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    • Spring leaf and bloom index dates (1880-2013) and migratory bird flyways

    Metadata Updated: January 20, 2026

    Historical values for the Extended Spring Index (SI-x) of First Leaf. Each pixel is assigned a day of year value for the First Leaf Index. The Extended Spring Indices are mathematical models that predict the "start of spring" (timing of leaf out or bloom for species active in early spring) at a particular location. This model was constructed using historical observations of the timing of first leaf in a cloned lilac cultivar (S. x chinensis 'Red Rothomagensis') and two cloned honeysuckle cultivars (Lonicera tatarica 'Arnold Red' and L. korolkowii 'Zabelii'). Primary inputs to the model are temperature events, beginning January 1 of each year. Layers are available for each year from 1880 to 2013. Input temperature data are historical BEST data at 1 degree resolution.

    Access & Use Information

    Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Created Date January 12, 2026
    Metadata Updated Date January 20, 2026

    Metadata Source

    Harvested from DOI USGS DCAT-US

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date January 12, 2026
    Metadata Updated Date January 20, 2026
    Publisher U.S. Geological Survey
    Maintainer
    Identifier http://datainventory.doi.gov/id/dataset/USGS_5b75d10ee4b0f5d5787fea6f
    Data Last Modified 2020-08-27T00:00:00Z
    Category geospatial
    Public Access Level public
    Bureau Code 010:12
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Metadata Catalog ID https://ddi.doi.gov/usgs-data.json
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Datagov Dedupe Retained 20260120094633
    Harvest Object Id da466c5a-3f52-49aa-a1a1-ee1d96e20d6a
    Harvest Source Id 2b80d118-ab3a-48ba-bd93-996bbacefac2
    Harvest Source Title DOI USGS DCAT-US
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": -180.0, 0.0, -180.0, 90.0, 0.0, 90.0, 0.0, 0.0, -180.0, 0.0}
    Source Datajson Identifier True
    Source Hash 560481b7e50d490080b49c65fb24c407b6eea96f21f2716b98aa1e58b22e8a4f
    Source Schema Version 1.1
    Spatial {"type": "Polygon", "coordinates": -180.0, 0.0, -180.0, 90.0, 0.0, 90.0, 0.0, 0.0, -180.0, 0.0}

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