Unique rainforest research shows the way towards successful restoration

18.500 hectares of rainforest are now recovering in northeast Borneo. The area was ravaged during the 1980s and 1990s by wildfires and intense logging. The future seemed clear; planting of oil palms. But local people, financiers, and researchers wanted otherwise.

Together they created what is today one of the world's largest rainforest restoration projects with the goal of bringing back the entire ecosystem.



It's constant; the noise from the cicadas is like a carpet of sound that's always around. Noises of calling, sometimes almost like screams, and then – before sunset – the sound is deafening. We are in northern Borneo, Malaysia, in a damaged rainforest that is being restored.


Map showing the Malaysian village of Luasong located in the north of the island of Borneo.

The restored area is located near the Malaysian village Luasong in the state Sabah.
Map: Freevectormaps Graphics: Susanna Bergström, SLU


To the untrained eye, the forest looks just fine. But it's not.

During El Niño drought in the eighties over four million hectares of forest in Borneo burned. After that, the forest has been intensively logged. What you see in the picture below is a forest where many species are no longer present. Where the trees with very soft and light wood that grow the fastest have taken over; the macarangas, considered a pioneer and ”weedy” species of limited use and low financial value .

But give this forest time and it will slowly recover, maybe in a hundred years. Give it some care, and the former diversity will be back sooner – both when it comes to trees, other plants, and animals. That, at least, is the aim of this restoration project.



  • Road in rainforest.

    In the late nineties, the 18.500 hectares in this area were set aside for restoration. The local governmental organization: Yayasan Sabah, have been restoring this forest with funding from the Swedish company IKEA. The project is locally known as INIKEA.

    Research led by the Swedish University of Agricultural Sciences (SLU) have been done in the area since the start to find out if it’s possible to speed up forest recovery and recreate biodiversity and value for people both locally and globally.

    Photo: Susanna Bergström, SLU

  • Man in shirt in rainforest talks and gestures with his hands.

    The project does not only provide ecological values. David Alloysius, project manager until late 2022 when he retired, emphasises the social values in particular.

    "I like this project because it's contributed a lot to the people of Sabah. We have recruited about 700 people, and if you count with families about 2000 people have benefited with the project until now".

    The project provide free accommodation, electricity and water. In Luasong there's also a  free government school.

    Photo: Susanna Bergström, SLU

  • Oil palm plantation.

    During the last decades tropical forests have been rapidly deforested. In Sabah, the state where this restoration project is taking place, 39,5% of the forests was deforested between 1973 and 2010. In 2009 only 8% of land area in Sabah was covered by intact forests under designated protected areas.

    Most often forests are cleared and converted into oil palm or timber plantations. Malaysia has long been the world's second largest exporter of palm oil.

    Oil palm grow fast, fruits can be harvested every two weeks. They provide economic value, but are depleting biodiversity.

    Photo: Susanna Bergström, SLU



A third of the world's tropical rainforests are lost. Half of the remaining are degraded.

Initiatives to reforest areas in the tropics often start to meet the interests of the market. Exotic species such as eucalyptus, acacia and pine have established markets and management models which give fast return on the investment. In fact, 4 out of 5 trees planted  are an exotic tree.

But plantations of exotic species have problems with soil erosion, water availability and low biodiversity. The use of native trees may therefore be a better choice. However, little is known about the management, site requirements and characteristics of native rainforest trees.

"A unique oppurtunity for research"

Listen to project manager Ulrik Ilstedt talk about the project.


In this project different tree species and different forest type’s ability to store carbon have been studied. The results show that it’s possible to replace exotic species with local ones to maintain characteristics such as rapid growth and efficient carbon sequestration – and by doing so also benefit biodiversity, culture, and a lot of other values.

"We believe there is a lot of potential in using native species; either planting them or protecting the recovery of the natural regeneration. But still the knowledge about native species and how to manage them are too limited for people to try them on a larger scale", says Ulrik Ilstedt, a researcher at the Swedish University of Agricultural Sciences (SLU).

Together with colleagues in Malaysia, USA and Sweden Ulrik's leading the research being done here.

"From a research point of view this project is unique. Most other research in this field has been either in conservation areas of undisturbed forests or on a handful of exotic tree species. We therefore know very little about how local tree species behave and which ones to use", says Ulrik Ilstedt.

  • Woman pruning plants.

    In this project only native species have been used. Seeds and seedlings from more than 85 species have been collected throughout the project and grown in the nursery in Luasong.

    In the picture Salimang LaNyang, the supervisor of the nursery, is pruning plants.

    Photo: Susanna Bergström, SLU

  • Rozina Sasan waters the plants. During the project, around 5.5 million seedlings were planted. In the first years, when the trees are small many die due to the harsh environment.

    However, after 20 years, most of the 20% that survived are big and strong enough to keep surviving. This means there will be about a million growing planted trees of different sizes in the forest.

    With 300-350 planted seedlings per hectare, this resulted in a density of old-growth forest tree species similar to an intact forest.

    Photo: Susanna Bergström, SLU



Skilled hands prune the thin roots that have made their way too far out from under the plant's pouch. Salimang LaNyang and her colleagues methodically work their way through plant after plant.

Salimang have been working in the nursery for the entire duration of the project, in fact she was here before.

“At that time we worked with rattan. But since the project started in 1998, I've been raising seedlings for the restoration project”, says Salimang LaNyang.

The nursery is impressive, rows of plants are taken care of, watered, pruned and checked for pests on a regular basis. But the number of plants here today is nothing compared to what it looked like a few years ago in the planting phase of the project.

“We had 300.000 plants the most. Now we have 30.000. And many of the plants you see here today are over two years, more than ready to leave the nursery and be planted in the forest”, says Salimang LaNyang.

Portrait of Salimang wearing a sun hat.

Salimang LaNyang.
Photo: Susanna Bergström, SLU


The restoration has been carried out in different phases, treating area after area. Depending on how damaged the forest was, new plants were planted, or natural regeneration was assisted. Now there is no more large-scale planting, the restoration has moved into a monitoring and management phase. Some seedlings are still being raised to replace newly planted ones that do not survive.

The research follows the new phase. The uniqueness of this project is the opportunity to follow a restored rainforest over time. To be able to study the recovery of the ecosystem and all the different benefits we humans get from the forest, and to learn what types of actions work best for different types of objectives, and when.

To compare the different functions of the restored forest, the researchers are using protected old-growth forests in nearby nature reserves as well as plots in different land use types, such as plantations.

Today, more than 10 experiments are being carried out in the area. The research ranges from genetic studies aimed at understanding the ability of local species to adapt to climate change, to the wider benefits of restoring degraded rainforests in terms of biodiversity, climate and other ecosystem services.


Two people measure a plant in a rainforest.

INIKEA forest ranger Albert Lojingi and researcher Petter Axelsson (SLU), are measuring seedlings in an experiment where seeds from mother trees in dry and wet climates are planted in the same place to see what different characteristics they develop. Photo: Susanna Bergström, SLU



Large ants scurry up and down a tiny seedling. Gibbons call from everywhere and species such as banteng, wild buffalo, clouded leopard and the critically endangered helmeted hornbill have all been spotted live, on camera or audio recordings. Several of the fast-growing dipterocarp trees planted during the restoration have produced many new plants.

The forest is coming back to life. And thanks to this project the area is classified as a fully protected forest reserve.

So, what happens next? As well as continuing to build knowledge in this unique area, the whole team working on this considers it important to share the lessons learnt so far.

"To prevent further degradation and successfully restore forests, we need to learn from the few early efforts, such as this project", says Ulrik Ilstedt.


Background image: Linne Murang working in the nursery in Luasong.
Photo: Susanna Bergström, SLU

More about the project

The research

We assess the potential of native rainforest restoration and management to deliver multiple benefits.

Two people measure a plant in a rainforest.

Key lessons for future restoration

More than 25 years of rainforest restoration experience and research distilled into five key lessons. Please use them!

Leaves in backlight.

Join us!

We welcome researchers, students and funders who wish to improve rainforest restoration with us.

Portrait of two malaysian master's students.


Story, film and photo:
Susanna Bergström, Communications Officer, e-mail

Press/research contact:
Ulrik Ilstedt, researcher e-mail, +46(0)701510075



Yayasan Sabah, Universiti Malasia Sabah (UMS), Northern Arizona University (NAU), The University of Western Australia (UWA), University of Copenhagen (UCPH), IKEA