General Browsing Guide for the NSCN Database
The NSCN Database is a growing, evolving data resource. Because it is
too large to present in one file, it is distributed via a collection of
documents, reports, and tables; because it changes frequently, there is
a strong web-based component and we encourage you to visit
the site frequently.
Data are input to and reported from the database using
standardized variable names (response variables and metadata). Each
of these variables fits within a broader hierarchy of spatial scales,
with some being classified as site-level (e.g., climate and geologic
formation), others relevant to individually collected soil profiles
(e.g., soil series and taxonomic order), and still others that are used
to describe the individually collected soil layers that comprise each
soil profile (e.g., horizon thickness or sampling depth, %carbon, bulk
density). We also have the capacity to catalog data from soil fractions
of all types, as well as data from sites that have experienced
disturbances or experimental treatments. In general, background and
summary information about database are presented on the
Dataset Information page; spreadsheet reports containing the data
themselves are on the
Data Browsing webpage (account required). By using the unique Site,
Profile, and Layer IDs that run throughout all the data reports, you can
perform your own manipulations using the data products that we have
provided as a starting point. One especially useful means of accessing
the response and metadata together is available from the link to all
Per-Layer Data on the Data Browsing page, which points to an Excel 2007
download (>40 MB) that has a row of data for every individual soil layer
currently available, and allows convenient filtering.
Note that the contents of the database and the data reports on this
website will change as new data are added; it is important to keep track
of the version date stamped in the upper-left portion of any data report
that you access.
The data in the database come from many sources, including academic
scientists, the U.S. Geological Survey, and the USDA-Natural Resources
Conservation Service, Soil Survey Lab. We hope that you will contribute
some of your own data to this effort to help it grow larger, more
capable and successful. Please
contact NSCN support to arrange data contributions. If you are eager
to get started, please visit the
data submission page and begin mapping your own spreadsheet over to
our database format. Take comfort in the fact that when you contribute
datasets, they remain hidden from broader viewing until you decide to
release them for that purpose, and that when you release your data you
will be cited by its users.
With as many different data sources as there are in the database, please
be aware that errors exist. It is our eventual goal to assign an
objective quality grade to each observation we receive from each
contributor. Reading our
document about database calculations and data quality is important,
as is establishing your own protocol for addressing outliers and
influential observations before beginning your analysis. If you detect
data that appear to be in error, please describe the problem on
the forum post devoted to database problems. If you need help with
data browsing, please contact
nscn-support@george.lbl.gov.
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