Like many tropical rainforests, the 157,875 hectares of tropical peatland forest protected through the Katingan Mentaya Project is home to a fascinating and complex community of plants and animals.

Arriving by air from Jakarta and looking north across Borneo, the forest appears uniformly green and perfectly flat, stretching far off between the Katingan and the Mentaya rivers to the horizon.

Closer up, the green becomes mottled and textured. Tall broad-leaved canopy trees tangled with thick woody vines block much of the direct sunlight from reaching the thick foliage of smaller trees and shrubs of the understorey. Down further still, at the forest floor, conditions are hot and humid, noisy with the drone of insects, bird calls, the creaking of branches and the dripping of rain on wet leaves.

Trekking through the forest on foot is a challenging and exhausting task, but it is a familiar part of the job for the Project’s Protection and Enforcement Manager, Meyner Nusalawo, known to everyone as Opo.

“Where possible, we leave the forest to do what forests do best – to grow, to store away carbon and to provide for all the species that live there. Nature has been doing that for millions of years, we just need to ensure it is given the space to thrive.

“As conservationists, though, there are occasions where we must go in. In extreme cases, this is to respond to fires alerts or prevent illegal logging, but by far the most rewarding is the survey and monitoring work we do to track the forest’s wildlife.”

With a diverse variety of tree and plant life, the forest is a vital habitat for a large number of mammals, birds, reptiles, and insects. Among the primates, Katingan Mentaya is thought to contains 5-10% of the remaining Bornean Orangutan, proboscis monkey and Bornean Southern Gibbon. And many of its animals are on the IUCN red list of endangered species, including the Sunda Pangolin, the Malaysian sun bear and the Bornean clouded leopard.

“We conduct a number of wildlife survey and monitoring programmes across the site, and part of this includes a growing network of camera traps,” Opo explains. “Determining orangutan populations, distribution and habits is an important and popular example, but we are also working on a complete picture of all the forest’s inhabitants, including for example the extremely rare hairy nosed otter.”

Biodiversity is more important than many of us often consider it to be. The air we breathe, water we drink and our food system is reliant on biodiversity. The threat of increasing species loss is therefore at least as profound as the climate crisis. Biodiversity is also a mark of a healthy natural forest. And natural forests sequester and store far more carbon and provide many more ecosystem services than other types of forest (see Mongabay News), especially plantations and agroforestry.