Southeastern Asia: Island of Seram in Indonesia

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The Seram Rain Forests [AA0118] are part of the region known as Wallacea, which contains a very distinctive fauna representing a mix of Asian and Australasian species. This small island ecoregion contains sixteen bird species, including a monotypic bird genus, that are found nowhere else on Earth. Nearly a fifth of the original forest cover has been cleared, mostly along the northern coast. However, large areas of contiguous, intact forest still exist, and the conservation status of this ecoregion is relatively stable.

  • Scientific Code
  • Ecoregion Category
  • Size
    7,500 square miles
  • Status
    Relatively Stable/Intact
  • Habitats

Location and General Description
This ecoregion represents the semi-evergreen and moist forests of Seram and associated islands in the easternmost section of the Indonesian Archipelago. Based on the Köppen climate zone system, this ecoregion falls in the tropical wet climate zone (National Geographic Society 1999). Seram is part remnant crustal fragment, probably from the Australian continent, and part of the volcanic Inner Banda Arc. Consequently, the surface geology of Seram is complex, consisting of older metamorphic schists and gneiss, younger volcanics, and recent alluvium (Monk et al. 1997). The interior of the island is mountainous, with several ranges reaching more than 1,000 m. The highest point on the island is the 3,027-m Merkele ridge (Stattersfield et al. 1998).

The natural vegetation of Seram is tropical lowland evergreen, semi-evergreen, and montane rain forest (Stattersfield et al. 1998). Semi-evergreen rain forest with trees that reach 30 m or more is a predominant forest type in this ecoregion. Rattans that exceed 100 m can be found in mature forests. The middle and lower layers include representatives of the Amaryllidaceae, sedges, and large ferns Angiopteris and Marattia, as well as climbers such as Freycinetia, Gnetum, Mucuna, Bauhinia, Piper, and Smilax. Most of the remaining dipterocarp forests are dominated by the endemic Shorea selanica, which can represent about 30 percent of the individual trees and 76 percent of the basal area in the forest. Also common are Anisoptera thurifera, Hopea gregaria, H. iriana, H. novoguineensis, Shorea assamica, S. montigena, S. selanica, and Vatica rassak (Monk et al. 1997).

This ecoregion also contains patches of ultrabasic rocks. The forests on these soils generally are poor in species, low, and shrubby. Tertiary limestone outcrops occur in the lowlands and on many mountains such as the Murkele Ridge and the top ridge of the central Mt. Binaiya, Seram's highest mountain (Monk et al. 1997).

In Seram's montane forests, the Fagaceae are represented by only two species. Castanopsis buruana dominates between 400 and 1,400 m above sea level, where individuals tend to clump together, and Lithocarpus celebicus is found along ridges. Above 2,400 m on Mt. Binaiya, a low, open scrubby woodland contains Dacrydium spp., Myrica spp., Rapanea spp., Rhamnus spp., Rhododendron spp., and Vaccinium spp. Tree ferns are also important and include Cyathea binayana and C. pukuana, which form distinctive groves that support many epiphytic ferns. Pockets of this tree-fern savanna extend to the summit along with low Vaccinium woodland. At the highest points, from 2,700 to 3,000 m above sea level, grassland dominates and is characterized by several endemic herbs such as Viola binayensis, Pterostylis papuanum, and Euphrasia ceramensis (Monk et al. 1997).

Biodiversity Features
The overall richness and endemism of this ecoregion are low to moderate when compared with those of other ecoregions in Indo-Malaya. The islands are part of Wallacea, a unique region that supports a mixture of Asian and Australian fauna.

The montane area of Seram supports the greatest number of endemic mammals of any island in the region (Flannery 1995). The ecoregion harbors thirty-eight mammal species and includes nine species that are endemic or near endemic (table 1), several of which are limited to montane habitats (Flannery 1995). The Seram flying-fox (Pteropus ocularis) and spiny Seram rat (Melomys feliceus) are considered vulnerable (IUCN 2000). The mammals found on Seram include Asian species (Murid rodents) as well as Australasian marsupials.

Table 1. Endemic and Near-Endemic Mammal Species.

Family Species
Perorictidae Rhyncholemes prattorum*
Pteropodidae Pteropus chrysoproctus
Pteropodidae Pteropus ocularis
Pteropodidae Pteropus argenatatus*
Muridae Rattus feliceus*
Muridae Melomys fulgens
Muridae Melomys aerosus*
Muridae Melomys fraterculus*
Muridae Stenomys ceramicus*

An asterisk signifies that the species' range is limited to this ecoregion.

The ecoregion harbors more than 213 bird species (Wikramanyake et al. 2001), of which 33 are endemic or near endemic (table 2). The ecoregion corresponds to the Seram EBA. The EBA contains thirty restricted-range species, including fourteen that are found nowhere else on Earth. Five species are threatened. The vulnerable Moluccan scrubfowl (Megapodius wallacei) is also found on Buru and Halmahera. The remaining four species are found nowhere else: the endangered black-chinned monarch (Monarcha boanensis) and vulnerable salmon-crested cockatoo (Cacatua moluccensis), purple-naped lory (Lorius domicella), and lazuli kingfisher (Todirhamphus lazuli). The bicoloured white-eye (Tephrozosterops stalkeri), the sole member of its genus, is also found only on Seram. The fourteen endemic restricted-range birds can be divided into three groups: five species found generally in lowland forests (below 1,000 m), three species found in montane forests above 1,000 m, and six species found in both lowland and montane habitats (Stattersfield et al. 1998). The ecoregion also harbors the largest bird in the Moluccas, the two-wattled cassowary (Casuarius casuarius) (Whitten and Whitten 1992).

Table 2. Endemic and Near-Endemic Bird Species.

Family Common Name Species
Accipitridae Rufous-necked sparrowhawk Accipiter erythrauchen
Megapodiidae Forsten's scrubfowl Megapodius forstenii
Megapodiidae Moluccan scrubfowl Megapodius wallacei
Columbidae White-eyed imperial-pigeon Ducula perspicillata
Columbidae Long-tailed mountain-pigeon Gymnophaps mada
Cacatuidae Salmon-crested cockatoo Cacatua moluccensis*
Loriidae Red lory Eos bornea
Loriidae Blue-eared lory Eos semilarvata*
Loriidae Purple-naped lory Lorius domicella*
Cuculidae Pied bronze-cuckoo Chrysococcyx crassirostris
Strigidae Moluccan hawk-owl Ninox squamipila
Tytonidae Lesser masked-owl Tyto sororcula
Alcedinidae Lazuli kingfisher Todirhamphus lazuli*
Meliphagidae Olive honeyeater Lichmera argentauris
Meliphagidae Seram honeyeater Lichmera monticola*
Meliphagidae Seram myzomela Myzomela blasii*
Meliphagidae Wakolo myzomela Myzomela wakoloensis
Meliphagidae Seram friarbird Philemon subcorniculatus*
Pachycephalida Drab whistler Pachycephala griseonota
Rhipiduridae Streaky-breasted fantail Rhipidura dedemi*
Monarchidae Black-chinned monarch Monarcha boanensis*
Monarchidae Moluccan flycatcher Myiagra galeata
Oriolidae Seram oriole Oriolus forsteni*
Campephagidae Moluccan cuckoo-shrike Coracina atriceps
Campephagidae Pale-grey cuckoo-shrike Coracina ceramensis
Turdidae Moluccan thrush Zoothera dumasi
Sturnidae Long-crested myna Basilornis corythaix*
Muscicapidae Cinnamon-chested flycatcher Ficedula buruensis
Zosteropidae Ambon white-eye Zosterops kuehni*
Zosteropidae Bicoloured white-eye Tephrozosterops stalkeri*
Zosteropidae Grey-hooded white-eye Lophozosterops pinaiae*
Sylviidae Chestnut-backed bush-warbler Bradypterus castaneus
Dicaeidae Ashy flowerpecker Dicaeum vulneratum

An asterisk signifies that the species' range is limited to this ecoregion.  Current Status

Nearly a fifth of the original forest of this ecoregion has been cleared, mostly along the northern coast. However, large areas of contiguous, intact forest still exist. Therefore, the conservation status of this ecoregion is relatively stable. Seven protected areas cover 3,121 km2 (16 percent) of the ecoregion area, and one-Manusela National Park-is more than 2,000 km2 (table 3). This last reserve, with a wide range of forest types, conserves the cassowary (Casuarius casuarius). However, wildlife trade has been strong since historical times, and it may threaten some bird species such as the salmon-crested cockatoo (Cacatua moluccensis). The Trans-Seram Highway also threatens forest habitat by illegal logging, land clearance, and soil erosion.

Table 3. WCMC (1997) Protected Areas That Overlap with the Ecoregion.

Protected Area Area (km2) IUCN Category
Sabuda Tataruga 10 IV
Manusela 2,340 II
Wae Bula 600 PRO
Gunung Sahuai 120 PRO
Pulau Kassa 1 IV
Pulau Pombo 20 I
Laut Banda 30 I
Pulau Manuk 1 ?
Total 3,122  

Ecoregion numbers of protected areas that overlap with additional ecoregions are listed in brackets.

Seram's moist lowland forests are being exploited by logging companies, primarily for their valuable damar trees (Agathis) (Whitten and Whitten 1992). The best dipterocarp stands were depleted by commercial loggers before the 1950s, and many other species were overexploited by intensive logging in the 1970s (Monk et al. 1997).

With no airport and only rudimentary ground transport, Seram is remote. Although this promotes conservation in many ways, it also prevents conservation employees from guarding boundaries, enlisting the support of local people, and conducting biological surveys (Whitten and Whitten 1992).

Types and Severity of Threats
The north Seram dipterocarp forests are still dominated by the endemic Shorea selanica and therefore are especially vulnerable to logging (Monk et al. 1997). The commercial wildlife trade is another significant threat. Parrots are captured and exported for the pet trade, with many casualties (Whitten and Whitten 1992).

Justification of Ecoregion Delineation
The Sula Islands were included within the Sulawesi Lowland Rain Forests [AA0123] and the Aru Islands in the Vogelkop-Aru Lowland Rain Forests [AA0128]. Buru Island, identified as a distinct subunit (13c) by MacKinnon (1997) and as an EBA (Stattersfield et al. 1998), was delineated as a distinct ecoregion, the Buru Rain Forests [AA0104]. Seram, the larger island to the east of Buru, was also delineated as an ecoregion: Seram Rain Forests [AA0118]. The larger Halmahera Rain Forests [AA0106] ecoregion includes Obi Island, which MacKinnon (1997) recognized as a separate subunit (13b) from Halmahera Island (subunit 13a). We created the Banda Sea Islands Moist Deciduous Forests [AA0102] by combining the islands in the Kai and Tanimbar archipelagos, which were distinguished as a biogeographic unit by Monk et al. (1997). The primary vegetation on the islands in both these archipelagos is moist deciduous forests and semi-evergreen forests, whereas the vegetation in the other, nearby large islands (Seram and Aru) is evergreen rain forests (Monk et al. 1997).

References for this ecoregion are currently consolidated in one document for the entire Indo-Pacific realm.
Indo-Pacific Reference List

Prepared by: John Morrison
Reviewed by:

This text was originally published in the book Terrestrial ecoregions of the Indo-Pacific: a conservation assessment from Island Press. This assessment offers an in-depth analysis of the biodiversity and conservation status of the Indo-Pacific's ecoregions.