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Regeneration of Tropical Rain Forest on New Britain Island, Papua New Guinea - Seiji Mori

Nissho Iwai Corporation, Japan

ABSTRACT

There is a marked decrease in tropical rain forest due to the increase in population especially in developing countries. Concessionaires of long term forest leases must, in their own interest, establish sustainable management in their leases. Reforestation will ensure and increase a constant supply of commercial raw material of acceptable species at reasonable cost. Studies in New Britain showed that the yield of commercial timber in managed reforestation is 10 times the yield of natural forest. This suggests sustainable development reforestation be carried out on at least 10% of the concession area; the remainder may be allocated to other end uses, e.g. agriculture, biodiversity protection, etc. The cost of reforestation and returns is examined and investment guidelines established. A 20 year cutting cycle is considered; the concession period must be long enough to harvest the reforested area; rights to the regenerated area need to be guaranteed; incentives be available in offsetting costs of investment on the provision of conversion facilities; further private investment be invited to participate in reforestation programs.

Key words: Papua New guinea, Eucalyptus deglupta, rain forest regeneration, sustainable management.

INTRODUCTION

It is expected that the world population will reach 10 billion by the middle of the next century. This figure represents four times as many people in the world as in 1945. Most of the increase in population will occur in developing countries, creating problems as the shortage of food, housing, fuel and widespread poverty.

The author worked in Papua New Guinea (PNG) for approximately ten years, January 1976 to May 1985 as a managing director of the timber company Stettin Bay Lumber Company (SBLC), located on New Britain island, also serving with the Forest Industries Council, PNG, as an executive member and vice chairman for nine years. He proposed to the government in 1977 that foreign owned timber companies be responsible for carrying out reafforestation for the purposes of sustainable management as a condition for the granting timber cutting permits This was registered under the new forest policy in 1979. The paper gives ideas on reforestation.

GENERAL BACKGROUND ON THE TROPICAL FOREST

Data of the situation of the global tropical forests, FAO 1981, is shown in Figure 1. In 1990 FAO warned that:

The main reason for the decrease in tropical forest area is the increase in population, especially in developing countries.

Figure 1. Tropical forest resources, 1981


Forest type

Tropical America

Tropical Africa

Tropical Asia

Total

Area of tropical forest (1980) Unit: million ha

Closed forest

679

217

306

1,201

Bush forest

217

486

31

734

Total

896

703

337

1,935

Annual deforestation rate Unit: 1,000 ha

Closed forest

4,340

1,330

1,830

7,500

Bush forest

1,270

2,340

190

3,800

Total

5,610

3,670

2,020

11,300

Deforestation caused by agriculture (%)


35

70

49

49

Total area (1980)

4,620

1,780

5,110

11,510

Manmade forest Unit: 1,000 ha

Annual planting (1981-85)

530

130

440

1,100

REFORESTATION: REASONS, METHODS AND RESULTS

After World War II, logging operations changed remarkably due to the development of heavy equipment. Once this equipment was applied to timber cutting operations in the natural forest, conditions there degraded rapidly. In addition to deliberate felling, young trees of small trunk diameter and regeneration replacements were destroyed by the machinery as well. At the same time the construction of wide logging roads and better working conditions due to the use of this heavy equipment, created employment opportunities and attracted more people to the timber industry. Heavy equipment related degradation of the forest also resulted in another problem; previously tropical forest regeneration under natural growth conditions occurred in 25 year cycles - it now requires 35-50 years for natural recovery.

As SBLC had obtained an industrial land lease for 99 years in PNG, sustainable management of the tropical forest is in its own best interest. Dependence solely on timber resources supplied by natural forest growth is not feasible for economic or sustainable reasons. In depleted areas, this would also increase log production costs due to the greater distances they must be transported. Reforestation helps to ensure and even increase, a constant supply of commercial and industrial timber, of the right species, at reasonable cost.

Most commercial wood for plywood and saw logs are from dominant species in the tropical rain forests, including lauan (meranti), apitong (keruin) and capore. Ecologically, however, they grow beneath shade intolerant species when young. These shade intolerant species have fast growth and a shorter life cycle than dominant species and are mostly of inferior commercial quality. As Japan imports a large quantity of tropical hardwood for plywood, there has been concern over the decreasing supply of resources - slow glowing dominant species. In order to obtain a steady, sustainable supply of tropical round wood without knots and good enough to produce plywood, an effort was made to select fast glowing species among these shade intolerant species. Thus, three species, ‘kamerere’ (Eucalyptus deglupta), ‘erima’ (Octomeles sumatrama) and ‘terminalia’ (Terminalia brassii) were selected by the author for PNG planting purposes. The species ecological characteristics and those of the log yard and sawmill were studied carefully, as neither erima nor terminalia had been planted in PNG at that time. Teak (Tectona grandis) was added as it is used as a decorative species for veneer and quality furniture.

The reforestation work as the first experimental phase began in 1975 and continued until 1978 with establishing 255 ha of kamerere. Subsequently in 1981, the other three species were added. Sample plots to observe growth and other factors were established in 1982. The detail field record of kamerere is attached in Annex I, because this is only one Eucalyptus species among others. However, their growth records are summarized in Figure 2, and estimated sizes and yields by the end of each cutting cycle are shown in Figure 3.

Figure 2. Growth records of four species by the end of 1992


Species

Age of trees (year)

Spacing (m)

Number of trees per ha

DBH (cm)

Height (m)

Standing

Ave. of top 80 trees

Stand average

Ave. of top 80 trees

Stand average

volume (m3/ha)

Eucalyptus deglupta (kamerere)

16

3 x 3

190

50.6

40.3

45.1

40.3

454

20

4 x 4

154

57.0

45.3

55.2

46.4

539

Octomeles sumatrana (erima)

9

4 x 4

432

39.6

28.1

32.5

25.7

356

10

5 x 5

374

43.7

32.8

33.1

29.2

451

Terminalia brassii (terminalia)

9

4 x 4

486

32.5

25.3

28.2

24.6

293

9

3 x 3

690

27.6

21.6

28.8

26.1

303

Tectona grandis (teak)

6

4 x 4

552

28.1

21.4

19.1

16.9

165

6

4 x 4

480

28.2

22.2

19.9

19.8

175

Figure 3. Estimated sizes and yields of planted trees by the end of cutting cycle

Species

Rotation (year)

Height (m)

DBH (cm)

Standing volume (m3/ha)

Log volume harvestable (m3/ha)

Utilisation as

Plywood & saw log

Pulp & fuel

Eucalyptus deglupta (kamerere)

20

50-60

60-75

400-500

300-400

Yes

Yes

Octomeles sumatrana (erima)

15

40-50

80-85

400-500

300-400

Yes

No

Terminalia brassii (terminalia)

20

50

65-75

400-450

300-400

Yes

No

Tectona grandis (teak)

25

40

65-70

400

300

Yes

Yes

HARVEST DATA

The volume recovered from the reforestation area is ten times higher than that of the natural forest. Logging cycle was approximately half that for the selective cutting applied in the natural forest. It should be, however, noted that these plantations were established in a volcanic ash soil area in the tropical rain forests of the island. It is assumed that there was no constraint in soil fertility.

Considering the increasing population and rising economic demand for logs, the PNG government should reforest 10% of the area where the selective cutting has been practiced. This means that the remaining 90% of natural forests could be remained in natural condition. These forests can be utilized either to produce slow growing hardwood timber or conserve biodiversity (plant, animal, bird and insect species) and environment. They can also provide enough spaces for traditional rural communities to live. A part of this area could also be used for staple food and cash crop cultivation, depending on the future social and economic development strategies and programmes of the country.

Estimated returns (cost and benefit in US$/m3) are calculated for each species in Figure 4, based on the growth rates recorded and estimated from the reforested area. Under the ratios of reforested areas with kamerere (67.3% of total area), erima (18.0%) terminalia (12.2%) and teak (2.5%), the overall average FOB selling price and average production cost are calculated as $102.50/m3 and $65.39/m3 respectively.

GOVERNMENT SUPPORTS

This presents an atractive investment in plantaion, but in the complex reality, the situation is quite different and hence the lack of investment from the private sector. Consequently, the need for incentives and government sipport in the context of plantation forestry becomes crucial. Therefore, the Government should provide the following guarantees to the national or foreign entrprise carrying out the reforestation:

The benefits of such arrangements for developing countries are numerous including:

CONCLUSIONS

Suggestions made to a reforestation workshop sponsored by the PNG Government in 1991 included that: i) assuming PNG has 50 million ha of land and 2% is volcanic ash soil area, there is 1 million ha available for reforestation. If plantation trees are replanted in a 20 year cutting cycle, the annual harvest area will be about 50,000 ha, giving an annual estimated harvest volume of 15 million m3, which is almost the same as that of Sarawak. The converted value of FOB log exports is expected to be about US$1.5 billion which is almost equal to the annual budget of the PNG Government.

It is, therefore, recommended that the PNG Government invite overseas investors to participate in reforestation projects while giving guarantees for the security of investment. It is essential for the Government, ODA and private enterprises to work together for wisely utilizing the country’s tropical forests resources in an environmentally sound and sustainable manner. It is to be hoped that both developing and developed countries jointly promote reforestation to conserve the tropical rain forests and their forest ecosystems and meet a demand for progressing social and economic development.

GROWTH CONDITION OF KAMARERE (1990/1991/1992) (1/4)

GROWTH CONDITION OF KAMARERE (1990/1991/1992) (2/4)

GROWTH CONDITION OF KAMARERE (1990/1991/1992) (3/4)

GROWTH CONDITION OF KAMARERE (1990/1991/1992) (4/4)

March 19, 1993
NISSHO IWAI CORP. (S. MOR I)


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