Filename: SUMMARY.DBF

About the Forest Health Monitoring (FHM) Program:
The FHM program is managed by the USDA Forest Service (FS) in
cooperation with other program participants. Funding comes largely from
the FS and the U.S. Environmental Protection Agency.  Other participants
include State Forestry and Agriculture agencies, the USDI Bureau of Land
Management, the Tennessee Valley Authority, the USDA Natural Resources
Conservation Service, and several universities. The National Association
of State Foresters provides essential program support, guidance, and
assistance. Detection Monitoring, the most extensive of FHM's three
monitoring activities, is designed to provide data to determine baseline
or current conditions of forest ecosystems, and to detect changes and
trends over time. This information is analyzed to determine if detected
changes are anticipated, and if those changes indicate improving forest
health or are cause for concern, warranting additional evaluation.
Detection Monitoring covers all forested land and has two components:
(1) the on-frame component, which is measurements made on the FHM
network of permanent plots; and (2) the off-frame component, which is
forest surveys made off of the FHM plot network and includes forest
insect, disease, and other stressor effects. (References: The Forest
Health Monitoring National Brochure, and the FHM Fact Sheet Series.
Available at the Forest Health Monitoring National Office, P.O. Box
12254, Research Triangle Park, NC, 27709)

Coverage:
FHM uses the EMAP sampling grid, which is formed from a triangular grid
of sampling points. The FHM ground plots are approximately 1-hectare in
size and contain 4 subplots approximately 1/60 hectare in size. Ground
plots are approximately 27 km apart. (Reference: Stevens, D.L. 1994.
Implementation of a national monitoring program. J. Environ. Manage.
42:1-29.)

About the Index/Measurements:

Live basal area was calculated using the following equation:

  BA = (ã/4)(dbh)2

     where dbh = the diameter at breast height and is the diameter of
                 the tree measured at 4.5 ft (1.37 m) above the
                 forest floor on the uphill side of the tree.


Definition of Data Set Variables (in the order they appear in the data
set):

HEX -  the unique 7-digit code assigned to each 40 km2 hexagon.

FORTYP -  defined as listed below:

  30 = White pine (White/Red/Jack Pine Group)
     Associates--pitch pine, gray birch, aspen, red maple, pin cherry,
     white oak, paper birch, sweet birch, yellow birch, black cherry,
     white ash, northern red oak, sugar maple, basswood, hemlock,
     northern white-cedar, yellow-poplar, white oak, chestnut oak,
     scarlet oak, and shortleaf pine.  Sites--wide variety, but best
     development on well drained sands and sandy loams.


  210 =   Longleaf pine (Longleaf/Slash Pine Group)
     Longleaf pine occurs as a pure type or comprises a majority of the
     trees in the overstory.  Associates-slash, loblolly and shortleaf
     pine, southern red oak, blackjack oak, water oak, persimmon, and
     sweetgum.  Sites--those areas that can and do burn on a periodic
     basis--usually occurs on middle and upper slopes with a low
     severity of hardwood and brush competition.  Regional
     distribution--coastal plain and piedmont units.

  310 =   Loblolly pine (Loblolly/Shortleaf Pine Group)
     Associates--sweetgum, southern red oak, post oak, blackjack oak,
     blackgum, yellow-poplar, and pond pine.  Sites--in Delaware and
     Maryland both on upland soils with abundant moisture but good
     drainage and on poorly drained depressions.

  320 =   Shortleaf pine (Loblolly/Shortleaf Pine Group)
     Associates--white oak, southern red oak, scarlet oak, black oak,
     hickory, post oak, blackjack oak, blackgum, red maple, pitch pine,
     and Virginia pine.  Sites--low, well drained ridges to rocky, dry,
     south slopes and the better drained spur ridges on north slopes
     and also on old fields.

  330 =   Virginia pine (Loblolly/Shortleaf Pine Group)
     Associates--shortleaf pine, white oak, chestnut oak, southern red
     oak, black oak, sweetgum, red maple, blackgum, and pitch pine. 
     Sites--dry sites, often abandoned fields.

  350 =   Eastern red cedar (Loblolly/Shortleaf Pine Group)
     Associates--gray birch, red maple, sweetbirch, Virginia Pine,
     shortleaf pine, oak.  Sites--usually dry uplands and abandoned
     fields on limestone outcrops and other shallow soils but can grow
     well on good sites.

  410 =   White pine/northern red oak/white ash (Oak/Pine Group)
     Associates--red maple, basswood, yellow birch, bigtooth aspen,
     sugar maple, beech, paper birch, black cherry, hemlock, and sweet
     birch. Sites--deep, fertile, well-drained soil.

  420 =   Eastern redcedar/hardwood (Oak/Pine Group)
     Associates--oak, hickory, walnut, ash, locust, dogwood, blackgum,
     hackberry, winged elm, shortleaf pine, and Virginia pine.  Sites--usually dry uplands and abandoned fields.

  440 =   Shortleaf pine/oak (Oak/Pine Group)
     Associates--(oaks generally include white, scarlet, blackjack,
     black, post, and southern red) hickory, blackgum, sweetgum,
     Virginia pine, and pitch pine.  Sites--generally in dry, low
     ridges, flats, and south slopes.

  450 =   Virginia pine/southern red oak (Oak/Pine Group)
     Associates--black oak, scarlet oak, white oak, post oak, blackjack
     oak, shortleaf pine, blackgum, hickory, pitch pine, table-mountain
     pine, chestnut oak. Sites--dry slopes and ridges.

  460 =   Loblolly pine/hardwood (Oak/Pine Group)
     Associates--wide variety of moist and wet site hardwoods including
     blackgum, sweetgum, yellow-poplar, red maple, white and green ash,
     and American elm; on drier sites associates include southern and
     northern red oak, white oak, post oak, scarlet oak, persimmon, and
     hickory.  Sites--usually moist to very moist though not wet all
     year but also on drier sites.

  490 =   Other oak/pine (Oak/Pine Group)

  510 =   Post, black, or bear oak (Oak/Hickory Group)
     Associates--blackjack oak, hickory, southern red oak, white oak,
     scarlet oak, shingle oak, live oak, shortleaf pine, Virginia pine,
     blackgum, sourwood, red maple, winged elm, hackberry, chinkapin
     oak, shumard oak, dogwood, and eastern redcedar.  Sites--dry
     uplands and ridges.

  520 =   Chestnut oak (Oak/Hickory Group)
     Associates--scarlet oak, white oak, black oak, post oak, pitch
     pine, blackgum, sweetgum, red maple, red oak, shortleaf pine,
     Virginia pine.  Sites--rocky outcrops with thin soil, ridge tops.

  530 =   White oak/red oak/hickory (Oak/Hickory Group)
     Associates--scarlet oak, bur oak, pinoak, white ash, sugar maple,
     red maple, walnut, basswood, locust, beech, sweetgum, blackgum,
     yellow-poplar, and dogwood.  Sites--wide variety of well drained
     upland soils.

  540 =   White oak (Oak/Hickory Group)
     Associates--black oak, northern red oak, bur oak, hickory, white
     ash, yellow-poplar.  Sites--scattered patches on upland, loamy
     soils but on drier sites than type 530.

  550 =   Northern red oak (Oak/Hickory Group)
     Associates--black oak, scarlet oak, chestnut oak, and
     yellow-poplar.   Sites--spotty distribution on ridge crests and
     north slopes in mountains but also found on rolling land, slopes,
     and benches on loamy soil.

  560 =   Yellow-poplar/white oak/northern red oak (Oak/Hickory Group)
     Associates--blackoak, hemlock, blackgum, and hickory.  Sites--northern slopes, coves, and moist flats.

  562 =   Sweetgum/yellow-poplar (Oak/Hickory Group)
     Associates--red maple, white ash, green ash, and other moist site
     hardwoods.  Sites--generally occupies moist, lower slopes.

  580 =   Black locust (Oak/Hickory Group)
     Associates--many species of hardwoods and hardpines may occur with
     it in mixture, either having been planted or from natural seeding. 
     Sites--may occur on any well-drained soil but best on dry sites,
     often in old fields.

  590 =   Mixed central hardwoods (Oak/Hickory Group)
     Associates--Any mixture of hardwoods of species typical of the
     upland central hardwood region, should include at least some oak. 
     Sites--wide variety of upland sites.

  592 =   Sassafras/persimmon (Oak/Hickory Group)
     Associates--elm, eastern redcedar, hickory, ash, sugar maple,
     yellow-poplar, and oaks.  Sites--abandoned farmlands and old
     fields.

  620 =   Sweetgum/Nuttall oak/willow oak (Oak/Gum/Cypress Group)
     Associates--green ash, American elm, pecan, cottonwood, red maple,
     honeylocust, and persimmon.  Sites--very wet.

  720 =   River birch/sycamore (Elm/Ash/Red Maple Group)
     Associates--red maple, black willow, and other moist-site
     hardwoods.  Sites--moist soils at edges of creeks and rivers.

  810 =   Sugar maple/beech/yellow birch (Maple/Beech/Birch Group)
     Associates--basswood, red maple, hemlock, northern red oak, white
     ash, white pine, black cherry, sweet birch, American elm, rock
     elm, and eastern hophornbeam.  Sites--fertile, moist, well-drained
     sites.

  850 =   Red maple/central hardwoods (Maple/Beech/Birch Group)
     Associates--the type is dominated by red maple and some of the
     wide variety of central hardwood associates include upland oak,
     hickory, yellow-poplar, black locust, sassafras as well as some
     central softwoods like Virginia and shortleaf pines.  Sites--uplands (see type 0840).

  999 =   Nonstocked
     The site qualifies as forest but is presently stocked with too few
     trees to assign a forest type.

AGE -  estimated stand age at plot establishment (in 1991). A code of
       -1 means there is no estimate of age. Change may have occurred
       in 1991 to 1994

HBA94 -   hardwood live basal area (square feet/acre) measured in 1994.

HTPA94 -  number of live hardwood trees per acre.

SBA94 -   softwood live basal area (square feet/acre) measured in 1994.

STPA94 -  number of live softwood trees per acre.