Condition Class DeterminationCondition Class Determination

National Manual Version 1.55

Condition Class DeterminationCondition Class Determination

• Only delineate conditions on plots that have at least one accessible forest land condition.

• Do not delineate conditions on plots that are completely nonforest, inaccessible, or hazardous

• New procedures to determine extent of forest land area due to national integration

• New condition attributes and codes due to the national movement toward “normalized” data

Three Basic StepsThree Basic Steps

1. Delineate conditions based on Condition Status:Basically, is it Accessible Forest Land or not?

2. Subdivide Accessible Forest Land based on seven condition defining attributes

3. Subdivide Nonforest Land

Step 1: Delineate Condition StatusStep 1: Delineate Condition StatusDelineate the plot into the following condition status categories:

1 Accessible forest land2 Nonforest land3 Noncensus water4 Census water

Change from previous manuals: • Noncensus water is now its own separate

condition status and is always delineated• Use code 9 when past forest condition data is not

available, or forested subplot is not relocated

5 Denied access area6 Area too hazardous to visit7 Area that is not in the sample (Mexico)9 Lost subplot/past condition data (forest only)

Delineating Condition StatusDelineating Condition StatusAccessible forest land (Code 1)

• Must be at least 1.0 acre in size, and 120.0 feet wide

Nonforest land (Code 2)• Must be at least 1.0 acre in size, and 120.0 feet wide• Exception: Developed nonforest conditions can be any

size (30 series land use codes)

Noncensus water (Code 3):• Linear water courses between 30.0-200.0 feet wide• Bodies of water between 1.0-4.5 acres

Census water (Code 4): • Linear water courses 200.0 feet wide or larger• Bodies of water 4.5 acres or larger

Delineating Condition StatusDelineating Condition StatusThe rest of the condition classes can be any size:

• Denied access (Code 5)• Hazardous area (Code 6)• Area not in the sample (Code 7)• Lost subplot/condition data (Code 9)

Note: Only use the lost subplot/condition data for accessible forest conditions• Nonforest subplots are never lost • Record Condition Status code 2 for nonforest conditions

on a plot that has no past condition data

Delineating Condition StatusDelineating Condition StatusMajor change in determining the boundaries of accessible

forest conditions:• Nonforest conditions that are less than 120 feet

wide or less than 1.0 acre do not stop a forest land condition from continuing across the nonforest entity

• This includes developed nonforest entities like right-of-ways, even though they are delineated as a nonforest condition on the plot

• Also includes noncensus water courses between 30-120 feet wide, even though they are delineated as a nonforest condition on the plot

Delineating Condition StatusDelineating Condition StatusDefinitely

Forest

Road

UtilityLine

Forest?

Forest

Definitely Nonforest

90 feet

30 ft

25 ft

Delineating Condition StatusDelineating Condition Status

Limit on size of forest area between nonforest conditions:

• Individual pieces of forest conditions divided by nonforest land cannot be smaller than 30 ft x 120 ft

• These individual pieces have to be within 120 ft of forest land that is 120 ft wide and 1.0 acre

Delineating Condition StatusDelineating Condition Status

Developed Nonforest

Forest Piece

Forest land >120 ft and >1.0 acre

Delineating Condition StatusDelineating Condition StatusAnother major change in determining boundaries of

accessible forest land:

• Application of the 90 degree rule• When bisecting forested points that are less than

90 degrees, no distinct boundary line exists on the the ground

• Classify the entire subplot according to where the subplot center falls

• If subplot center lands in the side of the woods that is greater than 120 feet wide, then the whole subplot is forest

• If the subplot falls in the side of the woods that is less than 120 feet wide, then the whole subplot is nonforest

Delineating Condition StatusDelineating Condition StatusForest point with no distinct boundary. Location of subplot

center determines condition status of entire subplot. In this case, the whole subplot is forest:

This rule holds true if the forest and nonforest areas in the above diagram were reversed. In that case the subplot would be nonforest.

Step 2: Subdivide Accessible Step 2: Subdivide Accessible Forest LandForest Land

• Subdivide accessible forest land on the plot into smaller forest conditions due to differences in any of the following condition defining attributes:

1 Past Condition Status

• Past Condition Status is a new condition defining attribute • Codes are listed from highest to lowest priority

2 Reserved Status3 Owner Group4 Forest Type5 Stand Size Class6 Regeneration Status (formerly “Stand Origin”)7 Tree Density

Subdividing Accessible Forest Subdividing Accessible Forest (Status Code 1)(Status Code 1)

Major change to size requirement of within forest conditions:• Size of within forest conditions must now be 120 feet

wide and 1.0 acre

• Special size exemption for “riparian areas” – 30 feet wide and 1.0 acre

• Associated with water course or body of water

• Differ in at least one of the condition defining variables

• Must be within forest – 30 ft strip of woods associated with a river that runs through nonforest land is not a forest condition

Subdividing Accessible Forest Subdividing Accessible Forest (Status Code 1)(Status Code 1)

Addition of Past Condition Status to forest condition defining attributes:

• All reverted forest areas are recorded as separate conditions on the plot

• Regardless of size

• Regardless of similarity between all other forest condition defining attributes

• Must be within forest – 30 ft strip of woods in middle of a large pasture is not a forested condition

Step 3: Subdivide Nonforest LandStep 3: Subdivide Nonforest Land

Nonforest land conditions generally recorded as one condition

Census water still its own separate condition status and is always delineated on the plot

Change from previous manuals: • Noncensus water is its own separate condition status• Now it is always delineated on the plot from other

nonforest land conditions if present • Subdivide landcleared conditions (Past Condition

Status = Forest) from other nonforest conditions on the plot

Subdividing Nonforest Land Subdividing Nonforest Land (Status Code 2)(Status Code 2)

Nonforest land areas usually recorded as one condition

Example:• Both a road and pasture land are on the current plot• Both were nonforest at last inventory• Both areas are recorded as ONE nonforest condition

status

This procedure is NOT different than the previous manuals

Subdividing Nonforest Land Subdividing Nonforest Land (Status Code 2)(Status Code 2)

Exception to grouping nonforest land uses:• Landcleared areas• Regardless of size and width

Example:• Both a road and pasture land are on the current plot• Only the road was nonforest at the last inventory• The pasture land was forest at last inventory• These are recorded as TWO separate nonforest

conditions on the plot, because the pasture was landcleared

This procedure IS different from the previous manuals!

Boundary ChangesBoundary Changes

Do not map the following “indistinct” boundaries on a subplot:

• Do not map the 120 foot line on a subplot when bisecting a point that is less than 90 degrees

• Stand Size must be at least 2 classes apart for it to delineate separate conditions on a subplot

Forest area that narrows to a point with no distinct boundary. The whole subplot is forest. Initial, or replacement plots are

no problem. The whole subplot is forest.

GREEN AREA:Present LU = 01New Past LU = 01OLD LU is not recorded on

SK1 or 3 plots

SK 1 & 3 PlotsSK 1 & 3 Plots

SK 2 PlotsSK 2 Plots• On SK2 plots, the 120 foot line was mapped on the

subplot last survey

• Need to show the area on the subplot that switched land uses due to landclearing, reversions, and procedural change

• Record the same boundary as previous crew

• Combination of Present Land Use, New Past Land Use, and OLD Land Use will indicate the procedural change

• Record Similar Identified Condition Number

Forest area that narrows to a point with no distinct boundary. The whole subplot is forest. Last time the green area was forest

and the red area was nonforest. Record the old crew’s boundary. Red area is separate condition.

GREEN AREA:Present LU = 01New Past LU = 01OLD LU = 01

RED AREA:Present LU = 01New Past LU = 01OLD LU = NonforestRecord Similar Identified

Condition > 0

SK 2 PlotsSK 2 Plots

Questions?Questions?