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Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the nine Chesapeake Bay River Input Monitoring (RIM) stations for the period 1985 through 2015. Nutrient and suspended-sediment loads and changes in loads were determined by applying a weighted regression approach called WRTDS (Weighted Regression on Time, Discharge, and Season). Yields (represents the mass of constituent transported from a unit area of a given watershed) are used to compare the export loads from one basin to another. Yield results are obtained by dividing the annual load (pounds) of a given constituent by the respective watershed...
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This data set consists of monthly averages of soil and litter properties. Rows are grouped in the following order: year, month, vegetation type, plot ID. Within a single month five plots were sampled within each of the 2 vegetation types (10 plots total). Columns F+ represent individual measurements.
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This dataset shows the estimated delivered nitrogen load from all sources (livestock manure from confined operations, livestock manure from pasture feeding, livestock manure from feedlots, fertilizer applied to crops, runoff from urban land, combined municipal and wastewater discharge, and from atmospheric deposition)into the estuaries, bays, and sounds along the U.S. Gulf of Mexico coast in 2002.
Categories: Data; Tags: Hypoxia, West Mississippi Sound, location, Timbalier Bay, Nutrient Runoff, All tags...
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This data set presents attributes of floodplain ecosystem characteristics including floodplain soil denitrification, floodplain soil biogeochemistry, floodplain vegetation, floodplain sedimentation, floodplain and channel morphometry, stream discharge and water quality, floodplain climate, floodplain physiographic region, and catchment land cover. Attributes are associated with 18 floodplains of the Chesapeake Bay watershed. For many of these attributes, mean values are summaries of multiple measurements made within each floodplain site.
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We examined the content and isotopic composition of nitrogen within soils of a juniper woodland and found that a cryptobiotic crust composed of cyanobacteria, lichens, and mosses was the predominant source of nitrogen for this ecosystem. Disturbance of the crust has resulted in considerable spatial variability in soil nitrogen content and isotopic composition; intercanopy soils were significantly depleted in nitrogen and had greater abundance of 15N compared to intra-canopy soils. Variations in the 15N\14N ratio for inter- and intracanopy locations followed similar Rayleigh distillation curves, indicating that the greater 15N/14N ratios for inter-canopy soils were due to relatively greater net nitrogen loss. Coverage...
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The following topics are currently covered by the MineralCommodity Summaries: domestic production and uses; U.S. salientstatistics; recycling; import sources; tariff; depletionallowance; government stockpile; events, trends, and issues;world production, reserves, and reserve base; world resources;and substitutes.
Tags: Vanadium, Tellurium, Minerals, Platinum-group metals, Diamond, All tags...
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Acetylene fermentation assays, nitrogen fixation assays, and growth studies were performed with Pelobacter sp. strain SFB93 and Pelobacter acetylenicus DSM3246. Data includes concentrations of acetylene and ethylene over time, and growth measured with OD680 and cell counts.
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The accretion history of fringing salt marshes located on the south shore of Cape Cod is reconstructed from sediment cores collected in low and high marsh vegetation zones. These marshes are micro-tidal, with a mean tidal range of 0.442 m. Their location within protected embayments and the absence of large rivers results in minimal sediment supply and a dominance of organic matter contributions to sediment peat. Age models based on 210-lead and 137-cesium are constructed to evaluate how vertical accretion and carbon burial rates have changed over the past century. The continuous rate of supply age model was used to age date 11 cores (10 low marsh and 1 high marsh) across four salt marshes. Both vertical accretion...


map background search result map search result map A Break in the Nitrogen Cycle in Aridlands? Evidence from δ 15N of Soils Discovery of Two Biological Mechanisms for Acetylene Metabolism in a Single Organism Estimates of Total Nitrogen and Phosphorus Delivery to Estuaries, Bays, and Sounds Along the U.S. Gulf of Mexico Coast, 2002 EFFECTS OF FLOOD INUNDATION AND INVASION BY Phalaris arundinacea ON NITROGEN CYCLING IN AN UPPER MISSISSIPPI RIVER FLOODPLAIN FOREST Chesapeake Bay Nontidal Network 2005-2014: Average Yields Data on denitrification and ecological characteristics of nontidal floodplains, Chesapeake Bay watershed, USA, 2013-2016 Collection, analysis, and age-dating of sediment cores from salt marshes on the south shore of Cape Cod, Massachusetts, from 2013 through 2014 Collection, analysis, and age-dating of sediment cores from salt marshes on the south shore of Cape Cod, Massachusetts, from 2013 through 2014 Discovery of Two Biological Mechanisms for Acetylene Metabolism in a Single Organism A Break in the Nitrogen Cycle in Aridlands? Evidence from δ 15N of Soils Data on denitrification and ecological characteristics of nontidal floodplains, Chesapeake Bay watershed, USA, 2013-2016 Chesapeake Bay Nontidal Network 2005-2014: Average Yields Estimates of Total Nitrogen and Phosphorus Delivery to Estuaries, Bays, and Sounds Along the U.S. Gulf of Mexico Coast, 2002