Key Habitats and forest formations

While the majority of the park is covered by rainforest, variations in salinity soils and topography have created a number of distinct habitats and forest formations, each with its ovn characteristic flora and fauna. These are discussed below For a broader explanation of tropical forest ecology.

Coastal forest

Tanjung Puting’s southern shores are lined with forests dominated by Casuarina trees, coconuts and salt-tolerant creepers. These coastal forests are sparse and contain little wildlife. They do, however, provide shelter and nesting sites for a number of sea and water birds. Significantly they also protect the beaches that are nesting grounds for green turtles.

Mangrove forest

Where the coast is more muddy mangrove forests predominate. Distinguished by their gnarled, twisted roots, mangrove trees grow  between the high- and low-tide levels. They are among the few species that can cope with regular immersion in salt water; indeed, some mangroves even have the ability to secrete salt. The most common in Tanjung Puting are Rhizophora and Avicennia.

Mangrove forests are home to large numbers of crabs and mudskippers — an unusual, semiaquatic fish that emerges at low tide — as well as a variety of birds. including fish and sea eagles, egrets and kingfishers. Proboscis monkeys ñiay also occasionally be seen in mangroves.

Nipa palm

Away from the coast, the lowet brackish reaches of all Tanjung Puting’s rivers are lined almost exclusively with nipa palm (Nypa fruricansj), Like mangroves, these provide important breeding grounds and hatcheries for fish. Otherwise. they are not a good home for wildlife, although long-tailed macaque also known as crab-eating macaques) and even  orangutans may occasionally pass through. At night fireflies swarm around the palms. lighting them up like Christmas trees. Local people harvest the fronds of the nipa to make thatch roofs and matting.

Riverine and freshwater swamp forests

The transition, or ecocline, from sea water through the brackish estuaries reaches its conclusion where the water becomes fresh. Pandanus replaces nipa along the river’s edge. Rehind this, tall, woody forests take advantage of nutrients washed down the rivers and out of inland swamps.

These riverine forests are rich in s4ldlife, including proboscis monkeys, otters and many birds. Orangutans frequently feed on fruiting or flowering riverside trees. 

Seasonal lakes

During the rainy season Tanjung Puting’s low lying, meandering rivers often overflow into open grassy plains to form seasonal lakes. They are an important habitat for many sp.ecies — including awana. or dragon fish, as well as various types of frog — which use the lakes as breeding grounds.

Peat swamp

Peat swamps are a distinctive feature of Tanjung Puting and prime orangutan habitat. They occupy as much as 30 per cent of its area and dedve their water entirely from ach leach out from fallen leaf litter and other debris. In this difficult, nutrient-poor environment, a number of tree species flourish, including ramin (Gbnysry/as species) and, around the edges, ironwood {Eusideroxylon zwagenj, some of which maybe more than 300 years old. Unfortunately, both these species are valuable timber and have attracted illegal loggers into the park see page 30). The forest’s understory is characterised by a rich vriety of palms, ferns and grasses, as well as by various epiphyres, climbers and stranglers. Because the soils are almost always moist, many swamp trees have stilt roots to lift their trunks out of the water, and some develop pneumatophores, or breathing roots. Around the bases of these trees, islands of vegetation form and are a common sight.

Dry-ground forests

Tanjung Puting’s dry-ground forests are predominantly rich “tropical heath forest with dipterocarps” reflecting the mix of a few tall trees of large diameter — the dipterocarps, Asia’s famous hardwood trees — being surrounded by many smaller trees. In the park, .Shorea species are among the most impressive dipterocarps, particularly the giant meranti, or kayo baru, trees which are distinguished by their huge buttress toots. However, because of the park’s poor alluvial and acidic soils, the dipterocarp trees ate not as large or as abundant as they are in either Sabah or East Kalimantan. Pure heath forest, or kerangas, by comparison generally has a lower canopy and thinner trees and, in its most extteme form is called “pole forest”,  In Tanjung Puting the canopy averages 20—30 metres high, with emergents rising to mote than 40 metres. Lianas and other climbers are usually well established, In all the dry-ground forests leaf litter and humus ovedie soils that are dry and vary in colour from black (peaty) to white sandy). In the park. pole forests are found on the sandiest soils where mosses may also be present.

Disturbed forest

As much as 30 per cent of the park’s original forest cover has been lost to human disturbance, typically slash-and-burn agriculture. In these areas it shows various stages of regeneration.  Elephant grass (/mperafa species, known locally as a/ang-a/ang) is the first plant to colonise cleared forest. After two or three years it will be replaced by ferns, Woody shrubs such as Me/asroma ma/aba rhricum and 0//len/a species are the next to appear. Trees such as Craroxylum glaucum and Casuarina sumarrana indicate at least ten years of regrowth.  Such areas are obvious and can be seen on Jalan Toges behind Camp Leakey and at Pondok Tanggui. They are called (adang a farming area) or padang if there is more secondary growth.  More advanced, secondary regrowth (known locally as be/uka,j is characterised by low dense forests; there will be leaf litter and humus on the ground. Some of the trees will be relatively thick but most will appear as saplings.  Visitors to the park can see a well-established secondary forest at Tanjung Harapan.

Orangutan Tour | Borneo Orangutan Tour | Orangutan Trip Tanjung Puting © 2016