Biodiversity in the Sebangau Forest

Research Blog

Written by Abi Gwynn (Research student from University of Exeter)
Some may say that at this time of year, Sebangau is at it’s most beautiful. A watery red carpet covers the forest floor concealing the network of tangled roots underfoot. Sebangau’s flooded forest is a highly important peat swamp; the largest unfragmented area remaining in Borneo’s lowlands. Sebangau is home to 215 tree species, 297 spider, 55 fish, 46 reptiles, 41 dragonfly/damselfly, 11 amphibia, 172 bird and 65 mammal species! In celebration of World Wetland Day, we’re talking about some of the weird and wonderful species that can be found in the Sebangau forest.

What’s most noticeable about the peat swamp forest is the water. The water is stained dark brown by the tannins that leach from the fallen leaves and peat, giving them the name blackwater swamps. The water is also highly acidic, creating conditions that support a specialised freshwater fish community. Indonesian peat swamps contain the smallest vertebrate in the world, Paedocypris progenetica, and its close relative, Paedocypris carbunculus, can be found in the blackwaters of Sebangau. Paedocypris is endemic to the peat swamps of South-east Asia and is not found anywhere else in the world. This is the case for 20% of fish species that have been identified in Sebangau, providing even more reason to protect this fragile habitat.

Paedocypris carbunculus

From the smallest vertebrate to the largest arboreal ape, high-quality peat swamps are considered a rich habitat for orangutans. Five of the eight largest orangutan populations are found in peat swamp forests and the largest protected population is in Sebangau! It was previously thought that peat swamps were poor orangutan habitat due to the low-quality food availability. However, the regularity of the food availability means that peat swamp orangutans have their own unique foraging strategy to survive in this environment (Morrogh-Bernard et al., 2009).

Georgia, one of Sebangau’s most loved residents
Photo by Abi Gwynn | BNF | UPT LLG CIMTROP

Peat swamps are highly important for another interesting character, the storm’s stork. A lesser known resident of Sebangau, it is thought that there are less than 500 individuals, with most of these occurring in Borneo. It is the rarest stork species in the world. These birds are elusive but often recorded on camera traps as a part of BNF’s long term camera trapping project. It is likely that Sebangau is an important refuge for this species as they are threatened by loss of habitat due to logging, conversion to oil palm plantations and forest fires as well as hunting pressure.

Storm’s stork was captured by BNF camera trap at Bukit Jack, Sebangau Forest

It’s not just animals that are interesting in peat swamps. Without the plants, there would be no animals! There are approximately 307 tree and plant species found in Sebangau, which require a unique set of adaptations in order to survive in the extreme chemical and hydrological conditions of peat swamp forests. These include pneumatophores, a kind of aerial root which protrudes above the water table so air can enter the root for respiration. Many trees also have impressive buttress and prop roots to stabilise them in the soft peat soil. Plants of the peat swamp have long been important for local communities in providing forest products for income and medicinal purposes. For example, local people harvest latex from the jelutong tree and the leaves of the tree Dracaena cantleyi provide an amazing treatment for sore joints – a treatment technique shared with the Bornean orangutan!

Left: Jelutong tree (Dyera costulata) Photo by Abi Gwynn ;Right: Dracaena cantleyi Photo by Siddarth Badri | BNF | UPT LLG CIMTROP

These case studies are just a snippet of the incredible biodiversity found in the Sebangau forest. The habitat is unique and precious, particularly due to the pressure it is facing from human development continuing at an unprecedented rate. Now more than ever it is critical that we work to protect the remaining peat swamp forests to preserve this remarkable biodiversity.