Sri Nugroho MARSOEM*, Joko Sulistyo, Vendy Eko Prasetyo, Puput Prasetyo

(Fac. of Forestry, Universitas Gadjah Mada)

Introduction

The role of community forest as a source of woody material (forest products) is becoming more and more important.

Various commercial as well as lesser used species are growing on the forest.

Popohan (Buchanania arborescens (BL) BL) is one of the lesser used tree species found relatively a lot in the community forest but it is valued low. This is because the information related to the properties of the wood is still limited.

Objective The objective of this study is to collect information

related to the properties of the wood in the stem of popohan trees and its variability.

Local & Botanical Name Popohan has various local name:

Sparrow’s mango (England) ; Cha muang and Luaet khwai (Thailand) Rengas laut (Malaysia)

Divisio : Spermatopyta Sub Divisio : Angiospermae Kelas : Dicotyledoneae Ordo : Sapindales Famili : Anarcadiaceae Genus : Buchanania Spesies : Buchanania arborescens (BL) BL

Material & Method Trees of Popohan were obtained from

the community forest in Wonolopo, Sanden, Jetis, Bantul Regency, Yogyakarta province

Located at 07o44'04" - 08 o 00'27“ South and 110 o 12'34" - 110 o 31'08“ East.

Soil type : regosol

Altitude: 25 – 100 m a.s.l

Material & Method Three healthy trees of popohan were firstly

measured its girth at breast height and then felled. After felling the trees were then measured its

height, and the free branch stem of the trees were then divided into three parts i.e bottom, middle, and top.

Cell proportion, cell dimensions, physical and mechanical properties of the woodwere observed at each part as well as at different radial position of the stem.

Physical and mechanical properties of the wood in each part of the stem were measured according to British Standard 373: 1957. Physical properties were measured continuously from pith to bark while mechanical were measured at three different radial position of the stem i.e near the pith, between pith and bark, and near the bark. Tree

No Height ( m)

Free Branch

Height ( m)

Canopy ( m)

DBH ( cm)

1 17.2 7.1 9.6 28.79

2 17.2 8.2 8.4 25.96

3 18.8 10.2 12.0 37.58

All physical and mechanical properties were conducted following British Standard BS 373 in the air-dry condition.

Free branch boles were bucked into three parts i.e. bottom, middle and top.

Physical Properties

Mechanical Properties

Materials and Methods

British Standard BS 373 in the air-dry condition.

1. Moisture Content & SG (2x2x2 cm) 2. Shrinkage & Swelling (2x2x4 cm)

3. CS // grain (2x2x8 cm) 4. CS ┴ grain (2x2x6 cm) 5. Bending (2x2x30 cm)

N

S 1

2

N

S

3

4

5

6

Physical properties

Mechanical properties

Materials and Methods

Results & Discussion

Sapwood has a creamy pale color

Heartwood with a reddish color can be easily distinguished from its sapwood

Anatomical Features of Popohan Wood

Notes :

•1 : Rays

•2. Vessels

•3. Parenchyma

•4. Fiber

1

3

2

4

1

3

2

4

4

1

3

2

Transverse Section of Popohan

Anatomical Properties

Parameter Significant

Interaksi Aksial Radial

Fiber Proportion 0,064 ns 0,031 * 0,000 **

Vessel Proportion 0,924 ns 0,261 ns 0,000 **

Rays Proportion 0,118 ns 0,057 * 0,003 **

Parenchyma Proportion 0,997 ns 0,175 ns 0,000 **

Fiber Length 0,962 ns 0,656 ns 0,000 **

Fiber Diameter 0,850 ns 0,150 ns 0,003 **

Lumina Diameter 0,914 ns 0,420 ns 0,031 *

Cell Wall Thickness 0,361 ns 0,000 ** 0,000 **

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

Serabut Pembuluh Jari-Jari Parenkim

50.29

12.70 24.31

12.70

59.28

8.01

21.81

10.90

65.15

7.50

18.4

8.95

Ce

ll P

rop

ort

ion

(%

)

Jenis Sel

Cell Proportion Near Pith, Middle and Near Bark

Dekat Hati

Tengah

Dekat Kulit

17,88

9,9

-36,93 -6,37

-10,28 -15,64

-14,17 -17,89

Cell Proportion at Various Radial Position

0

10

20

30

40

50

60

70

Serabut Jari-Jari

60.17

19.62

57.86

21.5

56.68

23.39

Ce

ll P

rop

ort

ion

(%

)

Cel Type

Fiber and Rays Proportion at Axial Position

Pangkal

Tengah

Ujung

-3,99 -2,08

9,58 8,79

Fiber and Rays Proportion at Axial Position

0

5

10

15

20

25

Panjang Serat (x10 ־¹ mm)

DiameterSerat (µm)

Tebal Dinding Serat

(x10 ־¹ µm)

DiameterLumen (µm)

8.60

16.67

18.80

12.90 10.30

16.87

20.40

12.79 10.70

18.69

22.50

14.19

R

Dekat Hati

Tengah

Dekat Kulit

-Fiber Length 0,99 mm -Fiber Diameter 17,41 µm

-Cell Wall Thickness 2.06 µm

-Lumina Diameter 13,29 µm

19,38 4,55

1,2 10,79

-0,85

10,95

8,51

10,29

Fiber Dimension at Radial Position

1.80

1.85

1.90

1.95

2.00

2.05

2.10

2.15

2.20

2.25

2.25

1.97 1.95

Ce

ll W

all T

hic

kne

ss (

µm

) Bottom, Middle and Top

Pangkal

Tengah

Ujung

-12,44 -1,02

Cell Wall Thickness at Axial Position

Statistical Analysis on Physical Properties

Parameter Significant

Interaction Axial Radial

Green MC 0,948 ns 0,764 ns 0,005 **

Air Dry MC 0,543 ns 0,000 ** 0,019 *

Green Specific Gravity 0,605 ns 0,004 ** 0,098 ns

Air Dry SG 0,367 ns 0,001 ** 0,079 ns

Oven Dry SG 0,345 ns 0,002 ** 0,048 ns

Longitudinal Shrinkage Green – AD 0,987 ns 0,775 ns 0,184 ns

Tangential Shrinkage Green – AD 0,716 ns 0,33 ns 0,367 ns

Radial Shrinkage Green – AD 0,976 ns 0,647 ns 0,971 ns

Longitudinal Shrinkage Green – OD 0,991 ns 0,928 ns 0,232 ns

Tangential Shrinkage Green – OD 0,126 ns 0,021 * 0,784 ns

Radial Shrinkage Green – OD 0,951 ns 0,516 ns 0,791 ns

Longitudinal Swelling OD – Green 0,991 ns 0,602 ns 0,255 ns

Tangential Swelling OD – Green 0,035 * 0,002 ** 0,484 ns

Radial Swelling OD – Green 0,944 ns 0,459 ns 0,841 ns

Moisture Content and Specific Gravity Radial Distribution Characteristics at

Popohan Stem

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0

20

40

60

80

100

120

140

160

Mo

istu

re C

on

ten

t (%

)

MC & SG Radial Distribution of Popohan

MC

SG

0.50 0.46

0.47

2.25 1.97 1.95

0.6017

0.5786

0.5668

0.54

0.55

0.56

0.57

0.58

0.59

0.6

0.61

0.00

0.50

1.00

1.50

2.00

2.50

Pangkal Tengah Ujung

Fib

er

Pro

po

rtio

n (

x10

² %

)

SG &

Ce

ll W

all T

hic

ne

ss

SG, Cell Wall Thickness, and Fiber Proportion at Axial Position

BJ Segar

Tebal DindingSerat (µm)

Proporsi SelSerabut (x10²%)

-8 2,17

-12,44 -1,02

-3,84

-2,04

SG, Cell Wall Thickness and Fiber Proportion at Axial Position

Parameter Significant

Interaksi Aksial Radial

Stress at the Proportional Limit 0,551 ns 0,448 ns 0,697 ns

Static Bending MoE 0,933 ns 0,874 ns 0,022 *

Static Bending MoR 0,772 ns 0,582 ns 0,134 ns

Compression Strength // Grain 0,332 ns 0,295 ns 0,332 ns

Compression Strength ┴ Grain 0,586 ns 0,005 * 0,924 ns

Tangential Surface Hardness 0,573 ns 0,601 ns 0,798 ns

Radial Surface Hardness 0,383 ns 0,758 ns 0,588 ns

Shearing Strength // Grain 0,657 ns 0,300 ns 0,877 ns

Statistical Analysis on Mechanical Properties

46.39

70.25 64.15

0.47

0.50

0.49

0.45

0.46

0.47

0.48

0.49

0.50

0.51

0.52

0.53

0

10

20

30

40

50

60

70

80

Dekat Hati Tengah Dekat Kulit

SG

Mo

E (x

10

³ k

g/c

m²)

Relationship Between MoE and SG at Radial Position

MoE

BJ

Species MoE (x10³ kg/cm²) SG

Popohan (Buchanania arborescens (BL) BL) 60,3 0,48

Meranti Merah (Shore Stenoptera) 67 0,49

Kayu Hujan (Enggelhardia spicata Lechen ex Blume 68,8 0,46

Mendarahan (Myristica langipes Warb) 107 0,47

51,43

-8,68

13,55

-1,82

Popohan as Compare to Other Species

146.66

118.03 117.48 0.50

0.46 0.47

0.42

0.44

0.46

0.48

0.50

0.52

0

20

40

60

80

100

120

140

160

Pangkal Tengah Ujung

BJ

(kg/

cm²)

Hubungan Tekan Tegak Lurus Serat Dengan BJ Kedudukan Aksial

Tekan TegakLurus Serat

BJ Segar

Species

Compression Perpendicular to Grain (kg/cm²)

BJ

Popohan (Buchanania arborescens (BL) BL) 127,39 0,48

Mendarahan (Myristica langipes Warb) 82,27 0,47

Kayu Hujan (Enggelhardia spicata Lechen ex Blume 75,84 0,46

Bayur (Pterospermum elangatum) 80,12 0,45

-19,52 -0,47

0,76

-8

Relationship Between Compression Strength and Specific Gravity at Axial Positions of Popohan Stem Wood

Popohan Trees with a High Growth Stress

-3000

-2000

-1000

0

1000

2000

3000

14 13 12 11 10 9 8 7 6 5 4 3 2 1 15 16 17 18 19 20 21 22 23 24Srai

n µ

m

Bark Pith Bark

Growth Strain Radial Distribution at Popohan Stem

Popohan1

Popohan2

Popohan3

• Based on the value of Specific Gravity, Static Bending and Compression Strengths , popohan wood belong to strength class III – IV.

• Axial and radial variation affect significantly on anatomical, physical as well as mechanical properties of popohan wood growing on Community forest in Bantul, Yogyakarta.

• Popohan has a high growth stress that caused severe defects in the timber

CONCLUDING REMARKS

Arigato gozaimashita