Sulawesi's biodiversity

Sulawesi, la 11th island in the world, represents the largest land area in the Wallacea biogeographic zone, with 175,000 km2 out of a total of 340,000 km2.

Wallacea, biodiversity hotspot

Carte de l'île de Sulawesi en Indonésie

The Wallacea is home to an incredible natural heritage, through a mosaic of habitats - coral reefs, mangroves, karstic massifs, primary forests - among which 98% of mammals, 1/3 of birds and nearly 80% of amphibians are endemic, that is to say that we can't find them anywhere else. In view of this richness in biodiversity and of the threats weighing on its ecosystems, it is one of the 36 hotspots of planetary biodiversity.

The island of Sulawesi boasts remarkable fauna including the knobbed hornbill (Aceros cassidix, top left), the Maleo (Macrocephalon maleo, center-top left), the Babirusa (Babyrousa babyrussa, lower right) and the Spectral tarsier (Tarsius tarsier, center-bottom left). These species are endemic to Sulawesi and/or neighbouring islands and are on the IUCN Red List of Threatened Species. On the right are a freshwater fish, a bat, a springtail (collembola), a tropical pitcher plant (nepenthes), a grasshopper, and water snails (Hydrobia gastropod).

The karst massifs

The karsts constitute biotopes sheltering true arks of biodiversity, given the distinctiveness of their flora and fauna, and the multitude, fragmentation, and isolation of their habitats. These habitats exist within geological domains with drastically different ecological requirements. Some groups of plants and animals with low capacity for dispersion have hence undergone evolutionary radiations that are hyperdiversified and specific to karstic environments.

Calao in Sulawesi
Anoa family in Sulawesi
Hydrosaurus on the island of Sulawesi

The heart of the coral triangle

The Coral Triangle is considered the epicenter of the planet's marine biodiversity. In 6 million km2 is located more biological wealth than anywhere else in the oceans : 30% of all corals on the planet, 76% of known coral species, 35% of coral reef fish, and 6 of the 7 species of sea turtles recorded in the world.

Whale sharks, sea turtles (especially the hawksbill turtle, classified as critically endangered) and several species of rays, including manta rays, frequent Matarape Bay. If some parts of the bay are degraded, some reefs are teeming with life. There are many giant clams.

Mangroves, an often neglected natural environment

Indonesia has the largest expanse of mangroves in the world. In addition to harboring abundant biodiversity, these provide irreplaceable ecosystem services, limiting coastal erosion and protecting coastal communities from cyclones and tsunamis. They also sequester an impressive amount of carbon that scientists are just beginning to measure. But their surface is shrunk by 30% over the last three decades, mainly due to the expansion of shrimp farms and coastal infrastructure projects.

The Konawe region is home to one of the last great mangroves in Sulawesi in the delta of the Lasolo river, as well as numerous small mangroves dotted around the bay of Matarape.

The mangrove swamps of the Lasolo delta on the island of Sulawesi
The mangrove swamp of the Lasolo Delta on the island of Sulawesi © Bagus Sanjaya

Natural habitats in decline

Only 15% of the natural habitats remain on the whole of Wallacea. In terms of biodiversity, more than 10% of mammals, birds and amphibians are on the IUCN Global Red List of Threatened Species. Deforestation and the expansion of plantations has not yet reached the disastrous scale that has taken place on the islands of Sumatra and Borneo, but with the scarcity of available land on them, Sulawesi, along with Papua, is acting. of 'new frontier' to develop new plantations. Read more

Vast expanses of forests are still intact, especially in the Konawe region, offering the prospect of creating large protected areas rich in this biodiversity so specific to Wallacea.

Distribution of intact forests on the island of Sulawesi
The intact forests of Sulawesi Island (in dark green); i.e., regions of forest untouched by humans in recent times, and sufficiently large and unfragmented to provide habitats for all of their native biodiversity, including species that require large areas. Map © Global Forest Watch

To find out more

Find out more about our first conservation activities and our long-term strategy for the preservation of Konawe karsts: Preserving the karsts of Konawe - Helloasso (French only).

English translation made possible thanks to the PerMondo project: Free translation of website and documents for non-profit organisations. A project managed by Mondo Agit. Translator: Cressida McDermott