the wide spectrum of lake types, water chemistries, and limnological processes that are operating in the modern settings. Hydrochemical data are available for about 800 of the lake brines in the region. Composition, textural, and geochemical information on the modern bottom sediments has been collected for just over 150 of these lakes. Characterization of the biological and ecological features of these lakes is based on even fewer investigations, and the stratigraphic records of only twenty basins have been examined. The lake waters show a considerable range in ionic composition and concentration. Early investigators, concentrating on the most saline brines, emphasized a strong predominance of Na+ and SO4-2 in the lakes. It is now realized, however, that not only is there a complete spectrum of salinities from less than 1 ppt TDS to nearly 400 ppt, but also virtually every water chemistry type is represented in lakes of the region. With such a vast array of compositions, it is difficult to generalize. Nonetheless, the paucity of Cl-rich lakes makes the northern Great Plains basins somewhat unusual compared with salt lakes in many other areas of the world (e.g., Australia, western United States). Compilations of the lake water chemistries show distinct

  2. Saline systems of the Great Plains of western Canada: an overview of the limnogeology and paleolimnology

    PubMed Central

    Last, William M; Ginn, Fawn M

    2005-01-01

    In much of the northern Great Plains, saline and hypersaline lacustrine brines are the only surface waters present. As a group, the lakes of this region are unique: there is no other area in the world that can match the concentration and diversity of saline lake environments exhibited in the prairie region of Canada and northern United States. The immense number of individual salt lakes and saline wetlands in this region of North America is staggering. Estimates vary from about one million to greater than 10 million, with densities in some areas being as high as 120 lakes/km2. Despite over a century of scientific investigation of these salt lakes, we have only in the last twenty years advanced far enough to appreciate the wide spectrum of lake types, water chemistries, and limnological processes that are operating in the modern settings. Hydrochemical data are available for about 800 of the lake brines in the region. Composition, textural, and geochemical information on the modern bottom sediments has been collected for just over 150 of these lakes. Characterization of the biological and ecological features of these lakes is based on even fewer investigations, and the stratigraphic records of only twenty basins have been examined. The lake waters show a considerable range in ionic composition and concentration. Early investigators, concentrating on the most saline brines, emphasized a strong predominance of Na+ and SO4-2 in the lakes. It is now realized, however, that not only is there a complete spectrum of salinities from less than 1 ppt TDS to nearly 400 ppt, but also virtually every water chemistry type is represented in lakes of the region. With such a vast array of compositions, it is difficult to generalize. Nonetheless, the paucity of Cl-rich lakes makes the northern Great Plains basins somewhat unusual compared with salt lakes in many other areas of the world (e.g., Australia, western United States). Compilations of the lake water chemistries show distinct

  3. Intermittent Elevated Radium Concentrations in Coastal Plain Groundwater of South Carolina, U.S.A.

    SciTech Connect

    Denham, Miles; Millings, Margaret; Noonkester, Jay

    2005-09-22

    To learn the cause of intermittent radium concentrations in groundwater of Coastal Plain aquifers, 31 groundwater wells in South Carolina, U.S.A. were sampled for radium and other geochemical parameters. Sediments cored from near the well screens were also sampled to examine any relationship between sediment properties and radium concentration in the groundwater. Elevated radium concentrations only occurred in groundwater with low electrical conductivity and pH values below 6.3. The adsorption edge for radium on hematite--a major surface active mineral in these aquifers--is at a pH value of about 6. Near this value, small changes in pH can result in significant adsorption or desorption of radium. In groundwater with initially low alkalinity, small intermittent decreases in partial pressure of carbon dioxide in groundwater cause decreases in pH and desorption of radium. The result is intermittent elevated radium concentrations.

  4. Ameliorating soil chemical properties of a hard setting subsoil layer in coastal plain USA with different designer biochars

    USDA-ARS?s Scientific Manuscript database

    Norfolk soils in the southeastern United States of America (USA) Coastal Plain region have meager soil fertility characteristics because of their sandy textures, acidic pH values, kaolinitic clays and with depleted organic carbon contents. Extensive clay mineral weathering and clay eluviation along ...

  5. A conceptual hydrologic model for a forested Carolina bay depressional wetland on the Coastal Plain of South Carolina, USA

    Treesearch

    Jennifer E. Pyzoha; Timothy J. Callahan; Ge Sun; Carl C. Trettin; Masato Miwa

    2008-01-01

    This paper describes how climate influences the hydrology of an ephemeral depressional wetland. Surface water and groundwater elevation data were collected for 7 years in a Coastal Plain watershed in South Carolina USA containing depressional wetlands, known as Carolina bays. Rainfall and temperature data were compared with water-table well and piezometer data in and...

  6. Comparison of soil amendments to decrease high strength in SE USA Coastal Plain soils using fuzzy decision-making analyses

    USDA-ARS?s Scientific Manuscript database

    Cemented subsurface layers restrict root growth in many southeastern USA Coastal Plain soils. Though cementation is usually reduced by tillage, soil amendments can offer a more permanent solution if they develop aggregation. To increase aggregation, we amended 450 g of a Norfolk soil blend of 90% E ...

  7. Comparison Between Lidar and Nephelometer Measurements of Aerosol Hygroscopicity at the Southern Great Plains Atmospheric Radiation Measurement Site

    NASA Technical Reports Server (NTRS)

    Pahlow, M.; Feingold, G.; Jefferson, A.; Andrews, E.; Ogren, J. A.; Wang, J.; Lee, Y.-N.; Ferrare, R. A.

    2004-01-01

    Aerosol hygroscopicity has a significant effect on radiative properties of aerosols. Here a lidar method, applicable to cloud-capped, well-mixed atmospheric boundary layers, is employed to determine the hygroscopic growth factor f(RH) under unperturbed, ambient atmospheric conditions. The data used for the analysis were collected under a wide range of atmospheric aerosol levels during both routine measurement periods and during the intensive operations period (IOP) in May 2003 at the Southern Great Plains (SGP) Climate Research Facility in Oklahoma, USA, as part of the Atmospheric Radiation Measurement (ARM) program. There is a good correlation (approx. 0.7) between a lidar-derived growth factor (measured over the range 85% RH to 96% RH) with a nephelometer-derived growth factor measured over the RH range 40% to 85%. For these RH ranges, the slope of the lidar-derived growth factor is much steeper than that of the nephelometer-derived growth factor, reflecting the rapid increase in particle size with increasing RH. The results are corroborated by aerosol model calculations of lidar and nephelometer equivalent f(RH) based on in situ aerosol size and composition measurements during the IOP. It is suggested that the lidar method can provide useful measurements of the dependence of aerosol optical properties on relative humidity, and under conditions closer to saturation than can currently be achieved with humidified nephelometers.

  8. ``Carolina Bays" on the Georgia (USA) Coastal Plain: Meteoritic Origin Revisited

    NASA Astrophysics Data System (ADS)

    Albin, E. F.

    2001-11-01

    In this investigation, forty-four elliptical depressions, with diameters > 1.0 km, have been mapped across the Georgia (USA) coastal plain. These curious features are often called pocosins (an Algonquin name for a bay-covered swamp); however, in the literature the depressions are the so-called ``Carolina Bays" [1]. Controversy has surrounded the origin of the Carolina Bays since they were first recognized in the late eighteenth century [e.g., 2]. Although terrestrial processes have been invoked to explain their origin, a meteoritic related mode of formation cannot be ruled out. Aerial imagery shows the bays on the Georgia coastal plain as dark ovals surrounded by white to light-gray rims. These rims are composed of sandy deposits that are typically less than two meters high and are better developed in the southeastern part of the oval. Magnetic anomalies occur outside of most bay depressions, approximately the distance of the short axis of the bay away from the southeastern rim. On a regional scale, bay trend is from NW to SE -- with the southern most occurring bays having a slight clockwise orientation relative to those found farther north. Arabia Bay, a 4.5 x 6.0 km feature, in Clinch County is the largest bay identified in Georgia. It is suggested that bays are late Pleistocene features produced by a series of ``Tunguska-like" atmospheric bursts associated with the fall of a massive chondritic or cometary bolide. Associated air-shock waves plowed into soft sediments, across the eastern North American coastal plain (from New Jersey to Georgia), forming a myriad of shallow depressions along its path. Further research, including laboratory modeling and field investigations, is ongoing. References: [1] Prouty, W.F., 1952, Bull. Geol. Soc. Amer., 63, 167-224. [2] Savage, H., 1982, The Mysterious Carolina Bays, Univ. South Carolina Press, 121 p.

  9. Partners in flight bird conservation plan for the Upper Great Lakes Plain (Physiographic Area 16)

    USGS Publications Warehouse

    Knutson, M.G.; Butcher, G.; Fitzgerald, J.; Shieldcastle, J.

    2001-01-01

    1 November 2001. Conservation of bird habitats is a major focus of effort by Partners in Flight, an international coalition of agencies, citizens, and other groups dedicated to 'keeping common birds common'. USGS worked on a planning team to publish a bird conservation plan for the Upper Great Lakes Plain ecoregion (PIF 16), which includes large portions of southern Wisconsin, southern Michigan and parts of Minnesota, Iowa, Illinois, Indiana, and Ohio. The conservation plan outlines specific habitat restoration and bird population objectives for the ecoregion over the next decade. The plan provides a context for on-the-ground conservation implementation by the US Fish and Wildlife Service, the USDA Natural Resources Conservation Service, the US Forest Service, states, and conservation groups. Citation: Knutson, M. G., G. Butcher, J. Fitzgerald, and J. Shieldcastle. 2001. Partners in Flight Bird Conservation Plan for The Upper Great Lakes Plain (Physiographic Area 16). USGS Upper Midwest Environmental Sciences Center in cooperation with Partners in Flight, La Crosse, Wisconsin. Download from website: http://www.blm.gov/wildlife/pifplans.htm. The Upper Great Lakes Plain covers the southern half of Michigan, northwest Ohio, northern Indiana, northern Illinois, southern Wisconsin, and small portions of southwest Minnesota and northwest Iowa. Glacial moraines and dissected plateaus are characteristic of the topography. Broadleaf forests, oak savannahs, and a variety of prairie communities are the natural vegetation types. A oDriftless Areao was not glaciated during the late Pleistocene and emerged as a unique area of great biological diversity. Priority bird species for the area include the Henslow's Sparrow, Sedge Wren, Bobolink, Golden-winged Warbler, Cerulean Warbler, Black-billed Cuckoo, and Red-headed Woodpecker. There are many large urban centers in this area whose growth and sprawl will continue to consume land. The vast majority of the presettlement forest and

  10. Liquefaction record of the great 1934 earthquake predecessors from the north Bihar alluvial plains of India

    NASA Astrophysics Data System (ADS)

    Rajendran, C. P.; John, Biju; Rajendran, Kusala; Sanwal, Jaishri

    2016-07-01

    The great 1934 Himalayan earthquake of moment magnitude (Mw) 8.1 generated a large zone of ground failure and liquefaction in north Bihar, India, in addition to the earthquakes of 1833 (Mw ~7.7) and 1988 (Mw 6.7) that have also impacted this region. Here, we present the results of paleoliquefaction investigations from four sites in the plains of north Bihar and one in eastern Uttar Pradesh. The liquefaction features generated by successive earthquakes were dated at AD 829-971, 886-1090, 907-1181, 1130-1376, 1112-1572, 1492-1672, 1733-1839, and 1814-1854. One of the liquefaction events dated at AD 829-971, 886-1090, and 907-1181 may correlate with the great earthquake of AD ~1100, recognized in an earlier study from the sections across the frontal thrust in central eastern Nepal. Two late medieval liquefaction episodes of AD 1130-1376 and 1492-1672 were also exposed in our sites. The sedimentary sections also revealed sandblows that can be attributed to the 1833 earthquake, a lesser magnitude event compared to the 1934. Liquefactions triggered by the 1934 and 1988 earthquakes were evident within the topmost level in some sections. The available data lead us to conjecture that a series of temporally close spaced earthquakes of both strong and large types, not including the infrequent great earthquakes like the 1934, have affected the Bihar Plains during the last 1500 years with a combined recurrence interval of 124 ± 63 years.

  11. Abrupt Climate Change in the Southern Great Plains during the Last Glacial Interval

    NASA Astrophysics Data System (ADS)

    Housson, A. L.; Maupin, C. R.; Roark, B.; Shen, C. C.; Baykara, O.; White, K.; Kampen-Lewis, S. V.; McChesney, C. L.

    2016-12-01

    Understanding how the climate of the North American Great Plains may change in the future is of tremendous socioeconomic importance, yet the regional response to previous abrupt global climate events, such as the Dansgaard-Oeschger (DO) cycles of the last glacial interval, are poorly known. Here we present two absolutely dated (U/Th), partially replicated oxygen isotope (δ18O) records from calcite speleothems in central Texas (30° N, 98° W) that grew during marine isotope stage 3 (MIS 3) (31 to 49 ky BP). The study site experiences boreal spring and fall maxima in precipitation with rainfall moisture sourced almost exclusively from the Gulf of Mexico. The two samples exhibit reproducible δ18O means and variability during overlapping growth intervals. Weak correlations between paired oxygen and carbon isotopic values coupled with reproducible δ18O strongly suggest that dripwater δ18O and calcite formation temperatures are the primary drivers of speleothem δ18O variations through time. We interpret more depleted (enriched) δ18O values to reconstruct warmer and wetter (cooler and drier) conditions based on observations of modern rainfall stable isotope variations at the study site. We find that warmer and wetter conditions in the Southern Plains are contemporaneous with MIS 3 DO interstadials, while cooler and more arid conditions prevail during stadials and Heinrich Events 4 and 5. Our results show a response opposite that of hydrologic reconstructions from the American Southwest, where wetter conditions occur with stadial conditions. Future work includes exploration of paleoclimate model results to examine potential mechanisms responsible for this opposite phasing. Our speleothem data indicate that further intensification of rainy seasons in the Southern Plains should not be ruled out as a response to anthropogenic global warming.

  12. Quantifying climate change mitigation potential in Great Plains wetlands for three greenhouse gas emission scenarios

    USGS Publications Warehouse

    Byrd, Kristin B.; Ratliff, Jamie L.; Wein, Anne; Bliss, Norman B.; Sleeter, Benjamin M.; Sohl, Terry L.; Li, Zhengpeng

    2015-01-01

    We examined opportunities for avoided loss of wetland carbon stocks in the Great Plains of the United States in the context of future agricultural expansion through analysis of land-use land-cover (LULC) change scenarios, baseline carbon datasets and biogeochemical model outputs. A wetland map that classifies wetlands according to carbon pools was created to describe future patterns of carbon loss and potential carbon savings. Wetland avoided loss scenarios, superimposed upon LULC change scenarios, quantified carbon stocks preserved under criteria of carbon densities or land value plus cropland suitability. Up to 3420 km2 of wetlands may be lost in the region by 2050, mainly due to conversion of herbaceous wetlands in the Temperate Prairies where soil organic carbon (SOC) is highest. SOC loss would be approximately 0.20 ± 0.15 megagrams of carbon per hectare per year (MgC ha−1 yr−1), depending upon tillage practices on converted wetlands, and total ecosystem carbon loss in woody wetlands would be approximately 0.81 ± 0.41 MgC ha−1 yr−1, based on biogeochemical model results. Among wetlands vulnerable to conversion, wetlands in the Northern Glaciated Plains and Lake Agassiz Plains ecoregions exhibit very high mean SOC and on average, relatively low land values, potentially creating economically competitive opportunities for avoided carbon loss. This mitigation scenarios approach may be adapted by managers using their own preferred criteria to select sites that best meet their objectives. Results can help prioritize field-based assessments, where site-level investigations of carbon stocks, land value, and consideration of local priorities for climate change mitigation programs are needed.

  13. The Younger Dryas phase of Great Salt Lake, Utah, USA

    USGS Publications Warehouse

    Oviatt, Charles G.; Miller, D.M.; McGeehin, J.P.; Zachary, C.; Mahan, S.

    2005-01-01

    Field investigations at the Public Shooting Grounds (a wildlife-management area on the northeastern shore of Great Salt Lake) and radiocarbon dating show that the Great Salt Lake rose to the Gilbert shoreline sometime between 12.9 and 11.2 cal ka. We interpret a ripple-laminated sand unit exposed at the Public Shooting Grounds, and dated to this time interval, as the nearshore sediments of Great Salt Lake deposited during the formation of the Gilbert shoreline. The ripple-laminated sand is overlain by channel-fill deposits that overlap in age (11.9-11.2 cal ka) with the sand, and by wetland deposits (11.1 to 10.5 cal ka). Consistent accelerator mass spectrometry radiocarbon ages were obtained from samples of plant fragments, including those of emergent aquatic plants, but mollusk shells from spring and marsh deposits yielded anomalously old ages, probably because of a variable radiocarbon reservoir effect. The Bonneville basin was effectively wet during at least part of the Younger Dryas global-cooling interval, however, conflicting results from some Great Basin locations and proxy records indicate that the regional effects of Younger Dryas cooling are still not well understood. ?? 2005 Elsevier B.V. All rights reserved.

  14. Sediment toxicity in mid-continent great rivers (USA)

    EPA Science Inventory

    In this study, 530 sediment samples were collected from 447 sites between 2004 and 2006 at randomly selected shoreline sites along the main channel of the Ohio, Missouri and Upper Mississippi Rivers as part of the Environmental Monitoring and Assessment Program for Great Rivers E...

  15. Sediment toxicity in mid-continent great rivers (USA)

    EPA Science Inventory

    In this study, 530 sediment samples were collected from 447 sites between 2004 and 2006 at randomly selected shoreline sites along the main channel of the Ohio, Missouri and Upper Mississippi Rivers as part of the Environmental Monitoring and Assessment Program for Great Rivers E...

  16. Road crossing designs and their impact on fish assemblages of Great Plains streams

    USGS Publications Warehouse

    Bouska, Wesley W.; Paukert, Craig P.

    2010-01-01

    A mark-recapture field study was conducted to determine fish passage at 5 concrete box culverts and 5 low-water crossings (concrete slabs vented by culverts) as well as 10 control sites (below a natural riffle) in Flint Hills streams of northeastern Kansas. Additionally, we tested the upstream passage of four fish species native to Great Plains streams (Topeka shiner Notropis topeka, green sunfish Lepomis cyanellus, red shiner Cyprinella lutrensis, and southern redbelly dace Phoxinus erythrogaster) through three simulated crossing designs (box culverts, round corrugated culverts, and natural rock riffles) at water velocities of 0.1 to 1.1 m/s in an experimental stream. The field study indicated that cyprinids were twice as likely to move upstream of box culverts than low-water crossings and 1.4 times as likely to move upstream of control reaches than any crossing type. The best models indicated that the proportion of cyprinids that moved upstream increased with decreased culvert slope and length, perching, and increased culvert width. Our controlled experiment indicated that fish can move through velocities up to 1.1 m/s in a 1.86-m simulated stream and that the proportion of fish that moved upstream did not differ among crossing designs for southern redbelly dace, green sunfish, or Topeka shiner; however, natural rock riffles had lower proportional movements (mean = 0.19) than the box (0.38) or corrugated culvert designs (0.43) for red shiners. Water velocity did not affect the proportional upstream movement of any species except that of Topeka shiners, which increased with water velocity. Crossing design alone may not determine fish passage, and water velocities up to 1.1 m/s may not affect the passage of many Great Plains fishes. Barriers to fish movement may be the result of other factors (e.g., perching, slope, and crossing length). The use of properly designed and installed crossings has promise in conserving Great Plains stream fishes.

  17. A one-year climatology using data from the Southern Great Plains (SGP) site micropulse lidar

    SciTech Connect

    Mace, G.G.; Ackerman, T.P.; Spinhirne, J.; Scott, S.

    1996-04-01

    The micropulse lidar (MPL) has been operational at the Southern Great Plains (SGP) site of the Atmospheric Radiation Measurement Program for the past 15 months. The compact MPL is unique among research lidar systems in that it is eye-safe and operates continuously, except during precipitation. The MPL is capable of detecting cloud base throughout the entire depth of the troposphere. The MPL data set is an unprecedented time series of cloud heights. It is a vital resource for understanding the frequency of cloud ocurrence and the impact of clouds on the surface radiation budget, as well as for large-scale model validation and satellite retrieval verification. The raw lidar data are processed for cloud base height at a temporal frequency of one minute and a vertical resolution of 270 m. The resultant time series of cloud base is used to generate histograms as a function of month and time of day. Sample results are described.

  18. Evaluating soil moisture and yield of winter wheat in the Great Plains using Landsat data

    NASA Technical Reports Server (NTRS)

    Heilman, J. L.; Kanemasu, E. T.; Bagley, J. O.; Rasmussen, V. P.

    1977-01-01

    Locating areas where soil moisture is limiting to crop growth is important for estimating winter-wheat yields on a regional basis. In the 1975-76 growing season, we evaluated soil-moisture conditions and winter-wheat yields for a five-state region of the Great Plains using Landsat estimates of leaf area index (LAI) and an evapotranspiration (ET) model described by Kanemasu et al (1977). Because LAI was used as an input, the ET model responded to changes in crop growth. Estimated soil-water depletions were high for the Nebraska Panhandle, southwestern Kansas, southeastern Colorado, and the Texas Panhandle. Estimated yields in five-state region ranged from 1.0 to 2.9 metric ton/ha.

  19. Shallow, low-permeability reservoirs of northern Great Plains - assessment of their natural gas resources.

    USGS Publications Warehouse

    Rice, D.D.; Shurr, G.W.

    1980-01-01

    Major resources of natural gas are entrapped in low-permeability, low-pressure reservoirs at depths less than 1200m in the N.Great Plains. This shallow gas is the product of the immature stage of hydrocarbon generation and is referred to as biogenic gas. Prospective low-permeability, gas-bearing reservoirs range in age from late Early to Late Cretaceous. The following facies were identified and mapped: nonmarine rocks, coastal sandstones, shelf sandstones, siltstones, shales, and chalks. The most promising low-permeability reservoirs are developed in the shelf sandstone, siltstone, and chalk facies. Reservoirs within these facies are particularly attractive because they are enveloped by thick sequences of shale which serve as both a source and a seal for the gas.-from Author

  20. AmeriFlux US-ARc ARM Southern Great Plains control site- Lamont

    DOE Data Explorer

    Torn, Margaret [Lawrence Berkeley National Laboratory

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-ARc ARM Southern Great Plains control site- Lamont. Site Description - The ARM SGP Control site is located in the native tallgrass prairies of the USDA Grazinglands Research Laboratory near El Reno, OK. One of two adjacent 35 ha plots with identical towers, measurements at the US-ARc unburned plot are used as the experimental control. The second plot, US-Arb, was burned on 2005/03/08. Measurement comparisons between the control and burn plot are used to address questions regarding the effects of burning activities on carbon fluxes. The region evaded burning activities for at least 15 years. Current disturbances consist of only light grazing activities.

  1. Selected hydrogeologic data from the Northern Great Plains area of Montana

    USGS Publications Warehouse

    Levings, Gary W.

    1981-01-01

    Selected hydrologic data have been used in a 4-year study of aquifers of Cenozoic and Mesozoic age in the northern Great Plains to define the hydrologic system and to generate hydrologic maps. Records of 6,754 wells and 188 springs are tabulated in the report. The well data include site location, county, date completed, depth of well, casing diameter, type of lift, use of water, principal aquifer, altitude of land surface, water level, discharge, specific capacity, specific conductance, and water temperature. The spring data include site location, county, use of water, principal aquifer, altitude of land surface, type of spring, discharge, date discharge measured, specific conductance, and water temperature. Locations of the wells and springs are shown on a map at a scale of 1:1,000,000. (USGS)

  2. Clear Sky Identification Using Data From Remote Sensing Systems at ARM's Southern Great Plains Site

    SciTech Connect

    Delle Monache, L.; Rodriguez, D.; Cederwall, R.

    2000-06-27

    Clouds profoundly affect our weather and climate due, in large part, to their interactions with radiation. Unfortunately, our understanding of these interactions is, at best, incomplete, making it difficult to improve the treatment of atmospheric radiation in climate models. The improved treatment of clouds and radiation, and a better understanding of their interaction, in climate models is one of the Department of Energy's Atmospheric Radiation Measurement (ARM) Program's major goals. To learn more about the distribution of water and ice, i.e., clouds, within an atmospheric column, ARM has chosen to use the remote sensing of clouds, water vapor and aerosols at its three climatologically-diverse sites as its primary observational method. ARM's most heavily instrumented site, which has operated continuously for more than a decade, is its Southern Great Plains (SGP) Central Facility, located near Lamont, OK. Cloud-observing instruments at the Central Facility include the Whole Sky Imager, ceilometers, lidar, millimeter cloud radar, microwave radiometers and radiosondes.

  3. Stratum variance estimation for sample allocation in crop surveys. [Great Plains Corridor

    NASA Technical Reports Server (NTRS)

    Perry, C. R., Jr.; Chhikara, R. S. (Principal Investigator)

    1980-01-01

    The problem of determining stratum variances needed in achieving an optimum sample allocation for crop surveys by remote sensing is investigated by considering an approach based on the concept of stratum variance as a function of the sampling unit size. A methodology using the existing and easily available information of historical crop statistics is developed for obtaining initial estimates of tratum variances. The procedure is applied to estimate stratum variances for wheat in the U.S. Great Plains and is evaluated based on the numerical results thus obtained. It is shown that the proposed technique is viable and performs satisfactorily, with the use of a conservative value for the field size and the crop statistics from the small political subdivision level, when the estimated stratum variances were compared to those obtained using the LANDSAT data.

  4. Toxic fables: the advertising and marketing of agricultural chemicals in the great plains, 1945-1985.

    PubMed

    Vail, David D

    2012-12-01

    This paper examines how pesticides and their technologies were sold to farmers and pilots throughout the midtwentieth century. It principally considers how marketing rhetoric and advertisement strategies used by chemical companies and aerial spraying firms influenced the practices and perspectives of farm producers in the Great Plains. In order to convince landowners and agricultural leaders to buy their pesticides, chemical companies generated advertisements that championed local crop health, mixture accuracy, livestock safety and a chemical-farming 'way of life' that kept fields healthy and productive. Combining notions of safety, accuracy and professionalism with pest eradication messages reinforced the standards that landowners, pilots and agriculturalists would hold regarding toxicity and risk when spraying their fields. As the politics of health changed in the aftermath of Rachel Carson's Silent Spring, these companies and aerial spraying outfits responded by keeping to a vision of agricultural health that required poisons for protection through technological accuracy.

  5. The Saga of Leafy Spurge (Euphorbia esula) in the Northern Great Plains

    USGS Publications Warehouse

    Larson, Diane L.

    2009-01-01

    Leafy spurge (Euphorbia esula L.) is an invasive Eurasian perennial introduced into the United States as a contaminant of crop seed in the 1880s and 1890s. It typically forms monocultures in rangeland and natural areas of the northern Great Plains where, because of the latex that occurs in all parts of the plant, it is not consumed by naturally occurring herbivores. U.S. Geological Survey (USGS) scientists and their collaborators have been studying leafy spurge at Theodore Roosevelt National Park (TRNP) and at Arrowwood and Tewaukon National Wildlife Refuges in North Dakota since 1998. Study findings have been published in Larson and Grace (2004), Larson and others (2006), Larson and others (2007), Jordan and others (2008), and Larson and others (2008). This fact sheet summarizes that body of research.

  6. Biological Conditions and Economic Development: Nineteenth-Century Stature on the U.S. Great Plains.

    PubMed

    Carson, Scott Alan

    2015-06-01

    Average stature is now a well-accepted measure of material and economic well-being in development studies when traditional measures are sparse or unreliable, but little work has been done on the biological conditions for individuals on the nineteenth-century U.S. Great Plains. Records of 14,427 inmates from the Nebraska state prison are used to examine the relationship between stature and economic conditions. Statures of both black and white prisoners in Nebraska increased through time, indicating that biological conditions improved as Nebraska's output market and agricultural sectors developed. The effect of rural environments on stature is illustrated by the fact that farm laborers were taller than common laborers. Urbanization and industrialization had significant impacts on stature, and proximity to trade routes and waterways was inversely related to stature.

  7. Design of the aerosol sampling manifold for the Southern Great Plains site

    SciTech Connect

    Leifer, R.; Knuth, R.H.; Guggenheim, S.F.; Lee, H.N.

    1995-04-01

    To meet the needs of the ARM program, the Environmental Measurements Laboratory (EML) has the responsibility to establish a surface aerosol measurements program at the Southern Great Plains (SGP) site in Lamont, OK. At the present time, EML has scheduled installation of five instruments at SGP: a single wavelength nephelometer, an optical particle counter (OPC), a condensation particle counter (CPC), an optical absorption monitor (OAM), and an ozone monitor. ARM`s operating protocol requires that all the observational data be placed online and sent to the main computer facility in real time. EML currently maintains a computer file containing back trajectory (BT) analyses for the SGP site. These trajectories are used to characterize air mass types as they pass over the site. EML is continuing to calculate and store the resulting trajectory analyses for future use by the ARM science team.

  8. Cost-effective sulfur control strategies for the Great Plains gasification project

    SciTech Connect

    Doctor, R.D.; Wilzbach, K.E. . Energy and Environmental Systems Div.)

    1989-09-01

    The Great Plains gasification plant in Beulah, North Dakota, uses 14 Lurgi gasifiers to produce 152x10/sup 6/ scf/d (4.1x10/sup 6/ Nm/sup 3//d) of pipeline-quality gas from lignite. Since start-up in mid-1984, the plant has provided a serious challenge to the reliable operation of the Stretford sulfur recovery system. To address this challenge, over forty options for mitigating sulfur emissions were evaluated on an economic and technical basis, beginning at the emissions source (the stack) and working back through the plant. Although this study was directed toward providing a timely solution to the sulfur dioxide emissions problem, the status and opportunities for a number of emerging technologies were brought into focus. This evaluation is detailed here by the authors.

  9. Grassland bird use of Conservation Reserve Program Fields in the Great Plains

    USGS Publications Warehouse

    Johnson, Douglas H.

    2000-01-01

    The area enrolled in the Conservation Reserve Program in the Great Plains is enormous: nearly 18 million acres, or more than 7 million hectares, in Montana, North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, and Texas. This change in land use has had a huge influence on grassland bird populations. Many, but certainly not all, grassland species flourish in CRP habitats. Responses to the program vary not only by species, but by region, year, vegetation composition in a field, and whether or not a field was hayed or grazed. Further, the large scale of CRP has allowed researchers to begin to address other important conservation questions, such as the effect of the size of habitat patch and the influences of landscape features. Although the CRP provisions of farm bills have been beneficial to grassland birds, it is critical that gains in grassland habitat induced by the program not be offset by losses due to sodbusting.

  10. Surface Forcing from CH4 at the North Slope of Alaska and Southern Great Plains Sites

    NASA Astrophysics Data System (ADS)

    Collins, W.; Feldman, D.; Turner, D. D.

    2014-12-01

    Recent increases in atmospheric CH4 have been spatially heterogeneous as indicated by in situ flask measurements and space-borne remote-sensing retrievals from the AIRS instrument, potentially leading to increased radiative forcing. We present detailed, specialized measurements at the DOE ARM North Slope of Alaska (NSA) and Southern Great Plains (SGP) sites to derive the time-series of both CH4 atmospheric concentrations and associated radiative implications at highly-contrasting natural and anthropogenic sources. Using a combination of spectroscopic measurements, in situ observations, and ancillary data for the atmospheric thermodynamic state from radiosondes and cloud-clearing from active sounders, we can separate out the contribution of CH4 to clear-sky downwelling radiance spectra and its infrared surface forcing. The time-series indicates year-to-year variation in shoulder season increases of CH4 concentration and forcing at NSA and large signals from anthropogenic activity at SGP.

  11. Development of the alkenone-based temperature proxy: insights from lakes in the Northern Great Plains

    NASA Astrophysics Data System (ADS)

    Plancq, J.; Toney, J. L.; Haig, H.

    2016-12-01

    Alkenones have been used for decades to reconstruct quantitative marine temperature records. Their use as terrestrial temperature proxy is however hampered by the fact that different lakes can contain different species of haptophyte algae implying different temperature calibrations. This can be overcome by creating a site-specific core top calibration, using environmental genomics to determine the specie(s) of haptophyte present, and/or using enrichment or isolated algal cultures to generate a culture-based temperature calibration. In the framework of the ERC-funded Project "ALKENoNE: Algal Lipids, Key to Earth Now and aNcient Earth", a large set of surface sediments collected in 106 lakes from the Northern Great Plains (Canadian prairies, Saskatchewan region) is currently being studied for alkenone composition and alkenone producers. These lakes span a 5° latitudinal gradient and a large range of salinity (Δ 102 ppt). Alkenones are common in these Canadian lakes, with 55% of surveyed lakes containing alkenones. Their concentration is on average of 10 μg/g sediment, but very high concentrations (up to 1.7 mg/g sediment) are recorded in 12% of the alkenone-containing lakes. Principal component analyses indicate that alkenones are more abundant in sulfate-rich and more saline lakes, which is in agreement with previous studies in lakes from Spain and the United States Great Plains. Almost all alkenone-containing lakes (93%) have a C37:4 dominated profile, which suggests the presence of a single haptophyte species, showing the potential of these lakes to develop the temperature proxy. The alkenone unsaturation indice (UK37) is however not significantly correlated with average summer water temperature, probably because summer season does not correspond to the timing of maximum alkenone production. These results will be confirmed by environmental genomics and the isolation of the alkenone-producing haptophyte for culture experiments and the development of a culture

  12. Adaptive data-driven models for estimating carbon fluxes in the Northern Great Plains

    USGS Publications Warehouse

    Wylie, B.K.; Fosnight, E.A.; Gilmanov, T.G.; Frank, A.B.; Morgan, J.A.; Haferkamp, Marshall R.; Meyers, T.P.

    2007-01-01

    Rangeland carbon fluxes are highly variable in both space and time. Given the expansive areas of rangelands, how rangelands respond to climatic variation, management, and soil potential is important to understanding carbon dynamics. Rangeland carbon fluxes associated with Net Ecosystem Exchange (NEE) were measured from multiple year data sets at five flux tower locations in the Northern Great Plains. These flux tower measurements were combined with 1-km2 spatial data sets of Photosynthetically Active Radiation (PAR), Normalized Difference Vegetation Index (NDVI), temperature, precipitation, seasonal NDVI metrics, and soil characteristics. Flux tower measurements were used to train and select variables for a rule-based piece-wise regression model. The accuracy and stability of the model were assessed through random cross-validation and cross-validation by site and year. Estimates of NEE were produced for each 10-day period during each growing season from 1998 to 2001. Growing season carbon flux estimates were combined with winter flux estimates to derive and map annual estimates of NEE. The rule-based piece-wise regression model is a dynamic, adaptive model that captures the relationships of the spatial data to NEE as conditions evolve throughout the growing season. The carbon dynamics in the Northern Great Plains proved to be in near equilibrium, serving as a small carbon sink in 1999 and as a small carbon source in 1998, 2000, and 2001. Patterns of carbon sinks and sources are very complex, with the carbon dynamics tilting toward sources in the drier west and toward sinks in the east and near the mountains in the extreme west. Significant local variability exists, which initial investigations suggest are likely related to local climate variability, soil properties, and management.

  13. Indirect Effects of Climate Change on Heat Waves in the Great Plains

    NASA Astrophysics Data System (ADS)

    Branstator, G.; Teng, H.

    2015-12-01

    When we analyze a large ensemble RCP8.5 climate change experiment we find that heat waves have become more common and intense in the Great Plains during 2070-2100 compared to 1980-2010. Much of this can be attributed to the simple direct additive effect of a 5.8°C increase in Jun-Aug surface mean temperatures in that region. But there is also a non-additive effect in that daily temperature departures from the new mean during heat waves are about 0.6°C warmer in the future epoch. Here we consider two often-proposed mechanisms by which this change in the variability of surface temperature could result from indirect influences of changes in the mean state. One mechanism involves changes in the variability of upper tropospheric planetary waves, which we are especially interested in because we have found planetary wave structures that both affect the likelihood of heat waves and have unusually high predictability on subseasonal time scales. Our analysis does show that the amplitude of planetary wave variability has been modified in the future modeled climate. And calculations with a mechanistic model show this is indeed a consequence of the change in the mean circulation. But further analysis indicates this modification of planetary wave fluctuations is probably not responsible for the increase in Great Plains heat waves. By contrast we find changes in the magnitude of surface fluxes during heat wave events could be responsible for their strengthening and these can be attributed to the decrease in soil moisture that occurs during the future period. Hence it is changes in zonally asymmetric mean land surface quantities rather than changes in upper tropospheric fluctuations brought on by changes to the mean circulation that are of primary importance in producing the enhanced variability of surface temperature in the future climate.

  14. Mechanisms of Diurnal Precipitation over the United States Great Plains: A Cloud-Resolving Model Simulation

    NASA Technical Reports Server (NTRS)

    Lee, M.-I.; Choi, I.; Tao, W.-K.; Schubert, S. D.; Kang, I.-K.

    2010-01-01

    The mechanisms of summertime diurnal precipitation in the US Great Plains were examined with the two-dimensional (2D) Goddard Cumulus Ensemble (GCE) cloud-resolving model (CRM). The model was constrained by the observed large-scale background state and surface flux derived from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program s Intensive Observing Period (IOP) data at the Southern Great Plains (SGP). The model, when continuously-forced by realistic surface flux and large-scale advection, simulates reasonably well the temporal evolution of the observed rainfall episodes, particularly for the strongly forced precipitation events. However, the model exhibits a deficiency for the weakly forced events driven by diurnal convection. Additional tests were run with the GCE model in order to discriminate between the mechanisms that determine daytime and nighttime convection. In these tests, the model was constrained with the same repeating diurnal variation in the large-scale advection and/or surface flux. The results indicate that it is primarily the surface heat and moisture flux that is responsible for the development of deep convection in the afternoon, whereas the large-scale upward motion and associated moisture advection play an important role in preconditioning nocturnal convection. In the nighttime, high clouds are continuously built up through their interaction and feedback with long-wave radiation, eventually initiating deep convection from the boundary layer. Without these upper-level destabilization processes, the model tends to produce only daytime convection in response to boundary layer heating. This study suggests that the correct simulation of the diurnal variation in precipitation requires that the free-atmospheric destabilization mechanisms resolved in the CRM simulation must be adequately parameterized in current general circulation models (GCMs) many of which are overly sensitive to the parameterized boundary layer heating.

  15. Evaluation of cooling tower and wastewater treatment operations at the Great Plains Coal Gasification Plant

    SciTech Connect

    Lang, R.A.

    1984-12-01

    The objective of this study was to provide a technical assessment of the Great Plains Coal Gasification Plant Wastewater Treatment System. This Scope of Work consisted of five primary tasks described as follows: Task 1 - Determine the quantity of hydantoins in the stripped gas liquor (SGL), their precursors, and the kinetics of their formation in condensed liquor for the Great Plains Gasification Associates (GPGA) gasification facility. The University of North Dakota Energy Research Center (UNDERC) has measured a high concentration of hydantoins in the gas liquor from their slagging gasifier. UNDERC has tested the use of SGL in a pilot cooling tower and they witnessed some adverse effects in the cooling tower and heat exchanger systems. Task 2 - Investigate the adverse Department of Energy (DOE) findings at UNDERC with regard to corrosion, foaming, biological and organic fouling, chemical attack on concrete and organic emissions resulting from the use of SGL in a pilot plant cooling tower. Task 3 - Validate the heat load on the cooling tower for both summer and winter operation and determine the adequacy of the surge pond to store the maximum predicted amount of excess water accumulated during winter operation. Task 4 - Assess potential fouling, foaming and organic carry-over problems associated with operability of the multiple-effect evaporator and develop recommendations on possible alternate use of evaporator condensate to alleviate possible problems in disposing of excess wastewater. Task 5 - Provide DOE with recommendations on the wastewater treatment backup design and test program already committed to by GPGA. This paper presents Fluor's findings regarding the five primary tasks. 12 refs., 4 figs., 15 tabs.

  16. Mesoscale simulations of convective systems with data assimilation during June 1993 in the Southern Great Plains

    SciTech Connect

    Dudhia, J.

    1995-04-01

    An intensive observation period (IOP) took place at the Southern Great Plains Cloud and Radiation Testbed (CART) site from June 16-26,1993. Additional observations came from two integrated sounding systems (ISSs) and three National Center for Atmospheric Research (NCAR) cross-chain loran atmospheric sounding system (CLASS) sites to complement the central CART site and the seven National Weather Service (NWS) profilers of the demonstration network in the area. The NCAR/Penn State Mesoscale Model (MM5) has been used to simulate this period on a 60-km domain with 20- and 6.67-km nests centered on Lamont, Oklahoma. Simulations are being run with data assimilated by the nudging technique to incorporate upper-air and surface data from a variety of platforms. One goal of this work is to use all the available data collected in the Southern Great Plains CART area in conjunction with a continuously running mesoscale model to provide complete hourly datasets of the wind, temperature, humidity, and cloud distributions at high resolution. The model maintains dynamical consistency between the fields, while the data correct for model biases that may occur during long-term simulations and provide boundary conditions. In this study the feasibility of driving the model with surface data, rawinsonde data, profiler winds, microwave radiometer moisture data, and radio-acoustic sounding system (RASS) temperatures is being demonstrated. The dataset provided will be a valuable resource for comparison with general circulation model (GCM) parameterizations of cloud and radiation fields, as well as for mesoscale studies of convective events during this period.

  17. Warming in the Northern Great Plains: Impact and Response in the Agricultural Community

    NASA Astrophysics Data System (ADS)

    Seielstad, G.; Welling, L.

    2001-12-01

    Because agricultural production in the northern Great Plains contributes significantly to both domestic and international markets the impacts of climate change, as well as the response strategies undertaken by the region's residents, will be felt throughout the nation and the world. The national assessment of Climate Change Impacts on the United States has pointed out that the northern Great Plains could be favored under global warming scenarios in that future climates could increase crop yields [Reilly, Tubiello, McCarl, and Melillo, 2000]. Yield, though, is only one measure of the consequences that rapid warming might have on this region. Challenges to a changing environment must be met by people. Producers here, as well as in other agricultural regions, already function under multiple stresses that are completely separate from climate variability and change. These include falling prices, globalization, complex trade relations, changes in government policy, environmental constraints, and changing consumer preferences. It is against the backdrop of these stresses that pending climate changes must be considered. Interactions with stakeholders through the NGP Assessment workshops, held in 1997 and 1999, identified key concerns and outlined potential mitigation and optimization strategies for the consequences of climate change in this region. We will present examples of the successful implementation of some of these strategies: actions that farmers and ranchers are employing to 1) increase their awareness of environmental factors, 2) enhance their ability to respond quickly to environmental change, 3) improve their economic returns, and 4) decrease environmental degradation. We will also highlight other "no regrets" actions and policies under consideration that may offer individual producers greater flexibility in their management decisions and provide a healthier environment for society at large.

  18. Late quaternary temperature record from buried soils of the North American Great Plains

    USGS Publications Warehouse

    Nordt, L.; Von Fischer, J.; Tieszen, L.

    2007-01-01

    We present the first comprehensive late Quaternary record of North American Great Plains temperature by assessing the behavior of the stable isotopic composition (??13C) of buried soils. After examining the relationship between the ??13C of topsoil organic matter and July temperature from 61 native prairies within a latitudinal range of 46??-38??N, we applied the resulting regression equation to 64 published ??13C values from buried soils of the same region to construct a temperature curve for the past 12 k.y. Estimated temperatures from 12 to 10 ka (1 k.y. = 1000 14C yr B.P.) fluctuated with a periodicity of ???1 k.y. with two cool excursions between -4.5 and -3.5 ??C and two warmer excursions between -1 and 0 ??C, relative to modern. Early Holocene temperatures from ca. 10-7.5 ka were -1.0 to -2.0 ??C before rising to +1.0 ??C in the middle Holocene between 6.0 and 4.5 ka. After a cool interlude from 4.2 to 2.6 ka, when temperatures dropped to slightly below modern, another warm interval ensued from 2.6 to 1 ka as temperatures increased to ???+0.5 ??C. A final decline in temperature to below modern occurred beginning ca. 0.5 ka. Cooler than present temperatures in the Great Plains indicate telecommunications with cool-water episodes in the Gulf of Mexico and North Atlantic potentially governed by a combination of glacial meltwater pulses and low solar irradiance. ?? 2007 Geological Society of America.

  19. Urban influences on land surface phenologies in the U.S. Great Plains

    NASA Astrophysics Data System (ADS)

    Walker, J.; de Beurs, K.; Henebry, G. M.

    2013-12-01

    Global populations are increasingly found in urban environments. The associated transformation of rural landscapes into regions of highly concentrated human activity drives broad climatic and environmental changes at multiple scales. The elevated surface and air temperatures of urban areas compared to surrounding rural environments (the urban heat island [UHI] effect) can influence the timing of vegetation growth dynamics within and outside the urban boundary, thereby affecting regional surface radiation and energy budgets. We examined patterns of land surface phenology (LSP) across the U.S. Great Plains region, which contains a range of metropolitan areas within herbaceous-dominated landscapes. We assembled a time series (2002-2012) of MODIS surface reflectance data (MCD43A4) and land surface temperature data (MOD11A2) at 500m and 1000m spatial resolution, respectively. We derived measures of the vegetated land surface and the thermal regime of the growing season at 8-day intervals using the Normalized Difference Vegetation Index (NDVI) and Accumulated Growing Degree-Days (AGDD). Fitting the convex quadratic LSP model of NDVI as a function of AGDD yielded several model parameter coefficients and phenometrics for each growing season: start, end, and length of growing season; thermal time at start of season; thermal time to peak NDVI; peak NDVI; and coefficients of determination for the LSP model. We linked the phenometrics with impervious surface area measures extracted from the National Land Cover Database (NLCD) and urban characteristics to (1) determine the UHI impacts across the Great Plains under a variety of climatic conditions, and (2) explore scaling relationships between the phenometrics and the extent of each urbanized area.

  20. Incorporating biodiversity into rangeland health: Plant species richness and diversity in great plains grasslands

    USGS Publications Warehouse

    Symstad, A.J.; Jonas, J.L.

    2011-01-01

    Indicators of rangeland health generally do not include a measure of biodiversity. Increasing attention to maintaining biodiversity in rangelands suggests that this omission should be reconsidered, and plant species richness and diversity are two metrics that may be useful and appropriate. Ideally, their response to a variety of anthropogenic and natural drivers in the ecosystem of interest would be clearly understood, thereby providing a means to diagnose the cause of decline in an ecosystem. Conceptual ecological models based on ecological principles and hypotheses provide a framework for this understanding, but these models must be supported by empirical evidence if they are to be used for decision making. To that end, we synthesize results from published studies regarding the responses of plant species richness and diversity to drivers that are of management concern in Great Plains grasslands, one of North America's most imperiled ecosystems. In the published literature, moderate grazing generally has a positive effect on these metrics in tallgrass prairie and a neutral to negative effect in shortgrass prairie. The largest published effects on richness and diversity were caused by moderate grazing in tallgrass prairies and nitrogen fertilization in shortgrass prairies. Although weather is often cited as the reason for considerable annual fluctuations in richness and diversity, little information about the responses of these metrics to weather is available. Responses of the two metrics often diverged, reflecting differences in their sensitivity to different types of changes in the plant community. Although sufficient information has not yet been published for these metrics to meet all the criteria of a good indicator in Great Plains Grasslands, augmenting current methods of evaluating rangeland health with a measure of plant species richness would reduce these shortcomings and provide information critical to managing for biodiversity. ?? Society for Range

  1. Grassland bird use of Conservation Reserve Program fields in the Great Plains

    USGS Publications Warehouse

    Johnson, Douglas H.; Haufler, Jonathan B.

    2005-01-01

    An enormous area in the Great Plains is currently enrolled in the Conservation Reserve Program (CRP): 19.5 million acres (nearly 8 million ha) in Montana, North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, and Texas. This change in land use from cropland to grassland since 1985 has markedly influenced grassland bird populations. Many, but certainly not all, grassland species do well in CRP fields. The responses by birds to the program differ not only by species but also by region, year, the vegetation composition in a field, and whether or not a field has been hayed or grazed. The large scale and extent of the program has allowed researchers to address important conservation questions, such as the effect of the size of habitat patch and the influence of landscape features on bird use. However, most studies on nongame bird use of CRP in or near the Great Plains have been short-lived; 83% lasted only 1-3 years. Further, attention to the topic seems to have waned in recent years; the number of active studies peaked in the early 1990s and dramatically declined after 1995. Because breeding-bird use of CRP fields varies dramatically in response both to vegetational succession and to climatic variation, long-term studies are important. What was learned about CRP in its early stages may no longer be applicable. Finally, although the CRP provisions of the Farm Bill have been beneficial to many grassland birds, it is critical that gains in grassland habitat produced by the program not be off set by losses of native prairie.

  2. Mechanisms of diurnal precipitation over the US Great Plains: a cloud resolving model perspective

    NASA Astrophysics Data System (ADS)

    Lee, Myong-In; Choi, Ildae; Tao, Wei-Kuo; Schubert, Siegfried D.; Kang, In-Sik

    2010-02-01

    The mechanisms of summertime diurnal precipitation in the US Great Plains were examined with the two-dimensional (2D) Goddard Cumulus Ensemble (GCE) cloud-resolving model (CRM). The model was constrained by the observed large-scale background state and surface flux derived from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program’s Intensive Observing Period (IOP) data at the Southern Great Plains (SGP). The model, when continuously-forced by realistic surface flux and large-scale advection, simulates reasonably well the temporal evolution of the observed rainfall episodes, particularly for the strongly forced precipitation events. However, the model exhibits a deficiency for the weakly forced events driven by diurnal convection. Additional tests were run with the GCE model in order to discriminate between the mechanisms that determine daytime and nighttime convection. In these tests, the model was constrained with the same repeating diurnal variation in the large-scale advection and/or surface flux. The results indicate that it is primarily the surface heat and moisture flux that is responsible for the development of deep convection in the afternoon, whereas the large-scale upward motion and associated moisture advection play an important role in preconditioning nocturnal convection. In the nighttime, high clouds are continuously built up through their interaction and feedback with long-wave radiation, eventually initiating deep convection from the boundary layer. Without these upper-level destabilization processes, the model tends to produce only daytime convection in response to boundary layer heating. This study suggests that the correct simulation of the diurnal variation in precipitation requires that the free-atmospheric destabilization mechanisms resolved in the CRM simulation must be adequately parameterized in current general circulation models (GCMs) many of which are overly sensitive to the parameterized boundary layer

  3. Movement, home range, and site fidelity of bluegills in a Great Plains Lake

    USGS Publications Warehouse

    Paukert, C.P.; Willis, D.W.; Bouchard, M.A.

    2004-01-01

    Little is known about the distribution, movement, and home ranges of bluegills Lepomis macrochirus in lentic environments. Therefore, the objectives of this study were to evaluate the seasonal and diel differences in movement rates, site fidelity, and home range of bluegills in a shallow, natural Great Plains lake. A total of 78 bluegills (200-273 mm total length) were implanted with radio transmitters in March and May 2000. Of these fish, 10 males and 10 females were randomly selected and located every 2 h during one 24-h period each month from April to September 2000. Bluegill movement peaked during midsummer: however, there was little difference in diel movements, suggesting relatively consistent movement throughout the 24-h period. Home range estimates (which included the 24-h tracking plus an additional six locations from the same fish located once per day for six consecutive days each month) ranged up to 172 ha, probably because only about half of the bluegills exhibited site fidelity during any month sampled. Bluegill movement did not appear to be strongly linked with water temperature, barometric pressure, or wind speed. These results suggest that bluegills move considerable distances and that many roam throughout this 332-ha shallow lake. However, diel patterns were not evident. Sampling bluegills in Great Plains lakes using passive gears (e.g., trap nets) may be most effective during the summer months, when fish are most active. Active sampling (e.g., electrofishing) may be more effective than the use of passive gears in spring and fall, when bluegills are less active.

  4. Geohydrologic systems in Kansas, geohydrology of the Great Plains aquifer system

    USGS Publications Warehouse

    McGovern, Harold E.; Wolf, R.J.

    1993-01-01

    Sedimentary rocks of Late Cambrian through Early Cretaceous age in Kansas are part of a regional flow system of hydraulically connected aquifers and confining units. Future demands for water require that these deeply buried rocks be studied to describe hydrologic properties and ground-water-flow conditions and to provide information that will serve as the basis for decisions concerning the protection and the management of the water resources contained therein, Toward this end, the U.S. Geological Survey, as a part of its Central Midwest Regional Aquifer-System Analysis (CMRASA), began a 5-year hydrologic investigation of this regional flow system in Arkansas, Colorado, Kansas, Missouri, Nebraska, New Mexico, Oklahoma, South Dakota, and Texas (Jorgensen and Signor, 1981).This chapter is one of nine contained in Hydrologic Investigations Atlas HA-722, which present a description of the physical framework (Chapters B-F) and the geohydrology (Chapters G-I} of principal aquifers and confining systems in Upper Cambrian through Lower Cretaceous rocks in Kansas; the stratigraphic relations of these geohydrologic systems are discussed in detail in Chapter A (Wolf and others, 1990). This chapter (G) describes the geohydrology of the Great Plains aquifer system; the physical framework of the Great Plains aquifer system is presented in Chapter B (Spinazola and others, 1992).The maps in this chapter are based on existing data from selected geophysical and lithologic logs, drill-stem tests, water-level measurements, water-quality analyses, and published maps of stratigraphically equivalent units. An index to the geohydrologic data compiled for the CMRASA in Kansas is presented in Spinazola and others (1987). For the most part, data used to construct the maps were collected over many years and do not reflect aquifer conditions for any specific time period.

  5. Brown-headed cowbird, Molothrus ater, parasitism and abundance in the northern Great Plains

    USGS Publications Warehouse

    Igl, L.D.; Johnson, D.H.

    2007-01-01

    The Brown-headed Cowbird (Molothrus ater) reaches its highest abundance in the northern Great Plains, but much of our understanding of cowbird ecology and host-parasite interactions comes from areas outside of this region. We examine cowbird brood parasitism and densities during two studies of breeding birds in the northern Great Plains during 1990-2006. We found 2649 active nests of 75 species, including 746 nonpasserine nests and 1902 passerine nests. Overall, <1% of non-passerine nests and 25% of passerine nests were parasitized by Brown-headed Cowbirds. Although the overall frequency of cowbird parasitism in passerine nests in these two studies is considered moderate, the frequency of multiple parasitism among parasitized nests was heavy (nearly 50%). The mean number of cowbird eggs per parasitized passerine nest was 1.9 ?? 1.2 (SD; range = 1-8 cowbird eggs). The parasitism rates were 9.5% for passerines that typically nest in habitats characterized by woody vegetation, 16.4% for grassland-nesting passerines, 4.7% for passerines known to consistently eject cowbird eggs, and 28.2% for passerines that usually accept cowbird eggs. The Red-winged Blackbird (Agelaius phoeniceus) was the most commonly parasitized species (43.1 % parasitism, 49.6% multiple parasitism, 71.2% of all cases of parasitism). Passerine nests found within areas of higher female cowbird abundance experienced higher frequencies of cowbird parasitism than those found in areas of lower female cowbird abundance. Densities of female cowbirds were positively related to densities and richness of other birds in the breeding bird community.

  6. Great Salt Lake and Bonneville Salt Flats, UT, USA

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This is a view of the Great Salt Lake and nearby Bonneville Salt Flats, UT, (41.0N, 112.5W). A railroad causeway divides the lake with a stark straight line changing the water level and chemistry of the lake as a result. Fresh water runoff enters from the south adding to the depth and reducing the salinity. The north half receives little frsh water and is more saline and shallow. The Bonnieville Salt Flats is the lakebed of a onetime larger lake.

  7. Great Salt Lake and Bonneville Salt Flats, UT, USA

    NASA Image and Video Library

    1992-04-02

    This is a view of the Great Salt Lake and nearby Bonneville Salt Flats, UT, (41.0N, 112.5W). A railroad causeway divides the lake with a stark straight line changing the water level and chemistry of the lake as a result. Fresh water runoff enters from the south adding to the depth and reducing the salinity. The north half receives little frsh water and is more saline and shallow. The Bonnieville Salt Flats is the lakebed of a onetime larger lake.

  8. Effects of plain package branding and graphic health warnings on adolescent smokers in the USA, Spain and France.

    PubMed

    Andrews, J Craig; Netemeyer, Richard G; Burton, Scot; Kees, Jeremy

    2016-12-01

    The purpose of this study is to provide an experimental test of the effects of plain pack branding and graphic health warnings (GHWs) in three different countries for an important and vulnerable population, that is, adolescents who are experimenting with smoking. The effects of plain pack branding (logo present, logo absent), and graphic visual warning level (absent, low, medium, high) are studied experimentally for their impact on adolescent cigarette craving, evoked fear, pack feelings and thoughts of quitting in the USA, Spain and France. A total of 1066 adolescents who were experimenting with smoking served as participants in the study. A quota sample produced 375 respondents in the USA, 337 in Spain and 354 in France. Overall findings indicate that the GHWs were effective in impacting adolescent cigarette craving, evoked fear, pack feelings and thoughts of quitting. The plain pack effects were not as strong, yet reduced craving, increased fear, and decreased pack feelings for all three samples combined, and for US adolescent smokers individually, irrespective of the GHWs. For French adolescent smokers, plain pack effects for craving were limited to low/moderate GHW levels. For Spanish adolescent smokers, plain pack feeling effects were limited to the absence of the GHWs. The results show that plain packs can independently strengthen the more instantaneous, direct effects (short of quitting thoughts) found with the GHWs. Yet, the plain pack results were attenuated for Spanish and French adolescent smokers, who are currently exposed to GHWs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. Climate variability controls on unsaturated water and chemical movement, High Plains aquifer, USA

    USGS Publications Warehouse

    Gurdak, J.J.; Hanson, R.T.; McMahon, P.B.; Bruce, B.W.; McCray, J.E.; Thyne, G.D.; Reedy, R.C.

    2007-01-01

    Responses in the vadose zone and groundwater to interannual, interdecadal, and multidecadal climate variability have important implications for groundwater resource sustainability, yet they are poorly documented and not well understood in most aquifers of the USA. This investigation systematically examines the role of interannual to multidecadal climate variability on groundwater levels, deep infiltration (3-23 m) events, and downward displacement (>1 m) of chloride and nitrate reservoirs in thick (15-50 m) vadose zones across the regionally extensive High Plains aquifer. Such vadose zone responses are unexpected across much of the aquifer given a priori that unsaturated total-potential profiles indicate upward water movement from the water table toward the root zone, mean annual potential evapotranspiration exceeds mean annual precipitation, and millennia-scale evapoconcentration results in substantial vadose zone chloride and nitrate reservoirs. Using singular spectrum analysis (SSA) to reconstruct precipitation and groundwater level time-series components, variability was identified in all time series as partially coincident with known climate cycles, such as the Pacific Decadal Oscillation (PDO) (10-25 yr) and the El Nin??o/Southern Oscillation (ENSO) (2-6 yr). Using these lag-correlated hydrologic time series, a new method is demonstrated to estimate climate-varying unsaturated water flux. The results suggest the importance of interannual to interdecadal climate variability on water-flux estimation in thick vadose zones and provide better understanding of the climate-induced transients responsible for the observed deep infiltration and chemical-mobilization events. Based on these results, we discuss implications for climate-related sustainability of the High Plains aquifer. ?? Soil Science Society of America.

  10. Chemical evolution of groundwater in the Wilcox aquifer of the northern Gulf Coastal Plain, USA

    NASA Astrophysics Data System (ADS)

    Haile, Estifanos; Fryar, Alan E.

    2017-07-01

    The Wilcox aquifer is a major groundwater resource in the northern Gulf Coastal Plain (lower Mississippi Valley) of the USA, yet the processes controlling water chemistry in this clastic aquifer have received relatively little attention. The current study combines analyses of solutes and stable isotopes in groundwater, petrography of core samples, and geochemical modeling to identify plausible reactions along a regional flow path ˜300 km long. The hydrochemical facies evolves from Ca-HCO3 upgradient to Na-HCO3 downgradient, with a sequential zonation of terminal electron-accepting processes from Fe(III) reduction through SO4 2- reduction to methanogenesis. In particular, decreasing SO4 2- and increasing δ34S of SO4 2- along the flow path, as well as observations of authigenic pyrite in core samples, provide evidence of SO4 2- reduction. Values of δ13C in groundwater suggest that dissolved inorganic carbon is contributed both by oxidation of sedimentary organic matter and calcite dissolution. Inverse modeling identified multiple plausible sets of reactions between sampled wells, which typically involved cation exchange, pyrite precipitation, CH2O oxidation, and dissolution of amorphous Fe(OH)3, calcite, or siderite. These reactions are consistent with processes identified in previous studies of Atlantic Coastal Plain aquifers. Contrasts in groundwater chemistry between the Wilcox and the underlying McNairy and overlying Claiborne aquifers indicate that confining units are relatively effective in limiting cross-formational flow, but localized cross-formational mixing could occur via fault zones. Consequently, increased pumping in the vicinity of fault zones could facilitate upward movement of saline water into the Wilcox.

  11. Prairie dog poisoning in northern Great Plains: An analysis of programs and policies

    NASA Astrophysics Data System (ADS)

    Roemer, David M.; Forrest, Steven C.

    1996-05-01

    This paper describes the programs and policies regarding prairie dog control in the northern Great Plains states of Montana, South Dakota, and Wyoming. The poisoning programs of federal and state agencies are described, along with the statutes and legal mandates that shape agency management of prairie dogs. Current policies on National Grasslands and other federal lands typically limit prairie dogs to small percentages of available potential habitat, to the detriment of prairie dogs and associated species. State programs to assist landowners in prairie dog control differ greatly, employing cost-share incentives (Wyoming) and regulatory fines (South Dakota) to encourage the poisoning of prairie dogs. Prairie dog control is not actively funded or practiced by state or county agencies in Montana. We document federal and state involvement in more than 1 million acres of prairie dog poisoning in the study area during 1978 1992. In combination with undocumented poisoning by private landowners, plague, and shooting, prairie dogs may be experiencing net regional declines, contributing to the disintegration of the prairie dog ecosystem. We recommend that Animal Damage Control operations concerning prairie dogs be terminated, on the basis that they duplicate state programs and are at cross purposes with federal wildlife management programs that seek to perpetuate and/or recover wildlife species that depend on the prairie dog ecosystem. We further recommend that federal range improvement funds be offered as subsidies for the integration of prairie dogs in range management, as opposed to funding prairie dog eradication programs.

  12. Using SMAP data to improve drought early warning over the US Great Plains

    NASA Astrophysics Data System (ADS)

    Fu, R.; Fernando, N.; Tang, W.

    2015-12-01

    A drought prone region such as the Great Plains of the United States (US GP) requires credible and actionable drought early warning. Such information cannot simply be extracted from available climate forecasts because of their large uncertainties at regional scales, and unclear connections to the needs of the decision makers. In particular, current dynamic seasonal predictions and climate projections, such as those produced by the NOAA North American Multi-Model Ensemble experiment (NMME) are much more reliable for winter and spring than for the summer season for the US GP. To mitigate the weaknesses of dynamic prediction/projections, we have identified three key processes behind the spring-to-summer dry memory through observational studies, as the scientific basis for a statistical drought early warning system. This system uses percentile soil moisture anomalies in spring as a key input to provide a probabilistic summer drought early warning. The latter outperforms the dynamic prediction over the US Southern Plains and has been used by the Texas state water agency to support state drought preparedness. A main source of uncertainty for this drought early warning system is the soil moisture input obtained from the NOAA Climate Forecasting System (CFS). We are testing use of the beta version of NASA Soil Moisture Active Passive (SMAP) soil moisture data, along with the Soil Moisture and Ocean Salinity (SMOS), and the long-term Essential Climate Variable Soil Moisture (ECV-SM) soil moisture data, to reduce this uncertainty. Preliminary results based on ECV-SM suggests satellite based soil moisture data could improve early warning of rainfall anomalies over the western US GP with less dense vegetation. The skill degrades over the eastern US GP where denser vegetation is found. We evaluate our SMAP-based drought early warning for 2015 summer against observations.

  13. Structural and functional diversity of soil bacterial and fungal communities following woody plant encroachment in the southern Great Plains

    SciTech Connect

    Hollister, Emily B; Schadt, Christopher Warren; Palumbo, Anthony Vito; Ansley, R J; Boutton, Thomas W

    2010-01-01

    In the southern Great Plains (USA), encroachment of grassland ecosystems by Prosopis glandulosa (honey mesquite) is widespread. Mesquite encroachment alters net primary productivity, enhances stores of C and N in plants and soil, and leads to increased levels of soil microbial biomass and activity. While mesquite's impact on the biogeochemistry of the region is well established, it effects on soil microbial diversity and function are unknown. In this study, soils associated with four plant types (C{sub 3} perennial grasses, C{sub 4} midgrasses, C{sub 4} shortgrasses, and mesquite) from a mesquite-encroached mixed grass prairie were surveyed to in an attempt to characterize the structure, diversity, and functional capacity of their soil microbial communities. rRNA gene cloning and sequencing were used in conjunction with the GeoChip functional gene array to evaluate these potential differences. Mesquite soil supported increased bacterial and fungal diversity and harbored a distinct fungal community relative to other plant types. Despite differences in composition and diversity, few significant differences were detected with respect to the potential functional capacity of the soil microbial communities. These results may suggest that a high level of functional redundancy exists within the bacterial portion of the soil communities; however, given the bias of the GeoChip toward bacterial functional genes, potential functional differences among soil fungi could not be addressed. The results of this study illustrate the linkages shared between above- and belowground communities and demonstrate that soil microbial communities, and in particular soil fungi, may be altered by the process of woody plant encroachment.

  14. A comparison of blood lead levels in bald eagles from two regions on the great plains of North America.

    PubMed

    Miller, M J; Restani, M; Harmata, A R; Bortolotti, G R; Wayland, M E

    1998-10-01

    The connection between bald eagles (Haliaeetus leucocephalus) and the consumption of waterfowl, lead shotshell pellet ingestion, and subsequent lead exposure is well documented in the United States and is presumed also to be widespread in Canada. We compared blood lead concentrations in samples from bald eagles ranging in age from 0.5- to 1.5-yr-old at Galloway Bay, Saskatchewan, Canada (n = 97) during October-November, 1992-95 and Hauser Lake, Montana, USA (n = 81) during October-December, 1990-94, within the Great Plains region of North America. Abundant prey are available in the form of hunter-injured waterfowl in Saskatchewan and spawning salmon in Montana; both areas attract large numbers of mid-continent bald eagles during fall migration. Blood lead concentrations suggestive of recent lead exposure (> 0.201 microgram/ml) were found in 32% and 8% of eagles at Hauser Lake and Galloway Bay, respectively, when samples from each study area were analyzed independently at two laboratories. To determine if this difference was an artifact of interlaboratory variation, we determined a correction factor by reanalyzing 14 Saskatchewan blood samples at each laboratory and predicted blood lead concentrations from Hauser Lake had the samples been analyzed at the Canadian laboratory. Adjusted blood lead concentrations of samples from Hauser Lake indicated that 21% of eagles were recently exposed to lead, a proportion not significantly different from the proportion of the same exposure category at Galloway Bay. Our data do not support the supposition that a large proportion of bald eagles feeding on waterfowl in areas of high hunting pressure will be exposed to lead via consumption of lead shotshell pellets in waterfowl.

  15. Control of one invasive plant species allows exotic grasses to become dominant in northern Great Plains grasslands

    USGS Publications Warehouse

    Larson, D.L.; Larson, J.L.

    2010-01-01

    Decline of leafy spurge (Euphorbia esula) in the northern Great Plains of the US is generally viewed as a success story for biological control, but quality of the vegetation that survived the infestation is key to recovery of ecosystem function. In addition, effects of other invasive species, notably cool-season exotic grasses, must be taken into account. Objectives of this study were (1) to evaluate direction and significance of changes in biomass of native and exotic grasses, forbs, and leafy spurge and in plant species composition following control of leafy spurge by flea beetles and (2) to evaluate the relative effects of leafy spurge and exotic grasses on biomass of native grasses, biomass of forbs, and richness of native species. We monitored species composition (1998-2003 and 2008) and biomass (2000, 2002, 2003 and 2008) of these groups on spurge-infested and noninfested permanent plots at three sites with unbroken prairie sod in North Dakota, USA. We found little evidence, in terms of species richness or biomass of native grasses or forbs, that leafy spurge was being replaced by desirable native species, although desirable as well as weedy and exotic species were characteristic of 2008 vegetation at all three sites. Structural equation models revealed that leafy spurge had temporally intermittent negative effects on forb biomass and species richness, but no effects on native grasses. In contrast, exotic grass had consistently strong, negative effects on native grass biomass, as well as stronger negative effects than leafy spurge on native species richness. Although substantial native plant diversity remains at these sites, exotic grasses pose an important threat to these crucial building blocks of native prairie ecosystems. ?? 2010.

  16. NDVI, C3 and C4 production, and distributions in Great Plains grassland land cover classes

    USGS Publications Warehouse

    Tieszen, L.L.; Reed, Bradley C.; Bliss, Norman B.; Wylie, Bruce K.; DeJong, Benjamin D.

    1997-01-01

    The distributions of C3 and C4 grasses were used to interpret the distribution, seasonal performance, and potential production of grasslands in the Great Plains of North America. Thirteen major grassland seasonal land cover classes were studied with data from three distinct sources. Normalized Difference Vegetation Index (NDVI) data derived from the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) sensor were collected for each pixel over a 5-yr period (1989–1993), analyzed for quantitative attributes and seasonal relationships, and then aggregated by land cover class. Data from the State Soil Geographic (STATSGO) database were used to identify dominant plant species contributing to the potential production in each map unit. These species were identified as C3 or C4, and contributions to production were aggregated to provide estimates of the percentage of C3 and C4 production for each intersection of the STATSGO map units and the seasonal land cover classes. Carbon isotope values were obtained at specific sites from the soil organic matter of the upper horizon of soil cores and were related to STATSGO estimates of potential production.The grassland classes were distributed with broad northwest-to-southeast orientations. Some classes had large variations in C3 and C4 composition with high proportions of C4species in the south and low proportions in the north. This diversity of photosynthetic types within land cover classes that cross regions of different temperature and precipitation results in similar seasonal patterns and magnitudes of NDVI. The easternmost class, 65, containing tallgrass prairie components, bluestem, Indiangrass, and switchgrass, possessed the highest maximum NDVI and time-integrated NDVI values each year. Grassland classes varied over 5 yr from a high integrated NDVI mean of 4.9 in class 65 in the east to a low of 1.2 in class 76 (sand sage, blue grama, wheatgrass, and buffalograss) in the

  17. Configuration and Intraseasonal Duration of Interannual Anomalies of the Great Plains Low-Level Jet

    NASA Technical Reports Server (NTRS)

    Helfand, H. M.

    2002-01-01

    Despite the fact that the low-level jet of the southern Great Plains (the GPLLJ) of the U.S. is primarily a nocturnal phenomenon that virtually vanishes during the daylight hours, it is one of the most persistent and stable climatological features of the low-level continental flow during the warm-season months, May through August. We have used significant-level data to validate the skill of the GEOS-1 Data Assimilation System (DAS) in realistically detecting this jet and inferring its structure and evolution. We have then carried out a 15-year reanalysis with the GEOS-1 DAS to determine its climatology and mean diurnal cycle and to study its interannual variability. Interannual anomalies of the meridional flow associated with the GPLLJ are much smaller than the mean diurnal fluctuations, than random intraseasonal anomalies, and than the mean wind itself. There are three maxima of low-level meridional flow variance over the Great Plains and the Gulf of Mexico: a 1.2 m2 s-2 peak over the southeast Texas, to the east and south of the mean velocity peak, a 1.0 m2 s-2 peak over the western Gulf of Mexico, and a .8 m2 s-2 peak over the upper Great Plains (UGP), near the Nebraska/South Dakota border. Each of the three variance maxima corresponds to a spatially coherent, jet-like pattern of low-level flow interannual variability. There are also three dominant modes of interannual variability corresponding to the three variance maxima, but not in a simple one-to-one relationship. Cross-sectional profiles of mean southerly wind over Texas remain relatively stable and recognizable from year to year with only its eastward flank showing significant variability. This variability, however, exhibits a distinct, biennial oscillation during the first six to seven years of the reanalysis period and only then. This intermittent biennial oscillation (IBO, one of the three modes discussed in the previous paragraph) in the lowlevel flow is restricted to the region surrounding eastern

  18. Land Surface Phenologies of the Northern Great Plains: Possible Futures Arising From Land and Climate Change

    NASA Astrophysics Data System (ADS)

    Henebry, G. M.; Wimberly, M. C.; Senay, G.; Wang, A.; Chang, J.; Wright, C. R.; Hansen, M. C.

    2008-12-01

    Land cover change across the Northern Great Plains of North America over the past three decades has been driven by changes in agricultural management (conservation tillage; irrigation), government incentives (Conservation Reserve Program; subsidies to grain-based ethanol), crop varieties (cold-hardy soybean), and market dynamics (increasing world demand). Climate change across the Northern Great Plains over the past three decades has been evident in trends toward earlier warmth in the spring and a longer frost-free season. Together these land and climate changes induce shifts in local and regional land surface phenologies (LSPs). Any significant shift in LSP may correspond to a significant shift in evapotranspiration, with consequences for regional hydrometeorology. We explored possible future scenarios involving land use and climate change in six steps. First, we defined the nominal draw areas of current and future biorefineries in North Dakota, South Dakota, Nebraska, Minnesota, and Iowa and masked those land cover types within the draw areas that were unlikely to change to agricultural use (open water, settlements, forests, etc.). Second, we estimated the proportion of corn and soybean remaining within the masked draw areas using MODIS-derived crop maps. Third, in each draw area, we modified LSPs to simulate crop changes for a control and two treatment scenarios. In the control, we used LSP profiles identified from MODIS Collection 5 NBAR data. In one treatment, we increased the proportion of tallgrass LSPs in the draw areas to represent widespread cultivation of a perennial cellulosic crop, like switchgrass. In a second treatment, we increased the proportion of corn LSPs in the draw areas to represent increased corn cultivation. Fourth, we characterized the seasonal progression of the thermal regime associated with the LSP profiles using MODIS Land Surface Temperature (LST) products. Fifth, we modeled the LSP profile as a quadratic function of accumulated

  19. Towards an Operational Vegetation Health Monitoring System for the Northern Great Plains

    NASA Astrophysics Data System (ADS)

    Aloysius, N.; Kim, H. J.

    2007-12-01

    Farmers and Rangers in the Northern Great Plains (NGP) of the United States had been devastated by the extremely dry weather conditions in the summer of 2006. The entire state of North Dakota was declared a primary agricultural disaster area in September, 2006 by the US Department of Agriculture. Emergency grazing on CRP lands was extended in several NGP states. On the contrary, the summer of 2005 had been exceptionally wet in certain parts of NGP which ruined crops. The occurrences of these weather extremes severely affect the natural resource based enterprises like farming and ranching, the effects of which ripple through the economies of several states in the region. In order to monitor and assess the impacts of these extreme events and to take mitigation strategies, variety of physical and environmental conditions have to be taken into consideration. Remote sensing based vegetation indices such as normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI), climate information and drought indices are employed to assess the growth of vegetation and its vigor, both spatially and temporally. A 25-year history of NDVI and seven-year history of EVI data were used to develop a near real-time vegetation growth monitoring system for the five Northern Great Plains states (ID, MT, ND, SD and WY). The EVI and EVI anomaly, computed based on 2000-2005 averages, are updated twice monthly for the growing season, April through September. In addition, precipitation anomalies based on a 30-year average and Palmer Z-index (a short term moisture availability index) are also updated monthly for the 45 climate divisions within the NGP states. The presentation will highlight how the near real-time monitoring of the combination of vegetation and climate parameters can help to identify the temporal and spatial patterns of vegetation dynamics at different spatial (from individual farms, climate divisions to states and, even, the whole NGP region) and temporal

  20. Causes of Long-Term Drought in the United States Great Plains

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried D.; Suarez, Max J.; Pegion, Philip J.; Koster, Randal

    2002-01-01

    The United States Great Plains (USGP) experienced a number of multi-year droughts during the last century, most notably the droughts of the 1930s and 1950s. This study examines the causes of such droughts using ensembles of long term (1930-1999) simulations carried out with the NASA Seasonal-to-Interannual Prediction Project (NSIPP-1) atmospheric general circulation model (AGCM) forced with observed sea surface temperatures (SSTs). The results show that the model produces long-term (multi-year) variations in the USGP precipitation that are similar to those observed. A correlative analysis suggests that the ensemble mean low frequency (time scales longer than about 6 years) rainfall variations in the USGP are linked to a pan-Pacific pattern of SST variability that is the leading empirical orthogonal function (EOF) in the low frequency SST data. The link between the SST and the Great Plains precipitation is confirmed in idealized AGCM simulations, in which the model is forced by the 2 polarities of the pan-Pacific SST pattern. The idealized simulations further show that it is primarily the tropical part of the SST anomalies that influence the USGP. As such, the USGP tend to have above normal precipitation when the tropical Pacific SSTs are above normal, while there is a tendency for drought when the tropical SSTs are cold. The upper tropospheric response to the pan-Pacific SST EOF shows a global-scale pattern with a strong wave response in the Pacific and a substantial zonally-symmetric component in which USGP pluvial (drought) conditions are associated with reduced (enhanced) heights throughout the extra-tropics. The potential predictability of rainfall in the USGP associated with SSTs is rather modest, with on average about 1/3 of the total low frequency rainfall variance forced by SST anomalies. Further idealized experiments with climatological SST, suggest that the remaining low frequency variance in the USGP precipitation is the result of interactions with soil

  1. A Unified Theory for the Great Plains Nocturnal Low-Level Jet

    NASA Astrophysics Data System (ADS)

    Shapiro, A.; Fedorovich, E.; Rahimi, S.

    2014-12-01

    The nocturnal low-level jet (LLJ) is a warm-season atmospheric boundary layer phenomenon common to the Great Plains of the United States and other places worldwide, typically in regions east of mountain ranges. Low-level jets develop around sunset in fair weather conditions conducive to strong radiational cooling, reach peak intensity in the pre-dawn hours, and then dissipate with the onset of daytime convective mixing. In this study we consider the LLJ as a diurnal oscillation of a stably stratified atmosphere overlying a planar slope on the rotating Earth. The oscillations arise from diurnal cycles in both the heating of the slope (mechanism proposed by Holton in 1967) and the turbulent mixing (mechanism proposed by Blackadar in 1957). The governing equations are the equations of motion, incompressibility condition, and thermal energy in the Boussinesq approximation, with turbulent heat and momentum exchange parameterized through spatially constant but diurnally varying turbulent diffusion coefficients (diffusivities). Analytical solutions are obtained for diffusivities with piecewise constant waveforms (step-changes at sunrise and sunset) and slope temperatures/buoyancies with piecewise linear waveforms (saw-tooth function with minimum at sunrise and maximum before sunset). The jet characteristics are governed by eleven parameters: slope angle, Coriolis parameter, environmental buoyancy frequency, geostrophic wind strength, daytime and nighttime diffusivities, maximum (daytime) and minimum (nighttime) slope buoyancies, duration of daylight, lag time between peak slope buoyancy and sunset, and a Newtonian cooling time scale. An exploration of the parameter space yields results that are broadly consistent with findings particular to the Holton and Blackadar theories, and agree with climatological observations, for example, that stronger jets tend to occur over slopes of 0.15-0.25 degrees characteristic of the Great Plains. The solutions also yield intriguing

  2. Site, environmental and airflow characteristics for mono-slope beef cattle facilities in the Northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    In conjunction with an emission monitoring study, long-term airflow and environmental data were collected from four regional producer-owned and -operated mono-slope beef cattle facilities in the Northern Great Plains. The barns were oriented east-west, with approximate dimensions of an 8-m south wal...

  3. Perennial biomass grasses and the Mason-Dixon Line: Comparative productivity across latitudes in the southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Understanding latitudinal adaptation of switchgrass (Panicum virgatum L.) and miscanthus (Miscanthus x giganteus J. M. Greef & Deuter ex Hodk. & Renvoize) to the southern Great Plains is key to maximizing productivity by matching each grass variety to its ideal production environment. Objectives of...

  4. Vulnerability of crops and native grasses to summer drying in the U.S. Southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    The Southern Great Plains are characterized by a fine-scale mixture of different land cover types, predominantly winter-wheat and pasture lands, with relatively small areas of other crops, native prairie, and switchgrass. Recent droughts and predictions of increased drought (especially during the s...

  5. Long-term agroecosystem research on northern Great Plains mixed-grass prairie near Mandan, North Dakota

    USDA-ARS?s Scientific Manuscript database

    In 1915, a stocking rate experiment was started on 101 ha of native mixed-grass prairie at the Northern Great Plains Research Laboratory (NGPRL) near Mandan, ND (100.9132 N 46.7710 W). Here, we document the origin, evolution, and scientific outcomes from this long-term experiment. Four pastures of 1...

  6. The nature conservancy's prairie wings project: a conservation strategy for the grassland birds of the Western Great plains

    Treesearch

    Bob McCready; David Mehlman; Danny Kwan; Becky Abel

    2005-01-01

    In the second half of the nineteenth century, driven by the cultural mandate of manifest destiny and economic expansion, the North American west was rapidly settled and permanently altered by hundreds of thousands of residents from the eastern United States, Canada, Central Mexico and Europe. The first region to fill up with new arrivals was the Great Plains, a &...

  7. Performance of early weaned (~80 d) vs normal weaned (~215 d) cows in the Northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Our objective was to determine effects of early weaning at the start of breeding on cow reproductive performance following AI with a 50-d cleanup breeding season among cows in the Northern Great Plains. Angus (n = 199) and Angus x Simmental (n = 158) cows stratified within breed by age, postpartum i...

  8. Stable-Carbon Isotopes of U.S. Great Plains Soils and Climate Events during the Holocene.

    USDA-ARS?s Scientific Manuscript database

    A suite of 12 soil profiles from the U.S. Great Plains and western Corn Belt were sampled to a depth of 2 m and radiocarbon dating control was established to investigate possible changes in stable-carbon isotope composition of SOC over space and time associated with major Holocene climate events. T...

  9. Research achievements and adoption of no-till, dryland cropping in the semi-arid US Great Plains

    USDA-ARS?s Scientific Manuscript database

    The Great Plains region of the United States and Canada is an area of widespread dryland crop production, with wheat being the dominant crop. Precipitation in the region ranges from 300 to 500 mm annually, with the majority of precipitatioCPRLn falling during hot summer months. The prevailing croppi...

  10. From Mothers' Pensions to Aid to Dependent Children in the Great Plains: The Course from Charity to Entitlement

    ERIC Educational Resources Information Center

    Lee, R. Alton

    2012-01-01

    The most important third-party movement in American history emerged out of the social and economic chaos brewing in the Great Plains in the last two decades of the nineteenth century. The maelstrom, labeled Populism, contained a powerful, indeed a truly revolutionary message--that man was his brother's keeper. This concept proved to have…

  11. Land cover dynamics across the Great Plains and their influence on breeding birds: Potential artefact of data and analysis limitations

    Treesearch

    C. H. Flather; M. S. Knowles; L. S. Baggett

    2017-01-01

    The distribution and abundance of obligate grassland breeding birds in the US have declined across the Great Plains as native habitats have been converted to intensive human land use. A major finding of Scholtz et al. (2017: Table 3) was that the group-wise extinction rate among 13 common grassland nesting birds declined with increasing cropland. This conclusion runs...

  12. Can subsurface drip irrigation (SDI) be a competitive irrigation system in the Great Plains region for commodity crops

    USDA-ARS?s Scientific Manuscript database

    Subsurface drip irrigation (SDI) as with all microirrigation systems is typically only used on crops with greater value. In the U.S. Great Plains region, the typical irrigated crops are the cereal and oil seed crops and cotton. These crops have less economic revenue than typical microirrigated cro...

  13. Capabilities of four novel warm-season legumes in the southern Great Plains: grain production and quality

    USDA-ARS?s Scientific Manuscript database

    Grain legumes could serve as a low cost nitrogen (N) and energy source for animal production in the southern Great Plains (SGP). This study evaluated the yield and nutritive value of grains of tropical annual legumes novel to the SGP. Included were cultivars of pigeon pea ([Cajanus cajan (L.) Millsp...

  14. Capabilities of four novel warm-season legumes in the southern Great Plains: biomass and forage quality

    USDA-ARS?s Scientific Manuscript database

    Grain legumes could provide high nitrogen (N), late summer forage for stocker cattle in the southern Great Plains (SGP). This study evaluated the forage yield and nutritive value of tropical annual legumes novel to the SGP. Included were cultivars of pigeon pea ([Cajanus cajan (L.) Millsp.], cv. ‘GA...

  15. Ammonia and hydrogen sulfide concentration and emission patterns for mono-slope beef cattle facilities in the Northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Mono-slope buildings are one type of roofed and confined cattle feeding facility that is becoming increasingly popular in the Northern Great Plains. In response to questions and concerns about the barn environment and air quality regulations, the objectives of this study were to determine gas concen...

  16. Casting the Buffalo Commons: A Rhetorical Analysis of Print Media Coverage of the Buffalo Commons Proposal for the Great Plains

    ERIC Educational Resources Information Center

    Umberger, Mary L.

    2002-01-01

    In 1987, Frank and Deborah Popper, a planner/geographer team from Rutgers University, proposed the Buffalo Commons. If implemented, the Buffalo Commons would have preserved a large area of the Great Plains, including land in ten states, in a national park to be used by exiting Native American reservations, and for the reintroduction of buffalo.

  17. Vulnerability of grazing and confined livestock in the Northern Great Plains to projected mid- and late- 21st century climate

    USDA-ARS?s Scientific Manuscript database

    The Northern Great Plains (NGP) region of the United States – which comprises Montana, Wyoming, Colorado, North Dakota, South Dakota and Nebraska – is a largely rural area that provides important agricultural and ecological services, including biological diversity. The region contains 25% of the Nat...

  18. Vulnerability of grazing and confined livestock in the Northern Great Plains to projected mid- and late- 21st century climate

    USDA-ARS?s Scientific Manuscript database

    The Northern Great Plains (NGP) region – Montana, Wyoming, Colorado, North Dakota, South Dakota and Nebraska – is a largely rural area that provides important agricultural and ecological services, including biological diversity. The NGP is projected to experience rising atmospheric CO2, warming and ...

  19. Dynamic cropping systems: Holistic approach for dryland agricultural systems in the northern Great Plains of North America

    USDA-ARS?s Scientific Manuscript database

    Cropping systems over the past century have developed greater crop specialization, more effectively conserve our soil and water resources, and are more resilient. The purpose of this chapter is to discuss the evolution of cropping systems in the Northern Great Plains and provide an approach to crop...

  20. From Mothers' Pensions to Aid to Dependent Children in the Great Plains: The Course from Charity to Entitlement

    ERIC Educational Resources Information Center

    Lee, R. Alton

    2012-01-01

    The most important third-party movement in American history emerged out of the social and economic chaos brewing in the Great Plains in the last two decades of the nineteenth century. The maelstrom, labeled Populism, contained a powerful, indeed a truly revolutionary message--that man was his brother's keeper. This concept proved to have…

  1. Casting the Buffalo Commons: A Rhetorical Analysis of Print Media Coverage of the Buffalo Commons Proposal for the Great Plains

    ERIC Educational Resources Information Center

    Umberger, Mary L.

    2002-01-01

    In 1987, Frank and Deborah Popper, a planner/geographer team from Rutgers University, proposed the Buffalo Commons. If implemented, the Buffalo Commons would have preserved a large area of the Great Plains, including land in ten states, in a national park to be used by exiting Native American reservations, and for the reintroduction of buffalo.

  2. Measuring and mitigating agricultural greenhouse gas production in the U.S. Great Plains 1870-2000

    USDA-ARS?s Scientific Manuscript database

    In the last 150 years the Great Plains region of the United States has become a major center of agricultural production for the global market. The initial agricultural settlement of this area and subsequent changes in production content and farming techniques have resulted in significant greenhouse ...

  3. The role of fire in managing for biological diversity on native rangelands of the Northern Great Plains

    Treesearch

    Carolyn Hull Sieg

    1997-01-01

    A strategy for using fire to manage for biological diversity on native rangelands in the Northern Great Plains incorporates an understanding of its past frequency, timing and intensity. Historically, lightning and humans were the major fire setters, and the role of fire varied both in space and time. A burning regime that includes fires at various intervals, seasons...

  4. Productivity and persistence of summer active and summer dormant tall fescue cultivars in the southern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Lack of persistence arising from high temperature and drought stresses during the summer limits lifetime productivity of tall fescue (Schedonorus arundinacea Schreb. [Dumort]) pastures in the southern Great Plains (SGP). A summer dormancy characteristic common in genotypes originating from the Medit...

  5. Modeled summer background concentration nutrients and suspended sediment in the mid-continent (USA) great rivers

    EPA Science Inventory

    We used regression models to predict background concentration of four water quality indictors: total nitrogen (N), total phosphorus (P), chloride, and total suspended solids (TSS), in the mid-continent (USA) great rivers, the Upper Mississippi, the Lower Missouri, and the Ohio. F...

  6. Challenges and limitations to native species restoration in the Great Basin, USA

    USDA-ARS?s Scientific Manuscript database

    The Great Basin of the western USA is an arid region characterized by high spatial and temporal variability. The region experienced high levels of ecological disturbance during the early period of Euro-American settlement, especially from about 1870 to 1935. The principal plant communities of the ...

  7. Historic fire regimes of eastern Great Basin (USA) mountains reconstructed from tree rings

    Treesearch

    Stanley G. Kitchen

    2010-01-01

    Management of natural landscapes requires knowledge of key disturbance processes and their effects. Fire and forest histories provide valuable insight into how fire and vegetation varied and interacted in the past. I constructed multi-century fire chronologies for 10 sites on six mountain ranges representative of the eastern Great Basin (USA), a region in which...

  8. The Characteristics of the Systems of Continuing Pedagogical Education in Great Britain, Canada and the USA

    ERIC Educational Resources Information Center

    Mukan, Nataliya; Myskiv, Iryna; Kravets, Svitlana

    2016-01-01

    In the article the systems of continuing pedagogical education in Great Britain, Canada and the USA have been characterized. The main objectives are defined as the theoretical analysis of scientific-pedagogical literature, which highlights different aspects of the problem under research; identification of the common and distinctive features of the…

  9. The Hadeninae (Lepidoptera: Noctuidae) of Great Smoky Mountains National Park, U.S.A.

    USDA-ARS?s Scientific Manuscript database

    Fifty-one species of Hadeninae are recorded from Great Smoky Mountains National Park, Tennessee and North Carolina, U.S.A. Of the six hadenine tribes, five are present in the Park. They include 12 species of Orthosiini, one species of Tholerini, eight species of Hadenini, nine species of Leucaniini,...

  10. The Characteristics of the Systems of Continuing Pedagogical Education in Great Britain, Canada and the USA

    ERIC Educational Resources Information Center

    Mukan, Nataliya; Myskiv, Iryna; Kravets, Svitlana

    2016-01-01

    In the article the systems of continuing pedagogical education in Great Britain, Canada and the USA have been characterized. The main objectives are defined as the theoretical analysis of scientific-pedagogical literature, which highlights different aspects of the problem under research; identification of the common and distinctive features of the…

  11. Late Paleogene topography of the Central Rocky Mountains and western Great Plains region using hydrogen isotope ratios in volcanic glass

    NASA Astrophysics Data System (ADS)

    Rossetto, G.; Fricke, H. C.; Cassel, E. J.; Evanoff, E.

    2015-12-01

    The Central Rocky Mountains (CRM), located in southern Wyoming, Colorado, and northern New Mexico, are characterized by the highest elevation basins (up to 2500 m) and mountains (over 4000 m) in the North American Cordillera. The timing and drivers for surface uplift of the CRM have not been conclusively determined. The goal of this study is to constrain the timing of surface uplift of the CRM by comparing hydrogen isotope ratios of hydration waters (δDglass) in late Paleogene volcanic glasses preserved in felsic tuffs deposited in CRM basins to δDglass values from glasses of similar age (34.9 to 32.2 Ma) preserved in tuffs from the surrounding Great Plains. The tuffs deposited in the Great Plains, to the north and east of the CRM, are currently at elevations of 1100-1600 m. Volcanic glass hydrates shortly after deposition, preserving the δD of ancient meteoric water on geologic timescales, and can thus be used as a proxy for ancient precipitation δD values. Volcanic glasses from the CRM have δDglass values that are an average of ~31‰ higher than δDglass values from the Great Plains, while modern day precipitation δD values in the CRM are ~25‰ lower than δD values in the Great Plains. These results suggest that the uplift of the CRM relative to the surrounding Great Plains occurred after ~32 Ma. This requires a mechanism such as mantle upwelling or differential crustal hydration, not solely Laramide tectonism, to uplift the CRM to current elevations. Elevation, however, may not have been the only control on the spatial distribution of precipitation δD values across the western US. Similar to the modern, mixing of Pacific and Gulf coast air masses likely occurred during the latest Paleogene, driving regional variability in δD values of precipitation.

  12. Site Scientific Mission Plan for the southern Great Plains CART site, July--December 1993

    SciTech Connect

    Schneider, J.M.; Lamb, P.J.; Sisterson, D.L.

    1993-08-01

    The southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This document defines the scientific priorities for site activities during the six-months beginning on July 1, 1993, and also looks forward in lesser detail to subsequent six-month periods. The primary purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides a planning focus for the ARM Functional Teams (Management Team, Experiment Support Team, Operations Team, Data Management Team, Instrument Team, and Campaign Team), and it serves to disseminate the current plans more generally within the ARM Program and among the Science Team. This document includes a description of the site`s operational status and the primary envisaged site activities, together with information concerning approved and proposed Intensive Observation Periods. Amendments will be prepared and distributed whenever the content changes by more than 30% within a six-month period. The primary users of this document are the site operator, the site scientist, the Science Team through the ARM Program Science Director, the ARM Program Experiment Center, and the aforementioned ARM Program Functional Teams. This plan is a living document that will be updated and reissued every six-months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  13. Site scientific mission plan for the Southern Great Plains CART site, January-June 1995

    SciTech Connect

    Schneider, J.M.; Lamb, P.J.; Sisterson, D.L.

    1994-12-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Measurement (ARM) Program Science Team. This document defines the scientific priorities for site activities during the six months beginning on January 1, 1995, and also looks forward in lesser detail to subsequent six-month periods. The primary purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Experiment Support Team [EST], Operations Team, Data Management Team [DMT], Instrument Team [IT], and Campaign Team) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary envisaged site activities, together with information concerning approved and proposed Intensive Observation Periods (IOPs). Amendments will be prepared and distributed whenever the content changes by more than 30% within a six-month period. The primary users of this document are the site operator, the site scientist, the Science Team through the ARM Program Science Director, The ARM Program Experiment Center, and the aforementioned ARM Program functional teams. This plan is a living document that will be updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  14. Site scientific mission plan for the southern Great Plains CART site, January--June 1998

    SciTech Connect

    Peppler, R.A.; Lamb, P.J.; Sisterson, D.L.

    1998-01-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. The primary purpose of this site scientific mission plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Data and Science Integration Team, Operations Team, and Instrument Team) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). The primary users of this document are the Site operator, the Site Scientist Team (SST), the Science Team through the ARM Program science director, the ARM Program Experiment Center, and the aforementioned ARM Program functional teams. This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  15. Site scientific mission plan for the Southern Great Plains CART site January--June 1996

    SciTech Connect

    Peppler, R.A.; Lamb, P.J.; Sisterson, D.L.

    1996-01-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This document defines the scientific priorities for site activities during the six months beginning on January 1, 1996, and looks forward in lesser detail to subsequent six-month periods. The primary purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Data and Science Integration Team [DSIT], Operations Team, instrument Team [IT], and Campaign Team) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed Intensive Observation Periods (IOPs). The primary users of this document are the site operator, the Site Scientist Team (SST), the Science Team through the ARM Program science director, the ARM Program Experiment Center, and the aforementioned ARM program functional teams. This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  16. Analysis of ecosystem controls on soil carbon source-sink relationships in the northwest Great Plains

    USGS Publications Warehouse

    Tan, Z.; Liu, S.; Johnston, C.A.; Liu, J.; Tieszen, L.L.

    2006-01-01

    Our ability to forecast the role of ecosystem processes in mitigating global greenhouse effects relies on understanding the driving forces on terrestrial C dynamics. This study evaluated the controls on soil organic C (SOC) changes from 1973 to 2000 in the northwest Great Plains. SOC source-sink relationships were quantified using the General Ensemble Biogeochemical Modeling System (GEMS) based on 40 randomly located 10 ?? 10 km2 sample blocks. These sample blocks were aggregated into cropland, grassland, and forestland groups based on land cover composition within each sample block. Canonical correlation analysis indicated that SOC source-sink relationship from 1973 to 2000 was significantly related to the land cover type while the change rates mainly depended on the baseline SOC level and annual precipitation. Of all selected driving factors, the baseline SOC and nitrogen levels controlled the SOC change rates for the forestland and cropland groups, while annual precipitation determined the C source-sink relationship for the grassland group in which noticeable SOC sink strength was attributed to the conversion from cropped area to grass cover. Canonical correlation analysis also showed that grassland ecosystems are more complicated than others in the ecoregion, which may be difficult to identify on a field scale. Current model simulations need finther adjustments to the model input variables for the grass cover-dominated ecosystems in the ecoregion. Copyright 2006 by the American Geophysical Union.

  17. Site scientific mission plan for the southern great plains CART site, July--December 1995

    SciTech Connect

    Splitt, M.E.; Lamb, P.J.; Sisterson, D.L.

    1995-07-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs Of the Atmospheric Radiation Measurement (ARM) Program Science Team. This document defines the scientific Priorities for site activities during the six months beginning on July 1, 1995, and looks forward in lesser detail to subsequent six-month periods. The Primary Purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary envisioned site activities, together with information concerning approved and proposed Intensive Observation Periods (IOPs). This plan is a living document that will be updated and reissued every six months as the observational facilities are developed, tested, and augmented and as Priorities are adjusted in response to developments in scientific planning and understanding.

  18. Organic and Elemental Carbon Aerosol Particulates at the Southern Great Plains Site Field Campaign Report

    SciTech Connect

    Cary, Robert

    2016-04-01

    The purpose of this study was to measure the organic carbon (OC) and elemental carbon (EC) fractions of PM2.5 particulate matter at the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) sampling site for a 6-month period during the summer of 2013. The site is in a rural location remote from any populated areas, so it would be expected to reflect carbon concentration over long-distance transport patterns. During the same period in 2012, a number of prairie fires in Oklahoma and Texas had produced large plumes of smoke particles, but OC and EC particles had not been quantified. In addition, during the summer months, other wild fires, such as forest fires in the Rocky Mountain states and other areas, can produce carbon aerosols that are transported over long distances. Both of these source types would be expected to contain mixtures of both OC and EC.

  19. Mapping carbon flux uncertainty and selecting optimal locations for future flux towers in the Great Plains

    USGS Publications Warehouse

    Gu, Y.; Howard, D.M.; Wylie, B.K.; Zhang, L.

    2012-01-01

    Flux tower networks (e. g., AmeriFlux, Agriflux) provide continuous observations of ecosystem exchanges of carbon (e. g., net ecosystem exchange), water vapor (e. g., evapotranspiration), and energy between terrestrial ecosystems and the atmosphere. The long-term time series of flux tower data are essential for studying and understanding terrestrial carbon cycles, ecosystem services, and climate changes. Currently, there are 13 flux towers located within the Great Plains (GP). The towers are sparsely distributed and do not adequately represent the varieties of vegetation cover types, climate conditions, and geophysical and biophysical conditions in the GP. This study assessed how well the available flux towers represent the environmental conditions or "ecological envelopes" across the GP and identified optimal locations for future flux towers in the GP. Regression-based remote sensing and weather-driven net ecosystem production (NEP) models derived from different extrapolation ranges (10 and 50%) were used to identify areas where ecological conditions were poorly represented by the flux tower sites and years previously used for mapping grassland fluxes. The optimal lands suitable for future flux towers within the GP were mapped. Results from this study provide information to optimize the usefulness of future flux towers in the GP and serve as a proxy for the uncertainty of the NEP map.

  20. Soil organic carbon dynamics as related to land use history in the northwestern Great Plains

    USGS Publications Warehouse

    Tan, Z.; Liu, S.; Johnston, C.A.; Loveland, T.R.; Tieszen, L.L.; Liu, J.; Kurtz, R.

    2005-01-01

    Strategies for mitigating the global greenhouse effect must account for soil organic carbon (SOC) dynamics at both spatial and temporal scales, which is usually challenging owing to limitations in data and approach. This study was conducted to characterize the SOC dynamics associated with land use change history in the northwestern Great Plains ecoregion. A sampling framework (40 sample blocks of 10 × 10 km2 randomly located in the ecoregion) and the General Ensemble Biogeochemical Modeling System (GEMS) were used to quantify the spatial and temporal variability in the SOC stock from 1972 to 2001. Results indicate that C source and sink areas coexisted within the ecoregion, and the SOC stock in the upper 20-cm depth increased by 3.93 Mg ha−1 over the 29 years. About 17.5% of the area was evaluated as a C source at 122 kg C ha−1 yr−1. The spatial variability of SOC stock was attributed to the dynamics of both slow and passive fractions, while the temporal variation depended on the slow fraction only. The SOC change at the block scale was positively related to either grassland proportion or negatively related to cropland proportion. We concluded that the slow C pool determined whether soils behaved as sources or sinks of atmospheric CO2, but the strength depended on antecedent SOC contents, land cover type, and land use change history in the ecoregion.

  1. Site scientific mission plan for the southern Great Plain CART site July-December 1997.

    SciTech Connect

    Lamb, P.J.; Peppler, R.A.; Sisterson, D.L.

    1997-08-28

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This document defines the scientific priorities for site activities during the six months beginning on July 1, 1997, and looks forward in lesser detail to subsequent six-month periods. The primary purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Data and Science Integration Team [DSIT], Operations Team, Instrument Team [IT], and Campaign Team) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). The primary users of this document are the site operator, the Site Scientist Team (SST), the Science Team through the ARM Program science director, the ARM Program Experiment Center, and the aforementioned ARM Program functional teams. This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  2. Site scientific mission plan for the Southern Great Plains CART site: January 1997--June 1997

    SciTech Connect

    Peppler, R.A.; Lamb, P.J.; Sisterson, D.L.

    1997-01-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This document defines the scientific priorities for site activities during the six months beginning on January 1, 1997, and looks forward in lesser detail to subsequent six-month periods. The primary purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Data and Science Integration Team [DSIT], Operations Team, Instrument Team [IT], and Campaign Team) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). The primary users of this document are the site operator, the Site Scientist Team (SST), the Science Team through the ARM Program science director, the ARM Program Experiment Center, and the aforementioned ARM Program functional teams. This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  3. Site scientific mission plan for the Southern Great Plains CART site: July--December 1997

    SciTech Connect

    Peppler, R.A.; Lamb, P.J.; Sisterson, D.L.

    1997-07-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This document defines the scientific priorities for site activities during the six months beginning on July 1, 1997, and looks forward in lesser detail to subsequent six-month periods. The primary purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  4. Site scientific mission plan for the Southern Great Plains CART site: July--December 1998

    SciTech Connect

    Peppler, R.A.; Lamb, P.; Sisterson, D.L.

    1998-07-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site was designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This Site Scientific Mission Plan defines the scientific priorities for site activities during the six months beginning on July 1, 1998, and looks forward in lesser detail to subsequent six-month periods. The primary purpose of this document is to provide scientific guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Data and Science Integration Team [DSIT], Operations Team, and Instrument Team [IT]) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). The primary users of this document are the site operator, the site program manager, the Site Scientist Team (SST), the Science Team through the ARM Program science director, the ARM program Experiment Center, and the aforementioned ARM Program functional teams. This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  5. Site scientific mission plan for the Southern Great Plains CART Site, January--June 1999

    SciTech Connect

    Peppler, R.A.; Sisterson, D.L.; Lamb, P.

    1999-03-10

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site was designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This Site Scientific Mission Plan defines the scientific priorities for site activities during the six months beginning on January 1, 1999, and looks forward in lesser detail to subsequent six-month periods. The primary purpose of this document is to provide scientific guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Data and Science Integration Team [DSIT], Operations Team, and Instrument Team [IT]) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). The primary users of this document are the site operator, the site program manager, the Site Scientist Team (SST), the Science Team through the ARM Program science director, the ARM Program Experiment Center, and the aforementioned ARM Program functional teams. This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  6. Potential effects of climate change on aquatic ecosystems of the Great Plains of North America

    USGS Publications Warehouse

    Covich, A.P.; Fritz, S.C.; Lamb, P.J.; Marzolf, R.D.; Matthews, W.J.; Poiani, K.A.; Prepas, E.E.; Richman, M.B.; Winter, T.C.

    1997-01-01

    The Great Plains landscape is less topographically complex than most other regions within North America, but diverse aquatic ecosystems, such as playas, pothole lakes, ox-bow lakes, springs, groundwater aquifers, intermittent and ephemeral streams, as well as large rivers and wetlands, are highly dynamic and responsive to extreme climatic fluctuations. We review the evidence for climatic change that demonstrates the historical importance of extremes in north-south differences in summer temperatures and east-west differences in aridity across four large subregions. These physical driving forces alter density stratification, deoxygenation, decomposition and salinity. Biotic community composition and associated ecosystem processes of productivity and nutrient cycling respond rapidly to these climatically driven dynamics. Ecosystem processes also respond to cultural effects such as dams and diversions of water for irrigation, waste dilution and urban demands for drinking water and industrial uses. Distinguishing climatic from cultural effects in future models of aquatic ecosystem functioning will require more refinement in both climatic and economic forecasting. There is a need, for example, to predict how long-term climatic forecasts (based on both ENSO and global warming simulations) relate to the permanence and productivity of shallow water ecosystems. Aquatic ecologists, hydrologists, climatologists and geographers have much to discuss regarding the synthesis of available data and the design of future interdisciplinary research. ?? 1997 by John Wiley & Sons, Ltd.

  7. Wind and wildlife in the Northern Great Plains: identifying low-impact areas for wind development.

    PubMed

    Fargione, Joseph; Kiesecker, Joseph; Slaats, M Jan; Olimb, Sarah

    2012-01-01

    Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW) than most other forms of energy production and has known and predicted adverse effects on wildlife. The Northern Great Plains (NGP) is home both to some of the world's best wind resources and to remaining temperate grasslands, the most converted and least protected ecological system on the planet. Thus, appropriate siting and mitigation of wind development is particularly important in this region. Steering energy development to disturbed lands with low wildlife value rather than placing new developments within large and intact habitats would reduce impacts to wildlife. Goals for wind energy development in the NGP are roughly 30 GW of nameplate capacity by 2030. Our analyses demonstrate that there are large areas where wind development would likely have few additional impacts on wildlife. We estimate there are ∼1,056 GW of potential wind energy available across the NGP on areas likely to have low-impact for biodiversity, over 35 times development goals. New policies and approaches will be required to guide wind energy development to low-impact areas.

  8. A Prototype Physical Database for Passive Microwave Retrievals of Precipitation over the US Southern Great Plains

    NASA Technical Reports Server (NTRS)

    Ringerud, S.; Kummerow, C. D.; Peters-Lidard, C. D.

    2015-01-01

    An accurate understanding of the instantaneous, dynamic land surface emissivity is necessary for a physically based, multi-channel passive microwave precipitation retrieval scheme over land. In an effort to assess the feasibility of the physical approach for land surfaces, a semi-empirical emissivity model is applied for calculation of the surface component in a test area of the US Southern Great Plains. A physical emissivity model, using land surface model data as input, is used to calculate emissivity at the 10GHz frequency, combining contributions from the underlying soil and vegetation layers, including the dielectric and roughness effects of each medium. An empirical technique is then applied, based upon a robust set of observed channel covariances, extending the emissivity calculations to all channels. For calculation of the hydrometeor contribution, reflectivity profiles from the Tropical Rainfall Measurement Mission Precipitation Radar (TRMM PR) are utilized along with coincident brightness temperatures (Tbs) from the TRMM Microwave Imager (TMI), and cloud-resolving model profiles. Ice profiles are modified to be consistent with the higher frequency microwave Tbs. Resulting modeled top of the atmosphere Tbs show correlations to observations of 0.9, biases of 1K or less, root-mean-square errors on the order of 5K, and improved agreement over the use of climatological emissivity values. The synthesis of these models and data sets leads to the creation of a simple prototype Tb database that includes both dynamic surface and atmospheric information physically consistent with the land surface model, emissivity model, and atmospheric information.

  9. A Prototype Physical Database for Passive Microwave Retrievals of Precipitation over the US Southern Great Plains

    NASA Technical Reports Server (NTRS)

    Ringerud, S.; Kummerow, C. D.; Peters-Lidard, C. D.

    2015-01-01

    An accurate understanding of the instantaneous, dynamic land surface emissivity is necessary for a physically based, multi-channel passive microwave precipitation retrieval scheme over land. In an effort to assess the feasibility of the physical approach for land surfaces, a semi-empirical emissivity model is applied for calculation of the surface component in a test area of the US Southern Great Plains. A physical emissivity model, using land surface model data as input, is used to calculate emissivity at the 10GHz frequency, combining contributions from the underlying soil and vegetation layers, including the dielectric and roughness effects of each medium. An empirical technique is then applied, based upon a robust set of observed channel covariances, extending the emissivity calculations to all channels. For calculation of the hydrometeor contribution, reflectivity profiles from the Tropical Rainfall Measurement Mission Precipitation Radar (TRMM PR) are utilized along with coincident brightness temperatures (Tbs) from the TRMM Microwave Imager (TMI), and cloud-resolving model profiles. Ice profiles are modified to be consistent with the higher frequency microwave Tbs. Resulting modeled top of the atmosphere Tbs show correlations to observations of 0.9, biases of 1K or less, root-mean-square errors on the order of 5K, and improved agreement over the use of climatological emissivity values. The synthesis of these models and data sets leads to the creation of a simple prototype Tb database that includes both dynamic surface and atmospheric information physically consistent with the land surface model, emissivity model, and atmospheric information.

  10. Feasibility of producing jet fuel from GPGP (Great Plains Gasification Plant) by-products

    SciTech Connect

    Willson, W.G.; Knudson, C.L.; Rindt, J.R.

    1987-01-01

    The Great Plains Gasification Plant (GPGP) in Beulah, North Dakota, is in close proximity to several Air Force bases along our northern tier. This plant is producing over 137 million cubic feet per day high-Btu SNG from North Dakota lignite. In addition, the plant generates three liquid streams, naphtha, crude phenol, and tar oil. The naphtha may be directly marketable because of its low boiling point and high aromatic content. The other two streams, totalling about 4300 barrels per day, are available as potential sources of aviation jet fuel for the Air Force. The overall objective of this project is to assess the technical and economic feasibility of producing aviation turbine fuel from the by-product streams of GPGP. These streams, as well as fractions thereof, will be characterized and subsequently processed over a wide range of process conditions. The resulting turbine fuel products will be analyzed to determine their chemical and physical characteristics as compared to petroleum-based fuels to meet the military specification requirements. A second objective is to assess the conversion of the by-product streams into a new, higher-density aviation fuel. Since no performance specifications currently exist for a high-density jet fuel, reaction products and intermediates will only be characterized to indicate the feasibility of producing such a fuel. This report describes results on feedstock characterization. 6 figs., 5 tabs.

  11. A study of Quaternary landforms and materials in the Midwest and Great Plains

    NASA Technical Reports Server (NTRS)

    Morrison, R. B.; Hallberg, G. R. (Principal Investigator)

    1972-01-01

    The author has identified the following significant results. Measurements made from prints of ERTS-1, MSS 5 images, show practical limits of detectability for this imagery in the Midwest. The smallest high contrast object detectable has an approximate measured diameter of 150 feet. The smallest clearly identifiable cultural feature is roughly 300 feet for high contrast, and 400 to 500 feet for low contrast objects. Rural roadways, with an average width of 75 feet, are clearly defined due to high reflectivity, linearity, and the instantaneous field of view of the scanner. On the infrared a farm pond slightly greater than one acre is detectable. Crop and natural foliage cover in the Midwest during summar months obscures geologic and soils information and hinders detailed mapping. In the western Great Plains large-scale mapping of this kind may be possible, even at this time of year. In southwestern Iowa, topographic and drainage system anomalies, revealed by the imagery, are related to the slope of and depth to the buried bedrock surface. In eastern Iowa land use classification can be done from ERTS-1 imagery.

  12. A boundary-layer cloud study using Southern Great Plains Cloud and radiation testbed (CART) data

    SciTech Connect

    Albrecht, B.; Mace, G.; Dong, X.; Syrett, W.

    1996-04-01

    Boundary layer clouds-stratus and fairweather cumulus - are closely coupled involves the radiative impact of the clouds on the surface energy budget and the strong dependence of cloud formation and maintenance on the turbulent fluxes of heat and moisture in the boundary layer. The continuous data collection at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site provides a unique opportunity to study components of the coupling processes associated with boundary layer clouds and to provide descriptions of cloud and boundary layer structure that can be used to test parameterizations used in climate models. But before the CART data can be used for process studies and parameterization testing, it is necessary to evaluate and validate data and to develop techniques for effectively combining the data to provide meaningful descriptions of cloud and boundary layer characteristics. In this study we use measurements made during an intensive observing period we consider a case where low-level stratus were observed at the site for about 18 hours. This case is being used to examine the temporal evolution of cloud base, cloud top, cloud liquid water content, surface radiative fluxes, and boundary layer structure. A method for inferring cloud microphysics from these parameters is currently being evaluated.

  13. Microscopic composition measurements of organic individual particles collected in the Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Bonanno, D.; China, S.; Fraund, M. W.; Pham, D.; Kulkarni, G.; Laskin, A.; Gilles, M. K.; Moffet, R.

    2016-12-01

    The Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) Campaign was carried out to gain a better understanding of the lifecycle of shallow clouds. The HISCALE experiment was designed to contrast two seasons, wet and dry, and determine their effect on atmospheric cloud and aerosol processes. The spring component to HISCALE was selected to characterize mixing state for particles collected onto substrates. Sampling was performed before and after rain events to obtain airborne soil organic particles (ASOP), which are ejected after rain events. The unique composition of the ASOP may affect optical properties and/or hygroscopic properties. The collection of particles took place at the Atmospheric Radiation Measurement Southern Great Plains (ARM SGP) field site. The Scanning Transmission X-Ray Microscope (STXM) was used to image the samples collected during the first HI-SCALE Campaign to determine the carbonaceous mixing state. Scanning Electron Microscopy Energy-dispersive X-ray (SEM/EDX) analysis is more sensitive to the inorganic makeup of particles, while STXM renders a more comprehensive analysis of the organics. Measurements such as nephelometry, Particle Soot Absorption Photometry (PSAP), and Aerosol Mass Spectrometry (AMS) from the ARM archive will be correlated with microscopy measurements. The primary focus is the relation between composition and morphology of ASOP with hygroscopicity and optical properties. Further investigation of these organic particles will be performed to provide a mixing state parameterization and aid in the advancement of current climate models.

  14. The role of the US Great Plains low-level jet in nocturnal migrant behavior

    NASA Astrophysics Data System (ADS)

    Wainwright, Charlotte E.; Stepanian, Phillip M.; Horton, Kyle G.

    2016-10-01

    The movements of aerial animals are under the constant influence of atmospheric flows spanning a range of spatiotemporal scales. The Great Plains nocturnal low-level jet is a large-scale atmospheric phenomenon that provides frequent strong southerly winds through a shallow layer of the airspace. The jet can provide substantial tailwind assistance to spring migrants moving northward, while hindering southward migration during autumn. This atmospheric feature has been suspected to play a prominent role in defining migratory routes, but the flight strategies used with respect to these winds are yet to be examined. Using collocated vertically pointing radar and lidar, we investigate the altitudinal selection behavior of migrants over Oklahoma during two spring and two autumn migration seasons. In general, migrants choose to fly within the jet in spring, often concentrating in the favorable wind speed maximum. Autumn migrants typically fly below the jet, although some will rapidly climb to reach altitudes above the inhibiting winds. The intensity of migration was relatively constant throughout the spring due to the predominantly favorable southerly jet winds. Conversely, autumn migrants were more apt to delay departure to wait for the relatively infrequent northerly winds.

  15. Site scientific mission plan for the Southern Great Plains CART site: July--December 1996

    SciTech Connect

    Peppler, R.A.; Lamb, P.J.; Sisterson, D.L.

    1996-07-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This document defines the scientific priorities for site activities during the six months beginning on July 1, 1996, and looks forward in lesser detail to subsequent six-month periods. The primary purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Data and Science Integration Team [DSIT], Operations Team, Instrument Team [IT], and Campaign Team) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding. The primary objectives of the ARM program are: to describe the radiative energy flux profile of the clear and cloudy atmosphere; to understand the processes determining the flux profile; and to parameterize the processes determining the flux profile for incorporation into general circulation models.

  16. Causes of Long-Term Drought in the United States Great Plains

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried D.; Suarez, Max J.; Pegion, Philip J.; Koster, Randal D.; Bacmeister, Julio T.

    2003-01-01

    This study examines the causes of long term droughts in the United States Great Plains (USGP). The focus is on the relative roles of slowly varying SSTs and interactions with soil moisture. The results from ensembles of long term (1930-1999) simulations carried out with the NASA Seasonal-to- Interannual Prediction Project (NSIPP-1) atmospheric general circulation model (AGCM) show that the SSTs account for about 1/3 of the total low frequency rainfall variance in the USGP. Results from idealized experiments with climatological SST suggest that the remaining low frequency variance in the USGP precipitation is the result of interactions with soil moisture. In particular, simulations with soil moisture feedback show a five-fold increase in the variance in annual USGP precipitation compared with simulations in which the soil feedback is excluded. In addition to increasing variance, the interactions with the soil introduce year-to-year memory in the hydrological cycle that is consistent with a red noise process, in which the deep soil is forced by white noise and damped with a time scale of about 2 years. As such, the role of low frequency SST variability is to introduce a bias to the net forcing on the soil moisture that drives the random process preferentially to either wet or dry conditions.

  17. The role of the US Great Plains low-level jet in nocturnal migrant behavior.

    PubMed

    Wainwright, Charlotte E; Stepanian, Phillip M; Horton, Kyle G

    2016-10-01

    The movements of aerial animals are under the constant influence of atmospheric flows spanning a range of spatiotemporal scales. The Great Plains nocturnal low-level jet is a large-scale atmospheric phenomenon that provides frequent strong southerly winds through a shallow layer of the airspace. The jet can provide substantial tailwind assistance to spring migrants moving northward, while hindering southward migration during autumn. This atmospheric feature has been suspected to play a prominent role in defining migratory routes, but the flight strategies used with respect to these winds are yet to be examined. Using collocated vertically pointing radar and lidar, we investigate the altitudinal selection behavior of migrants over Oklahoma during two spring and two autumn migration seasons. In general, migrants choose to fly within the jet in spring, often concentrating in the favorable wind speed maximum. Autumn migrants typically fly below the jet, although some will rapidly climb to reach altitudes above the inhibiting winds. The intensity of migration was relatively constant throughout the spring due to the predominantly favorable southerly jet winds. Conversely, autumn migrants were more apt to delay departure to wait for the relatively infrequent northerly winds.

  18. Nitrogen-limitation and invasive sweetclover impacts vary between two Great Plains plant communities

    USGS Publications Warehouse

    Van Riper, Laura C.; Larson, Diane L.; Larson, Jennifer L.

    2010-01-01

    Yellow sweetclover is an exotic herbaceous legume common in the Great Plains of the US. Although woody legumes have been shown to affect ecosystem processes through nitrogen (N) fixation (i.e., they can be considered "transformers" sensu Richardson et al. (2000)), the same has not been shown for short-lived herbaceous species. The objectives of this study were to (1) quantify the effects of yellow sweetclover on N mineralization and nitrification and (2) assess the effects of N fertilization on two plant communities, badlands sparse vegetation and western wheatgrass prairie. We used in situ (in wheatgrass prairie) and laboratory incubations (for both plant communities) to assess N dynamics at sites with high and low sweetclover cover in the two plant communities. We found that both N mineralization and nitrification were higher in the high sweetclover plots in the sparse plant community, but not in the wheatgrass prairie. To assess fertilization effects and determine if nutrients or water were limiting at our sites, we conducted a field experiment with five resource addition treatments, (1) N, (2) N + water, (3) water, (4) phosphorus, and (5) no addition. Water was limiting in the wheatgrass prairie but contrary to expectation, N was not. In contrast, N was limiting in the sparse community, where a fertilization effect was seen in exotic forbs, especially the toxic invader Halogeton glomeratus. Our results emphasize the contingent nature of plant invasion in which effects are largely dependent on attributes of the recipient vegetation.

  19. Wind and Wildlife in the Northern Great Plains: Identifying Low-Impact Areas for Wind Development

    PubMed Central

    Fargione, Joseph; Kiesecker, Joseph; Slaats, M. Jan; Olimb, Sarah

    2012-01-01

    Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW) than most other forms of energy production and has known and predicted adverse effects on wildlife. The Northern Great Plains (NGP) is home both to some of the world’s best wind resources and to remaining temperate grasslands, the most converted and least protected ecological system on the planet. Thus, appropriate siting and mitigation of wind development is particularly important in this region. Steering energy development to disturbed lands with low wildlife value rather than placing new developments within large and intact habitats would reduce impacts to wildlife. Goals for wind energy development in the NGP are roughly 30 GW of nameplate capacity by 2030. Our analyses demonstrate that there are large areas where wind development would likely have few additional impacts on wildlife. We estimate there are ∼1,056 GW of potential wind energy available across the NGP on areas likely to have low-impact for biodiversity, over 35 times development goals. New policies and approaches will be required to guide wind energy development to low-impact areas. PMID:22848505

  20. Future petroleum resource potential of northern Rocky Mountain-Great Plains area

    SciTech Connect

    Peterson, J.A. )

    1989-09-01

    The northern Rocky Mountain-Great Plains area includes nine main petroleum exploration provinces: (1) Wyoming-Utah-Idaho thrust belt; (2) southwestern Wyoming basins, (3) Big Horn basin, (4) Wind River basin, (5) Powder River basin, (6) western Montana province, (7) Sweetgrass arch province, (8) central Montana province, and (9) Williston basin-Sioux uplift province. More than 2,500 oil and gas fields have been discovered in these provinces, with cumulative production up to 1986 of approximately 8 billion bbl of oil and more than 15 tcf of gas. Twenty-five giants fields (> 100 million bbl of oil), many of which were discovered early in the century, account for more than half of the cumulative production. Oil and gas production is from carbonate and sandstone reservoirs ranging in age from Cambrian to Tertiary. Organic-rich petroleum source rocks are present in the Ordovician, Devonian, Mississippian, Pennsylvanian, Permian, Cretaceous, and Tertiary stratigraphic sections. US Geological Survey mean estimates of undiscovered conventional recoverable petroleum resources in the region are approximately 4.4 billion bbl of oil and 29 tcf of gas. Significant resources of unconventional gas in low-permeability reservoirs and as coal-bed methane also are present in the region. The future potential is encouraging, depending on economic factors, but increasingly refined exploration and production technology will be necessary to explore for the remaining resources, a large part of which is expected to be in relatively small accumulations.

  1. Feasibility of producing jet fuel from GPGP (Great Plains Gasification Plant) by-products

    SciTech Connect

    Willson, W.G.; Knudson, C.L.; Rindt, J.R.; Smith, E. )

    1987-01-01

    The Great Plains Gasification Plant (GPGP) in Beulah, North Dakota, is in close proximity to several Air force bases along our northern tier. This plant is producing over 137 million cubic feet per day of high-Btu SNG from North Dakota lignite. In addition, the plant generates three liquid streams, naphtha, crude phenol, and tar oil. The naphtha may be directly marketable because of its low boiling point and high aromatic content. The other two streams, totalling about 4300 barrels per day, are available as potential sources of aviation jet fuel for the Air Force. The overall objective of this project is to assess the technical and economic feasibility of producing aviation turbine fuel from the by-product streams of GPGP. These streams, as well as fractions thereof, will be characterized and subsequently processed over a wide range of process conditions. The resulting turbine fuel products will be analyzed to determine their chemical and physical characteristics as compared to petroleum-based fuels to meet the military specification requirements. A second objective is to assess the conversion of the by-product streams into a new, higher-density aviation fuel. Since no performance specifications currently exist for a high-density jet fuel, reaction products and intermediates will only be characterized to indicate the feasibility of producing such a fuel. This report describes the stream assessment. 6 refs., 3 figs., 3 tabs.

  2. Breaking sod or breaking even? Flax on the northern Great Plains and Prairies, 1889-1930.

    PubMed

    MacFayden, Joshua D

    2009-01-01

    A new thirst for paint and color in cities made extensive flax production profitable in the northern Great Plains and Prairies and contributed to the cultivation of the most fragile grassland ecosystems. The production of flax seed for linseed oil became an early spin-off of the Prairie wheat economy but, unlike wheat, flax vanished from old land after one or two rotations and reappeared in districts with the most new breaking. Officials explained the migrant crop as preparing native grasslands for cultivation or exhausting soil in old land, but farmers brought flax to their new breaking for other reasons. Producers would only put flax on any land when a range of economic and environmental conditions were in place. It was never sown without promise of adequately high prices or in the absence of affordable seed and other inputs. When price allowed, it usually appeared on new breaking because it could be planted later and transported further without upsetting the balance of other activities and without farmers learning many new techniques. Scientists discovered that diseased soil drove flax off old land, not soil exhaustion. Circumventing the disease was possible but costly, and farmers simply replaced flax with the next most lucrative commodity.

  3. Late-Quaternary recharge determined from chloride in shallow groundwater in the central Great Plains

    USGS Publications Warehouse

    Macfarlane, P.A.; Clark, J.F.; Davisson, M.L.; Hudson, G.B.; Whittemore, D.O.

    2000-01-01

    An extensive suite of isotopic and geochemical tracers in groundwater has been used to provide hydrologic assessments of the hierarchy of flow systems in aquifers underlying the central Great Plains (southeastern Colorado and western Kansas) of the United States and to determine the late Pleistocene and Holocene paleotemperature and paleorecharge record. Hydrogeologic and geochemical tracer data permit classification of the samples into late Holocene, late Pleistocene-early Holocene, and much older Pleistocene groups. Paleorecharge rates calculated from the Cl concentration in the samples show that recharge rates were at least twice the late Holocene rate during late Pleistocene-early Holocene time, which is consistent with their relative depletion in 16O and D. Noble gas (Ne, Ar, Kr, Xe) temperature calculations confirm that these older samples represent a recharge environment approximately 5??C cooler than late Holocene values. These results are consistent with the global climate models that show a trend toward a warmer, more arid climate during the Holocene. (C) 2000 University of Washington.

  4. Feasibility of producing jet fuel from GPGP (Great Plains Gasification Plant) by-products

    SciTech Connect

    Willson, W.G.; Knudson, C.L.; Rindt, J.R.

    1987-01-01

    The Great Plains Gasification Plant (GPGP) in Beulah, North Dakota, is in close proximity to several Air Force bases along our northern tier. This plant is producing over 137 million cubic feet per day of high-Btu Natural Gas from North Dakota lignite. In addition, the plant generates three liquid streams, naphtha, crude phenol, and tar oil. The naphtha may be directly marketable because of its low boiling point and high aromatic content. The other two streams, totalling about 4300 barrels per day, are available as potential sources of aviation fuel jet fuel for the Air Force. The overall objective of this project is to assess the technical and economic feasibility of producing aviation turbine fuel from the by-product streams of GPGP. These streams, as well as fractions, thereof, will be characterized and subsequently processed over a wide range of process conditions. The resulting turbine fuel products will be analyzed to determine their chemical and physical characteristics as compared to petroleum-based fuels to meet the military specification requirements. A second objective is to assess the conversion of the by-product streams into a new, higher-density aviation fuel. Since no performance specifications currently exist for a high-density jet fuel, reaction products and intermediates will only be characterized to indicate the feasibility of producing such a fuel. This report discusses the suitability of the tar oil stream. 5 refs., 20 figs., 15 tabs.

  5. Grazing improves C and N cycling in the Northern Great Plains: a meta-analysis.

    PubMed

    Wang, Xiaoyu; McConkey, Brian G; VandenBygaart, A J; Fan, Jianling; Iwaasa, Alan; Schellenberg, Mike

    2016-09-12

    Grazing potentially alters grassland ecosystem carbon (C) and nitrogen (N) storage and cycles, however, the overall direction and magnitude of such alterations are poorly understood on the Northern Great Plains (NGP). By synthesizing data from multiple studies on grazed NGP ecosystems, we quantified the response of 30 variables to C and N pools and fluxes to grazing using a comprehensive meta-analysis method. Results showed that grazing enhanced soil C (5.2 ± 4.6% relative) and N (11.3 ± 9.1%) pools in the top layer, stimulated litter decomposition (26.8 ± 18.4%) and soil N mineralization (22.3 ± 18.4%) and enhanced soil NH4(+) (51.5 ± 42.9%) and NO3(-) (47.5 ± 20.7%) concentrations. Our results indicate that the NGP grasslands have sequestered C and N in the past 70 to 80 years, recovering C and N lost during a period of widespread grassland deterioration that occurred in the first half of the 20(th) century. Sustainable grazing management employed after this deterioration has acted as a critical factor for C and N amelioration of degraded NGP grasslands and about 5.84 Mg C ha(-1) CO2-equivalent of anthropogenic CO2 emissions has been offset by these grassland soils.

  6. Subtask 7.3 - The Socioeconomic Impact of Climate Shifts in the Northern Great Plains

    SciTech Connect

    Jaroslav Solc; Tera Buckley; Troy Simonsen

    2007-12-31

    The Energy & Environmental Research Center (EERC) evaluated the water demand response/vulnerability to climate change factors of regional economic sectors in the northern Great Plains. Regardless of the cause of climatic trends currently observed, the research focused on practical evaluation of climate change impact, using water availability as a primary factor controlling long-term regional economic sustainability. Project results suggest that the Upper Missouri, Red River, and Upper Mississippi Watersheds exhibit analogous response to climate change, i.e., extended drought influences water availability in the entire region. The modified trend suggests that the next period for which the Red River Basin can expect a high probability of below normal precipitation will occur before 2050. Agriculture is the most sensitive economic sector in the region; however, analyses confirmed relative adaptability to changing conditions. The price of agricultural commodities is not a good indicator of the economic impact of climate change because production and price do not correlate and are subject to frequent and irregular government intervention. Project results confirm that high water demand in the primary economic sectors makes the regional economy extremely vulnerable to climatic extremes, with a similar response over the entire region. Without conservation-based water management policies, long-term periods of drought will limit socioeconomic development in the region and may threaten even the sustainability of current conditions.

  7. Site Scientific Mission Plan for the Southern Great Plains CART site, July--December 1994

    SciTech Connect

    Schneider, J.M.; Lamb, P.J.; Sisterson, D.L.

    1994-07-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This document defines the scientific priorities for site activities during the six months beginning on July 1, 1994, and also looks forward in lesser detail to subsequent six-month periods. The primary purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM Functional Teams (Management Team, Experiment Support Team, Operations Team, Data Management Team, Instrument Team, and Campaign Team), and it serves to disseminate the plans more generally within the ARM Program and among the Science Team. This document includes a description of the site`s operational status and the primary envisaged site activities, together with information concerning approved and proposed Intensive Observation Periods. Amendments will be prepared and distributed whenever the content changes by more than 30% within a six-month period. The primary users of this document are the site operator, the site scientist, the Science Team through the ARM Program Science Director, the ARM Program Experiment Center, and the aforementioned ARM Program Functional Teams. This plan is a living document that will be updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  8. Grazing improves C and N cycling in the Northern Great Plains: a meta-analysis

    PubMed Central

    Wang, Xiaoyu; McConkey, Brian G.; VandenBygaart, A. J.; Fan, Jianling; Iwaasa, Alan; Schellenberg, Mike

    2016-01-01

    Grazing potentially alters grassland ecosystem carbon (C) and nitrogen (N) storage and cycles, however, the overall direction and magnitude of such alterations are poorly understood on the Northern Great Plains (NGP). By synthesizing data from multiple studies on grazed NGP ecosystems, we quantified the response of 30 variables to C and N pools and fluxes to grazing using a comprehensive meta-analysis method. Results showed that grazing enhanced soil C (5.2 ± 4.6% relative) and N (11.3 ± 9.1%) pools in the top layer, stimulated litter decomposition (26.8 ± 18.4%) and soil N mineralization (22.3 ± 18.4%) and enhanced soil NH4+ (51.5 ± 42.9%) and NO3− (47.5 ± 20.7%) concentrations. Our results indicate that the NGP grasslands have sequestered C and N in the past 70 to 80 years, recovering C and N lost during a period of widespread grassland deterioration that occurred in the first half of the 20th century. Sustainable grazing management employed after this deterioration has acted as a critical factor for C and N amelioration of degraded NGP grasslands and about 5.84 Mg C ha−1 CO2-equivalent of anthropogenic CO2 emissions has been offset by these grassland soils. PMID:27616184

  9. American-Indian diabetes mortality in the Great Plains Region 2002–2010

    PubMed Central

    Kelley, Allyson; Giroux, Jennifer; Schulz, Mark; Aronson, Bob; Wallace, Debra; Bell, Ronny; Morrison, Sharon

    2015-01-01

    Objective To compare American-Indian and Caucasian mortality rates from diabetes among tribal Contract Health Service Delivery Areas (CHSDAs) in the Great Plains Region (GPR) and describe the disparities observed. Research design and methods Mortality data from the National Center for Vital Statistics and Seer*STAT were used to identify diabetes as the underlying cause of death for each decedent in the GPR from 2002 to 2010. Mortality data were abstracted and aggregated for American-Indians and Caucasians for 25 reservation CHSDAs in the GPR. Rate ratios (RR) with 95% CIs were used and SEER*Stat V.8.0.4 software calculated age-adjusted diabetes mortality rates. Results Age-adjusted mortality rates for American-Indians were significantly higher than those for Caucasians during the 8-year period. In the GPR, American-Indians were 3.44 times more likely to die from diabetes than Caucasians. South Dakota had the highest RR (5.47 times that of Caucasians), and Iowa had the lowest RR, (1.1). Reservation CHSDA RR ranged from 1.78 to 10.25. Conclusions American-Indians in the GPR have higher diabetes mortality rates than Caucasians in the GPR. Mortality rates among American-Indians persist despite special programs and initiatives aimed at reducing diabetes in these populations. Effective and immediate efforts are needed to address premature diabetes mortality among American-Indians in the GPR. PMID:25926992

  10. Grazing improves C and N cycling in the Northern Great Plains: a meta-analysis

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoyu; McConkey, Brian G.; Vandenbygaart, A. J.; Fan, Jianling; Iwaasa, Alan; Schellenberg, Mike

    2016-09-01

    Grazing potentially alters grassland ecosystem carbon (C) and nitrogen (N) storage and cycles, however, the overall direction and magnitude of such alterations are poorly understood on the Northern Great Plains (NGP). By synthesizing data from multiple studies on grazed NGP ecosystems, we quantified the response of 30 variables to C and N pools and fluxes to grazing using a comprehensive meta-analysis method. Results showed that grazing enhanced soil C (5.2 ± 4.6% relative) and N (11.3 ± 9.1%) pools in the top layer, stimulated litter decomposition (26.8 ± 18.4%) and soil N mineralization (22.3 ± 18.4%) and enhanced soil NH4+ (51.5 ± 42.9%) and NO3‑ (47.5 ± 20.7%) concentrations. Our results indicate that the NGP grasslands have sequestered C and N in the past 70 to 80 years, recovering C and N lost during a period of widespread grassland deterioration that occurred in the first half of the 20th century. Sustainable grazing management employed after this deterioration has acted as a critical factor for C and N amelioration of degraded NGP grasslands and about 5.84 Mg C ha‑1 CO2-equivalent of anthropogenic CO2 emissions has been offset by these grassland soils.

  11. Site scientific mission plan for the Southern Great Plains CART Site, July--December 1999

    SciTech Connect

    Peppler, R.A.; Sisterson, D.L.; Lamb, P.

    1999-12-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site was designed to help satify the data needs of the Atmospheric Radiation Measurement (ARM) program science team. The site scientific mission plan defines the scientific priorities for site activities during the 6-month period beginning 1 July 1999, and looks forward in lesser detail to subsequent 6-month periods. The primary purpose of this document is to provide scientific guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams and serves to disseminate the plans more generally within the ARM program and among the members of the science team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  12. Potential Effects of Climate Change on Aquatic Ecosystems of the Great Plains of North America

    NASA Astrophysics Data System (ADS)

    Covich, A. P.; Fritz, S. C.; Lamb, P. J.; Marzolf, R. D.; Matthews, W. J.; Poiani, K. A.; Prepas, E. E.; Richman, M. B.; Winter, T. C.

    1997-06-01

    The Great Plains landscape is less topographically complex than most other regions within North America, but diverse aquatic ecosystems, such as playas, pothole lakes, ox-bow lakes, springs, groundwater aquifers, intermittent and ephemeral streams, as well as large rivers and wetlands, are highly dynamic and responsive to extreme climatic fluctuations. We review the evidence for climatic change that demonstrates the historical importance of extremes in north-south differences in summer temperatures and east-west differences in aridity across four large subregions. These physical driving forces alter density stratification, deoxygenation, decomposition and salinity. Biotic community composition and associated ecosystem processes of productivity and nutrient cycling respond rapidly to these climatically driven dynamics. Ecosystem processes also respond to cultural effects such as dams and diversions of water for irrigation, waste dilution and urban demands for drinking water and industrial uses. Distinguishing climatic from cultural effects in future models of aquatic ecosystem functioning will require more refinement in both climatic and economic forecasting. There is a need, for example, to predict how long-term climatic forecasts (based on both ENSO and global warming simulations) relate to the permanence and productivity of shallow water ecosystems. Aquatic ecologists, hydrologists, climatologists and geographers have much to discuss regarding the synthesis of available data and the design of future interdisciplinary research.

  13. Application of Pheromone Traps for Managing Hessian Fly (Diptera: Cecidomyiidae) in the Southern Great Plains.

    PubMed

    Knutson, Allen E; Giles, K L; Royer, T A; Elliott, N C; Bradford, N

    2017-06-01

    The Hessian fly, Mayetiola destructor Say, is an important pest of winter wheat in the Southern Great Plains of the United States. As larvae feed behind the leaf sheath, infestations often go undetected until crop damage is evident, and there are no remedial actions that can prevent economic loss once a field is infested. The recent discovery of the sex-attractant pheromone of the Hessian fly provides an opportunity to use pheromone traps to detect and monitor adult activity and potentially better manage this pest. Adult male Hessian fly activity was monitored during 4 yr at six locations from northcentral Oklahoma, 36° N latitude, south to central Texas, 31° N latitude. In Oklahoma, trap captures were low in the fall, no flies were captured during the winter, and the largest number of flies was captured in the spring. However, in southcentral Texas, adults were captured throughout the fall, winter, and in the spring when trap captures were again the greatest. The relationship between trap captures and density of Hessian fly larvae per tiller was investigated during the fall and spring. Although large numbers of adults (>100 per trap per day) were often captured, economic infestation of larvae rarely developed. Results identify optimum times for field sampling to determine immature Hessian fly infestations in wheat in Oklahoma and Texas. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Assessing vegetation response to drought in the northern Great Plains using vegetation and drought indices

    USGS Publications Warehouse

    Ji, Lei; Peters, Albert J.

    2003-01-01

    The Normalized Difference Vegetation Index (NDVI) derived from the Advanced Very High Resolution Radiometer (AVHRR) has been widely used to monitor moisture-related vegetation condition. The relationship between vegetation vigor and moisture availability, however, is complex and has not been adequately studied with satellite sensor data. To better understand this relationship, an analysis was conducted on time series of monthly NDVI (1989–2000) during the growing season in the north and central U.S. Great Plains. The NDVI was correlated to the Standardized Precipitation Index (SPI), a multiple-time scale meteorological-drought index based on precipitation. The 3-month SPI was found to have the best correlation with the NDVI, indicating lag and cumulative effects of precipitation on vegetation, but the correlation between NDVI and SPI varies significantly between months. The highest correlations occurred during the middle of the growing season, and lower correlations were noted at the beginning and end of the growing season in most of the area. A regression model with seasonal dummy variables reveals that the relationship between the NDVI and SPI is significant in both grasslands and croplands, if this seasonal effect is taken into account. Spatially, the best NDVI–SPI relationship occurred in areas with low soil water-holding capacity. Our most important finding is that NDVI is an effective indicator of vegetation-moisture condition, but seasonal timing should be taken into consideration when monitoring drought with the NDVI.

  15. Estimation of Regional Net CO2 Exchange over the Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Biraud, S. C.; Riley, W. J.; Fischer, M. L.; Torn, M. S.; Cooley, H. S.

    2004-12-01

    Estimating spatially distributed ecosystem CO2 exchange is an important component of the North American Carbon Program. We describe here a methodology to estimate Net Ecosystem Exchange (NEE) over the Southern Great Plains, using: (1) data from the Department Of Energy's Atmospheric Radiation Measurement (ARM) sites in Oklahoma and Kansas; (2) meteorological forcing data from the Mesonet facilities; (3) soil and vegetation types from 1 km resolution USGS databases; (4) vegetation status (e.g., LAI) from 1 km satellite measurements of surface reflectance (MODIS); (5) a tested land-surface model; and (6) a coupled land-surface and meteorological model (MM5/ISOLSM). This framework allows us to simulate regional surface fluxes in addition to ABL and free troposphere concentrations of CO2 at a continental scale with fine-scale nested grids centered on the ARM central facility. We use the offline land-surface and coupled models to estimate regional NEE, and compare predictions to measurements from the 9 Extended Facility sites with eddy correlation measurements. Site level comparisons to portable ECOR measurements in several crop types are also presented. Our approach also allows us to extend bottom-up estimates to periods and areas where meteorological forcing data are unavailable.

  16. Grassland vegetation and bird communities in the southern Great Plains of North America

    USGS Publications Warehouse

    Chapman, R.N.; Engle, David M.; Masters, R.E.; Leslie, David M.

    2004-01-01

    Structure and composition of vegetation and abundance of breeding birds in grasslands seeded to Old World bluestem (Bothriochloa ischmaeum) were compared to native mixed prairie in the southern Great Plains of North America. Abundance of birds was determined using fixed-radius point counts. Detrended correspondence analysis was used to compare plant community composition and canonical correspondence analysis was used to examine the relationships between plant species composition and vegetation structure with the bird community. Plant species composition differed distinctly between seeded grassland and native mixed prairie, but the differences were not reflected in habitat structure, bird community composition, or abundance of bird species. Seeded grassland was inferior to native mixed prairie in terms of diversity of plant species, but that difference did not translate into meaningful differences in structure that drove habitat selection by breeding birds. Conservation programs that promote establishment of seeded grassland and do not allow for suitable disturbance regimes will selectively benefit a narrow suite of birds regardless of plant species composition. ?? 2004 Elsevier B.V. All rights reserved.

  17. Assessing Spectral Shortwave Cloud Observations at the Southern Great Plains Facility

    NASA Technical Reports Server (NTRS)

    McBride, P. J.; Marshak, A.; Wiscombe, W. J.; Flynn, C. J.; Vogelmann, A. M.

    2012-01-01

    The Atmospheric Radiation Measurement (ARM) program (now Atmospheric System Research) was established, in part, to improve radiation models so that they could be used reliably to compute radiation fluxes through the atmosphere, given knowledge of the surface albedo, atmospheric gases, and the aerosol and cloud properties. Despite years of observations, discrepancies still exist between radiative transfer models and observations, particularly in the presence of clouds. Progress has been made at closing discrepancies in the spectral region beyond 3 micron, but the progress lags at shorter wavelengths. Ratios of observed visible and near infrared cloud albedo from aircraft and satellite have shown both localized and global discrepancies between model and observations that are, thus far, unexplained. The capabilities of shortwave surface spectrometry have been improved in recent years at the Southern Great Plains facility (SGP) of the ARM Climate Research Facility through the addition of new instrumentation, the Shortwave Array Spectroradiometer, and upgrades to existing instrumentation, the Shortwave Spectroradiometer and the Rotating Shadowband Spectroradiometer. An airborne-based instrument, the HydroRad Spectroradiometer, was also deployed at the ARM site during the Routine ARM Aerial Facility Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign. Using the new and upgraded spectral observations along with radiative transfer models, cloud scenes at the SGP are presented with the goal of characterizing the instrumentation and the cloud fields themselves.

  18. Hydrology of Area 61, Northern Great Plains and Rocky Mountain Coal Provinces, Colorado and New Mexico

    USGS Publications Warehouse

    Abbott, P.O.; Geldon, Arthur L.; Cain, Doug; Hall, Alan P.; Edelmann, Patrick

    1983-01-01

    Area 61 is located on the Colorado-New Mexico boundary in Huerfano and Las Animas Counties, Colorado, and Colfax County, New Mexico, and includes the Raton Mesa coal region. The 5 ,900-square-mile area is an asymmetrical structural trough bounded by the Rocky Mountains on the west and the Great Plains on the east. The area is drained by the Huerfano, Apishapa, Purgatoire, and Canadian Rivers (and their tributaries), all tributary to the Arkansas River. The principal coal-bearing formations are the Vermejo Formation of Late Cretaceous age and the Raton Formation of Late Cretaceous and Paleocene age. Much of the coal in the area is of coking quality, important to the metallurgical industry. Topographic relief in the area is greater than 8,700 feet, and this influences the climate which in turn affects the runoff pattern of area streams. Summer thunderstorms often result in flash floods. Virtually all geologic units in the region yield water. Depth to ground water ranges from land surface to 400 feet. Surface and ground water in the area contain mostly bicarbonate and sulfate ions; locally in the ground water, chloride ions predominate. Potential hydrologic problems associated with surface coal mining in the area are water-quality degradation, water-table decline, and increased erosion and sedimentation. (USGS)

  19. Potential Agricultural Uses of Flue Gas Desulfurization Gypsum in the Northern Great Plains

    SciTech Connect

    DeSutter, T.M.; Cihacek, L.J.

    2009-07-15

    Flue gas desulfurization gypsum (FGDG) is a byproduct from the combustion of coal for electrical energy production. Currently, FGDG is being produced by 15 electrical generating stations in Alabama, Florida, Indiana, Iowa, Kentucky, Ohio, North Carolina, South Carolina, Tennessee, Texas, and Wisconsin. Much of this byproduct is used in the manufacturing of wallboard. The National Network for Use of FGDG in Agriculture was initiated to explore alternative uses of this byproduct. In the northern Great Plains (North Dakota, South Dakota, and Montana), FGDG has the potential to be used as a Ca or S fertilizer, as an acid soil ameliorant, and for reclaiming or mitigating sodium-affected soils. Greater than 1.4 million Mg of FGDG could initially be used in these states for these purposes. Flue gas desulfurization gypsum can be an agriculturally important resource for helping to increase the usefulness of problem soils and to increase crop and rangeland production. Conducting beneficial use audits would increase the public awareness of this product and help identify to coal combustion electrical generating stations the agriculturally beneficial outlets for this byproduct.

  20. Culture-independent analysis of the soil bacterial assemblage at the Great Salt Plains of Oklahoma

    PubMed Central

    Caton, Ingrid R.; Schneegurt, Mark A.

    2013-01-01

    The Great Salt Plains (GSP) of Oklahoma is a natural inland terrestrial hypersaline environment that forms evaporite crusts of mainly NaCl. Previous work described GSP bacterial assemblages through the phylogenetic and phenetic characterization of 105 isolates from 46 phylotypes. The current report describes the same bacterial assemblages through culture-independent 16S rRNA gene clone libraries. Although from similar hypersaline mud flats, the bacterial libraries from two sites, WP3 and WP6, were quite different. The WP3 library was dominated by cyanobacteria, mainly Cyanothece and Euhalothece. The WP6 library was rich in anaerobic sulfur-cycle organisms, including abundant Desulfuromonas. This pattern likely reflects differences in abiotic factors, such as frequency of flooding and hydrologic push. While more than 100 OTUs were identified, the assemblages were not as diverse, based on Shannon indexes, as bacterial communities from oligohaline soils. Since natural inland hypersaline soils are relatively unstudied, it was not clear what kind of bacteria would be present. The bacterial assemblage is predominantly genera typically found in hypersaline systems, although some were relatives of microbes common in oligohaline and marine environments. The bacterial clones did not reflect wide functional diversity, beyond phototrophs, sulfur metabolizers, and numerous heterotrophs. PMID:21953014

  1. Causes of Long-Term Drought in the United States Great Plains

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried D.; Suarez, Max J.; Pegion, Philip J.; Koster, Randal D.; Bacmeister, Julio T.

    2003-01-01

    This study examines the causes of long term droughts in the United States Great Plains (USGP). The focus is on the relative roles of slowly varying SSTs and interactions with soil moisture. The results from ensembles of long term (1930-1999) simulations carried out with the NASA Seasonal-to- Interannual Prediction Project (NSIPP-1) atmospheric general circulation model (AGCM) show that the SSTs account for about 1/3 of the total low frequency rainfall variance in the USGP. Results from idealized experiments with climatological SST suggest that the remaining low frequency variance in the USGP precipitation is the result of interactions with soil moisture. In particular, simulations with soil moisture feedback show a five-fold increase in the variance in annual USGP precipitation compared with simulations in which the soil feedback is excluded. In addition to increasing variance, the interactions with the soil introduce year-to-year memory in the hydrological cycle that is consistent with a red noise process, in which the deep soil is forced by white noise and damped with a time scale of about 2 years. As such, the role of low frequency SST variability is to introduce a bias to the net forcing on the soil moisture that drives the random process preferentially to either wet or dry conditions.

  2. Surface summertime radiative forcing by shallow cumuli at the Atmospheric Radiation Measurement Southern Great Plains site

    SciTech Connect

    Berg, Larry K.; Kassianov, Evgueni I.; Long, Charles N.; Mills Jr., David L.

    2011-01-08

    Although shallow cumuli are common over large areas of the globe, their impact on the surface radiative forcing has not been carefully evaluated. This study addresses this shortcoming by analyzing data from days with shallow cumuli collected over eight summers (2000-2007) at the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (collectively ACRF) Southern Great Plains site. During periods with clouds, the average shortwave and longwave radiative forcings are 45.5 W m-2 and +11.6 W m-2, respectively. The forcing has been defined so that a negative (positive) forcing indicates a surface cooling (warming). On average, the shortwave forcing is negative, however, instances with positive shortwave forcing are observed approximately 20% of the time. These positive values of shortwave forcing are associated with three-dimensional radiative effects of the clouds. The three-dimensional effects are shown to be largest for intermediate cloud amounts. The magnitude of the three-dimensional effects decreased with averaging time, but it is not negligibly small even for large averaging times as long as four hours.

  3. Validation of regional wind resource predictions in the Northern Great Plains

    SciTech Connect

    Elliott, D; Schwartz, M

    1998-08-01

    The development and validation of computerized wind mapping tools for regional assessment purposes is an important step in accelerating wind energy deployment. This paper summarizes the results of a validation study of the automated wind resource mapping technique developed at the National Renewable Energy Laboratory (NREL). This technique uses Geographic Information System (GIS) software and produces high horizontal resolution (1 km) wind resource maps. The automated wind maps have been used to help plan wind measurement programs and to define potential areas for wind energy projects in countries such as Mexico, Chile, Indonesia, and China. The authors chose a US location for this project to test the accuracy of the automated mapping technique in a region where the wind resource distribution was already fairly well known. The Buffalo Ridge region of the Northern Great Plains served as the subject area. The study area covered northwestern Iowa, southwestern Minnesota, and adjacent parts of South Dakota and Nebraska. This area had several advantages for use in a validation study. First, this area has active wind energy development and the results would be of interest to the wind energy community. Second, a validation data set would be fairly easy to derive because recent wind measurements were taken in that region specifically for wind energy purposes. These data were publicly available and easily obtained. Finally, the relatively simple terrain in that region enabled this study to be completed in a timely manner.

  4. Site Scientific Mission Plan for the Southern Great Plains CART site: January--June 1994

    SciTech Connect

    Schneider, J.M.; Lamb, P.J.; Sisterson, D.L.

    1993-12-01

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This document defines the scientific priorities for site activities during the six months beginning on January 1, 1994, and also looks forward in lesser detail to subsequent six-month periods. The primary purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM Functional Teams (Management Team, Experiment Support Team, Operations Team, Data Management Team, Instrument Team, and Campaign Team), and it serves to disseminate the plans more generally within the ARM Program and among the Science Team. This document includes a description of the site`s operational status and the primary envisaged site activities, together with information concerning approved and proposed Intensive Observation Periods. Amendments will be prepared and distributed whenever the content changes by more than 30% within a six-month period. The primary users of this document are the site operator, the site scientist, the Science Team through the ARM Program Science Director, the ARM Program Experiment Center, and the aforementioned ARM Program Functional Teams. This plan is a living document that will be updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.

  5. Simulated responses of soil organic carbon stock to tillage management scenarios in the Northwest Great Plains

    USGS Publications Warehouse

    Tan, Z.; Liu, S.; Li, Z.; Loveland, T.R.

    2007-01-01

    Background: Tillage practices greatly affect carbon (C) stocks in agricultural soils. Quantification of the impacts of tillage on C stocks at a regional scale has been challenging because of the spatial heterogeneity of soil, climate, and management conditions. We evaluated the effects of tillage management on the dynamics of soil organic carbon (SOC) in croplands of the Northwest Great Plains ecoregion of the United States using the General Ensemble biogeochemical Modeling System (GEMS). Tillage management scenarios included actual tillage management (ATM), conventional tillage (CT), and no-till (NT). Results: Model simulations show that the average amount of C (kg C ha-1yr-1) released from croplands between 1972 and 2000 was 246 with ATM, 261 with CT, and 210 with NT. The reduction in the rate of C emissions with conversion of CT to NT at the ecoregion scale is much smaller than those reported at plot scale and simulated for other regions. Results indicate that the response of SOC to tillage practices depends significantly on baseline SOC levels: the conversion of CT to NT had less influence on SOC stocks in soils having lower baseline SOC levels but would lead to higher potentials to mitigate C release from soils having higher baseline SOC levels. Conclusion: For assessing the potential of agricultural soils to mitigate C emissions with conservation tillage practices, it is critical to consider both the crop rotations being used at a local scale and the composition of all cropping systems at a regional scale. ?? 2007 Tan et al; licensee BioMed Central Ltd.

  6. High concentrations of regional dust from deserts to plains across the central Rocky Mountains, USA

    NASA Astrophysics Data System (ADS)

    Reynolds, R. L.; Munson, S. M.; Fernandez, D. P.; Neff, J. C.

    2015-12-01

    Regional mineral dust in the American Southwest affects snow-melt rates, biogeochemical cycling, visibility, and public health. We measured total suspended particulates (TSP) across a 500-km-long sampling network of five remote sites in Utah and Colorado, USA, forming a gradient in distance from major dust emitting areas. The two westernmost sites on the Colorado Plateau desert had similar TSP concentrations (2008-2012, daily average=126 μg m-3; max. daily average over a two-week period=700 μg m-3 at Canyonlands National Park, Utah), while the easternmost High Plains site, close to cropped and grazed areas in northeastern Colorado, had an average concentration of 143 μg m-3 in 2011-2012 (max. daily average=656 μg m-3). Such concentrations rank comparably with those of TSP in several African and Asian cities in the paths of frequent dust storms. Dust loadings at the two intervening montane sites decreased from the western slope of the Rocky Mountains (Telluride, daily average=68 μg m-3) to an eastern site (Niwot Ridge, daily average=58 μg m-3). Back-trajectory analyses and satellite retrievals indicated that the three westernmost sites received most dust from large desert-source regions as far as 300 km to their southwest. These sources also sometimes sent dust to the two easternmost sites, which additionally captured dust from sources north and northwest of the central Rocky Mountains as well as locally at the Plains site. The PM10 fraction accounted for <15% of TSP, but most TSP is only slightly larger (typical median size, 15-20 μm) after about 100-800 km transport distances. Correlations between TSP and PM10 values indicate increases in both fractions during regional wind storms, especially related to Pacific frontal systems during late winter to late spring. These measurements and observations indicate that most dust deposition and associated air-quality problems in the interior American West are connected to regional dust sources and not to those in

  7. Diversity, Seasonality, and Context of Mammalian Roadkills in the Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Smith-Patten, Brenda D.; Patten, Michael A.

    2008-06-01

    Thousands of mammals are killed annually from vehicle collisions, making the issue an important one for conservation biologists and environmental managers. We recorded all readily identifiable kills on or immediately adjacent to roads in the southern Great Plains from March 2004-March 2007. We also recorded distance traveled, whether a road was paved or divided, the number of lanes, and prevailing habitat. Surveys were opportunistic and were conducted by car during conditions of good visibility. Over our 239 surveys and >16,500 km traveled, we recorded 1412 roadkills from 18 different mammal species (size ranged from Sciurus squirrels to the white-tailed deer, Odocolieus virginianus). The overall kill rate was 8.50 / 100 km. Four species were prone to collisions: the Virginia opossum ( Didelphis virginiana), nine-banded armadillo ( Dasypus novemcinctus), striped skunk ( Mephitis mephitis), and northern raccoon ( Procyon lotor). Together they accounted for approximately 85% (1198) of all roadkills. Mortality rate differed significantly between 2- and 4-lane roads (8.39 versus 7.79 / 100 km). Kill rates were significantly higher on paved versus unpaved roads (8.60 versus 3.65 / 100 km), but did not depend on whether a road was divided. Roadkills were higher in spring than in fall (1.5×), winter (1.4×), or summer (1.3×). The spring peak (in kills / 100 km) was driven chiefly by the armadillo (2.76 in spring/summer versus 0.73 in autumn/winter) and opossum (2.65 versus 1.47). By contrast, seasonality was dampened by a late winter/early spring peak in skunk mortalities, for which 41% occurred in the 6-week period of mid-February through March. The raccoon did not exhibit a strong seasonal pattern. Our data are consistent with dispersal patterns of these species. Our results underscore the high rate of highway mortality in the southern plains, as well as differences in seasonality and road type that contribute to mortality. Conservation and management efforts should

  8. Modeling Irrigation Pumping and Groundwater Depletion in the High Plains Aquifer, USA

    NASA Astrophysics Data System (ADS)

    Pokhrel, Y. N.; Koirala, S.; Yamada, T.; Hanasaki, N.; Yeh, P. J.; Yoshimura, K.; Kanae, S.; Oki, T.

    2011-12-01

    model captures the observed groundwater withdrawals in the highly-monitored principal aquifers in the USA. In the High Plains Aquifer (HPA), which is a major source of groundwater irrigation in the USA, simulated groundwater withdrawal of ~25 km3/yr closely corresponds with the observational record of ~24 km3/yr for the year 2000. Simulated groundwater depletion in the HPA agrees fairly well with the observations from GRACE satellite mission. Closely matching with the observations by the United States Geological Survey (USGS), results indicate that the groundwater levels averaged over the HPA declined by 1.2 m from 2002 to 2007. Moreover, country-based simulated irrigation water requirements and total groundwater withdrawals agree well with the reported country statistics.

  9. Microbial Responses to Forest Management in the Western Gulf Coastal Plain, USA

    NASA Astrophysics Data System (ADS)

    Foote, J. A.; Boutton, T. W.; Scott, D. A.

    2013-12-01

    Microbial communities are integral components of the biogeochemistry, fertility, and structure of forest soils, and land management practices that alter the microbial environment may influence the long-term sustainability and productivity of forestlands. In 1989 the Long-term Soil Productivity (LTSP) program was initiated to address the National Forest Management Act's concerns over possible losses in soil productivity due to soil disturbance from forest management on National Forest lands. The LTSP program is a network of 62 sites across the USA and Canada that employs the same 3X3 replicated (X3) factorial experimental design consisting of three harvest intensities (bole only, whole tree, whole tree + forest floor removal) with three soil compaction intensities (none, intermediate, severe) and plots that were split for herbicide when the experiment was initiated. Our purpose was to determine the impact of forest harvest intensity, soil compaction, and their interaction on soil microbial biomass C and N (SMB-C, -N) and soil total nitrogen (TN) and soil organic carbon (SOC) storage in a Pinus taeda L. forest 15-years post-treatment at the Davy Crockett National Forest LTSP site in eastern Texas, USA. We quantified SMB-C and -N using the chloroform fumigation extraction method, and TN and SOC by dry combustion. Soils are loamy sand and were sampled 5X during 2011-2012. In each split-plot, five samples were obtained between two living P. taeda stems to a depth of 10-cm and pooled in the field. Because soil compaction, harvest by soil compaction interaction, and herbicide had no effect on the measured soil properties, results are based on repeated measures ANOVA using harvest and time. Both SMB-C and -N were impacted by harvest and varied with time, and SMB-C had a harvest by time interaction. Generally, both microbial indices decreased in the order: bole only >whole tree > whole tree + forest floor. Soil TN and SOC were both higher in the bole only treatment compared

  10. Modeling regional salinization of the Ogallala aquifer, Southern High Plains, TX, USA

    USGS Publications Warehouse

    Mehta, S.; Fryar, A.E.; Brady, R.M.; Morin, R.H.

    2000-01-01

    Two extensive plumes (combined area > 1000 km2) have been delineated within the Ogallala aquifer in the Southern High Plains, TX, USA. Salinity varies within the plumes spatially and increases with depth; Cl ranges from 50 to >500 mg 1-1. Variable-density flow modeling using SUTRA has identified three broad regions of upward cross-formational flow from the underlying evaporite units. The upward discharge within the modeled plume area is in the range of 10-4-10-5 m3 day-1, and the TDS concentrations are typically >3000 mg 1-1. Regions of increased salinity, identified within the Whitehorse Group (evaporite unit) underlying the Ogallala aquifer, are controlled by the structure and thickness variations relative to the recharge areas. Distinct flow paths, on the order of tens of km to >100 km in length, and varying flow velocities indicate that the salinization of the Ogallala aquifer has been a slow, ongoing process and may represent circulation of waters recharged during Pleistocene or earlier times. On-going pumping has had negligible impact on the salinity distribution in the Ogallala aquifer, although simulations indicate that the velocity distribution in the underlying units may have been affected to depths of 150 m after 30 years of pumping. Because the distribution of saline ground water in this region of the Ogallala aquifer is heterogeneous, careful areal and vertical characterization is warranted prior to any well-field development. (C) 2000 Elsevier Science B.V.Two extensive plumes (combined area >1000 km2) have been delineated within the Ogallala aquifer in the Southern High Plains, TX, USA. Salinity varies within the plumes spatially and increases with depth; Cl ranges from 50 to >500 mg l-1. Variable-density flow modeling using SUTRA has identified three broad regions of upward cross-formational flow from the underlying evaporite units. The upward discharge within the modeled plume area is in the range of 10-4-10-5 m3 day-1, and the TDS concentrations

  11. WRF model sensitivity to land surface model and cumulus parameterization under short-term climate extremes over the southern Great Plains of the United States

    Treesearch

    Lisi Pei; Nathan Moore; Shiyuan Zhong; Lifeng Luo; David W. Hyndman; Warren E. Heilman; Zhiqiu. Gao

    2014-01-01

    Extreme weather and climate events, especially short-term excessive drought and wet periods over agricultural areas, have received increased attention. The Southern Great Plains (SGP) is one of the largest agricultural regions in North America and features the underlying Ogallala-High Plains Aquifer system worth great economic value in large part due to production...

  12. Coherent changes in relative C4 plant productivity and climate during the late Quaternary in the North American Great Plains

    USGS Publications Warehouse

    Nordt, L.; Von Fischer, J.; Tieszen, L.; Tubbs, J.

    2008-01-01

    Evolution of the mixed and shortgrass prairie of the North American Great Plains is poorly understood because of limited proxies available for environmental interpretations. Buried soils in the Great Plains provide a solution to the problem because they are widespread both spatially and temporally with their organic reservoirs serving as a link to the plants than once grew on them. Through stable carbon isotopic analysis of soil organic carbon (??13C), the percent carbon from C4 plants (%C4) can be ascertained. Because C4 plants are primarily warm season grasses responding positively to summer temperature, their representation has the added advantage of serving as a climate indicator. To better understand grassland and climate dynamics in the Great Plains during the last 12 ka (ka=1000 radiocarbon years) we developed an isotopic standardization technique by: determining the difference in buried soil ??13C and modern soil ??13C expected for that latitude (????13C), and transferring the ????13C to ??%C4 (% C4) using mass balance calculations. Our analysis reveals two isotopic stages in the mixed and shortgrass prairie of the Great Plains based on trends in ??%C4. In response to orbital forcing mechanisms, ??%C4 was persistently below modern in the Great Plains between 12 and 6.7 ka (isotopic stage II) evidently because of the cooling effect of the Laurentide ice sheet and proglacial lakes in northern latitudes, and glacial meltwater pulses cooling the Gulf of Mexico and North Atlantic Ocean. The ??%C4 after 6.7 ka (isotopic stage I) increased to modern levels as conditioned by the outflow of warm, moist air from the Gulf of Mexico and dry incursions from the west that produced periodic drought. At the millennial-scale, time series analysis demonstrates that ??%C4 oscillated with 0.6 and 1.8 ka periodicities, possibly governed by variations in solar irradiance. Our buried soil isotopic record correlates well with other environmental proxy from the Great Plains and

  13. Hydrological and Dynamical Characteristics of Summertime Droughts over U.S. Great Plains.

    NASA Astrophysics Data System (ADS)

    Chang, Fong-Chiau; Smith, Eric A.

    2001-05-01

    A drought pattern and its time evolution over the U.S. Great Plains are investigated from time series of climate divisional monthly mean surface air temperature and total precipitation anomalies. The spatial pattern consists of correlated occurrences of high (low) surface air temperature and deficit (excess) rainfall. The center of maximum amplitude in rain fluctuation is around Kansas City; that of temperature is over South Dakota. Internal consistency between temperature and precipitation variability is the salient feature of the drought pattern. A drought index is used to quantify drought severity for the period 1895-1996. The 12 severest drought months (in order) during this period are June 1933, June 1988, July 1936, August 1983, July 1934, July 1901, June 1931, August 1947, July 1930, June 1936, July 1954, and August 1936. Hydrological conditions are examined using National Centers for Environmental Prediction (NCEP) reanalysis precipitable water (PW) and monthly surface observations from Kansas City, Missouri, and Bismarck, North Dakota, near the drought centers. This analysis explains why droughts exhibit negative surface relative humidity anomalies accompanied by larger than normal monthly mean daily temperature ranges and why maximum PWs are confined to a strip of about 10° longitude from New Mexico and Arizona into the Dakotas and Minnesota.Dynamical conditions are examined using NCEP reanalysis sea level pressures and 500- and 200-mb geopotential heights. The analysis indicates a midtroposphere wave train with positive centers situated over the North Pacific, North America, and the North Atlantic, with negative centers in the southeastern Gulf of Alaska and Davis Strait. Above-normal sea level pressures over New Mexico, the North Atlantic, and the subtropical Pacific along with below-normal sea level pressures over the Gulf of Alaska eastward to Canada, Davis Strait, and Greenland are present during drought periods. The most prominent feature is the

  14. Buteo Nesting Ecology: Evaluating Nesting of Swainson's Hawks in the Northern Great Plains.

    PubMed

    Inselman, Will M; Datta, Shubham; Jenks, Jonathan A; Jensen, Kent C; Grovenburg, Troy W

    2015-01-01

    Swainson's hawks (Buteo swainsoni) are long-distance migratory raptors that nest primarily in isolated trees located in areas of high grassland density. In recent years, anthropogenic conversion of grassland habitat has raised concerns about the status of the breeding population in the northern Great Plains. In 2013, we initiated a study to investigate the influence of extrinsic factors influencing Swainson's hawk nesting ecology in north-central South Dakota and south-central North Dakota. Using ground and aerial surveys, we located and monitored nesting Swainson's hawk pairs: 73 in 2013 and 120 in 2014. We documented 98 successful breeding attempts that fledged 163 chicks; 1.52 and 1.72 fledglings per successful nest in 2013 and 2014, respectively. We used Program MARK to evaluate the influence of land cover on nest survival. The top model, SDist2Farm+%Hay, indicated that nest survival (fledging at least one chick) decreased as nests were located farther from farm sites and as the percent of hay cover increased within 1200-m of the nest site (34.4%; 95% CI = 27.6%-42.3%). We used logistic regression analysis to evaluate the influence of landscape variables on nest-site selection; Swainson's hawks selected for nest sites located closer to roads. We suggest that tree belts associated with farm sites, whether occupied or not, provide critical breeding sites for Swainson's hawks. Additionally, poor breeding success may be related to the late migratory behavior of this species which requires them to occupy marginal habitat due to other raptors occupying the most suitable habitat prior to Swainson's hawks arriving to the breeding grounds.

  15. Land-atmosphere coupling and climate prediction over the U.S. Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Williams, I. N.; Lu, Y.; Kueppers, L. M.; Riley, W. J.; Biraud, S.; Bagley, J. E.; Torn, M. S.

    2016-12-01

    Biases in land-atmosphere coupling in climate models can contribute to climate prediction biases, but land models are rarely evaluated in the context of this coupling. We tested land-atmosphere coupling and explored effects of land surface parameterizations on climate prediction in a single-column version of the NCAR Community Earth System Model (CESM1.2.2) and an offline Community Land Model (CLM4.5). The correlation between leaf area index (LAI) and surface evaporative fraction (ratio of latent to total turbulent heat flux) was substantially underpredicted compared to observations in the U.S. Southern Great Plains, while the correlation between soil moisture and evaporative fraction was overpredicted by CLM4.5. These correlations were improved by prescribing observed LAI, increasing soil resistance to evaporation, increasing minimum stomatal conductance, and increasing leaf reflectance. The modifications reduced the root mean squared error (RMSE) in daytime 2 m air temperature from 3.6 C to 2 C in summer (JJA), and reduced RMSE in total JJA precipitation from 133 to 84 mm. The modifications had the largest effect on prediction of summer drought in 2006, when a warm bias in daytime 2 m air temperature was reduced from +6 C to a smaller cold bias of -1.3 C, and a corresponding dry bias in total JJA precipitation was reduced from -111 mm to -23 mm. Thus, the role of vegetation in droughts and heat waves is likely underpredicted in CESM1.2.2, and improvements in land surface models can improve prediction of climate extremes.

  16. Pesticides in surface drinking-water supplies of the northern Great Plains.

    PubMed

    Donald, David B; Cessna, Allan J; Sverko, Ed; Glozier, Nancy E

    2007-08-01

    Human health anomalies have been associated with pesticide exposure for people living in rural landscapes in the northern Great Plains of North America. The objective of this study was to investigate the occurrence of 45 pesticides in drinking water from reservoirs in this area that received water primarily from snowmelt and rainfall runoff from agricultural crop lands. Water from 15 reservoirs was sampled frequently during the spring pesticide application period (early May to mid-August) and less frequently for the remainder of the year. Drinking water was sampled in early July. Sample extracts were analyzed for pesticide content using mass spectrometric detection. We detected two insecticides and 27 herbicides in reservoir water. Consistent detection of a subset of 7 herbicides suggested that atmospheric deposition, either directly or in rain, was the principal pathway from fields to the reservoirs. However, the highest concentrations and number of herbicides in drinking water were associated with runoff from a localized 133-mm rainfall over 15 days toward the end of spring herbicide application. Water treatment removed from 14 to 86% of individual herbicides. Drinking water contained 3-15 herbicides (average, 6.4). We estimated the mean annual calculated concentration of herbicides in drinking water to be 75 ng/L (2,4-dichlorophenoxy)acetic acid, 31 ng/L (2-chloro-4-methylphenoxy)acetic acid, 24 ng/L clopyralid, 11 ng/L dichlorprop, 4 ng/L dicamba, 3 ng/L mecoprop, and 1 ng/L bromoxynil. The maximum total concentration of herbicides in drinking water was 2,423 ng/L. For the seven herbicides with established drinking water guidelines, all concentrations of the individual chemicals were well below their respective guideline. However, guidelines have not been established for the majority of the herbicides found in drinking water or for mixtures of pesticides.

  17. Archaeal Diversity at the Great Salt Plains of Oklahoma Described by Cultivation and Molecular Analyses

    PubMed Central

    Caton, T. M.; Caton, I. R.; Witte, L. R.; Schneegurt, M. A.

    2014-01-01

    The Great Salt Plains of Oklahoma is a natural inland terrestrial hypersaline environment that forms evaporite crusts of mainly NaCl. Previous work described the bacterial community through the characterization of 105 isolates from 46 phylotypes. The current report describes the archaeal community through both microbial isolation and culture-independent techniques. Nineteen distinct archaea were isolated, and ten were characterized phenetically. Included were isolates phylogenetically related to Haloarcula, Haloferax, Halorubrum, Haloterrigena, and Natrinema. The isolates were aerobic, non-motile, Gram-negative organisms and exhibited little capacity for fermentation. All of the isolates were halophilic, with most requiring at least 15% salinity for growth, and all grew at 30% salinity. The isolates were mainly mesothermic and could grow at alkaline pH (8.5). A 16S rRNA gene library was generated by polymerase chain reaction amplification of direct soil DNA extracts, and 200 clones were sequenced and analyzed. At 99% and 94% sequence identity, 36 and 19 operational taxonomic units (OTUs) were detected, respectively, while 53 and 22 OTUs were estimated by Chao1, respectively. Coverage was relatively high (100% and 59% at 89% and 99% sequence identity, respectively), and the Shannon Index was 3.01 at 99% sequence identity, comparable to or somewhat lower than hypersaline habitats previously studied. Only sequences from Euryarchaeota in the Halobacteriales were detected, and the strength of matches to known sequences was generally low, most near 90% sequence identity. Large clusters were observed that are related to Haloarcula and Halorubrum. More than two-thirds of the sequences were in clusters that did not have close relatives reported in public databases. PMID:19306116

  18. Pesticides in Surface Drinking-Water Supplies of the Northern Great Plains

    PubMed Central

    Donald, David B.; Cessna, Allan J.; Sverko, Ed; Glozier, Nancy E.

    2007-01-01

    Background Human health anomalies have been associated with pesticide exposure for people living in rural landscapes in the northern Great Plains of North America. Objective The objective of this study was to investigate the occurrence of 45 pesticides in drinking water from reservoirs in this area that received water primarily from snowmelt and rainfall runoff from agricultural crop lands. Methods Water from 15 reservoirs was sampled frequently during the spring pesticide application period (early May to mid-August) and less frequently for the remainder of the year. Drinking water was sampled in early July. Sample extracts were analyzed for pesticide content using mass spectrometric detection. Results We detected two insecticides and 27 herbicides in reservoir water. Consistent detection of a subset of 7 herbicides suggested that atmospheric deposition, either directly or in rain, was the principal pathway from fields to the reservoirs. However, the highest concentrations and number of herbicides in drinking water were associated with runoff from a localized 133-mm rainfall over 15 days toward the end of spring herbicide application. Water treatment removed from 14 to 86% of individual herbicides. Drinking water contained 3–15 herbicides (average, 6.4). Conclusions We estimated the mean annual calculated concentration of herbicides in drinking water to be 75 ng/L (2,4-dichlorophenoxy)acetic acid, 31 ng/L (2-chloro-4-methylphenoxy)acetic acid, 24 ng/L clopyralid, 11 ng/L dichlorprop, 4 ng/L dicamba, 3 ng/L mecoprop, and 1 ng/L bro-moxynil. The maximum total concentration of herbicides in drinking water was 2,423 ng/L. For the seven herbicides with established drinking water guidelines, all concentrations of the individual chemicals were well below their respective guideline. However, guidelines have not been established for the majority of the herbicides found in drinking water or for mixtures of pesticides. PMID:17687445

  19. Increased in Variability in Climatological Means and Extremes in the Great Plains

    NASA Astrophysics Data System (ADS)

    Basara, J. B.; Flanagan, P. X.; Christian, J.; Christian, K.

    2016-12-01

    The Great Plains (GP) of North America is characterized by orthogonal gradients of temperature and precipitation extending from the Gulf of Mexico in the south to the coniferous forests of Canada to the north and are bordered on the west by the Rocky Mountains and then spread east approximately 1000 km into the interior regions of North America. As a result, significant biodiversity exists across relatively short distances within the region. However, because the gradient of precipitation is large across the GP, multiple environmental factors can lead to significant variability in temperature and precipitation at periods spanning seasonal, to interannual, to decadal scales. In addition, the GP region has shown significant coupling between the surface and the atmosphere, especially during the warm season. As a result, the GP often experiences significant hydrometeorological and hydroclimatological extremes across varying spatial and temporal scales including long-term drought, flash drought, flash flooding, and long-term pluvial periods with significant impacts to ecosystem function. Results into analyses of drought to pluvial dipole events in the GP noted that on average, over twice as many dipoles existed in the latter half of the dataset (1955-2013) relative to the first half (1896-1954). In addition an Asynchronous Difference Index (ADI) computed by determining the difference between the dates of precipitation and temperature maxima revealed two physically distinct regimes of ADI (positive and negative), with comparable shifts in the timing of both the maximum of precipitation and temperature within the GP. Time series analysis of decadal average ADI yielded moderate shifts in ADI with increased variability occurring over much of the GP region.

  20. Implications of invasion by Juniperus virginiana on small mammals in the southern Great Plains

    USGS Publications Warehouse

    Horncastle, V.J.; Hellgren, E.C.; Mayer, P.M.; Ganguli, A.C.; Engle, David M.; Leslie, David M.

    2005-01-01

    Changes in landscape cover in the Great Plains are resulting from the range expansion and invasion of eastern red cedar (Juniperus virginiana). By altering the landscape and local vegetation, red cedar is changing the structure and function of habitat for small mammals. We examined effects of invasion by eastern red cedar on small mammals in 3 plant communities (tallgrass prairie, old field, and cross-timbers forest) in the cross-timbers ecoregion in Oklahoma. We sampled small mammals seasonally from May 2001 to August 2002 by using Sherman live traps and mark-recapture techniques on 3.24-ha, 450-trap grids in each plant community. We sampled vegetation in two hundred twenty-five 12 x 12-m cells within each grid. The structure of the small-mammal community differed among the 3 habitat types, with higher species diversity and richness in the tallgrass-prairie and old-field sites. Overall, the small-mammal community shifted along a gradient of increasing eastern red cedar. In the old-field and tallgrass-prairie plots, occurrence of grassland mammals decreased with increasing red cedar, whereas only 1 woodland mammal species increased. In the cross-timbers forest site, percent woody cover (<1 m in height), rather than cover of red cedar, was the most important factor affecting woodland mammal species. Examination of our data suggests that an increase in overstory cover from 0% to 30% red cedar can change a species-rich prairie community to a depauperate community dominated by 1 species, Peromyscus leucopus. Losses in species diversity and changes in mammal distribution paralleled those seen in avian communities invaded by eastern red cedar. Our results highlight ecological effects of invasion by eastern red cedar on diversity and function at multiple trophic levels. ?? 2005 American Society of Mammalogists.

  1. Eco-Efficiency Model for Evaluating Feedlot Rations in the Great Plains, United States.

    PubMed

    Hengen, Tyler J; Sieverding, Heidi L; Cole, Noel A; Ham, Jay M; Stone, James J

    2016-07-01

    Environmental impacts attributable to beef feedlot production provide an opportunity for economically linked efficiency optimization. Eco-efficiency models are used to optimize production and processes by connecting and quantifying environmental and economic impacts. An adaptable, objective eco-efficiency model was developed to assess the impacts of dietary rations on beef feedlot environmental and fiscal cost. The hybridized model used California Net Energy System modeling, life cycle assessment, principal component analyses (PCA), and economic analyses. The model approach was based on 38 potential feedlot rations and four transportation scenarios for the US Great Plains for each ration to determine the appropriate weight of each impact. All 152 scenarios were then assessed through a nested PCA to determine the relative contributing weight of each impact and environmental category to the overall system. The PCA output was evaluated using an eco-efficiency model. Results suggest that water, ecosystem, and human health emissions were the primary impact category drivers for feedlot eco-efficiency scoring. Enteric CH emissions were the greatest individual contributor to environmental performance (5.7% of the overall assessment), whereas terrestrial ecotoxicity had the lowest overall contribution (0.2% of the overall assessment). A well-balanced ration with mid-range dietary and processing energy requirements yielded the most eco- and environmentally efficient system. Using these results, it is possible to design a beef feed ration that is more economical and environmentally friendly. This methodology can be used to evaluate eco-efficiency and to reduce researcher bias of other complex systems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. Contrasting above- and belowground sensitivity of three Great Plains grasslands to altered rainfall regimes.

    PubMed

    Wilcox, Kevin R; von Fischer, Joseph C; Muscha, Jennifer M; Petersen, Mark K; Knapp, Alan K

    2015-01-01

    Intensification of the global hydrological cycle with atmospheric warming is expected to increase interannual variation in precipitation amount and the frequency of extreme precipitation events. Although studies in grasslands have shown sensitivity of aboveground net primary productivity (ANPP) to both precipitation amount and event size, we lack equivalent knowledge for responses of belowground net primary productivity (BNPP) and NPP. We conducted a 2-year experiment in three US Great Plains grasslands--the C4-dominated shortgrass prairie (SGP; low ANPP) and tallgrass prairie (TGP; high ANPP), and the C3-dominated northern mixed grass prairie (NMP; intermediate ANPP)--to test three predictions: (i) both ANPP and BNPP responses to increased precipitation amount would vary inversely with mean annual precipitation (MAP) and site productivity; (ii) increased numbers of extreme rainfall events during high-rainfall years would affect high and low MAP sites differently; and (iii) responses belowground would mirror those aboveground. We increased growing season precipitation by as much as 50% by augmenting natural rainfall via (i) many (11-13) small or (ii) fewer (3-5) large watering events, with the latter coinciding with naturally occurring large storms. Both ANPP and BNPP increased with water addition in the two C4 grasslands, with greater ANPP sensitivity in TGP, but greater BNPP and NPP sensitivity in SGP. ANPP and BNPP did not respond to any rainfall manipulations in the C3 -dominated NMP. Consistent with previous studies, fewer larger (extreme) rainfall events increased ANPP relative to many small events in SGP, but event size had no effect in TGP. Neither system responded consistently above- and belowground to event size; consequently, total NPP was insensitive to event size. The diversity of responses observed in these three grassland types underscores the challenge of predicting responses relevant to C cycling to forecast changes in precipitation regimes even

  3. Energy and Water Fluxes across a Heterogeneous Landscape in the Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Bagley, J. E.; Williams, I. N.; Kueppers, L. M.; Lu, Y.; Torn, M. S.; Biraud, S.

    2015-12-01

    Fluxes of energy and water between the atmosphere and the land surface influence weather and climate. These fluxes depend on the state of the landscape, which contributes to differences in land-atmosphere coupling strength over space and time. One region with potentially strong land-atmosphere coupling is the Southern Great Plains (SGP) in North America. In this region, managed vegetation plays a key role in moderating the surface energy through effects on surface albedo, transpiration, precipitation interception, and other surface properties. However accurately modeling these effects is challenging because the vegetation in this region is very heterogeneous. Winter wheat is the dominant crop, but pasture, hayfields, corn, and recently introduced crops such as canola cover significant portions of the landscape as well. Winter wheat has a unique phenology with fall planting, maximum leaf area in late spring, and harvest in early summer. This phenology contrasts significantly with most other crops and with pastures and hayfields in the region, which have more typical spring-fall growing seasons. Therefore, to sufficiently model and assess land-atmosphere interactions in this region accurate characterization of differences in the seasonality of water and energy fluxes between vegetation types are necessary. We used observations including eddy covariance flux estimates, soil moisture data, state-of-the-art longwave and shortwave radiation measurements, and other observations available for several facilities within the SGP Atmospheric Radiation Measurement (ARM) site in north-central Oklahoma and southern Kansas. We compared the timing and variations in fluxes of water and energy between winter wheat and other land cover types, focusing on vegetation influences on rates of soil dry-down following precipitation events. We found distinct differences in fluxes between winter wheat and other land types. These flux differences had a nonlinear dependency on disparities in

  4. Runoff generation on the northern Great Plains: What's changing, what's not and why?

    NASA Astrophysics Data System (ADS)

    Coles, A.; McConkey, B.; Appels, W. M.; McDonnell, J.

    2016-12-01

    Understanding and modeling runoff generation in seasonally-frozen regions is a major challenge in hydrology. At the hillslope-scale, multiple interacting processes control connectivity and runoff generation, and the relative importance and hierarchy of controls are poorly understood in space and time. While short-term experiments and single-season studies reveal individual process controls, much longer records are needed to witness the nonlinearities and interactions between controls in the activation of runoff. Here, we present findings from three 5 ha hillslopes in Saskatchewan (where snowmelt drives c.80% of annual runoff), including analysis of a 52-year (1962-2013) dataset, and high-resolution spatial mapping of process controls during two snowmelt seasons (2013 and 2014). We found that spring snowmelt-runoff has decreased in response to long-term winter snowfall decreases, but that rainfall-runoff amounts have shown no response to increases in rainfall or shifts to more multi-day rain events. The most important controls on the snowmelt-runoff ratio (through their influence on infiltration into frozen ground) over the 52-year period were, in order of importance: snowfall, snow cover amount, fall soil moisture, melt rate and melt season length. The hierarchy of these controls was time-varying, with runoff being triggered by different control combinations depending on whether there was high or low snow cover, and wet or dry soil antecedent wetness conditions. Finally, analysis of these controls during an intensive field campaign showed that frozen ground accentuates the importance of meso- and micro-topography and that connectivity is determined by the filling and spilling of surface depressions over frozen ground. Our results have implications for the management of surface water on the northern Great Plains and for focussing experimentalists on what to measure, when and why, in the prediction of runoff response in seasonally-frozen regions.

  5. Seismic anisotropy and mantle flow beneath the northern Great Plains of North America

    NASA Astrophysics Data System (ADS)

    Yang, B.; Gao, S. S.; Liu, K. H.; Elsheikh, A. A.; Lemnifi, A. A.; Refayee, H. A.; Yu, Y.

    2013-12-01

    A diverse set of tectonic features and the recent availability of high-quality broadband seismic data from the USArray and other stations on the northern Great Plains of North America provide a distinct opportunity to test different anisotropy-forming mechanisms. A total of 4138 pairs of well-defined shear-wave splitting parameters observed at 445 stations show systematic spatial variations of anisotropic characteristics. Azimuthally invariant fast directions sub-parallel to the absolute plate motion (APM) direction are observed at most of the stations on the Superior craton and the southern Yavapai province, indicating that a single layer of anisotropy with a horizontal axis of symmetry is sufficient to explain the anisotropic structure. For areas with simple anisotropy, the application of a procedure for estimating the depth of anisotropy using spatial coherency of splitting parameters results in a depth of 200-250 km, suggesting that the observed anisotropy mostly resides in the upper asthenosphere. In the vicinity of the northern boundary of the Yavapai province and the Wyoming craton, the splitting parameters can be adequately explained by a two-horizontal layer model. The lower layer has an APM-parallel fast direction, and the upper layer has a fast direction that is mostly consistent with the regional strike of the boundary. Based on the splitting measurements and previous results from seismic tomography and geodynamic modeling, we propose a model involving deflecting of asthenosphere flow by the cratonic root and channeling of flow by a zone of thinned lithosphere approximately along the northern boundary of the Yavapai province.

  6. Seismic anisotropy and mantle flow beneath the northern Great Plains of North America

    NASA Astrophysics Data System (ADS)

    Yang, Bin B.; Gao, Stephen S.; Liu, Kelly H.; Elsheikh, Ahmed A.; Lemnifi, Awad A.; Refayee, Hesham A.; Yu, Youqiang

    2014-03-01

    A diverse set of tectonic features and the recent availability of high-quality broadband seismic data from the USArray and other stations on the northern Great Plains of North America provide a distinct opportunity to test different anisotropy-forming mechanisms. A total of 4138 pairs of well-defined splitting parameters observed at 445 stations show systematic spatial variations of anisotropic characteristics. Azimuthally invariant fast orientations subparallel to the absolute plate motion (APM) direction are observed at most of the stations on the Superior Craton and the southern Yavapai province, indicating that a single layer of anisotropy with a horizontal axis of symmetry is sufficient to explain the anisotropic structure. For areas with simple anisotropy, the application of a procedure for estimating the depth of anisotropy using spatial coherency of splitting parameters results in a depth of 200-250 km, suggesting that the observed anisotropy mostly resides in the upper asthenosphere. In the vicinity of the northern boundary of the Yavapai province and the Wyoming Craton, the splitting parameters can be adequately explained by a two-horizontal layer model. The lower layer has an APM-parallel fast orientation, and the upper layer has a fast orientation that is mostly consistent with the regional strike of the boundary. Based on the splitting measurements and previous results from seismic tomography and geodynamic modeling, we propose a model involving deflecting of asthenosphere flow by the bottom of the lithosphere and channeling of flow by a zone of thinned lithosphere approximately along the northern boundary of the Yavapai province.

  7. Comparison between active sensor and radiosonde cloud boundaries over the ARM Southern Great Plains site

    NASA Astrophysics Data System (ADS)

    Naud, Catherine M.; Muller, Jan-Peter; Clothiaux, Eugene E.

    2003-02-01

    In order to test the strengths and limitations of cloud boundary retrievals from radiosonde profiles, 4 years of radar, lidar, and ceilometer data collected at the Atmospheric Radiation Measurements Southern Great Plains site from November 1996 through October 2000 are used to assess the retrievals of [1995] and [1996]. The lidar and ceilometer data yield lowest-level cloud base heights that are, on average, within approximately 125 m of each other when both systems detect a cloud. These quantities are used to assess the accuracy of coincident cloud base heights obtained from radar and the two radiosonde-based methods applied to 200 m resolution profiles obtained at the same site. The lidar/ceilometer and radar cloud base heights agree by 0.156 ± 0.423 km for 85.27% of the observations, while the agreement between the lidar/ceilometer and radiosonde-derived heights is at best -0.044 ± 0.559 km for 74.60% of all cases. Agreement between radar- and radiosonde-derived cloud boundaries is better for cloud base height than for cloud top height, being at best 0.018 ± 0.641 km for 70.91% of the cloud base heights and 0.348 ± 0.729 km for 68.27% of the cloud top heights. The disagreements between radar- and radiosonde-derived boundaries are mainly caused by broken cloud situations when it is difficult to verify that drifting radiosondes and fixed active sensors are observing the same clouds. In the case of the radar the presence of clutter (e.g., vegetal particles or insects) can affect the measurements from the surface up to approximately 3-5 km, preventing comparisons with radiosonde-derived boundaries. Overall, [1995] tend to classify moist layers that are not clouds as clouds and both radiosonde techniques report high cloud top heights that are higher than the corresponding heights from radar.

  8. Perception of the drought hazard on the Great Plains and its sociological impacts

    NASA Astrophysics Data System (ADS)

    Woudenberg, Donna Louise

    Drought, a defining characteristic of the Great Plains, continues to be one of the most expensive natural disasters in the United States, with the lion's share of financial losses shouldered by crop and livestock producers. These producer's perceptions of and responses to drought were studied in the mid-1960s, the mid-1980s, and were examined again in this study, providing valuable longitudinal data. A number of direct and indirect impacts are experienced by non-farm businesses, communities, and individuals, as well. Some of those impacts have not been well researched and were integral to this project. Interviews with crop producers, livestock producers, and community members were conducted in Frontier County, Nebraska in late summer 2006. It was found that producers are very perceptive of the drought hazard, a result found in the two previous studies; recollections and estimates were well supported with 100 years of SPI and PDSI values. Adoption of drought mitigation practices has increased over the past 40 years. Producers were concerned about the myriad of factors they must consider when planning their farm/ranch operations, particularly as they are trying to adjust to water restrictions imposed as an outcome of the Kansas-Nebraska lawsuit on the Republican River (a task exacerbated by the long-term drought in recent years), but overall they are basically optimistic. Community members were very concerned about the future of farming and the quality of rural life. They expressed fears that changes in farming practices may lower the value of land, affect the tax base, and ultimately impact the school system and other county services.

  9. Estimating switchgrass productivity in the Great Plains using satellite vegetation index and site environmental variables

    USGS Publications Warehouse

    Gu, Yingxin; Wylie, Bruce K.; Howard, Daniel M.

    2015-01-01

    Switchgrass is being evaluated as a potential feedstock source for cellulosic biofuels and is being cultivated in several regions of the United States. The recent availability of switchgrass land cover maps derived from the National Agricultural Statistics Service cropland data layer for the conterminous United States provides an opportunity to assess the environmental conditions of switchgrass over large areas and across different geographic locations. The main goal of this study is to develop a data-driven multiple regression switchgrass productivity model and identify the optimal climate and environment conditions for the highly productive switchgrass in the Great Plains (GP). Environmental and climate variables used in the study include elevation, soil organic carbon, available water capacity, climate, and seasonal weather. Satellite-derived growing season averaged Normalized Difference Vegetation Index (GSN) was used as a proxy for switchgrass productivity. Multiple regression analyses indicate that there are strong correlations between site environmental variables and switchgrass productivity (r = 0.95). Sufficient precipitation and suitable temperature during the growing season (i.e., not too hot or too cold) are favorable for switchgrass growth. Elevation and soil characteristics (e.g., soil available water capacity) are also an important factor impacting switchgrass productivity. An anticipated switchgrass biomass productivity map for the entire GP based on site environmental and climate conditions and switchgrass productivity model was generated. Highly productive switchgrass areas are mainly located in the eastern part of the GP. Results from this study can help land managers and biofuel plant investors better understand the general environmental and climate conditions influencing switchgrass growth and make optimal land use decisions regarding switchgrass development in the GP.

  10. Mapping marginal croplands suitable for cellulosic feedstock crops in the Great Plains, United States

    USGS Publications Warehouse

    Gu, Yingxin; Wylie, Bruce K.

    2016-01-01

    Growing cellulosic feedstock crops (e.g., switchgrass) for biofuel is more environmentally sustainable than corn-based ethanol. Specifically, this practice can reduce soil erosion and water quality impairment from pesticides and fertilizer, improve ecosystem services and sustainability (e.g., serve as carbon sinks), and minimize impacts on global food supplies. The main goal of this study was to identify high-risk marginal croplands that are potentially suitable for growing cellulosic feedstock crops (e.g., switchgrass) in the US Great Plains (GP). Satellite-derived growing season Normalized Difference Vegetation Index, a switchgrass biomass productivity map obtained from a previous study, US Geological Survey (USGS) irrigation and crop masks, and US Department of Agriculture (USDA) crop indemnity maps for the GP were used in this study. Our hypothesis was that croplands with relatively low crop yield but high productivity potential for switchgrass may be suitable for converting to switchgrass. Areas with relatively low crop indemnity (crop indemnity <$2 157 068) were excluded from the suitable areas based on low probability of crop failures. Results show that approximately 650 000 ha of marginal croplands in the GP are potentially suitable for switchgrass development. The total estimated switchgrass biomass productivity gain from these suitable areas is about 5.9 million metric tons. Switchgrass can be cultivated in either lowland or upland regions in the GP depending on the local soil and environmental conditions. This study improves our understanding of ecosystem services and the sustainability of cropland systems in the GP. Results from this study provide useful information to land managers for making informed decisions regarding switchgrass development in the GP.

  11. Site scientific mission plan for the southern great plains CART site January-June 2000.

    SciTech Connect

    Peppler, R. A.; Sisterson, D. L.; Lamb, P.

    2001-03-15

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site was designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This Site Scientific Mission Plan defines the scientific priorities for site activities during the six months beginning on January 1, 2000, and looks forward in less detail to subsequent six-month periods. The primary purpose of this document is to provide scientific guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Data and Science Integration Team [DSIT], Operations Team, and Instrument Team [IT]) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). The primary users of this document are the site operator, the site program manager, the Site Scientist Team (SST), the Science Team through the ARM Program science director, the ARM Program Experiment Center, and the aforementioned ARM Program functional teams. This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding. With this issue, many aspects of earlier Site Scientific Mission Plan reports have been moved to ARM sites on the World Wide Web. This report and all previous reports are available on the SGP CART web site.

  12. AVHRR estimates of surface temperature during the Southern Great Plains 1997 Experiment

    NASA Astrophysics Data System (ADS)

    Kaleita, Amy L.; Kumar, Praveen

    2000-08-01

    In this study we aim to (1) explore the differences in the accuracy of satellite-derived land-surface skin temperature for day and nighttime observations, (2) assess the effects of large solar zenith angles, and (3) develop an understanding of the spatial variability of the observed temperatures. Land-surface skin temperatures are obtained using the split-window technique from observations of the AVHRR instrument aboard the NOAA-12 and NOAA-14 satellites for the SGP97 (Southern Great Plains 1997) hydrology experiment. From the study of several days of observations we find that observed biases with respect to the ground temperature, both during day and night, are small. However, except for one rainy day measurement, there consistently was a warm bias during the day and cold bias during the night. Contrary to the hypothesis that at large solar zenith angles the observed temperatures are representative of the shelter height air temperature, we find that the observed temperatures are still closer to the ground temperatures than the air temperature. The spatial correlation is nearly isotropic and has an exponential decay. The correlation lengths demonstrate tremendous spread both during the day and during the night with the mean during the day being about 50% larger than that during the night. The average correlation length of 8.63 km during the day is much smaller than the grid sizes typically used in short-time hydrology/mesoscale forecasts. This suggests that for modeling purposes the temperatures in each grid box may be treated as uncorrelated. However, the variance captured can be significantly smaller than the true value.

  13. Efficacy of Aerosol-Cloud Interactions Under Varying Meteorological Conditions: Southern Great Plains Vs. Pt. Reyes

    SciTech Connect

    Dunn, M.; Schwartz, S.; Kim, B.-G.; Miller, M.; Liu, Y.; Min, Q.

    2008-03-10

    Several studies have demonstrated that cloud dynamical processes such as entrainment mixing may be the primary modulator of cloud optical properties in certain situations. For example, entrainment of dry air alters the cloud drop size distribution by enhancing drop evaporation. However, the effect of entrainment mixing and other forms or turbulence is still quite uncertain. Although these factors and aerosol-cloud interactions should be considered together when evaluating the efficacy of aerosol indirect effects, the underlying mechanisms appear to be dependent upon each other. In addition, accounting for them is impossible with the current understanding of aerosol indirect effect. Therefore, careful objective screening and analysis of observations are needed to determine the extent to which mixing related properties affect cloud optical properties, apart from the aerosol first indirect effect. This study addresses the role of aerosol-cloud interactions in the context of varying meteorological conditions based on ARM data obtained at the Southern Great Plains (SGP) site in Oklahoma and at Pt. Reyes, California. Previous analyses of the continental stratiform clouds at the SGP site have shown that the thicker clouds of high liquid water path (LWP) tend to contain sub adiabatic LWPs. These sub adiabatic LWPs, which result from active mixing processes, correspond to a lower susceptibility of the clouds to aerosol-cloud interactions, and, hence, to reduced aerosol indirect effects. In contrast, the consistently steady and thin maritime stratus clouds observed at Pt. Reyes are much closer to adiabatic. These clouds provide an excellent benchmark for the study of the aerosol influence on modified marine clouds relative to continental clouds, since they form in a much more homogeneous meteorological environment than those at the continental site.

  14. Performance of TMPA satellite precipitation product over the Northern Great Plains

    NASA Astrophysics Data System (ADS)

    Kharel, G.; Kirilenko, A.; Zhang, X.

    2011-12-01

    Satellite derived precipitation can be used as supplement and/or replacement to ground data in various applications including modeling and weather forecasting based on its accuracy, reliability and validity. We analyzed Tropical Rainfall Measuring Mission Multisatellite Precipitation Analysis (TMPA) 3B42 v.6 Level 3 product (0.25° × 0.25°, 3-hour resolution) against the United States Historical Climatology Network (USHCN) ground data from 98 stations in the Northern Great Plains (NGP) over the period of seven years (2003 to 2009). NGP, comprised of Wyoming, Montana, North Dakota, Minnesota, South Dakota and Nebraska states of the US, is located between the latitudes 41° - 49° N and longitudes 94° - 113.5° E within the TMPA product latitude band (50° NS).The goal of this research was to investigate the performance of TMPA over the NGP region. Results showed that the TMPA daily data has poor rainfall detection ability (POD ~ 0.3), weak correlation with the meteorological data (ρ=0.46) and high root mean square deviation (RMSD = 4.9 mm/day). We also found noticeable seasonal differences in the daily TMPA product performance. It underperformed during cold season (November to March) with weaker correlation (0.25) and worse POD (~ 0.15), as compared to relatively modest correlation (0.47) and POD (~0.30) during warm season (April to October). Our analysis at monthly scale revealed significantly better performance of TMPA with higher correlation (0.82) and lower RMSD (0.72 mm/day). Based on our findings, the TMPA daily data might be a poor replacement to ground data, however, at a monthly scale, TMPA can be used to estimate spatial rainfall distribution in NGP and/or as an input to a stochastic daily weather generator.

  15. Regional Ecosystem Carbon Exchange in the Southern Great Plains: Measurements, Modeling, and Scaling

    NASA Astrophysics Data System (ADS)

    Torn, M. S.; Riley, W. J.; Biraud, S. C.; Fischer, M. L.; Billesbach, D. S.; Berry, J. A.

    2007-12-01

    The extremely heterogeneous landscape of the ARM (Atmospheric Radiation Measurement) Climate Research Facility (ACRF) in the U.S. Southern Great Plains is representative of the southern boundary of the NACP Midwest intensive experiment. The area is largely agricultural with vegetation cover type and status that vary on sub- kilometer scales. In this study we developed, applied, and tested a "bottom- up" approach to inferring terrestrial C exchanges at fine scales (down to 250 m). Measurements at the ACRF include a 60 m tower instrumented with eddy covariance (ECOR) systems at several heights, about 20 permanent ECOR towers, several portable ECOR systems, many atmospheric and cloud sensing systems, and regular balloon sonde and aircraft measurements. We applied the land-surface model ISOLSM (with recent modifications to the plant physiological submodel) forced with OK and KS Mesonet climate datasets and MODIS vegetation indices. A method to infer vegetation cover type using satellite data and archetypal LAI annual profiles was developed and successfully tested against USDA census data for the region. The model's net CO2 exchange estimates were calibrated and tested using eddy correlation data from the dominant surface covers. Three years spanning a substantial precipitation gradient (2003 - 2005) were then simulated. Large differences in annual regional CO2 exchanges were predicted corresponding to expected system responses to available moisture. Spatial scaling analysis from 250 m to 100 km indicated that homogenizing LAI and vegetation cover can impact annual NEE substantially, including changing the region from a predicted net CO2 source to a net sink. Further, differences in NEE associated with spatial scaling differed between years, indicating that accurate bottom-up NEE estimates in this heterogeneous region require fine-scale analysis approaches.

  16. Preserving prairies: Understanding temporal and spatial patterns of invasive annual bromes in the Northern Great Plains

    USGS Publications Warehouse

    Ashton, Isabel; Symstad, Amy; Davis, Christopher; Swanson, Daniel J.

    2016-01-01

    Two Eurasian invasive annual brome grasses, cheatgrass (Bromus tectorum) and Japanese brome (Bromus japonicus), are well known for their impact in steppe ecosystems of the western United States where these grasses have altered fire regimes, reduced native plant diversity and abundance, and degraded wildlife habitat. Annual bromes are also abundant in the grasslands of the Northern Great Plains (NGP), but their impact and ecology are not as well studied. It is unclear whether the lessons learned from the steppe will translate to the mixed-grass prairie where native plant species are adapted to frequent fires and grazing. Developing a successful annual brome management strategy for National Park Service units and other NGP grasslands requires better understanding of (1) the impact of annual bromes on grassland condition; (2) the dynamics of these species through space and time; and (3) the relative importance of environmental factors within and outside managers' control for these spatiotemporal dynamics. Here, we use vegetation monitoring data collected from 1998 to 2015 in 295 sites to relate spatiotemporal variability of annual brome grasses to grassland composition, weather, physical environmental characteristics, and ecological processes (grazing and fire). Concern about the impact of these species in NGP grasslands is warranted, as we found a decline in native species richness with increasing annual brome cover. Annual brome cover generally increased over the time of monitoring but also displayed a 3- to 5-yr cycle of reduction and resurgence. Relative cover of annual bromes in the monitored areas was best predicted by park unit, weather, extant plant community, slope grade, soil composition, and fire history. We found no evidence that grazing reduced annual brome cover, but this may be due to the relatively low grazing pressure in our study. By understanding the consequences and patterns of annual brome invasion, we will be better able to preserve and restore

  17. Buteo Nesting Ecology: Evaluating Nesting of Swainson’s Hawks in the Northern Great Plains

    PubMed Central

    Inselman, Will M.; Datta, Shubham; Jenks, Jonathan A.; Jensen, Kent C.; Grovenburg, Troy W.

    2015-01-01

    Swainson’s hawks (Buteo swainsoni) are long-distance migratory raptors that nest primarily in isolated trees located in areas of high grassland density. In recent years, anthropogenic conversion of grassland habitat has raised concerns about the status of the breeding population in the northern Great Plains. In 2013, we initiated a study to investigate the influence of extrinsic factors influencing Swainson’s hawk nesting ecology in north-central South Dakota and south-central North Dakota. Using ground and aerial surveys, we located and monitored nesting Swainson’s hawk pairs: 73 in 2013 and 120 in 2014. We documented 98 successful breeding attempts that fledged 163 chicks; 1.52 and 1.72 fledglings per successful nest in 2013 and 2014, respectively. We used Program MARK to evaluate the influence of land cover on nest survival. The top model, SDist2Farm+%Hay, indicated that nest survival (fledging at least one chick) decreased as nests were located farther from farm sites and as the percent of hay cover increased within 1200-m of the nest site (34.4%; 95% CI = 27.6%–42.3%). We used logistic regression analysis to evaluate the influence of landscape variables on nest-site selection; Swainson’s hawks selected for nest sites located closer to roads. We suggest that tree belts associated with farm sites, whether occupied or not, provide critical breeding sites for Swainson’s hawks. Additionally, poor breeding success may be related to the late migratory behavior of this species which requires them to occupy marginal habitat due to other raptors occupying the most suitable habitat prior to Swainson’s hawks arriving to the breeding grounds. PMID:26327440

  18. Land-atmosphere coupling and climate prediction over the U.S. Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Williams, Ian N.; Lu, Yaqiong; Kueppers, Lara M.; Riley, William J.; Biraud, Sebastien C.; Bagley, Justin E.; Torn, Margaret S.

    2016-10-01

    Biases in land-atmosphere coupling in climate models can contribute to climate prediction biases, but land models are rarely evaluated in the context of this coupling. We tested land-atmosphere coupling and explored effects of land surface parameterizations on climate prediction in a single-column version of the National Center for Atmospheric Research Community Earth System Model (CESM1.2.2) and an off-line Community Land Model (CLM4.5). The correlation between leaf area index (LAI) and surface evaporative fraction (ratio of latent to total turbulent heat flux) was substantially underpredicted compared to observations in the U.S. Southern Great Plains, while the correlation between soil moisture and evaporative fraction was overpredicted by CLM4.5. To estimate the impacts of these errors on climate prediction, we modified CLM4.5 by prescribing observed LAI, increasing soil resistance to evaporation, increasing minimum stomatal conductance, and increasing leaf reflectance. The modifications improved the predicted soil moisture-evaporative fraction (EF) and LAI-EF correlations in off-line CLM4.5 and reduced the root-mean-square error in summer 2 m air temperature and precipitation in the coupled model. The modifications had the largest effect on prediction during a drought in summer 2006, when a warm bias in daytime 2 m air temperature was reduced from +6°C to a smaller cold bias of -1.3°C, and a corresponding dry bias in precipitation was reduced from -111 mm to -23 mm. The role of vegetation in droughts and heat waves is underpredicted in CESM1.2.2, and improvements in land surface models can improve prediction of climate extremes.

  19. Grassland and Cropland Net Ecosystem Production of the U.S. Great Plains

    NASA Astrophysics Data System (ADS)

    Howard, D. M.; Wylie, B. K.; Ji, L.; Gilmanov, T. G.; Zhang, L.

    2014-12-01

    At observation sites throughout the world, carbon dioxide (CO2) levels and other ecosystem resources are measured by instruments known as flux towers. Although flux towers only measure the surrounding vicinity or spatial footprint of their placement ecosystem, the data recorded at these towers can be up-scaled to much greater levels through the use of comprehensive remote sensing data and advanced computer modeling. The purpose of this study was to develop ecological net ecosystem production (NEP) models capable of producing weekly cropland and grassland NEP maps of the U.S. Great Plains at 250 meter resolution for 2000 - 2008. Separate NEP regression tree models were developed for each land cover type (cropland and grassland) with 15 flux towers supporting the grassland model and 13 towers supporting the cropland model. The NEP regression tree models were established through training based on data from the supporting flux towers, remote sensing data, and other biogeophysical inputs. Map results of this study indicate, as anticipated, grassland ecosystems generally perform as net carbon (C) sinks, absorbing and storing C from the atmosphere, and conversely, croplands generally as net C sources (crop yields were not taken into account), releasing C, in the form of CO2, into the atmosphere. The models were evaluated by implementing a leave-one-out cross validation method, which withholds data form one particular year or site for testing a model developed with the remaining data. The cropland model validation analysis received an average Pearson's correlation coefficient (r) of 0.85 for the yearly validation and an average r = 0.73 for the site withholding. The grassland model validation analysis received an average r = 0.86 for the yearly validation and an average r = 0.83 for the site withholding.

  20. Investigating Compositional Variation of Ceramic Materials during the Late Neolithic on the Great Hungarian Plain - Preliminary LA-ICP-MS Results

    NASA Astrophysics Data System (ADS)

    Riebe, Danielle J.; Niziolek, Lisa C.

    2015-10-01

    Investigations have been undertaken to assess the extent to which compositional analysis can be used to determine trade and interaction on the Great Hungarian Plain during the Late Neolithic. Ceramic and clay samples in the Körös and Berettyó River Basins were analyzed at the Elemental Analysis Facilities (EAF) at The Field Museum of Natural History in Chicago, IL, USA. With the use of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), the aim of the project was to ascertain if micro-regional or site-specific compositional signatures could be determined in a region that is typically characterized as highly geologically homogenous. Identifying site-specific signatures enables archaeologists to model prehistoric interactions and, in turn, determine the relationship between interaction and various socio-cultural changes. This paper focuses on the preliminary compositional results of materials analyzed from three different sites across the Plain and the methodological implications for future anthropological research in the region.

  1. Hydrology of area 59, northern Great Plains and Rocky Mountain coal provinces, Colorado and Wyoming

    USGS Publications Warehouse

    Gaggiani, Neville G.; Britton, Linda J.; Minges, Donald R.; Kilpatrick, F.A.; Parker, Randolph S.; Kircher, James E.

    1987-01-01

    Hydrologic information and analysis aid in decisions to lease federally owned coal and to prepare necessary Environmental Assessments and Impact Study reports. This need has become even more critical with the enactment of Public Law 95-87, the "Surface Mining Control and Reclamation Act of 1977." This act requires an appropriate regulatory agency to issue permits, based on the review of permit-application data to assess hydrologic impacts. This report, which partially fulfills this requirement, is one in a series of nationwide coal province reports that present information thematically, through the use of a brief text and accompanying maps, graphs, charts, or other illustrations for single hydrologic topics. The report broadly characterizes the hydrology of Area 59 in north-central Colorado and southeastern Wyoming.The report area, located within the South Platte River basin, covers a 16,000-square-mile area of diverse geology, topography, and climate. This diversity results in contrasting hydrologic characteristics.The South Platte River, the major stream in the area, and most of its tributaries originate in granitic mountains and flow into and through the sedimentary rocks of the Great Plains. Altitudes range from less than 5,000 feet to more than 14,000 feet above sea level. Precipitation in the mountains may exceed 40 inches annually, much of it during the winter, and produces deep snowpacks. Snowmelt during the spring and summer produces most streamflow. Transmountain diversion of water from the streams on the western slope of the mountains also adds to the streamflow. Precipitation in the plains is as little as 10 inches annually. Streams that originate in the plains are ephemeral.Streamflow quality is best in the mountains, where dissolved-solids concentrations are generally small. Concentrations increase in the plains as streams flow through sedimentary basins, and as urbanization and irrigation increase. The quality of some mountain streams is affected by

  2. Distinctive upper mantle anisotropy beneath the High Lava Plains and Eastern Snake River Plain, Pacific Northwest, USA

    NASA Astrophysics Data System (ADS)

    Wagner, Lara S.; Long, Maureen D.

    2013-10-01

    The Pacific Northwest (PNW) has experienced voluminous intraplate volcanism over the past ˜17 Ma, beginning with the Steens/Columbia River flood basalts and continuing with the still-ongoing volcanism in the High Lava Plains (HLP) and eastern Snake River Plain (SRP). Here we present two complementary datasets (SKS splitting and Rayleigh wave phase velocity anisotropy) that place constraints on the anisotropic structure of the upper mantle beneath the HLP and SRP regions. Beneath the HLP, SKS phases reveal dominantly E-W fast splitting directions and large (up to ˜2.7 s) delay times, with pronounced lateral variations in δt. Lateral and depth variability in the strength of anisotropy beneath the HLP is also evident from Rayleigh wave dispersion. Beneath the SRP, SKS splitting delay times are much smaller (˜0.5 s), and surface wave observations suggest a region of upper mantle anisotropy (˜50-150 km depth) with a geometry that deviates significantly from the generally plate motion parallel fast directions observed just outside of the SRP. Beneath the HLP, the geometry of the anomalously strong anisotropy is similar to the anisotropy in the deeper parts of the upper mantle, resulting in constructive interference and large SKS splitting delay times. Beneath the SRP, the geometry of the anomalous anisotropic region in the shallow mantle is different, resulting in destructive interference and reduced SKS splitting delay times. We discuss several possible explanations for these observations, including variations in olivine lattice-preferred orientation (LPO) strength, transitions in olivine fabric type, and a contribution from aligned partial melt.

  3. Critical Review of Technical Questions Facing Low Impact Development and Green Infrastructure: A Perspective from the Great Plains.

    PubMed

    Vogel, Jason R; Moore, Trisha L; Coffman, Reid R; Rodie, Steven N; Hutchinson, Stacy L; McDonough, Kelsey R; McLemore, Alex J; McMaine, John T

    2015-09-01

    Since its inception, Low Impact Development (LID) has become part of urban stormwater management across the United States, marking progress in the gradual transition from centralized to distributed runoff management infrastructure. The ultimate goal of LID is full, cost-effective implementation to maximize watershed-scale ecosystem services and enhance resilience. To reach that goal in the Great Plains, the multi-disciplinary author team presents this critical review based on thirteen technical questions within the context of regional climate and socioeconomics across increasing complexities in scale and function. Although some progress has been made, much remains to be done including continued basic and applied research, development of local LID design specifications, local demonstrations, and identifying funding mechanisms for these solutions. Within the Great Plains and beyond, by addressing these technical questions within a local context, the goal of widespread acceptance of LID can be achieved, resulting in more effective and resilient stormwater management.

  4. Applied regional monitoring of the vernal advancement and retrogradation (Green wave effect) of natural vegetation in the Great Plains corridor

    NASA Technical Reports Server (NTRS)

    Rouse, J. W., Jr. (Principal Investigator); Deering, D. W.; Haas, R. H.; Welch, R. I.; Harlan, J. C.; Whitney, P. R.

    1977-01-01

    The author has identified the following significant results. LANDSAT 2 has shown that digital data products can be effectively employed on a regional basis to monitor changes in vegetation conditions. The TV16 was successfully applied to an extended test site and the Great Plains Corridor in tests of the ability to assess green forage biomass on rangelands as an index to vegetation condition. A strategy for using TV16 on a regional basis was developed and tested. These studies have shown that: (1) for rangelands with good vegetative cover, such as most of the Great Plains, and which are not heavily infested with brush or undesirable weed species, the LANDSAT digital data can provide a good estimate (within 250 kg/ha) of the quantity of green forage biomass, and (2) at least five levels of pasture and range feed conditions can be adequately mapped for extended regions.

  5. Landscape-scale patterns of fire and drought on the high plains, USA

    Treesearch

    Paulette Ford; Charles Jackson; Matthew Reeves; Benjamin Bird; Dave Turner

    2015-01-01

    We examine 31 years (1982-2012) of temperature, precipitation and natural wildfire occurrence data for Federal and Tribal lands to determine landscape-scale patterns of drought and fire on the southern and central High Plains of the western United States. The High Plains states of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas and...

  6. Factors contributing to record-breaking heat waves over the Great Plains during the 1930s Dust Bowl

    NASA Astrophysics Data System (ADS)

    Cowan, T.; Hegerl, G. C.

    2016-12-01

    Record-breaking summer heat waves that plagued contiguous United States in the 1930s emerged during the decade-long "Dust Bowl" drought. Using high-quality daily temperature observations, the Dust Bowl heat wave characteristics for the Great Plains are assessed using metrics that describe variations in heat wave activity and intensity. We also quantify record-breaking heat waves over the pre-industrial period for 22 CMIP5 model multi-century realisations. The most extreme Great Plains heat wave summers in the Dust Bowl decade (e.g. 1931, 1934, 1936) were pre-conditioned by anomalously dry springs, as measured by proxy drought indices. In general, summer heat waves over the Great Plains develop 15-20 days earlier after anomalously dry springs, and are also significantly longer and hotter, indicative of the importance of land surface feedbacks in heat wave intensification. The majority of pre-industrial climate model experiments capture regionally clustered summer heat waves across North America, although the North Pacific and Atlantic sea surface temperature patterns associated with the heat waves vary considerably between models. Sea surface temperature patterns may be more important for influencing winter and spring precipitation, thus amplifying summer heat waves during drought periods. The synoptic pattern that commonly appeared during the exceptional Dust Bowl heat waves featured an anomalous broad surface pressure ridge straddling an upper level blocking anticyclone over the western United States. This forced significant subsidence and adiabatic warming over the Great Plains, and triggered anomalous southward warm advection over southern regions, prolonging and amplifying the heat waves over central United States. Importantly, the results show that despite the sparsity of stations in the 1930s, homogeneous observations are crucial in accurately quantifying the Dust Bowl decade heat waves, as opposed to solely relying on atmospheric reanalysis.

  7. Ecological Niche of the 2003 West Nile Virus Epidemic in the Northern Great Plains of the United States

    PubMed Central

    Wimberly, Michael C.; Hildreth, Michael B.; Boyte, Stephen P.; Lindquist, Erik; Kightlinger, Lon

    2008-01-01

    Background The incidence of West Nile virus (WNv) has remained high in the northern Great Plains compared to the rest of the United States. However, the reasons for the sustained high risk of WNv transmission in this region have not been determined. To assess the environmental drivers of WNv in the northern Great Plains, we analyzed the county-level spatial pattern of human cases during the 2003 epidemic across a seven-state region. Methodology/Principal Findings County-level data on WNv cases were examined using spatial cluster analysis, and were used to fit statistical models with weather, climate, and land use variables as predictors. In 2003 there was a single large cluster of elevated WNv risk encompassing North Dakota, South Dakota, and Nebraska along with portions of eastern Montana and Wyoming. The relative risk of WNv remained high within the boundaries of this cluster from 2004–2007. WNv incidence during the 2003 epidemic was found to have a stronger relationship with long-term climate patterns than with annual weather in either 2002 or 2003. WNv incidence increased with mean May–July temperature and had a unimodal relationship with total May–July precipitation. WNv incidence also increased with the percentage of irrigated cropland and with the percentage of the human population living in rural areas. Conclusions/Significance The spatial pattern of WNv cases during the 2003 epidemic in the northern Great Plains was associated with both climatic gradients and land use patterns. These results were interpreted as evidence that environmental conditions across much of the northern Great Plains create a favorable ecological niche for Culex tarsalis, a particularly efficient vector of WNv. Further research is needed to determine the proximal causes of sustained WNv transmission and to enhance strategies for disease prevention. PMID:19057643

  8. Phylogeographical structure and evolutionary history of two Buggy Creek virus lineages in the western Great Plains of North America.

    PubMed

    Padhi, Abinash; Moore, Amy T; Brown, Mary Bomberger; Foster, Jerome E; Pfeffer, Martin; Gaines, Kathryn P; O'Brien, Valerie A; Strickler, Stephanie A; Johnson, Allison E; Brown, Charles R

    2008-09-01

    Buggy Creek virus (BCRV) is an unusual arbovirus within the western equine encephalitis complex of alphaviruses. Associated with cimicid swallow bugs (Oeciacus vicarius) as its vector and the cliff swallow (Petrochelidon pyrrhonota) and house sparrow (Passer domesticus) as its amplifying hosts, this virus is found primarily in the western Great Plains of North America at spatially discrete swallow nesting colonies. For 342 isolates collected in Oklahoma, Nebraska, Colorado and North Dakota, from 1974 to 2007, we sequenced a 2076 bp region of the 26S subgenomic RNA structural glycoprotein coding region, and analysed phylogenetic relationships, rates of evolution, demographical histories and temporal genetic structure of the two BCRV lineages found in the Great Plains. The two lineages showed distinct phylogeographical structure: one lineage was found in the southern Great Plains and the other in the northern Great Plains, and both occurred in Nebraska and Colorado. Within each lineage, there was additional latitudinal division into three distinct sublineages. One lineage is showing a long-term population decline. In comparing sequences taken from the same sites 8-30 years apart, in one case one lineage had been replaced by the other, and in the other cases there was little evidence of the same haplotypes persisting over time. The evolutionary rate of BCRV is in the order of 1.6-3.6x10(-4) substitutions per site per year, similar to that estimated for other temperate-latitude alphaviruses. The phylogeography and evolution of BCRV could be better understood once we determine the nature of the ecological differences between the lineages.

  9. The role of reproductive behavior in the conservation of fishes: examples from the Great Plains riverine fishes

    USGS Publications Warehouse

    Wildhaber, M.L.

    2006-01-01

    Recovery efforts for threatened and endangered fish species are hampered by lack of knowledge of their reproductive ecology. Habitat requirements and environmental stimuli necessary for reproduction are often unknown and vary widely among species. For Great Plains riverine fishes, this is often complicated by the high turbidity of the system in which the species occur, which precludes direct visual observation of behavior. Innovative methods for collectng behavioral data are required to better understand the conditions necessary for successful reproduction.

  10. Hydrology of area 54, Northern Great Plains, and Rocky Mountain coal provinces, Colorado and Wyoming

    USGS Publications Warehouse

    Kuhn, Gerhard; Daddow, P.D.; Craig, G.S.; ,

    1983-01-01

    A nationwide need for information characterizing hydrologic conditions in mined and potential mine areas has become paramount with the enactment of the Surface Mining Control and Reclamation Act of 1977. This report, one in a series covering the coal provinces nationwide, presents information thematically by describing single hydrologic topics through the use of brief texts and accompanying maps, graphs, or other illustrations. The summation of the topical discussions provides a description of the hydrology of the area. Area 54, in north-central Colorado and south-central Wyoming, is 1 of 20 hydrologic reporting areas of the Northern Great Plains and Rocky Mountain coal provinces. Part of the Southern Rocky Mountains and Wyoming Basin physiographic provinces, the 8,380-square-mile area is one of contrasting geology, topography, and climate. This results in contrasting hydrologic characteristics. The major streams, the North Platte, Laramie, and Medicine Bow Rivers, and their principal tributaries, all head in granitic mountains and flow into and through sedimentary basins between the mountain ranges. Relief averages 2,000 to 3,000 feet. Precipitation in the mountains may exceed 40 inches annually, much of it during the winter, which produces deep snowpacks. Snowmelt in spring and summer provides most streamflow. Precipitation in the basins averages 10 to 16 inches annually, insufficient for sustained streamflow; thus, streams originating in the basins are ephemeral. Streamflow quality is best in the mountains where dissolved-solids concentrations generally are least. These concentrations increase as streams flow through sedimentary basins. The increases are mainly natural, but some may be due to irrigation in and adjacent to the flood plains. In the North Platte River, dissolved-solids concentrations are usually less than 300 milligrams per liter; in the Laramie and the Medicine Bow Rivers, the concentrations may average 500 to 850 milligrams per liter. However

  11. Carbon, nitrogen, and phosphorus accumulation in floodplains of Atlantic Coastal Plain rivers, USA

    USGS Publications Warehouse

    Noe, G.B.; Hupp, C.R.

    2005-01-01

    Net nutrient accumulation rates were measured in riverine floodplains of the Atlantic Coastal Plain in Virginia, Maryland, and Delaware, USA. The floodplains were located in watersheds with different land use and included two sites on the Chickahominy River (urban), one site on the Mattaponi River (forested), and five sites on the Pocomoke River (agricultural). The Pocomoke River floodplains lie along reaches with natural hydrogeomorphology and on reaches with restricted flooding due to channelization and levees. A network of feldspar clay marker horizons was placed on the sediment surface of each floodplain site 3-6 years prior to sampling. Sediment cores were collected from the material deposited over the feldspar clay pads. This overlying sediment was separated from the clay layer and then dried, weighed, and analyzed for its total carbon (C), nitrogen (N), and phosphorus (P) content. Mean C accumulation rates ranged from 61 to 212 g??m-2??yr-1, N accumulation rates ranged from 3.5 to 13.4 g??m -2??yr-1, and P accumulation rates ranged from 0.2 to 4.1 g??m-2??yr-1 among the eight floodplains. Patterns of intersite variation in mineral sediment and P accumulation rates were similar to each other, as was variation in organic sediment and C and N accumulation rates. The greatest sediment and C, N, and P accumulation rates were observed on Chickahominy River floodplains downstream from the growing metropolitan area of Richmond, Virginia. Nutrient accumulation rates were lowest on Pocomoke River floodplains that have been hydraulically disconnected from the main channel by channelization and levees. Sediment P concentrations and P accumulation rates were much greater on the hydraulically connected floodplain immediately downstream of the limit of channelization and dense chicken agriculture of the upper Pocomoke River watershed. These findings indicate that (1) watershed land use has a large effect on sediment and nutrient retention in floodplains, and (2) limiting

  12. Understanding Land-Atmosphere Coupling and its Predictability at the ARM Southern Great Plains Site

    NASA Astrophysics Data System (ADS)

    Ferguson, C. R.; Song, H. J.; Roundy, J. K.

    2015-12-01

    Ten years ago, the Global Energy and Water EXchanges Global Land Atmosphere Coupling Experiment (GLACE) spotlighted the Southern Great Plains (SGP) for being one of three hotspots globally for land-derived precipitation predictability. Since then, the GLACE results have served as the underlying motivation for numerous subsequent land-atmosphere (L-A) coupling studies over the SGP domain. The range of these studies includes: local point scale studies leveraging surface meteorological and flux measurements at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement SGP (ARM-SGP) Central Facility, regional pentad to monthly scale atmospheric moisture budget analyses based on atmospheric reanalysis, and regional limited duration (2-7 day) coupled model sensitivity experiments. This study has the following three objectives: (1) to provide the common historical context necessary for bridging past and future interdisciplinary characterizations of L-A coupling, (2) to isolate the mechanism(s) for the region's L-A coupling signal, and (3) to evaluate the short range (12-18hr) predictability of soil moisture-precipitation feedbacks. We produce a convective triggering potential—low-level humidity index (CTP-HI)—based climatology of L-A coupling at ARM-SGP for the period 1979-2014 using North American Regional Reanalysis and North American Land Data Assimilation System Phase 2 data. We link the underlying coupling regime classification timeseries to corresponding synoptic-mesoscale weather patterns and bulk atmospheric moisture budget analyses. On the whole, the region's precipitation variability is largely dependent on large-scale moisture transport and the role of the land is nominal. However, we show that surface sensible heat flux can play an important role in modulating diurnal precipitation cycle phase and amplitude—either directly (enhancing CTP) in water-limited conditions or indirectly (increasing HI) in energy-limited conditions. In fact, both 0700

  13. Linking suspended sediment transport metrics with fish functional traits in the Northwestern Great Plains (Invited)

    NASA Astrophysics Data System (ADS)

    Schwartz, J. S.; Simon, A.; Klimetz, L.

    2009-12-01

    Loss of ecological integrity due to excessive suspended sediment in rivers and streams is a major cause of water quality impairment in the United States. Although 32 states have developed numeric criteria for turbidity or suspended solids, or both according to the USEPA (2006), criteria is typically written as a percent exceedance above background and what constitutes background is not well defined. Defining a background level is problematic considering suspended sediments and related turbidity levels change with flow stage and season, and limited scientific data exists on relationships between sediment exposure and biotic response. Current assessment protocols for development of sediment total maximum daily loads (TMDLs) lack a means to link temporally-variable sediment transport rates with specific losses of ecological functions as loads increase. This study, within the in Northwestern Great Plains Ecoregion, co-located 58 USGS gauging stations with existing flow and suspended sediment data, and fish data from federal and state agencies. Suspended sediment concentration (SSC) transport metrics were quantified into exceedance frequencies of a given magnitude, duration as the number of consecutive days a given concentration was equaled or exceeded, dosage as concentration x duration, and mean annual suspended sediment yields. A functional traits-based approach was used to correlate SSC transport metrics with site occurrences of 20 fish traits organized into four main groups: preferred rearing mesohabitat, trophic structure, feeding habits, and spawning behavior. Negative correlations between SSC metrics and trait occurrences were assumed to represent potential conditions for impairment, specifically identifying an ecological loss by functional trait. Potential impairment conditions were linked with presence of the following traits: habitat preferences for stream pool and river shallow waters; feeding generalists, omnivores, piscivores; and several spawning

  14. EVALUATING SHORT-TERM CLIMATE VARIABILITY IN THE LATE HOLOCENE OF THE NORTHERN GREAT PLAINS

    SciTech Connect

    Joseph H. Hartman

    1999-09-01

    This literature study investigated methods and areas to deduce climate change and climate patterns, looking for short-term cycle phenomena and the means to interpret them. Many groups are actively engaged in intensive climate-related research. Ongoing research might be (overly) simplified into three categories: (1) historic data on weather that can be used for trend analysis and modeling; (2) detailed geological, biological (subfossil), and analytical (geochemical, radiocarbon, etc.) studies covering the last 10,000 years (about since last glaciation); and (3) geological, paleontological, and analytical (geochemical, radiometric, etc.) studies over millions of years. Of importance is our ultimate ability to join these various lines of inquiry into an effective means of interpretation. At this point, the process of integration is fraught with methodological troubles and misconceptions about what each group can contribute. This project has met its goals to the extent that it provided an opportunity to study resource materials and consider options for future effort toward the goal of understanding the natural climate variation that has shaped our current civilization. A further outcome of this project is a proposed methodology based on ''climate sections'' that provides spatial and temporal correlation within a region. The method would integrate cultural and climate data to establish the climate history of a region with increasing accuracy with progressive study and scientific advancement (e. g., better integration of regional and global models). The goal of this project is to better understand natural climatic variations in the recent past (last 5000 years). The information generated by this work is intended to provide better context within which to examine global climate change. The ongoing project will help to establish a basis upon which to interpret late Holocene short-term climate variability as evidenced in various studies in the northern Great Plains, northern

  15. Evaluation of a single column model at the Southern Great Plains climate research facility

    NASA Astrophysics Data System (ADS)

    Kennedy, Aaron D.

    Despite recent advancements in global climate modeling, models produce a large range of climate sensitivities for the Earth. This range of sensitivities results in part from uncertainties in modeling clouds. To understand and to improve cloud parameterizations in Global Climate Models (GCMs), simulations should be evaluated using observations of clouds. Detailed studies can be conducted at Atmospheric Radiation Measurements (ARM) sites which provide adequate observations and forcing for Single Column Model (SCM) studies. Unfortunately, forcing for SCMs is sparse and not available for many locations or times. This study had two main goals: (1) evaluate clouds from the GISS Model E AR5 SCM at the ARM Southern Great Plains site and (2) determine whether reanalysis-based forcing was feasible at this location. To accomplish these goals, multiple model runs were conducted from 1999--2008 using forcing provided by ARM and forcing developed from the North American Regional Reanalysis (NARR). To better understand cloud biases and differences in the forcings, atmospheric states were classified using Self Organizing Maps (SOMs). Although model simulations had many similarities with the observations, there were several noticeable biases. Deep clouds had a negative bias year-round and this was attributed to clouds being too thin during frontal systems and a lack of convection during the spring and summer. These results were consistent regardless of the forcing used. During August, SCM simulations had a positive bias for low clouds. This bias varied with the forcing suggesting that part of the problem was tied to errors in the forcing. NARR forcing had many favorable characteristics when compared to ARM observations and forcing. In particular, temperature and wind information were more accurate than ARM when compared to balloon soundings. During the cool season, NARR forcing produced results similar to ARM with reasonable precipitation and a similar cloud field. Although NARR

  16. Thermodynamic and Turbulence Characteristics of the Southern Great Plains Nocturnal Boundary Layer Under Differing Turbulent Regimes

    NASA Astrophysics Data System (ADS)

    Bonin, Timothy A.; Blumberg, William G.; Klein, Petra M.; Chilson, Phillip B.

    2015-12-01

    The nocturnal stable boundary layer (SBL) can generally be classified into the weakly stable boundary layer (wSBL) and very stable boundary layer (vSBL). Within the wSBL, turbulence is relatively continuous, whereas in the vSBL, turbulence is intermittent and not well characterized. Differentiating characteristics of each type of SBL are still unknown. Herein, thermodynamic and kinematic data collected by a suite of instruments in north central Oklahoma in autumn 2012 are analyzed to better understand both SBL regimes and their differentiating characteristics. Many low-level jets were observed during the experiment, as it took place near a climatological maximum. A threshold wind speed, above which bulk shear-generated turbulence develops, is found to exist up to 300 m. The threshold wind speed must also be exceeded at lower heights (down to the surface) in order for strong turbulence to develop. Composite profiles, which are normalized using low-level jet scaling, of potential temperature, wind speed, vertical velocity variance, and the third-order moment of vertical velocity (overline{w'^3}) are produced for weak and moderate/strong turbulence regimes, which exhibit features of the vSBL and wSBL, respectively. Within the wSBL, turbulence is generated at the surface and transported upward. In the vSBL, values of vertical velocity variance are small throughout the entire boundary layer, likely due to the fact that a strong surface inversion typically forms after sunset. The temperature profile tends to be approximately isothermal in the lowest portions of the wSBL, and it did not substantially change over the night. Within both types of SBL, stability in the residual layer tends to increase as the night progresses. It is thought that this stability increase is due to differential warm air advection, which frequently occurs in the southern Great Plains when southerly low-level jets and a typical north-south temperature gradient are present. Differential radiative

  17. Multiple new-particle growth pathways observed at the US DOE Southern Great Plains field site

    NASA Astrophysics Data System (ADS)

    Hodshire, Anna L.; Lawler, Michael J.; Zhao, Jun; Ortega, John; Jen, Coty; Yli-Juuti, Taina; Brewer, Jared F.; Kodros, Jack K.; Barsanti, Kelley C.; Hanson, Dave R.; McMurry, Peter H.; Smith, James N.; Pierce, Jeffery R.

    2016-07-01

    New-particle formation (NPF) is a significant source of aerosol particles into the atmosphere. However, these particles are initially too small to have climatic importance and must grow, primarily through net uptake of low-volatility species, from diameters ˜ 1 to 30-100 nm in order to potentially impact climate. There are currently uncertainties in the physical and chemical processes associated with the growth of these freshly formed particles that lead to uncertainties in aerosol-climate modeling. Four main pathways for new-particle growth have been identified: condensation of sulfuric-acid vapor (and associated bases when available), condensation of organic vapors, uptake of organic acids through acid-base chemistry in the particle phase, and accretion of organic molecules in the particle phase to create a lower-volatility compound that then contributes to the aerosol mass. The relative importance of each pathway is uncertain and is the focus of this work. The 2013 New Particle Formation Study (NPFS) measurement campaign took place at the DOE Southern Great Plains (SGP) facility in Lamont, Oklahoma, during spring 2013. Measured gas- and particle-phase compositions during these new-particle growth events suggest three distinct growth pathways: (1) growth by primarily organics, (2) growth by primarily sulfuric acid and ammonia, and (3) growth by primarily sulfuric acid and associated bases and organics. To supplement the measurements, we used the particle growth model MABNAG (Model for Acid-Base chemistry in NAnoparticle Growth) to gain further insight into the growth processes on these 3 days at SGP. MABNAG simulates growth from (1) sulfuric-acid condensation (and subsequent salt formation with ammonia or amines), (2) near-irreversible condensation from nonreactive extremely low-volatility organic compounds (ELVOCs), and (3) organic-acid condensation and subsequent salt formation with ammonia or amines. MABNAG is able to corroborate the observed differing growth

  18. Evaluation and comparison of gross primary production estimates for the Northern Great Plains grasslands

    USGS Publications Warehouse

    Zhang, L.; Wylie, B.; Loveland, T.; Fosnight, E.; Tieszen, L.L.; Ji, L.; Gilmanov, T.

    2007-01-01

    Two spatially-explicit estimates of gross primary production (GPP) are available for the Northern Great Plains. An empirical piecewise regression (PWR) GPP model was developed from flux tower measurements to map carbon flux across the region. The Moderate Resolution Imaging Spectrometer (MODIS) GPP model is a process-based model that uses flux tower data to calibrate its parameters. Verification and comparison of the regional PWR GPP and the global MODIS GPP are important for the modeling of grassland carbon flux. This study compared GPP estimates from PWR and MODIS models with five towers in the grasslands. Among them, PWR GPP and MODIS GPP showed a good agreement with tower-based GPP at three towers. The global MODIS GPP, however, did not agree well with tower-based GPP at two other towers, probably because of the insensitivity of MODIS model to regional ecosystem and climate change and extreme soil moisture conditions. Cross-validation indicated that the PWR model is relatively robust for predicting regional grassland GPP. However, the PWR model should include a wide variety of flux tower data as the training data sets to obtain more accurate results. In addition, GPP maps based on the PWR and MODIS models were compared for the entire region. In the northwest and south, PWR GPP was much higher than MODIS GPP. These areas were characterized by the higher water holding capacity with a lower proportion of C4 grasses in the northwest and a higher proportion of C4 grasses in the south. In the central and southeastern regions, PWR GPP was much lower than MODIS GPP under complicated conditions with generally mixed C3/C4 grasses. The analysis indicated that the global MODIS GPP model has some limitations on detecting moisture stress, which may have been caused by the facts that C3 and C4 grasses are not distinguished, water stress is driven by vapor pressure deficit (VPD) from coarse meteorological data, and MODIS land cover data are unable to differentiate the sub

  19. Observational Evaluation of Simulated Land-Atmosphere Coupling on the U.S. Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Phillips, T. J.; Klein, S. A.

    2014-12-01

    In a recent study of observed features of land-atmosphere coupling (LAC) at the ARM Southern Great Plains (ARM SGP) site in northern Oklahoma (Phillips and Klein, 2014 Journal of Geophysical Research), we identified statistically significant interactions between 1997-2008 summertime daily averages of soil moisture (at 10 cm depth) and a number of surface atmospheric variables, such as surface evaporation, relative humidity, and temperature. Here we will report on an evaluation of similar features of LAC simulated by version 5 of the global Community Atmosphere Model (CAM5), coupled to its native CLM4 land model, and downscaled to the vicinity of the ARM SGP site. In these case studies, the CAM5 was initialized from a 6-hourly atmospheric reanalysis for each day of the years 2008 and 2009 (where the CLM4 land state was equilibrated to the atmospheric model state), thus permitting a close comparison of the modeled and observed summer daily average features of the LAC in these years. Correlation coefficients R and "sensitivity indices" I (a measure of the comparative change of an atmospheric variable for a one-standard-deviation change in soil moisture) provided quantitative measures of the respective coupling strengths. Such a comparison of observed versus modeled LAC is complicated by differences in atmospheric forcings of the land; for example, the CAM5's summertime precipitation is too scant, and thus the model's upper soil layer often is drier than observed. The modeled daily average covariations of soil moisture with lower atmospheric variables also display less coherence (lower R values), but sometimes greater "sensitivity" (higher I values) than are observed at the ARM SGP site. Since the observational estimate of LAC may itself be sensitive to soil moisture measurement biases, we also will report on a planned investigation of the dependence of LAC on several alternative choices of soil moisture data sets local to the ARM SGP site. AcknowledgmentsThis work was

  20. Radioactivity and uranium content of some Cretaceous shales, central Great Plains

    USGS Publications Warehouse

    Tourtelot, Harry A.

    1955-01-01

    The Sharon Springs member of the Pierre shale of Cretaceous age, a hard black organic-rich shale similar to the Chattanooga shale, is radioactive throughout central and western South Dakota, most of Nebraska, northern Kansas, and northeastern Colorado. In the Missouri River valley, thin beds of the shale contain as much as 0.01 percent uranium. Beds as much as 20 feet thick or more have a radioactivity of about 0.01 percent equivalent uranium in southwestern Nebraska according to interpretation of gamma-ray well logs. The radioactivity and uranium content is highest in the Missouri River valley in South Dakota and in southwestern Nebraska where the shale rests disconformably on the underlying Niobrara formation of Cretaceous age. Near the Black Hills, and in the area to the north, the shale of the Sharon Springs member rests on a wedge of the Gammon ferruginous member of the Pierre, which is represented by a disonformity to the east and south, and the radioactivity of the shale is low although greater than that of over-lying strata. The shale also contains a suite of trace elements in which arsenic, boron, chromium, copper, molybdenum, nickel, selenium, and vanadium are conspicuous. Molybdenum and tin are less abundant in the Sharon Springs than in similar shales of Palezoic age and silver and selenium are more abundant. In the Great Plains region, the upper 30-50 feet of Cretaceous shales overlain unconformably by the White River group of Oligocene age has been altered to bright-colored material. This altered zone is chiefly the result of pre-Oligocene weathering although post-Oligocene ground water conditions also have affected the zone. The greatest radioactivity occurs in masses of unaltered shale measuring about 1 x 4 feet in cross section included in the lower part of the altered zone. Where the zone is developed on shale and marl of the Niobrara formation, parts of the included unaltered shale contains as much as 0.1 percent equivalent uranium and 0

  1. Climate Extremes Triggered State Shifting of US Great Plains Prairie under Experimental Warming

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Xu, X.; Sherry, R.; Niu, S.; Li, D.; Xia, J.

    2012-04-01

    Ecosystems can exist under multiple stable states. Transition from one stable state to another is usually triggered by perturbations such as climate extremes, which should be large enough to push the ecosystem over a threshold. Ecosystem state changes can alter ecosystem functions and services as dramatically as in Sahara with vegetation changes from tropical forests to grassland and deserts over 6000 years. Thus it is crucial to understand mechanisms underlying ecosystem state changes. State changes of ecosystem vegetation have been well documented in paleo-records and predicted to occur under climate change by dynamic global vegetation models. Paleo-records usually offer broad-scale patterns of ecosystem state changes over time and rarely offer much insight into fundamental mechanisms underlying the state changes. Model predictions may be calibrated against contemporary and paleo vegetation distributions but have not been carefully tested against experimental evidence. The latter, however, is extremely rare largely because global chance experiments are mostly short term. We have observed state shifting of a US Great Plains prairie under long-term experimental warming and clipping treatments. Our analysis of 11-year data from the experiment showed two-stage stimulations of aboveground net primary production (ANPP) with small increases in the first 7 followed by distinctly large increases under experimental warming in comparison with those under control. The two-stage ANPP simulations were corresponded with species reordering with the plant community over time but not related to warming-induced changes in temperature, soil moisture and nitrogen dynamics in the grassland. The state shifting of the grassland under the experimental warming was partly because our experimental site locates in an ecotone between the mixed and tall grass prairies. Under the experimental warming, the prairie was shifting from the mixed prairie as dominated by Schizachyrium scoparium

  2. Mercury and methylmercury dynamics in a coastal plain watershed, New Jersey, USA

    USGS Publications Warehouse

    Barringer, J.L.; Riskin, M.L.; Szabo, Z.; Reilly, P.A.; Rosman, R.; Bonin, J.L.; Fischer, J.M.; Heckathorn, H.A.

    2010-01-01

    The upper Great Egg Harbor River watershed in New Jersey's Coastal Plain is urbanized but extensive freshwater wetlands are present downstream. In 2006-2007, studies to assess levels of total mercury (THg) found concentrations in unfiltered streamwater to range as high as 187 ng/L in urbanized areas. THg concentrations were <20 ng/L in streamwater in forested/wetlands areas where both THg and dissolved organic carbon concentrations tended to increase while pH and concentrations of dissolved oxygen and nitrate decreased with flushing of soils after rain. Most of the river's flow comes from groundwater seepage; unfiltered groundwater samples contained up to 177 ng/L of THg in urban areas where there is a history of well water with THg that exceeds the drinking water standard (2,000 ng/L). THg concentrations were lower (<25 ng/L) in unfiltered groundwater from downstream wetland areas. In addition to higher THg concentrations (mostly particulate), concentrations of chloride were higher in streamwater and groundwater from urban areas than in those from downstream wetland areas. Methylmercury (MeHg) concentrations in unfiltered streamwater ranged from 0.17 ng/L at a forest/wetlands site to 2.94 ng/L at an urban site. The percentage of THg present as MeHg increased as the percentage of forest + wetlands increased, but also was high in some urban areas. MeHg was detected only in groundwater <1 m below the water/sediment interface. Atmospheric deposition is presumed to be the main source of Hg to the wetlands and also may be a source to groundwater, where wastewater inputs in urban areas are hypothesized to mobilize Hg deposited to soils. ?? 2010 US Government.

  3. Mapping the spatio-temporal evolution of irrigation in the Coastal Plain of Georgia, USA

    Treesearch

    Marcus D. Williams; Christie M.S. Hawley; Marguerite Madden; J. Marshall Shepherd

    2017-01-01

    This study maps the spatial and temporal evolution of acres irrigated in the Coastal Plain of Georgia over a 38 year period. The goal of this analysis is to create a time-series of irrigated areas in the Coastal Plain of Georgia at a sub-county level. From 1976 through 2013, Landsat images were obtained and sampled at four year intervals to manually...

  4. Environmental significance of 13C/ 12C and 18O/ 16O ratios of modern land-snail shells from the southern great plains of North America

    NASA Astrophysics Data System (ADS)

    Balakrishnan, Meena; Yapp, Crayton J.; Theler, James L.; Carter, Brian J.; Wyckoff, Don G.

    2005-01-01

    13C/ 12C and 18O/ 16O ratios of aragonite shells of modern land snails from the southern Great Plains of North America were measured for samples from twelve localities in a narrow east-west corridor that extended from the Flint Hills in North Central Oklahoma to the foothills of the Sangre de Cristo Mountains in Northern New Mexico, USA. Across the study area, shell δ 18O values (PDB scale) ranged from -4.1‰ to 1.2‰, while δ 13C values ranged from -13.2‰ to 0.0‰. δ 18O values of the shell aragonite were predicted with a published, steady state, evaporative flux balance model. The predicted values differed (with one exception) by less than 1‰ from locality averages of measured δ 18O values. This similarity suggests that relative humidity at the time of snail activity is an important control on the δ 18O values of the aragonite and emphasizes the seasonal nature of the climatic information preserved in the shells. Correlated δ 13C values of coexisting Vallonia and Gastrocopta suggest similar feeding habits and imply that these genera can provide information on variations in southern Great Plains plant ecology. Although there is considerable scatter, multispecies, transect average δ 13C values of the modern aragonite shells are related to variations in the type of photosynthesis (i.e., C 3, C 4) in the local plant communities. The results of this study emphasize the desirability of obtaining isotope ratios representing averages of many shells in a locale to reduce possible biases associated with local variations among individuals, species, etc., and thus better represent the "neighborhood" scale temporal and/or spatial environmental variations of interest in studies of modern and ancient systems.

  5. Carbon substrate utilization, antibiotic sensitivity, and numerical taxonomy of bacterial isolates from the Great Salt Plains of Oklahoma.

    PubMed

    Litzner, Brandon R; Caton, Todd M; Schneegurt, Mark A

    2006-05-01

    The current work extends the phenotypic characterization of a bacterial culture collection from the Great Salt Plains of Oklahoma. This barren expanse of mud flats is typically crusted with thalassohaline salt evaporites. The initial account of the aerobic heterotrophic bacteria from the Great Salt Plains described 105 halotolerant isolates that represented 47 phylotypes. Extensive phenotypic analyses were performed on 76 isolates representing 37 unique phylotypes. The current report extends these observations for 60 of the isolates by measuring a wider set of phenotypic characteristics. Utilization patterns for 45 carbon substrates were used to assign the isolates into seven coherent phenons, along with several singletons and a group of isolates that did not grow on single carbon substrates. Most of the isolates were able to utilize nearly all of the nitrogen sources tested, with nitrate being the least utilized. Little antibiotic resistance was seen in the collection as a whole; however, certain phenons were enriched for antibiotic-resistant organisms. A total of 81 phenotypic characteristics were used to generate dendrograms. The numerical taxonomy trees essentially agreed with those generated using 16S rRNA gene sequences. The pattern of carbon substrate utilization showed substantial changes at different salinities that may have relevance to the variable salinities microbes experience at the Salt Plains over time.

  6. Contrasting above- and belowground sensitivity of three Great Plains grasslands to altered rainfall regimes

    USDA-ARS?s Scientific Manuscript database

    To assess primary productivity responses to increases in precipitation amount and altered rainfall patterns, we conducted an experiment in 2011 and 2012 in shortgrass prairie (SGP; C4 dominated; Central Plains Experimental Grassland), northern mixed grass prairie (NMP; C3 dominated; Fort Keogh Lives...

  7. Refining Rural Spaces: Women and Vernacular Gentility in the Great Plains, 1880-1920

    ERIC Educational Resources Information Center

    Radke, Andrea G.

    2004-01-01

    In 1887 the Plains photographer Solomon Butcher met the David Hilton family in Custer County, Nebraska. Mrs. Hilton desired a photograph to send to relatives back East, but felt embarrassed by the family's sod dwelling. She insisted that Butcher not take a photo of the house, but asked the men to drag the Hiltons' beautiful new pump organ out into…

  8. Spatial variation in seed bank dynamics of two annual brome species in the northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Annual bromes decrease forage production in northern central plains rangelands of North America. Early life history stages are when plants are most failure-prone, yet studying death post-germination and prior to emergence is difficult. In seed bank collections conducted over the course of two growin...

  9. Dynamic topography of the western Great Plains: landscape evidence for mantle-driven uplift associated with the Jemez lineament of NE New Mexico and SE Colorado

    NASA Astrophysics Data System (ADS)

    Nereson, A. L.; Karlstrom, K. E.; McIntosh, W. C.; Heizler, M. T.; Kelley, S. A.; Brown, S. W.

    2011-12-01

    Dynamic topography results when viscous stresses created by flow within the mantle are transmitted through the lithosphere and interact with, and deform, the Earth's surface. Because dynamic topography is characterized by low amplitudes and long wavelengths, its subtle effects may be best recorded in low-relief areas such as the Great Plains of the USA where they can be readily observed and measured. We apply this concept to a unique region of the western Great Plains in New Mexico and Colorado where basalt flows of the Jemez lineament (Raton-Clayton and Ocate fields) form mesas (inverted topography) that record the evolution of the Great Plains surface through time. This study uses multiple datasets to evaluate the mechanisms which have driven the evolution of this landscape. Normalized channel steepness index (ksn) analysis identifies anomalously steep river gradients across broad (50-100 km) convexities within a NE- trending zone of differential river incision where higher downstream incision rates in the last 1.5 Ma suggest headwater uplift. At 2-8 Ma timescales, 40Ar/39Ar ages of basalt-capped paleosurfaces in the Raton-Clayton and Ocate volcanic fields indicate that rates of denudation increase systematically towards the NW from a NE-trending zone of approximately zero denudation (that approximately coincides with the high ksn zone), also suggestive of regional warping above the Jemez lineament. Onset of more rapid denudation is observed in the Raton-Clayton field beginning at ca. 3.6 Ma. Furthermore, two 300-400-m-high NE-trending erosional escarpments impart a staircase-like topographic profile to the region. Tomographic images from the EarthScope experiment show that NE-trending topographic features of this region correspond to an ~8 % P-wave velocity gradient of similar trend at the margin of the low-velocity Jemez mantle anomaly. We propose that the erosional landscapes of this unique area are, in large part, the surface expression of dynamic mantle

  10. Toxicity of a glufosinate- and several glyphosate-based herbicides to juvenile amphibians from the Southern High Plains, USA.

    PubMed

    Dinehart, Simon K; Smith, Loren M; McMurry, Scott T; Anderson, Todd A; Smith, Philip N; Haukos, David A

    2009-01-15

    Pesticide toxicity is often proposed as a contributing factor to the world-wide decline of amphibian populations. We assessed acute toxicity (48 h) of a glufosinate-based herbicide (Ignite 280 SL) and several glyphosate-based herbicide formulations (Roundup WeatherMAX, Roundup Weed and Grass Killer Super Concentrate, Roundup Weed and Grass Killer Ready-To-Use Plus on two species of amphibians housed on soil or moist paper towels. Survival of juvenile Great Plains toads (Bufo cognatus) and New Mexico spadefoots (Spea multiplicata) was reduced by exposure to Roundup Weed and Grass Killer Ready-To-Use Plus on both substrates. Great Plains toad survival was also reduced by exposure to Roundup Weed and Grass Killer Super Concentrate on paper towels. New Mexico spadefoot and Great Plains toad survival was not affected by exposure to the two agricultural herbicides (Roundup WeatherMAX and Ignite 280 SL) on either substrate, suggesting that these herbicides likely do not pose an immediate risk to these species under field conditions.

  11. Responses of soil respiration and ecosystem productivity to climate change in southern Great Plains

    NASA Astrophysics Data System (ADS)

    Zhou, Xuhui

    RH) in a tallgrass prairie ecosystem. Interannual variability of these fluxes was also examined. Using the deep-collar insertion to partition soil respiration, heterotrophic respiration accounted for approximately 66% of soil respiration over the six years. Warming treatment significantly stimulated soil respiration and its components (i.e., RA and RH) in most years. In contrast, yearly clipping significantly reduced soil respiration only in the last two years, although it decreased RH in every year of the study. Temperature sensitivity (i.e., apparent Q10 values) of soil respiration was slightly lower under warming (p>0.05) and reduced considerably by clipping (p<0.05) compared to that in the control. However, warming did not change relative contributions of RA or RH to soil respiration. In addition, the apparent Q10 values for RA were higher than those for RH and soil respiration. Annual soil respiration did not vary substantially among years as precipitation did. The interannual variability of soil respiration may be mainly caused by precipitation distribution and summer severe drought. Our results suggest that the effects of warming and yearly clipping on soil respiration and its components did not result in significant changes in R H or RA contribution, and rainfall timing may be more important in determining interannual variability of soil respiration than the amount of annual precipitation. The third is to investigate the role of precipitation on ecosystem carbon processes (i.e., biomass, litterfall, and soil respiration) along a natural precipitation gradient in southern Great Plains. Our results show that aboveground biomass (AGB), standing litter (ST), surface litter (SU), and soil respiration often linearly increased with an increase in precipitation along the gradient, although belowground biomass (BGB) and total biomass did not largely change. (Abstract shortened by UMI.)

  12. Multiple new-particle growth pathways observed at the US DOE Southern Great Plains field site

    DOE PAGES

    Hodshire, Anna L.; Lawler, Michael J.; Zhao, Jun; ...

    2016-07-28

    New-particle formation (NPF) is a significant source of aerosol particles into the atmosphere. However, these particles are initially too small to have climatic importance and must grow, primarily through net uptake of low-volatility species, from diameters  ∼  1 to 30–100 nm in order to potentially impact climate. There are currently uncertainties in the physical and chemical processes associated with the growth of these freshly formed particles that lead to uncertainties in aerosol-climate modeling. Four main pathways for new-particle growth have been identified: condensation of sulfuric-acid vapor (and associated bases when available), condensation of organic vapors, uptake of organic acids through acid–base chemistrymore » in the particle phase, and accretion of organic molecules in the particle phase to create a lower-volatility compound that then contributes to the aerosol mass. The relative importance of each pathway is uncertain and is the focus of this work. The 2013 New Particle Formation Study (NPFS) measurement campaign took place at the DOE Southern Great Plains (SGP) facility in Lamont, Oklahoma, during spring 2013. Measured gas- and particle-phase compositions during these new-particle growth events suggest three distinct growth pathways: (1) growth by primarily organics, (2) growth by primarily sulfuric acid and ammonia, and (3) growth by primarily sulfuric acid and associated bases and organics. To supplement the measurements, we used the particle growth model MABNAG (Model for Acid–Base chemistry in NAnoparticle Growth) to gain further insight into the growth processes on these 3 days at SGP. MABNAG simulates growth from (1) sulfuric-acid condensation (and subsequent salt formation with ammonia or amines), (2) near-irreversible condensation from nonreactive extremely low-volatility organic compounds (ELVOCs), and (3) organic-acid condensation and subsequent salt formation with ammonia or amines. MABNAG is able to corroborate the

  13. Northern Great Plains Network water quality monitoring design for tributaries to the Missouri National Recreational River

    USGS Publications Warehouse

    Rowe, Barbara L.; Wilson, Stephen K.; Yager, Lisa; Wilson, Marcia H.

    2013-01-01

    The National Park Service (NPS) organized more than 270 parks with important natural resources into 32 ecoregional networks to conduct Inventory and Monitoring (I&M) activities for assessment of natural resources within park units. The Missouri National Recreational River (NRR) is among the 13 parks in the NPS Northern Great Plain Network (NGPN). Park managers and NGPN staff identified surface water resources as a high priority vital sign to monitor in park units. The objectives for the Missouri NRR water quality sampling design are to (1) assess the current status and long-term trends of select water quality parameters; and (2) document trends in streamflow at high-priority stream systems. Due to the large size of the Missouri River main stem, the NGPN water quality design for the Missouri NRR focuses on wadeable tributaries within the park unit. To correlate with the NGPN water quality protocols, monitoring of the Missouri NRR consists of measurement of field core parameters including dissolved oxygen, pH, specific conductance, and temperature; and streamflow. The purpose of this document is to discuss factors examined for selection of water quality monitoring on segments of the Missouri River tributaries within the Missouri NRR.Awareness of the complex history of the Missouri NRR aids in the current understanding and direction for designing a monitoring plan. Historical and current monitoring data from agencies and entities were examined to assess potential NGPN monitoring sites. In addition, the U.S. Environmental Protection Agency 303(d) list was examined for the impaired segments on tributaries to the Missouri River main stem. Because major tributaries integrate water quality effects from complex combinations of land use and environmental settings within contributing areas, a 20-mile buffer of the Missouri NRR was used to establish environmental settings that may impact the water quality of tributaries that feed the Missouri River main stem. For selection of

  14. Relations between productivity, climate, and normalized difference vegetation index in the central Great Plains

    NASA Astrophysics Data System (ADS)

    Wang, Jue

    Understanding the influences of climate on productivity remains a major challenge in landscape ecology. Satellite remote sensing of normalized difference vegetation index (NDVI) provides a useful tool to study landscape patterns, based on generalization of local measurements, and to examine relations between climate and variation in productivity. This dissertation examines temporal and spatial relations between NDVI, productivity, and climatic factors over the course of nine years in the central Great Plains. Two general findings emerge: (1) integrated NDVI is a reliable measure of production, as validated with ground-based productivity measurements; and (2) precipitation is the primary factor that determines spatial and temporal patterns of NDVI. NDVI, integrated over appropriate time intervals, is strongly correlated with ground productivity measurements in forests, grasslands, and croplands. Most tree productivity measurements (tree ring size, tree diameter growth, and seed production) are strongly correlated with NDVI integrated for a period during the early growing season; foliage production is most strongly correlated with NDVI integrated over the entire growing season; and tree height growth corresponds with NDVI integrate during the previous growing season. Similarly, productivity measurements for herbaceous plants (grassland biomass and crop yield) are strongly correlated with NDVI. Within the growing season, the temporal pattern of grassland biomass production covaries with NDVI, with a four-week lag time. Across years, grassland biomass production covaries with NDVI integrated from part to all of the current growing season. Corn and wheat yield are most strongly related to NDVI integrated from late June to early August and from late April to mid-May, respectively. Precipitation strongly influences both temporal and spatial patterns of NDVI, while temperature influences NDVI only during the early and late growing season. In terms of temporal patterns

  15. Climate change impacts on dryland cropping systems in the central Great Plains, USA

    USDA-ARS?s Scientific Manuscript database

    Agricultural systems models are essential tools to assess potential climate change (CC) impacts on crop production and help guide policy decisions. In this study, impacts of GCM projected CC on dryland crop rotations of wheat-fallow (WF), wheat-corn-fallow (WCF), and wheat-corn-millet (WCM) at Akro...

  16. An assessment of predictive forecasting of Juniperus ashei pollen movement in the Southern Great Plains, USA.

    PubMed

    Van de Water, Peter K; Keever, Thomas; Main, Charles E; Levetin, Estelle

    2003-12-01

    Juniperus ashei pollen, a significant aeroallergen, has been recorded during December and January in Tulsa, Oklahoma, over the past 20 years. The nearest upwind source for this pollen is populations growing in southern Oklahoma and central Texas, at distances of 200 km and 600 km respectively. Long-distance dispersal of J. ashei pollen into the Tulsa area shows a strong correlation with the trajectories of wind blowing across southern populations before traveling north towards eastern Oklahoma. The strong tie between climatic conditions and the occurrence of this aeroallergen within the Tulsa, Oklahoma, atmosphere provided a unique opportunity to forecast the dispersal, entrainment, and downwind deposition of this significant aeroallergen. Forecasts of long-distance J. ashei pollen dispersal began during the winter of 1998/1999. Each forecast uses defined climatic parameters to signal pollination at each source site. Coupled to these estimates of pollen release, forecast weather conditions and modeled wind trajectories are used to determine the threat of dispersal to downwind communities. The accuracy of these forecasts was determined by comparing the forecast "threat" to aerobiological records for the same period collected in the "Tulsa region". Analysis of the two seasons revealed only a single occurrence of "high" or "very high" pollen concentrations in Tulsa not directly linked to "moderate" or "severe" forecast threats from the southern source areas.

  17. Glomalin and soil aggregation under six management systems in the Northern Great Plains, USA

    USDA-ARS?s Scientific Manuscript database

    The soil environment is linked to aboveground management including plant species composition, grazing intensity, lev-els of soil disturbance, residue management, and the length of time of a living plant is growing. Soil samples were col-lected under rangeland [native grass, rotational grazing (NGRG)...

  18. Importance of agricultural landscapes to nesting burrowing owls in the Northern Great Plains, USA

    USGS Publications Warehouse

    Restani, M.; Davies, J.M.; Newton, W.E.

    2008-01-01

    Anthropogenic habitat loss and fragmentation are the principle factors causing declines of grassland birds. Declines in burrowing owl (Athene cunicularia) populations have been extensive and have been linked to habitat loss, primarily the decline of black-tailed prairie dog (Cynomys ludovicianus) colonies. Development of habitat use models is a research priority and will aid conservation of owls inhabiting human-altered landscapes. From 2001 to 2004 we located 160 burrowing owl nests on prairie dog colonies on the Little Missouri National Grassland in North Dakota. We used multiple linear regression and Akaike's Information Criterion to estimate the relationship between cover type characteristics surrounding prairie dog colonies and (1) number of owl pairs per colony and (2) reproductive success. Models were developed for two spatial scales, within 600 m and 2,000 m radii of nests for cropland, crested wheatgrass (Agropyron cristatum), grassland, and prairie dog colonies. We also included number of patches as a metric of landscape fragmentation. Annually, fewer than 30% of prairie dog colonies were occupied by owls. None of the models at the 600 m scale explained variation in number of owl pairs or reproductive success. However, models at the 2,000 m scale did explain number of owl pairs and reproductive success. Models included cropland, crested wheatgrass, and prairie dog colonies. Grasslands were not included in any of the models and had low importance values, although percentage grassland surrounding colonies was high. Management that protects prairie dog colonies bordering cropland and crested wheatgrass should be implemented to maintain nesting habitat of burrowing owls. ?? 2008 Springer Science+Business Media B.V.

  19. The Economic Impact of Universities in Non-Metropolitan Areas of the Great Plains, USA

    ERIC Educational Resources Information Center

    Falconer, John

    2007-01-01

    Public universities cite their economic impact to help justify state financial support, but the literature offers no comprehensive theory that can guide analysis of such claims. This research used qualitative methodology to complement the ubiquitous economic impact studies, and showed that mission, leadership and geography determine how public…

  20. Fire and nutrient cycling in shortgrass steppe of the southern Great Plains, USA

    Treesearch

    P.L. Ford; C.S. White

    2005-01-01

    Fire in semi-arid grasslands releases nutrients bound up in organic matter and accelerates the rate of decomposition in the soil. This research experimentally tested effects of season and frequency of fire on nutrient cycling dynamics in shortgrass steppe. The objective was to identify if fire treatments have the ability to increase potential grassland productivity...