Forest Dweller: Kapur Forest Association-Segregate

Tuesday, 15 November 2011

Kapur Forest Association-Segregate

The term "lowland dipterocarp forest" was used by Symington (1943) to comprise all the Malaysian well-drained primary climatic climax forests (as opposed to edaphic climax forests) of the plains, undulating land and foothills up to an average elevation of about 1,000 feet (300 m) above sea level, or in other words the forests that would be included in Burtt Davy's (1938) tropical lowland evergreen rain-forest formation (Wyatt-Smith 1995).

The forests are usually dense, though comparative freedom of movement on the ground is possible. They are composed of many thousands of species of trees (often up to one hundred different species to the acre), as well as shrubs, herbs and woody climbers (Wyatt-Smith 1995).

It has usually been considered impossible to subdivide these lowland dipterocarp forests into recognised associations or consociations. It has been long been recognized, however, that species in each of the storeys may be segregated and grouped to form a number of plant communities but it has been thought probable with the exception of Dryobalanops aromatica that the main factors determining distribution of species within the forest were chance and opportunity. Symington (1943) found it convenient to apply the term association-segregate of Braun (1935) to these communities (Wyatt-Smith 1995).

One of these types of forest is kapur (Dryobalanops aromatica) forests. These following information about Dryobalanops aromatica has been republished from Symington reprinted 2007, Forester's Manual of Dipterocarps reviewed by P.S. Ashton & S. Appanah and edited by H.S. Barlow.

A kapur (Dryobalanops aromatica) forest association-segregate scenery at Kancing Forest Reserved, Rawang, Selangor.

Dryobalanops aromatica is mainly a species of the lowland dipterocarp forests although it does occasionally enter the hill zone.

Dryobalanops aromatica Gaertn. f.

Vernacular name. The preferred name, kapur, is well known and has long been established for Dryobalanops aromatica wherever it occurs in the peninsula.

Distribution. Dryobalanops aromatica occurs in Sumatra, the Malay Peninsula, the Lingga Archipelago, and Borneo. In the peninsula, it is confined to the eastern side south of 5 degree North latitude, with the exception of a small but important area in the Rawang district of Selangor. This exceptional pocket of kapur on the west coast of the peninsula begs an explanation. Wyatt-Smith (1963) believed they were planted by aborigines in the days when camphor fetched a high price. Ashton thinks not-it seems the ridges of Kancing F.R. have quartzite backbones, and hence could well produce a soil more comparable to the sandy loams of the east coast than to the granite typical of the Kancing area. This is mainly a species of the lowland dipterocarp forests although it does occasionally enter the hill zone. It demands well-drained soil, and seems to prefer rather steep slopes and ridges to flat and undulating land. The altitudinal range is between about 70 and 350 m. Of all our dipterocarps, Dryobalanops aromatica is the most markedly gregarious. In certain localities it has been estimated that this species forms 60-90% of the total volume of timber, and over large areas it is the most common and sometimes dominant tree species. Though greatly reduced by habitat conversion and logging, this species is not under threat.

Field description. The chief diagnostic characters are the purple-brown, shaggy bole, the aromatic cut, and the small, ovate-rotundate, many nerved, aromatic leaves.

Form: Very large tree sometimes exceeding 65 m height and 10 m girth (average of mature trees in virgin jungle = 70 cm diam. [Foxworthy 1927: 45]; buttresses short and stout, or large; bole tall and well shaped, usually purple-brown in color, smooth in young trees, to shaggy, with large, irregular, thin flakes of bark in old specimens; crown conical in young trees, umbrella-shaped in large, small-leafed, usually a greyish green tinge. In plantations the characteristic crown shyness is clearly visible, whereby each individual shows clear separation from the crowns of neighbouring trees by a gap of about a meter.

A typical scrolled-bark of Dryobalanops aromatica bole.

A kapur trees "crown shyness" phenomenon.

Leaves: Oval to rotundate, with an acumen about 1 cm long, about 5 x 3 cm, but considerably variable, glabrous, drying reddish brown and sometimes glaucescent beneath; midrib sunk on the upper surface; petioles slender, about 1 cm long, slightly channelled.

A leaf of Dryobalanops aromatica.

Fruits: Very shortly stalked; nut ovate-oblong, apiculate, shining, about 2.5 cm long, calyx lobes enlarged into five equal, broad, spatulate, about 9-nerved wings, each to about 6 cm long.