Original HEP cover type definitions

C4 (Conifer late-successional)
A mature (typically 80 plus years) forest with the canopy comprising at least 75 percent conifers, a multilayered canopy crown closure (dominant, codominant, subdominant) of at least 70 percent, an average dominant tree height of at least 40 feet with at least 20 stems per acre that are equal or greater than 21 inched DBH.

C4T (Conifer late-successional, thinned)
A mature (typically 80 plus years) forest with 75 percent or more of the canopy as conifers that has been thinned at least once and contains less than 70 percent collective (dominant, codominant, subdominant) canopy crown closure. Average dominant tree height is at least 40 feet and the average DBH is at least 21 inches. An unthinned stand that meets all the criteria except 70 percent or more canopy closure may be typed C4T.

C3 (Conifer mature)
A mature (typically 31 to 80 years) forest with at least 75 percent or more of the canopy as conifers, the collective canopy crown closure is at least 70 percent, and the avenge DBH is 12 to 21 inches.

C3T (Conifer mature, thinned)
A mature (typically 31 to 80 years) forest with at least 75 percent or more of the canopy as conifers that has been thinned at least once, the canopy crown closure is less than 70 percent, and the average DBH is 12 to 21 inches. An unthinned stand that meets all the criteria except 70 percent canopy crown closure may be typed C3T.

C2 (Conifer pole)
A young forest that is typically 16 to 30 years old, with 50 percent or more tree cover, of which at least 75 percent are conifers, the average DBH is greater that 4 inches and less than 12 inches.

C1 (Conifer early-successional)
A young forest that is typically between 1 and 15 years old that is natural and/or hand planted, with at least 75 percent of the stems as conifers, the average tree height is less than 15 feet, the stocking is at least 150 stems per acre, and the DBH ranges from 1 to 4 inches.

M3 (Mixed mature)
A mature (typically 31 to 80 years) conifer/deciduous forest with less than 75 percent of the canopy as conifers and less than 75 percent as deciduous, dominant tree height is 40 feet or more, and the collective canopy crown is 70 percent or more. The average DBH is 12 to 21 inches.

M2 (Mixed pole)
A young (typically 16 to 30 years) conifer/deciduous forest with at least 50 percent or more tree cover of which less than 75 percent of the canopy are conifers and less than 75 percent of the canopy are deciduous. The average DBH is 4 to 12 inches.

M1 (Mixed early-successional)
A young (typically 1 to 15 years) conifer/deciduous forest that is natural or hand planted, with less that 75 percent of the canopy as conifers and lass than 75 percent of the canopy as deciduous, and stocking is at least 150 stems per acre. The average DBH is 1 to 4 inches.

H3 (Deciduous mature)
A mature forest with at least 50 percent tree cover of which 75 percent or more are deciduous trees with an average DBH over 12 inches.

H2 (Deciduous sapling)
A young forest with at least 50 percent tree cover of which 75 percent or more are deciduous trees with an average DBH of 4 to 12 inches.

H1 (Deciduous early-successional)
A young forest with at least 50 percent tree cover of which 75 percent or more are deciduous trees with an average DBH 1 to 4 inches.

PF (Palustrine forested wetland)
A wetland that has a vegetative cover of at least 30 percent and is dominated by woody vegetation averaging 20 feet in height.

PS (Palustrine shrub wetland)
A wetland with total vegetative cover of at least 30 percent that is dominated by woody vegetation averaging less than 20 feet in height.

PE (Palustrine emergent wetland)
A wetland that has a vegetative cover of at least 30 percent and is dominated by emergent species. Emergent species are erect-rooted herbaceous angiosperms that can be temporarily or permanently flooded at their base and include such species as cattail, bulrush and reed canarygrass.

P (Pond)
Open water, either permanent or seasonal, and emergent wetland vegetation. Pond areas can contain minor amounts of forest edge.

G (Grass)
Areas with vegetative cover of at least 25 percent and dominated by native or introduced grasses or forbs.

B (Brush)
Land that is dominated by shrubs, brush or seedling trees with less than 50 percent tree cover but at least 25 percent of the area covered by vegetation.

BA (Barren)
Areas that have been disturbed but are not subject to intense human use, with less than 25 percent of the area covered by vegetation, and the remaining area is bare ground (gravel, soil).

D (Developed)
Areas in which much of the land is covered by buildings and developed areas which are subject to intense human use.

Issues discovered in automating HEP
During the initial runs of the cover typing code some were found when some stands failed to be classified or were mis-classified based on field checks fo the stands.  Modifications were then made to the cover typing rules.  These changes were:

• % conifer - % deciduous:  The rules were unclear about how to determine this.  Initial runs were made based on trees per acre.  After field checks and discussions with wildlife biologists this was changed to percentage of stand basal area.
• C1 cover type rule of maximum height of 15':  This was removed since stands of 4" DBH seldom, if ever have an average height of 15'.
• M3 maximum DBH of 21":  This was removed when projected stand conditions gave average DBH of >21" and stands failed to be classified.

Updated 19/12/2000 by Kevin "thujaman" Ceder