crown-condition classification tutorial (revised january 2008)

Crown-Condition Classification Tutorial

(Revised January 2008)

To assess tree vigor and growth potential Early warning sign of tree health deterioration Crowns form the structural architecture of forests Crowns influence understory flora and fauna To assess individuals, ecosystems, states, regions

Why Crowns?

Crown Variables

Uncompacted Live Crown RatioCrown PositionCrown Light ExposureCrown DensityCrown DiebackFoliage TransparencySapling Vigor Class

Size Classes of Trees

Seedlings <1.0-inch DBH/DRC

Saplings 1 inch to 4.9 inches DBH/DRC

Trees 5 inches + DBH/DRC

Crown Variables Both Saplings and Trees

Uncompacted Live Crown Ratio Crown Position Crown Light Exposure

Trees Only Crown Density Crown Dieback Foliage Transparency

Saplings Only Crown Vigor Class

FIA Plot Configuration

Subplot-trees

Microplot-saplings

Macroplot-trees

Definitions Live branch

Woody lateral growth supporting foliage and larger than 1 inch at the base just above the swelling where it joins the main stem.

Definitions

TwigWoody lateral growth with secondary branching and less than 1 inch in diameter at the point of attachment to a branch or crown stem.

Definitions

SprigWoody or non-woody lateral growth without secondary branching and less than 1 inch.

Definitions

Snag branchDead upper crown branches without fine twigs.

Definitions

Epicormic branchesWoody or non-woody lateral growths, usually on the bole or crown stem and initiated by sudden exposure or loss of crown stem.

Definitions

Crown Outline

Exclude abnormally long branches

Outline

Definitions

Crown Top

Crown Top

Definitions

Obvious Live Crown

Obvious Live Crown Base Crown

Base

Obvious Live Crown

Crown Base

Definitions

Live Crown Base, Saplings

> 5 feet

Definitions

5-ft Rule

Point 1

Point 2

Point 1

Point 2

Definitions

5-ft Rule

< 5 ft

Quality Crown Measurements Require… A calibrated eye A positive attitude Good weather and daylight 2 certified crown raters working as a crew

Viewing the Crown

Get Two Separate Views Of Every Crown!

Viewing the Crown

½ to 1 tree length away

View from grade level or upslope

90o

Separate the subject from other trees

Rate the whole crown, not just the easiest part to see

Viewing the Crown

Viewing the Crown

DON’T stand under the tree to make your ratings.

DON’T stand at 180o from your partner.

Field Aid

Useful for…

Live Crown Ratio

Crown Density

Foliage Transparency

Both Saplings and Trees Uncompacted Live Crown Ratio Crown Position Crown Light Exposure



Crown Variables

Uncompacted Live Crown Ratio

X

Y

ULCR = X/Y(100)

X

Y


Determine the LIVE TOP of the tree (dieback & dead branches excluded)

Establish the OBVIOUS LIVE CROWN BASE

Determine the ACTUAL LENGTH of the tree (same as defined in the Phase 2 field guide)

Express the length of the Obvious Live Crown as a PERCENTAGE of the Actual Length

Agree on best answer with your partner or average and record to the nearest percent


For trees:

The Obvious Live Crown includes foliage and branches down to the lowest foliage of the lowest 1-inch branch.


<5 feet; include

>1 inch >5 feet; exclude

New Live

Crown Base

For trees:

The 5-foot, 1-inch rule


>5 feet, >1 inch

ULCR = 50 - 75%?

?

?

?

?

Include leafed twigs

50%

75%

Exclude sprigs

35%

For saplings:

The Obvious Live Crown includes twigs, but not sprigs.


XYX/Y(100)

Obvious Live Crown (X) excludes dieback.

Actual Length (Y) includes dieback.


Epicormic branches:

If tree or sapling crown contains only epicormics, ULCR = 00


Crown Position

The relative position of each tree in relation to the main overstory canopy

Four Codes:• Superstory• Overstory• Understory• Open Grown

Overstory Canopy Zone

Average Live Crown

Lengths of

overstory trees

Crown Position

2

2 2

2 2

3

3

1

midpoint

Crown Position

Open Canopy:

All saplings and trees coded 44

4

4

4

Crown Position

All coded 4

<50% crown cover, > 1 acre in size

Scattered

Clumped

Crown Position

2 Conditions (> 1 acre in size)

>50% crown cover 1=Superstory (Never for saplings) 2=Overstory 3=Understory

<50% crown cover 4=Open grown (all saplings/trees)

Crown Light Exposure

The number of sides of a crown (including the top) that receive sunlight when the sun is directly overhead.


In this case, the code for exposure would be 2


ULCR = 25%

Code as 1


5403 1 2




Crown Variables

Codes for 5-percent Classes

Crown density, crown dieback and foliage transparency…

00 No Crown 05 1-5% 10 6-10% 15 11-15% … … 99 96-100%

Crown Density

The amount of crown branches, foliage, and reproductive structures that block light visibility through the crown

Crown Density

Crown Density

plywood

Density: 100%

Crown Density

Density: 50%

Crown Density

Density: 25%

Crown Density

Density: 55%

Crown Density

Density: 35%

Crown Density

Dead, no density estimate necessary!

Density: 20%

If there was some green, then….

Crown Density

Oval shapeDensity 65%

Crown Density

Conical shape

Density 80%

Crown Density

Fan-shaped crown

Density 75%

Crown Dieback

Recent mortality of branches with fine twigs

Begins at the terminal portion of a branch and proceeds downward and inward towards the crown stem

Only considered when in the upper and outer portions of the crown

Crown Dieback

Crown Dieback

•Must be recent•Fine twigs attached

Crown Dieback

Dieback?

Exclude coarse, stubby dead branches

Crown Dieback

Crown Dieback

Dieback: 15%

Crown Dieback

Dieback: 25%

Crown Dieback

Dieback: 75%


The amount of skylight visible through the live, normally foliated portion of the crown


Transparency Outline

Defoliation


Transparency 20%


Transparency 25%


Transparency 5%


Transparency 10%


Transparency 20%


Transparency 50%


Transparency 15%

Ignore dieback


Ignore Dieback

Include Defoliation

Complete defoliation =99 (not 0!)

•Transparency 70%

Crown Outline for Density

Include dead branches, dieback and/or missing top

Include gaps

for symmetry

Crown Outline for DiebackInclude live foliage and recent dieback

Crown Outline for TransparencyInclude live foliage only

Crown Outline for TransparencyIf large gaps, average transparency across foliated segments




Crown Variables

3 Crown Vigor Classes: Vigor Class 1 – High Vigor Class 2 – Moderate Vigor Class 3 – Low

Sapling Vigor Class

Rating Factors: Uncompacted Live Crown Ratio Dieback Percent Normal Foliage

Normal foliage Individual leaf has > 50% of the surface area present and free of damage

Sapling Vigor Class

Sapling Vigor Class

Abnormal foliage Individual leaf has < 50% of the surface area present and free of

damage.

Sapling Vigor Class

Abnormal foliage Dead leaves count as abnormal foliage Recent dieback counts as abnormal foliage

Sapling Vigor Class

50% Normal foliage

Sapling Vigor Class

95% Normal foliage

Sapling Vigor Class

Vigor Class 1 > 80% normal foliage ULCR > 35% < 5% dieback

Vigor Class 2 > 20% normal foliage (can have any ULCR; may or may not have

dieback)

Vigor Class 3 < 20% normal foliage (can have any ULCR; may or may not have

dieback)

Sapling Vigor Class 1

ULCR > 35%

< 5% dieback

>80% normal foliage

50% ULCR

35% ULCR

Dieback < 5%


< 20% normal foliage

Dieback = abnormal foliage


> 20% normal foliage

Dieback

Normal Foliage: 100% ULCR: 40%

Dieback: 0

Vigor Class: 1

Sapling Vigor Class


Dieback: 50%

Vigor Class: 2

Sapling Vigor Class

Sapling Vigor Class


Dieback: 5%

Vigor Class: 3

Special Situations

Special Situations

Leaning Trees• Live Crown Ratio

Special Situations

Leaning Trees• Crown Density

Special Situations

Leaning Trees• Crown Position• Crown Exposure

Special Situations

Forked Trees• Crown Density

Special Situations

Dead Top• Included in ULCR• Included in Density Outline

denominator of ULCRActual Length used in

Special Situations

Missing Top• NOT included ULCR• Included in Density Outline

Actual Length used in

denominator of ULCR

Coding for trees/saplings with only epicormics or sprigs:

ULCR = 00 Light Exposure = 0 Position = 3 (or 4) Density = 00 Dieback = 99 Transparency = 99

Special Situations

Special Situations

Species with delayed development of 1-inch branches:

•These small branches are

part of the obvious live

crown (i.e., not epicormics)

•5-ft. rule may be applied

Crown Variable Tolerance MQO

Uncompacted Live Crown Ratio Crown Density Crown Dieback Foliage Transparency

+- 10% 90%

Crown Light Exposure +-1 if >0 85%

Crown Position 0 85%

Sapling Crown Vigor 0 90%

Measurement Quality Objectives (MQO’s)

Crown Indicator Homepage

Crowns Home

Methods

DataAnalysisData QualityTraining MaterialsPublicationsAdditional LinksContacts

http://srsfia2.fs.fed.us/crowns/index.shtml

crown-condition classification tutorial (revised january 2008)

Documents

loss of crown stem

tree vigor

tree length awayview

inch branch

actual length y

main stem

point of attachment

lowest foliage