FVSRegenerationImputation

Don Vandendriesche

USDA Forest ServiceForest Management Service Center

Growth and Yield Group

- Regeneration Imputation

• To impute implies the assignment of something to another.

• The process calls for querying existing data sets for representative stand types and tabulating their seedling/sapling component.

- Regeneration Questions

Relative to stand conditions …

• Quantity ~ Seedling Count?

• Quality ~ Species Composition?

Regeneration Imputation Methods

Colville-Okanogan-Wenatchee National Forests

- Spatial Data: 5.6 million acres

- Inventory Data: CVS

Topics

I. Ground Rules

II. Pattern Revelation

III. Repute the Program

IV. Prorating Multipliers

V. West vs. East

I. Ground Rules

• Established seedlings generally have an acceptable minimum girth and height that indicates having a root system firmly entrenched in mineral soil.

• Vegetation states are described as a composite of size and density classes. Size is based on QMD. Density is based on canopy cover.

- Ground Rules• Tally 2” saplings

- {1” – 3” diameter, ~ 10’ height}

• Bracket Tally by 5” size class- {0-5”, 5-10”, 10-15”, 15-20”, 20-25”}

• Bracket Tally by 30% canopy cover- {10-40%, 40-70%, 70%+}

II. Pattern Revelation: “½ - Rule”

- Pattern Revelation: “½ - Rule”

III. REPUTE the Program

• REPUTE embodies the concept of Regeneration Imputation.

• REPUTE reads the ‘Stand Table’ output files from the FVSSTAND program to develop regeneration keyword component files.

Grand fir

TREES AVG AVG /AC DBH HGT 30.095 1.83 13.6

DIA. CLASS 2.

Natural 0 Parms(GF, &((30.095*_SAPX)* &

IV. Prorating Multipliers

• The REPUTE program produces an average representation of the strata. This condition depicts the average size and density class.

• Proportioning the 2” saplings by size/density class based on shade tolerance renders multiplicative factors that can be used in conjunction with REPUTE.

7.5 QMD12.5 QMD

17.5 QMD22.5 QMD

10-40% CC

40-70% CC

70%+ CC

0

50

100

150

200

250

300

350

CV

S P

lots

Colville-Okanogan-Wenatchee Plot Distribution

Different species that have a higher tolerance to shade soon become established beneath the pioneers.

- Shade ToleranceIntolerant:Western larchLodgepole pinePonderosa pine

Mid-Tolerant:Western white pineDouglas-fir

Tolerant:Grand firSubalpine firEngelmann sprucePacific silver firWestern Redcedar

- Size Class Multipliers

7.5 QMD12.5 QMD

15.5 QMD22.5 QMD

Very Intolerant

Intolerant

Mid Tolerant

Tolerant

Very Tolerant

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50S

ize

Cla

ss M

ultip

lier

- Canopy Cover Multipliers

10-40%CC

40-70%CC 70%+ CC

Very Intolerant

Intolerant

Mid Tolerant

Tolerant

Very Tolerant

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

Can

opy

Cov

er M

ultip

lier

- Trial Results: Intolerants

7.5 QMD12.5 QMD

15.5 QMD22.5 QMD

Measured

Trial0

20

40

60

80

100

120

2"

Sa

plin

gs

40-70% Canopy Cover

7.5 QMD12.5 QMD

15.5 QMD22.5 QMD

Measured

Trial0

50

100

150

200

250

2"

Sa

plin

gs

40-70% Canopy Cover

- Trial Results: Mid Tolerants

7.5 QMD12.5 QMD

15.5 QMD22.5 QMD

Measured

Trial0

10

20

30

40

50

60

70

80

2"

Sa

plin

gs

40-70% Canopy Cover

- Trial Results: Tolerants

7.5 QMD12.5 QMD

15.5 QMD22.5 QMD

Measured

Trial0

50

100

150

200

250

300

350

400

2"

Sa

plin

gs

40-70% Canopy Cover

- Trial Results: All Shade Tolerances

V. West vs. East

Mark Twain National Forest

- Spatial Data: 1.5 million acres

- Inventory Data: FIA

7.5 QMD12.5 QMD

17.5 QMD22.5 QMD

10-40% CC

40-70% CC

70%+ CC

0

50

100

150

200

250

300

350

CV

S P

lots

Mark Twain Plot Distribution

7.5 QMD12.5 QMD

17.5 QMD22.5 QMD

10-40% CC

40-70% CC

70%+ CC

0

50

100

150

200

250

FIA

Plo

ts

- Pattern Revelation: “½ - Rule”

New Regeneration Paradigm

"move towards a full regenerationestablishment model for all variants"

Questions?