Forest area

Forest area by type group from condition proportions and expansion factors.

Area queries expand condition proportions (CONDPROP_UNADJ) rather than tree counts, using the condition’s PROP_BASIS to pick the right adjustment factor.

Minnesota — forest area by forest type group

EVALID: 272201 (Minnesota 2022) · Result: 17,599,046 forest acres across 10 forest type groups · source

View SQL

SELECT
    CASE
        WHEN rftg.VALUE IS NULL THEN '0999 Nonstocked'
        ELSE LPAD(CAST(rftg.VALUE AS VARCHAR), 4, '0') || ' ' || COALESCE(rftg.MEANING, 'Unknown')
    END AS forest_type_group,
    SUM(
        c.CONDPROP_UNADJ *
        CASE c.PROP_BASIS
            WHEN 'MACR' THEN ps.ADJ_FACTOR_MACR
            ELSE ps.ADJ_FACTOR_SUBP
        END * ps.EXPNS
    ) AS total_area_acres
FROM POP_STRATUM ps
JOIN POP_PLOT_STRATUM_ASSGN ppsa ON ppsa.STRATUM_CN = ps.CN
JOIN PLOT p ON ppsa.PLT_CN = p.CN
JOIN COND c ON c.PLT_CN = p.CN
LEFT JOIN REF_FOREST_TYPE rft ON rft.VALUE = c.FORTYPCD
LEFT JOIN REF_FOREST_TYPE_GROUP rftg ON rft.TYPGRPCD = rftg.VALUE
WHERE
    c.COND_STATUS_CD = 1            -- Forest conditions only
    AND c.CONDPROP_UNADJ IS NOT NULL
    AND ps.rscd = 23               -- Minnesota
    AND ps.evalid = 272201
GROUP BY rftg.VALUE, rftg.MEANING
ORDER BY total_area_acres DESC
LIMIT 10;

The Python equivalent is area() with grp_by="FORTYPCD".