FIA Forest land (National): Forest land has at least 10 percent canopy cover of trees of any size, or has had at least 10-percent canopy cover of trees in the past, based on the presence of stumps, snags, or other evidence, and that will be naturally or artificially regenerated. Additionally, the land is not subject to nonforest use(s) that prevent normal tree regeneration and succession, such as regular mowing, intensive grazing, or recreation activities. Forest land includes transition zones, such as areas between heavily forested and nonforested lands that are at least 10-percent canopy cover with trees and forest areas adjacent to urban and built-up lands. Also included are pinyon-juniper and chaparral areas in the West and afforested areas. The minimum area for classification of forest land is 1 acre in size and 120 feet wide measured stem-to-stem from the outer-most edge. Unimproved roads and trails, streams, and clearings in forest areas are classified as forest if less than 120 feet wide. This is the domestic reporting definition which is different from the definition used in international reporting (which includes a minimum tree canopy height criteria).

RPA Forest land (International): Land at least 10-percent canopy cover by trees at least 5 meters (16.5 feet) tall, or trees able to reach these thresholds in situ, including land that formerly had such tree cover and that will be naturally or artificially regenerated. Forest land includes transition zones, such as areas between heavily forested and nonforested lands that are at least 10-percent canopy cover with trees and forest areas adjacent to urban and built-up lands. The minimum area for classification of forest land is 1 acre in size and 120 feet wide measured stem-to-stem from the outer-most edge. Unimproved roads and trails, streams, and clearings in forest areas are classified as forest if less than 120 feet wide. This is the international reporting definition which is different from the domestic definition used in domestic FIA reporting (which does not include a minimum tree canopy height criteria).Resources Planning Act (RPA) (opens in new window))

The RPA forest definition, which contains an “in-situ” height requirement for trees simply adds the following filter to the retrieval:

    and not (16.4042 > coalesce((select avg(coalesce(atree.actualht, 0))
        from FS_FIADB.tree atree
        where atree.plt_cn = plot.cn
        and atree.statuscd = 1
        and atree.dia >= 5.0),0)
    and (cond.fortypcd in (180, 182, 184, 185, 970, 971, 972, 973, 974, 975, 976)
    and substr(plot.ecosubcd, 1, 4) in (' 311',' 313',' 315',' 321',' 322',' 331',' 332',' 341',' 342') and cond.siteclcd = 7))