Borneo Rainforest

By Irina Bright
We take a look at how Borneo rainforest has been utilized by humanity over the last several decades.

This article is part of our Environment section

See the complete list of all our Articles about Rainforests here.

borneo rainforest, mount nungkok, child of kinabalu Borneo Rainforest
Mount Nungkok, "Child of Kinabalu"
© Thienzie Yung

The Borneo rainforest has recently generated a lot of international interest, especially in respect of its continuous destruction and other conservation-related threats.

Borneo is a huge island located in South-East Asia, in between the Indian and Pacific oceans. The current area of Borneo is 743,330 km2. (Ref. 1)

It is the 3rd largest island in the world, after Greenland and New Guinea; it is larger in size than Germany and Britain combined, and is roughly one-sixth of the territory of the Amazon rainforest. (Ref. 2)

Borneo is sandwiched right in the middle of numerous other smaller islands.

Politically, the territory of Borneo is shared by three countries - Indonesia, Malaysia and Brunei. Indonesia controls central and southern parts of the island which make up its largest area, and Malaysia and Brunei cover northern territories.

As of 2009, the total combined population of Borneo was 18.5 million people, spread mostly around the coastal areas. (Ref. 3)

In this article, we are zooming into the wonderful and truly exceptional eco-system of Borneo Island to learn about its rainforests, geography and climate, a sad history of its rainforest destruction and degradation, and a lot more.

Borneo Rainforest Overview

The Borneo rainforest is certainly the largest, and the most important, forested land-area in Asia. The forest itself is estimated to be, extraordinarily, around 130 million years old (ref. 4), and is presumably older than the Amazon rainforest.

As I take my arm-chair journey into the depths of Borneo courtesy of Google Maps, I observe the island's forested landscapes adorned with marvellous green mountains and valleys, and interlaced with windy rivers.

I see heavy clouds ready to deliver downpours of rain - that same rain that had been sustaining the forests and keeping them healthy in the endless cycle of life.

I also imagine thousands of animals roaming the land, swinging on canopy treetops, or flying high up in the sky.

Scientists believe that the island was formed as a result of one big volcanic eruption under the sea followed by many smaller ones, which led to numerous pieces of land joining together into one big landmass.

It is as if this volcanic explosion was a way for the Universe to send us a gift of infinitely abundant biodiversity - so that we could admire and cherish it till the end of times.

But we also know that at some point in the past it most likely was part of the same landmass alongside other nearby areas.

Here is what botanist E.D.Merrill had to say about it back in 1921:

Borneo is situated on a submarine plateau of no great depth, and manifestly is geologically allied to the Malay Peninsula, Sumatra, and Java, and in past geologic times undoubtedly formed a continuous land mass with these three areas and probably with other islands of Malaya, at some time perhaps including the Philippines, the oluccas, and New Guinea. It is one of the larger islands of the World, the equator crossing it at about the middle. (Ref. 5)

So for millions of years, Borneo had been this divine tropical paradise with dense, uninterrupted expanses of rainforests covering the whole of its territory and hosting thousands of living creatures.

No surprise then that this ancient eco-system attracts us like a magnet, and draws us totally in.

In the first part of this article, we will talk about different types of Borneo rainforests which include: lowland rainforests, peat swamp rainforests and mountain rainforests.

In the second part of the article, we will discuss Borneo's rich biodiversity including animals and plants.

The third part will look into Borneo's rainforest destruction which happens, unfortunately, as a consequence of human actions.

Borneo Lowland Rainforest

Overview, Distribution and Climate

borneo map, rainforests Borneo
As extracted from

There are no clear-cut "borders" that would define distribution of Borneo's lowland rainforests.

If you look at the picture on the right, you'll see a mountain range stretching from the north down to the central part of the island.

The areas that lie around the mountains and below their level are lowland rainforests.

Some estimates put the total area of Borneo lowland rainforest at roughly 420,000 km2. (Ref. 6)

So we estimate that the lowland forest takes something like 57% of the island's total territory.

Most of the biological value of the lowland rainforest is contained in the vegetation above the ground. This is due to the domination of limestones and volcanic and other types of rocks, and Borneo's soils being generally of poor quality (ref. 7) - as is often the case with many other rainforests.

Despite that, some geologic formations, ex. limestones, do support a whole number of valuable plant species.

Borneo's lowland rainforest falls within the tropical monsoon climate zone. It is characterized by intense rainfalls and warm temperatures which hold at stable levels throughout the year, with few fluctuations.

The stability of its climate ensures an exceptionally high diversity of trees and plants.

Borneo lowland rainforest is often referred to as the dipterocarp rainforest, emphasizing its uniqueness in hosting the biggest number of species of dipterocarp trees in the world.

By World Wildlife Fund's estimates, Borneo has 267 species of dipterocarps, 60% of which are endemic (i.e., present only in Borneo and not found anywhere else). (Ref. 8)

Dipterocarps are large strong hardwood trees suitable for use in many commercial applications including, ex., furniture. But they are also harvested for numerous other applications such as aromatic oils, resins and so on. This type of demand makes them an unfortunate target for logging and leads to widespread deforestation. We discuss Borneo rainforest loss further down in this article.

Borneo Peat Swamp Rainforest

Overview and Distribution

borneo peat swamp forest, bako Borneo Peat Swamp Forest, Bako
© Clivid

Peat swamp forests are a very interesting phenomenon indeed.

Peat is, basically, a collection of partially decayed trees and plants accumulated in water-logged areas - that is, areas with low rates of drainage.

Borneo peat swamp forests are predominantly found around the coastal areas of West Kalimantan (Indonesia) and Sarawak (Malaysia).

Although peat swamp soils are nutrient-deficient and their forests are not as species-rich as lowland rainforests (with very few endemic species), many trees and animals found in lowland forests are found here as well.

Peat swamp forests serve a very important function of carbon reservoirs.

However, in times of droughts they can be highly susceptible to fires (some of which may be deliberately set by people) releasing carbon into the atmosphere. What makes the situation worse is the fact that peat fires can even spread underground and break out in unexpected locations.

Borneo Mountain (Montane) Rainforest

Overview, Distribution and Climate

borneo mountain rainforest, foot of mount kinabalu Foot of Mount Kinabalu
Borneo Montane Rainforest
© Thienzie Yung

While Borneo's lowland forests and peat swamp forests have a lot in common including many species of plants and animals, the island's mountain rainforests are quite different from the rest of its territory.

As we saw on the map above, most of Borneo mountain rainforests cover central and north-eastern parts of the island. Mountains are, of course, a natural setting for rivers and valleys, of which we find many in Borneo.

The climate in the mountains is obviously much cooler than that in the lowlands and peat swamp forests.

As mountains get higher, the temperatures get cooler; there will be lots of clouds hugging the mountains and offering plenty of moisture as well. The trees here are generally smaller in size, and shorter in height.

It is interesting to note that, due to these features, Borneo's montane rainforests have many plant species that are also found in temperate rainforests in other parts of the world.

Mount Kinabalu is the highest mountain in Borneo, with its peak located at 4,095 meters above the sea level. It is a popular tourist destination, especially for those who love climbing.

Borneo Rainforest Biodiversity, Animals and Plants

Borneo rainforest is, undoubtedly, one the world's top biodiversity hotspots.

A biodiversity hotspot is an area with an exceptionally high number of plant and animal species. The world's tropical rainforests are home to many of such concentrations of biodiversity.

Borneo is certainly one of these places that never stop to amaze us with all the variety of life that they offer.

Wikipedia reports that Borneo rainforest hosts (ref. 9):

  • 15,000 species of flowering plants and 3,000 species of trees;
  • 221 species of terrestrial mammals;
  • 420 species of birds; and
  • 440 species of freshwater fish.

Many of these species are endemic to Borneo.

On top of that, we know that an infinite number of species has not even been identified by science yet. So since we still don't know a lot about this eco-system, we can't quite appreciate a true extent of the richness of life on this island.

Lots of charismatic animals - such as the orangutan, the pygmy elephant, the rhinoceros - call Borneo home.

Unfortunately, many of Borneo's animal and plant species are becoming increasingly endangered and even extinct, mostly as a result of their rainforest habitat loss due to human actions.

The pressure is now on for us, the human race, to save as much of biodiversity on Borneo as we only can.

We are looking into Borneo's deforestation in the chapter below.

Borneo Rainforest Destruction


borneo deforestation, map Borneo Deforestation, 1950 - 2012
© Hugo Ahlenius, UNEP/GRID-Arendal

Nothing can depict any given situation better than a picture.

Let's take a look at the image on the right. It was produced by a UNEP/GRID-Arendal team demonstrating all too well just how badly destroyed the Borneo rainforest has become over the last several decades.

As of 1950, almost all of Borneo's territory was covered in rainforest. That was obviously before the demands of modern consumption-driven lifestyles have taken over the traditional ways of life - in harmony with nature.

By 2005, it appears as if at least 30% - 40% of the island's forest cover has been destroyed for good.

So what is causing such a sad state of affairs?

First and foremost, top-quality ancient trees are being cut down for all sorts of industrial and otherwise commercial use. Most of this timber is being exported to Asian and Western markets alike.

Second, forested lands are being actively cleared to make space for all types of agricultural exploitation but specifically for disastrous oil palm plantations.

Third, degraded Borneo rainforests are now highly susceptible to fires. In fact, two huge fires brought about by El Nino-caused droughts - one in 1982 and 1983, and another in 1997 and 1998 - led to a virtual obliteration of many thousands of square kilometers of the rainforest.

Generally speaking, lowland rainforests are hugely affected by logging because they are easier to access than mountainous forests. Peat forests catch fire easily and so are a target for clearance too. Montane rainforests have been a bit "luckier" - due to the difficulty in accessing them, they have not been as affected as lowland and peat rainforests.

And that is exactly what we can see on the map above - the north-eastern part of the island which is mostly covered in mountains is still green while other parts around the mountains have been vastly cleared.

Illegal logging is another huge problem. This process takes place outwith areas licensed for legally permitted logging. We know that China is the biggest consumer of illegal timber from Borneo, but many other countries are complicit in this crime as well.

In fact, our insatiable demand for timber plus corporate greed are probably the main root-causes of Borneo's deforestation.

Many conservation charities claim to support "sustainable logging".

Well, guess what? There is NO such a thing as sustainable logging.

Any type of logging implies degradation or complete destruction of ancient rainforests. Just exactly how can this process be "sustained" when Borneo's biodiversity - much of which has not even been scientifically described yet - is destroyed forever for the sake of producing some throw-away products?

Just think about it, create this picture in your mind: a huge trunk of an ancient tree is being dragged away by a truck for the manufacture of some furniture that will be discarded as waste 10 years down the road.

Looks horrible, doesn't it?

But also, think about this: a major conservation charity explains that if a certain type of machinery is used to remove this trunk from the forest, then a lot less damage will be done to the surrounding trees. And so this charity tries to get us to believe that this, actually, can be called "sustainable logging".

oil palm plantation, borneo, kalimantan Oil Palm Plantation, Central Kalimantan, Borneo
© Glenn Hurowitz

Well, here is my opinion - there is no such a thing as "sustainable logging". Logging of ancient trees is just that - logging. It doesn't matter what type of machinery is used - ancient trees are still being killed for some disposable products perpetuating our culture of throwaway consumption.

Unfortunately, many conservation charities pretend that they protect the rainforests, while in fact they end up protecting the profits of logging companies and peddling this classical type of green-washing along the way.

So, once the forests are logged and lands are cleared, what do we see next? Awful oil palm plantations.

They are the very opposite of lush, biodiverse rainforests.

Oil palm plantations look ugly and highly monotonous - rows upon rows of oil palm trees planted with an unnatural robotic precision - they now look more like a highly calculated computerized geometric shape rather than a natural, totally spontaneous forest habitat.

This is how modern cultures treat the nature - "civilized" societies believe that they need to "manage & control" the nature, instead of living in harmony with it.

But this has not always been like that. Numerous tribes that still reside within Borneo rainforests know how to use natural resources wisely, without causing any damage to the environment.

One local tribe shows us how to do just that.

Wisdom of Local Tribes in Borneo Rainforest Preservation

Indeed, local tribes have lived in harmony with nature for many thousands of years - they know how to tend to the land and look after their precious rainforests.

omalung, dayak tribe, setulang, borneo Omalung Tribe, Dayak
Setulang River
© United Nations University

One excellent example of that is a tribe called Oma'lung, which is part of the Dayak Kenyah tribe.

The Oma'lung live in Setulang Village, in the north-eastern part of Borneo.

The tribe leader tells us that each family within the tribe is allocated 10 plots for a rice paddy. Every year only one plot is used for growing rice. They cut down some trees on this land and then burn them - they believe this enriches the soil with nutrients.

During the second year another plot of land is cleared. And this cycle goes on for 10 years, after which the family returns to its first original plot for rice growing.

And there is also "the forbidden area" - where it is strictly forbidden to log the forest for any purpose. This area is called Tana Olen.

The tribe leader says that the village people understand the agreement of their great grandparents. There is a designated area for a paddy field, an area for gathering housing and construction wood, and an area that is Tana Olen ("forbidden forest") - where no one is allowed to damage or log trees.

They believe all of the trees in Tana Olen keep Setulang river's water clean. They always check that the trees in Tana Olen have not been illegally logged. And they understand that if the trees are cut, the river will eventually stagnate.

The traditional law of Setulang Village states that anyone who will cut down trees in Tana Olen will be punished.

Isn't this a wonderful example of how it is possible to meet one's physiological needs and preserve the forests at the same time?

* This information was extracted from the United Nations University's video on YouTube. (Ref. 10)

I am calling upon everyone to do everything we can to protect our rainforests - our future depends on it.

Written by:     Irina Bright
Original publication date:     2013
Republication date:     2020


1. Borneo. (December 13, 2012). In Wikipedia, The Free Encyclopedia. Retrieved December 30, 2012 from

2. Wikipedia references

3. Borneo. (December 13, 2012). In Wikipedia, The Free Encyclopedia. Retrieved December 30, 2012 from

4. Ibid.

5. Merrill, E.D (September, 1921). A Bibliographic Enumeration of Bornean Plants. Journal of the Straits Branch of the Royal Asiatic Society. Retrieved December 22, 2012 from

6. Borneo lowland rain forest. (November 21, 2012). In Wikipedia, The Free Encyclopedia. Retrieved December 30, 2012 from

7. World Wildlife Fund (Lead Author); McGinley, M.; Hogan, M. C. (Topic Editor). Borneo lowland rainforests. In: Encyclopedia of Earth. [Last revised Date August 21, 2011]. Retrieved December 30, 2012 from

8. Ibid.

9. Borneo. (December 13, 2012). In Wikipedia, The Free Encyclopedia. Retrieved December 30, 2012 from

10. Borneo: The Forbidden Forest of the Dayak (Indigenous Perspectives on Climate Change). (January 3, 2012). By United Nations University. Retrieved December 30, 2012 from