Johan J Möller, Nazmul Bhuiyan, John Arlinger, Björn Hannrup, Maria Nordström

Estimating thinning results based on standardized harvester data

The aims of automatic thinning follow up based on harvester data is to:

• improve the quality of thinning

• generate data for updating stand registers

• decrease costs and increase total productivity

Content of presentation

1. Describe StanForD 2010 data used in the system

2. Describe the model used for thinning follow up

3. Present result from test and validation of methods

Tree Species DBH X Y Crane angel

1 Spruce 330 6347115 1481603 25

Structure of harvester data according to StanForD 2010 – individual data - hpr

Recreating stems step 1

Tree Species DBH X Y Crane angel

1 Spruce 330 6347115 1481603 25

Structure of harvester data according to StanForD 2010 – individual data

Tree Species DBH X Y Bio adapted

1 Spruce 330 6347115 1481603 1

Tree Log Assortement Top diameter

Mid diameter

Length

1 1 Saw timber 271 302 553

1 2 Saw timber 233 252 432

1 3 Saw timber 196 212 512

1 4 Small timbr 165 178 342

1 5 Pulp 95 132 491

0

500

1000

1500

2000

2500

3000

Recreating stems step 2Tree heigth, cm

Forest is re-created…………our the felled forest….

Heigth segmentation

0

20

40

60

80

100

120

6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38

Felled trees

Pine Spruce Leave

Trees (no)

DBH (cm)

cv

cv

12.3 m2/hectar

597 stems/ hectar

74.8 m3/ hectar

15°

Crane angel

- 45°

Thinning quotient = DBH felled trees/ DBH remaning trees

+/- 30°

- 30° 30°

Thinning quotient

0.88

DBH (cm)

Share (%)

Crane angel

1. Decide the allowed basel area per hectaraccording to statistics

2. Calculating share of cutting per DBH according to thinning quotient

3. Calculating key figure for remaining stand afterthinning

2. Model - calculation of stand data after thinning

0

5

10

15

20

25

5 10 15 20 25

Bas

al a

rea

(m

2/

he

cta

r)

Heigth (m)

Model – allowed basal area after thinning

Spruce

0

20

40

60

80

100

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38

DBH (cm)

Felled stems share per DBHIntensity (%)

Thinning quotient

0.88

0

20

40

60

80

100

120

6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38

Prognosis after thinningTrees (no)

DBH (cm)

0

20

40

60

80

100

120

6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38

Prognosis after thinningTrees (no)

DBH (cm)

Basal area (m2/ hectar)

Heigth m)

20,2 m2/hectar

761 stems/ hectar

130 m3/ hectar

Practical test with 14 harvester

All over Sweden

• 50 first thinnings

• 10 later thinnings

Study

Manual reference measurements Harvester data

Prognosis after

0

5

10

15

20

25

30

35

40

45

50Th

inn

ing

inte

nsy

ty(%

)Manuell mätning Skördarprognos

Thinning intensity

First thinning

Manual measuring: 33,7 %

Harvester prognosis: 33,0 %

Standard dev. 2,9 %

Second thinning

Manual measuring: 25,9 %

Harvester prognosis 25,0 %

Standard dev. 2,8 %

Manuel measuring Harvester prognosis

0

50

100

150

200

(m3/h

ecta

r)

Manuell mätning Skördarprognos

Second

164,5 m3/ha

168,2 m3/ha

13,4 %

Volume after thinning

First thining

Manual measuring: 127,2 m3/ha

Harvester prognosis: 129,9 m3/ha

Standard dev.: 13,0 %

Manuel measuring Harvester prognosis

Diameter

0

50

100

150

200

250

300

Dia

metr

e(m

m)

Manuell mätning

Skördarprognos 2014

Manuel measuring: 190 mm

Harvester prognosis: 190 mm

Standard dev. 8 mm

Manuel measuring

Harvester prognosis

• New system for thinning follow up is established

• Good result from validations

• Today 250 harvesters using the functions in onboard computer

(January 2017)

• Implemented in first company systems (autumn 2016)

• New project is establish for futher development

Summary