SILVICULTURAL CONSIDERATIONS FOR RESTORATION & FUELS

TREATMENTS

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Discuss silvicultural principles related to restoration/fuels treatments

Compare conditions from the 1900 Cheesman Lake reconstruction to current project work.

◦ Comments apply to the Stand/Treatment level for 1 treatment entry.

◦ Recommended metrics apply to PSI treatments.

Objectives

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Regeneration (Reproduction) Method: A cutting method by which a new age class is created.

Stand Improvement: A term comprising all intermediate cuttings made to improve the composition, structure, condition, health, and growth of even- or uneven-aged stands.

Silviculture Terminology

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  Stand Density Index (SDI):

A relative measure of stand density that provides a relationship between stand basal area, trees per unit area, average stand diameter, and stocking of a forested stand (Reineke 1933).

The index is not influenced by age or site quality.

Residual Stand Relative Density

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Stages of Stand Development

Source: Oliver and Larson, 1990

25% RD 35% RD 60% RD

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Recommended Stocking Levels:Black Hills Ponderosa Pine

Gringrich stocking curves for ponderosa pine in the Forest Service’s Rocky Mountain Region (R2) (Forest Service Manual, R2 Supplement 2409.17-92-2 1992)

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Results:◦ Good seed crops produced

every 4-6 years.

◦ Predation by animals resulted in on 14% of total seedfall available for germination.

◦ Shelterwood Overstories between 25-60 BA over scarified seedbeds provided optimal conditions for natural seedling establishment.

Ponderosa Pine Regeneration Study

Shepperd et al. 2006

Long term study of ponderosa pine seedfall, natural regeneration, and seedling growth, 1981-2001, Manitou Experimental Forest

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Annual Avg Precip & Temp

USDA Forest Service General Technical Report RMRS-GTR-97. 2002

Black Hills

Rocky Mts & Southwest

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Density, structure, and species composition is highly variable by aspect.

Reconstructed stocking levels may be low due to:◦ Many of these plots burned severely in 1851.

◦ Mortality of pre 1900 trees was not factored in.

Cheesman Lake Study

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Riparian plot, 77 trees/ac, 57 BA

Cheesman Lake Study

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South plot, 65 trees/ac, 1 BA

Cheesman Lake Study

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Ridgetop plot, 32 trees/ac, 19 BA

Cheesman Lake Study

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West plot, 20 trees/ac, 5 BA

Cheesman Lake Study

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Cheesman Lake Study

North plot, 166 trees/ac, 36 BA

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Average Residual Basal Area = 60 sq. ft.

Phantom Creek 2

COVER TYPE RESIDUAL BA % PROJECT AREA

Aspen 20 5

Ponderosa Pine 50 40-50

Mixed Conifer 70 30-40

Douglas-fir 90 10-15

Spruce No Treatment <1%

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Phantom Creek 2

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Ponderosa pine stand, 46 trees/ac, 50 BA

Phantom Creek 2

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Phantom Creek 2

Mixed conifer stand, 73 trees/ac, 70 BA

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METRIC LOW HIGH

TPA (> 1.0 " dbh) 30 80

BA (sq. ft.) 40 60

% PP - Overstory (BA) 90 100

% DF - Overstory (BA) 0 10

CC (%) 15 25

CBD (kg/m¯³) 0.015 0.035

CBH (feet) 25 35

Age Classes Existing  

Understory Species %: TPA-seedlings Existing  Understory Species %: Shrubs, Forbs, Grasses Existing  

Noxious Weeds/Exotics Presence of  

Projected Metric Ranges: PSI

Ponderosa Pine Stands

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Projected Metric Ranges: PSI

Mixed Conifer: Ponderosa Pine/Douglas-fir

METRIC LOW HIGH

TPA (> 1.0 " dbh) 50 160

BA (sq. ft.) 60 80

% PP - Overstory (BA) 65 100

% DF - Overstory (BA) 0 35

CC (%) 15 25

CBD (kg/m¯³) 0.035 0.05

CBH (feet) 15 30

Age Classes Existing  

Understory Species %: TPA-seedlings Existing  Understory Species %: Shrubs, Forbs, Grasses Existing  

Noxious Weeds/Exotics Presence of  

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Comparison with Cheesman Data

Cheesman Basal Area (1900)

Basal area (ft2/acre)

0 10 20 30 40 50 60 70 80 90

Fre

qu

ency

0

2

4

6

8

10

12

Projected BA Distribution

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Comparison with Cheesman Data

Canopy base height (circa 1900)

X Data

0 1 2

feet

0

10

20

30

40

Projected CBH = 20-36

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Comparison with Cheesman Data

Canopy bulk density (circa 1900)

X Data

0 1 2

kg m

-3

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035Projected CBD = 0.019-0.046

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Treatments will result in a high level of variability for residual stand conditions within treatment areas.(density, structure, species composition, size classes)

Natural regeneration will occur at lower stand densities

Restoration ecology research should identify the target trend and range but may not be appropriate to assess precise post treatment conditions.

Target ranges must be wide enough to capture variation of major cover types in treatment areas:◦ For example: 40-80 sq. ft. of BA.

SUMMARY