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    • Terrestrial Condition Assessment (TCA) Nitrogen Deposition

    Metadata Updated: October 2, 2025

    Direct Download (Raster Data Gateway)Objective: Evaluate the impact of atmospheric nitrogen deposition on various ecosystem components including lichens, tree species (both growth and mortality), mycorrhizal communities, herbaceous plant species (changes in species richness), and leaching.Data: Deposition data is the 3-year average output from the Total Deposition (TDep) modeling system (https://nadp.slh.wisc.edu/committees/tdep/). TDep uses measurement-model fusion to bias correct modelled estimates (Tdep Program, https://nadp.slh.wisc.edu/committees/tdep/). TDep uses observations of air concentrations from the Clean Air Status and Trends Network (CASTNET) for measurements of dry deposition and observations of precipitation and precipitation chemistry from various National Atmospheric Deposition Program (NADP) networks. These observations are interpolated and used to create seasonal bias surfaces for results generated from CMAQ. Bias-adjusted CMAQ results are then merged with observations to create a set of deposition estimates that better align with measurements than model results alone. The full description of this methodology is available in: Schwede et al., 2014. There is a two year lag between the source data and the TCA Assessment year, so source data 3-year ranges with assessment year in parentheses are: 2016-2018 (2020 assessment), 2017-2019 (2021 assessment), 2018-2020 (2022 assessment), 2019-2021 (2023 assessment), 2020-2022 (2024 assessment). The data used in the 2024 assessment had a small gap in western North and South Dakota, which was filled with data from the 2019-2021 product due to the small amount of interannual variability in the region.Data Format: Raster data are continuousUnits: kg/ha/yrSpatial Resolution: 400m (resampled from 4km)Source data: Total Deposition Science Committee (TDep)Additional Resources:Details on Method Changes and Source Data VersionsOverview of the Terrestrial Condition Assessment: TCA Hubsite or Landfire Office Hour PresentationExplore the results of the most recent assessment: TCA Interactive Data ViewerLearn more about the TCA KPI: TCA Dashboard*if you have trouble viewing the Dashboard, please submit a Tableau Viewer Access Request

    Access & Use Information

    Public: This dataset is intended for public access and use. License: Creative Commons Attribution

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    Dates

    Metadata Created Date October 2, 2025
    Metadata Updated Date October 2, 2025

    Metadata Source

    Harvested from USDA JSON

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date October 2, 2025
    Metadata Updated Date October 2, 2025
    Publisher U.S. Forest Service
    Maintainer
    Identifier https://www.arcgis.com/home/item.html?id=510856e51e0545169cad569bb5e61fe0
    Data First Published 2025-09-25
    Data Last Modified 2025-09-25
    Category geospatial
    Public Access Level public
    Bureau Code 005:96
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Harvest Object Id abe15133-f2ce-4b6b-b70f-86cea441cc42
    Harvest Source Id d3fafa34-0cb9-48f1-ab1d-5b5fdc783806
    Harvest Source Title USDA JSON
    Homepage URL https://data-usfs.hub.arcgis.com/datasets/usfs::terrestrial-condition-assessment-tca-nitrogen-deposition-1
    License https://creativecommons.org/licenses/by/4.0/
    Metadata Type geospatial
    Old Spatial -135.9010,19.8686,-55.4371,52.9679
    Program Code 005:059
    Progresscode onGoing
    Source Datajson Identifier True
    Source Hash 7b64e9edcaea8dfffb39c0c6536c196e8481095e0f5b39226022ed407d7f470a
    Source Schema Version 1.1
    Spatial {"type": "Polygon", "coordinates": -135.9010, 19.8686, -135.9010, 52.9679, -55.4371, 52.9679, -55.4371, 19.8686, -135.9010, 19.8686}

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