Soekotjo and Eka Kusdiandra Wardhana

Faculty of Forestry, Gadjah Mada University, Yogyakarta 55281 Indonesia

Phone/Fax: 62-274-545639, E-mail: itto-gmu@yogya.wasantara.net.id

Abstract

Tropical rain forest in Indonesia is increasingly degraded at the rate estimated at about 2 millions hectare per year. The Government of Indonesia has placed much emphasis on the reforestation of degraded forest. The target is to establish commercial plantation, and this could be considered as one of the national priorities. In the long term, future supplies of forest products will increasingly come from commercial plantations, and commercial forest plantation will help Indonesia to relive pressure on and save the remaining natural forests. The ideal commercial forest plantation is to place the right species in the right site with the right growing space at each state of development. Twenty potential dipterocarp species were screened and tested in five replications by using randomized cComplete block design at test plantation. Preliminary findings indicated that the growth rate of the tested dipterocarps species could be grouped into slow, medium and fast. Four out of 20 species tested in PT. Sari Bumi Kusuma Forest Company had the fastest growth rate. At two-year-old the heights of these species are Shorea leprosula (4.64 m), Shorea parvifolia (4.58 m), Shorea platyclados (4.47 m) and Shorea johoriensis (4.10 m). These four species are now become the target species for commercial plantation in Indonesia, especially in Sumatra and Kalimantan. The species with medium growth rate are Shorea artinervosa (3.50 m), Shorea smithiana (3.16 m), Shorea stenoptera (3.59 m), and Hopea grifitii (2.85 m). Those with the slowest growth rate are Dipterocarpus caudiferus (1.94 m) and Vatica oblongifolia (1.83 m).

Key words: sites and species matching, inherent growth rate, rate of change, target species, commercial plantation.

Introduction

The continuous depletion of tropical rain forest of Indonesia due to illegal logging, forest fire and over-exploitation represents potential loss of forest resources (species, genetic of target species and other forest resources) and therefore, presents serious biological, ecological and economic consequences. To relieve the pressure on decreasing natural forests, the Government of Indonesia plans to rehabilitate degraded forests and converts them into commercial forest plantations.

To establish commercial plantation, site and species matching is critically needed. The ideal goal of silviculture is to place the right tree in the right place. There are about 400 species of dipterocarps in the humid tropical non-seasonal areas in Indonesia. Most of them are of commercial importance as timber trees. Despite the great commercial value, little information exists on their silviculture. On the other hand there are infinite varieties of sites, which further complicate the selection of suitable species for plantation establishment.

Question about what is the most suitable species to plant are matters involving much opinion and analytical thoughts about ecology and priorities to suit specific objectives. For commercial plantations the objective is to use genetic material that will not only survive and thrive on the site but also yield the wood at some optimum rate. The first step is then to determine the limitation imposed by the environmental factors that collectively constitute the site. The second step is the screening of groups of species that will most nearly meet the human objective.

Species trials, the second step, would match the species with site and also effects of appropriate silvicultural treatments. The present study evaluated the performance of 20 Dipterocarp species for their suitability for plantation establishment.

Material and Method

Study Sites

The study sites are located in PT. Sari Bumi Kusuma Company in Central Kalimantan about 400 km north west of Palangka Raya, the provincial capital of Central Kalimantan, and about 500 km east of Pontianak, the provincial capital of West Kalimantan. The two field trials (Blocks I and II) are located in Compartment 5 LL and the three field trials (Blocks III, IV and V) are located in Compartment 5 B. These two compartments were logged in January 2003. The soils are the Ordo Ultisol. This ordo is the most weathered and show the ultimate effects of leaching. Ultisols are characterized by mineral soils that have B₂ horizon, 20% more clay than the upper B₁. Ultisols have low base saturation, the base saturation decreases with increasing soil depth. Normally most of the bases are held in the vegetation and the upper few centimeters of soil. The higher base saturation in the upper soil layers reflects the direct cycling of bases by vegetation.

Central Kalimantan climate is almost uniform throughout the year. The annual rainfall varies from 2 909 mm to 3 424 mm, and the number of raining days varies from 95 to 112 days. Even though August is the month with the least rainfall (96.60 mm) it is still wet. Therefore, the soils just under the surface practically always remain continuously moist. This rainfall is important as a source of nutrient input into the ecosystem. Rainfall data is summarized in Table 1.

Table 1. Amount and distribution of rainfall on the study area

Nursery practice

Most dipterocarps fruits are recalcitrant; they do not retain their germinating capacity for a long time, not more than 10 days. Fruits that fall early are usually immature. Many fruits are often eaten by animals. To minimize losses from the predators, fruits of the 20 species tested in this study were collected daily from fresh ground collection during February and March 2002 (Photo 1). Many fruits were also infested with insect or fungi.

Sources: 8th Round-Table Conference on Dipterocarps

Latest news

• Project: Study on integrated management of insect pests and diseases on Docynia indica in northern Vietnam
• Project: Study on integrated pest management of major leaf insect pests and stem borer beetles in Acacia hybrid, A. mangium and A. auriculiformis in Vietnam
• Project: Research and develop an integrated management program for control of cinnamon pests in some main cinnamon growing areas (Northern mountainous region and Quang Nam province)
• Project: Pilot plantation and completion of planting techniques of technologically advanced germplasm of Acacia auriculiformis (AA42, AA53, AA56, AA92, AA95) for sawlog in the southeast and south central.
• Project "Research on selection of varieties and intensive afforestation techniques of Prunus arborea (Blume) Kalkman for providing lager timber in the Northeast and Northwest regions, Vietnam"

Oldest news

• Potential of wildlings of Parashorea malaanonan as planting stock
• Ectomycorrhizal inoculation of Anisoptera thurifera (Blanco) Blume and Shorea guiso (Blanco) Blume with ectomycorrhizal fungi in Philippine red soil
• Genetic conservation of Parashorea malaanonan (M. Blanco) Merr. in Mt. Makiling, Laguna, Philippines
• Photosynthesis and photoinhibition in canopy leaves of four Chinese dipterocarp species
• Genetic conservation of Parashorea malaanonan (M. Blanco) Merr. in Mt. Makiling, Laguna, Philippines