Skip to main content
USGS - science for a changing world
Advanced Search

Filters: Tags: Soil horizons (X)

43 results (41ms)   

View Results as: JSON ATOM CSV
To determine the dominant processes controlling nitrogen (N) dynamics in soils and increase insights into soil N cycling from nitrogen isotope (?15N) data, patterns of 15N enrichment in soil profiles were compiled from studies on tropical, temperate, and boreal systems. The maximum 15N enrichment between litter and deeper soil layers varied strongly with mycorrhizal fungal association, averaging 9.6 � 0.4? in ectomycorrhizal systems and 4.6 � 0.5? in arbuscular mycorrhizal systems. The 15N enrichment varied little with mean annual temperature, precipitation, or nitrification rates. One main factor controlling 15N in soil profiles, fractionation against 15N during N transfer by mycorrhizal fungi to host plants, leads...
This hydrologic and landscape database was developed by the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service for the Okefenokee National Wildlife Refuge and contributing watersheds in Florida and Georgia. The database was developed as an assessment and evaluation tool to use in examining refuge-specific hydrologic patterns and trends as related to water availability and water quality for refuge ecosystems, habits, and target species. The database includes hydrologic time series data, statistics on landscape and hydrologic time series data, and hydro-ecological metrics that can be used to assess refuge hydrologic conditions. The database is described in detail in Open File Report 2017-1018.
thumbnail
This dataset contains measurements of chemical concentrations of forest soil samples and associated site measurements collected in the Adirondack Ecoregion of New York State. Data are presented in four groups (tabs) in an Microsoft EXCEL 2013 spreadsheet (and comma-delimited CSV files): (1) Adirondack Sugar Maple Project (ASM), (2) Buck Creek North Watershed, (3) Buck Creek South Watershed, and (4) Western Adirondack Stream Survey (WASS) soil sampling. The ASM data were all collected in 2009 and the WASS data were all collected in 2004. The Buck Creek North Tributary Watershed was sampled in 1997 and repeated at the same plot locations in 2009/10. The Buck Creek South Tributary Watershed was sampled in 1998 and...
thumbnail
Thin loess deposits on the uplands of the southeastern Colorado Plateau have previously not been well studied. We sampled deposits and soils from trenches on Hatch Point mesa near Canyonlands National Park, Utah, and from two outcrops in Mesa Verde National Park, Colorado. At Hatch Point, the oldest buried unit yielded two OSL ages of 10,370 and 7,555 yr; the middle unit yielded 10 OSL ages from 6220 to 1385 yr; and the youngest unit has a single age of 1740 yr. At Mesa Verde, three loess units are preserved in the two outcrops we examined; six OSL ages range from 51 to 17 ka. At least one buried soil is present between two units with ages of about 50 and 40 ka. The ages of the loess units in both study areas correspond...


map background search result map search result map Adirondack New York soil chemistry data, 1997-2014 Data release for Late Quaternary loess and soils on uplands in the Canyonlands and Mesa Verde areas, Utah and Colorado Adirondack New York soil chemistry data, 1997-2014