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Florida 4-H Forest Ecology

Florida 4-H Forest Ecology

Tree Measurement

NEW as of March 3, 2022: The instructions and scoring for the Senior Tree Measurement Station at the 2022 4-H Forest Ecology Contest have been revised. Please read below for details.

Seniors will measure 4 standing trees and fill out the table below. For each tree, seniors will identify the species and estimate the diameter and merchantable height. Diameter should be measured and recorded in even 2-inch diameter classes. Height should be measured in 16-foot logs to the nearest full half-log. Merchantable height should be measured from stump height to either an 8-inch top diameter, a major fork, or a serious defect that affects more than half the tree's diameter at that point.

In addition, Seniors will determine the total volume in the plot and the volume per acre. Ten points will be allowed for the correct volume per acre. The plot acreage and tree volumes can be found in the table below. Remember, the total volume in the plot must be multiplied by a factor (20 for a 1/20-acre plot, 10 for a 1/10- acre plot, 5 for a 1/5-acre plot and 4 for a 1/4-acre plot) to determine the volume per acre. Point allocation will be 10 points for ±5% of the official volume, 8 points for ±10%, 6 points for ±15%, and no points over ±15%.

Tree volumes can be found on the table below, which will be provided on the contest scoresheet.

Volume Table

International ¼ inch Log Rule -- Form Class 78

VOLUME (board feet) BY NUMBER OF 16-FOOT LOGS

 

Height (number of 16-foot logs)

DBH

1

1½

2

2½

3

3½

4

4½

5

10

36

48

59

66

73

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12

56

74

92

106

120

128

137

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14

78

105

132

153

174

187

200

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16

106

143

180

210

241

263

285

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18

136

184

233

274

314

344

374

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20

171

234

296

348

401

440

480

511

542

22

211

290

368

434

500

552

603

647

691

24

251

346

441

523

605

664

723

782

840

26

299

414

528

626

725

801

877

949

1,021

28

347

482

616

733

850

938

1,027

1,114

1,201

30

403

560

718

854

991

1,094

1,198

1,306

1,415

32

462

644

826

988

1,149

1,274

1,400

1,518

1,637

34

521

728

934

1,119

1,304

1,447

1,590

1,727

1,864

36

589

826

1,063

1,274

1,485

1,650

1,814

1,974

2,135

38

656

921

1,186

1,428

1,670

1,854

2,038

2,224

2,410

40

731

1,030

1,329

1,598

1,868

2,081

2,294

2,494

2,693


Scoring

A total of 30 points are available for this station:

  • 20 total points for tree scores: 
    • One point for each correct tree identification
    • Two points for each correct DBH
    • Two points for each correct tree height
  • 10 points possible for volume per acre: Point allocation will be 10 points for ±5% of the official volume, 8 points for ±10%, 6 points for ±15%, and no points over ±15%.

You will need a Biltmore stick that fits your arm length. You can make your own Biltmore stick by purchasing a yard stick or a blank stick or strip of wood, and taping a scale to your stick.

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