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Tree GradingTree Grading

Why Tree Grading?

Provide a consistent estimate of tree quality

Provide a consistent estimate of stand value

Provide a more realistic estimate of stumpage value based on grades and lumber prices

Provide a linkage between the standing tree and lumber content by lumber grade

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Lumber Yield by Tree GradeLumber Yield by Tree Grade

Grade 1 Grade 2 Grade 30

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Grade 1 Grade 2 Grade 3

High

Low

%Yield1-com& Btr.

Tree Grade

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Tree Grading -- What's ImportantTree Grading -- What's Important

Tree grading focuses in on the tree characteristics that are most directly correlated with the grade of the lumber cut from that tree. Tree grading only considers the butt log of the tree since that is where the highest lumber grades are usually found.

1. Size -- dbh and dib at the top of the grading section

2. Clear Cuttings -- the total length of allowable clear cuttings on the second worst face of the grading section.

3. Cull Deductions -- the percentage of volume deducted for sweep and crook and the percentage of volume deducted for sweep, crook, and rot combined.

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Tree Grading -- How To Do ItTree Grading -- How To Do It

1. Find the best 12-ft grading section in the butt 16-ft log.

2. Determine the grading face of the grading section (i.e. the second worst face of the grading section).

3. Determine the dbh and dib at the top of the grading section.

4. Determine the total number of clear cuttings (portion that is free of defects and extends the width of the face) in the grading face.

5. Determine the amount of deductions for sweep, crook, and rot.

6. Use tree grading key.

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