LEUSER NATIONAL PARK - Patrick Morell

GUNUNG LEUSER NATIONAL PARK

Sumatra. Indonesia

The Leuser Ecosystem: A Sanctuary on the Brink

Stepping into the Leuser rainforest is like entering another world — dense, damp, and humming with life. Every breath of air is thick with moisture. Roots snake underfoot. The canopy stretches like a living ceiling above, fractured by sudden shafts of light and the echoing call of unseen creatures.

Gunung Leuser Nationa Park
Sumatra, Indonesia

2024
4K
Reel Duration: 2’11”

Related Reels

Reflections on Rain in the Rainforest

The rain is the rainforest’s heartbeat.

Essential to Biodiversity: Regular rainfall supports the astonishing density and diversity of life in tropical rainforests — from fungi and ferns to frogs, insects, and megafauna. Every drop helps regulate humidity levels that species are adapted to over millennia.

Part of the Hydrological Engine: Rainforests are giant atmospheric water pumps. Trees release moisture through transpiration, which rises, condenses, and falls again — making rain both a product and a cause of the forest itself.

Soil Nourishment & Decomposition: Rain triggers cycles of decay and renewal, helping fallen leaves, deadwood, and even animals return to the soil. The nutrients released are absorbed quickly by roots in this thin but dynamic topsoil layer.

Cultural and Spiritual Value: In many Indigenous cultures of Borneo (including the Dayaks and Kutai peoples), rain is seen as a gift from ancestral spirits or forest guardians, often tied to myths of fertility and cleansing.

Filmmaking in the Rainforest

For a filmmaker, the rainforest of Gunung Leuser is both a gift and a trial. The terrain is punishing — steep, tangled, and endlessly wet. Setting up a tripod becomes an act of acrobatics. The sound of falling rain competes with cicadas, gibbons, and the distant rumble of hornbills in flight. But it is here, in this last wild frontier of northern Sumatra, that Earth’s story still writes itself in ancient, unbroken verses of nature’s splendor and vulnerability.

Gunung Leuser National Park
Sumatra, Indonesia

Inside the forest

2024
4K
Reel Duration: 1’33”

Strangler Fig Root System

An ancient grip on life. Strangler figs wrap their roots around host trees, growing downward from seeds left by birds and bats high in the canopy. In time, they form their own mighty trunks — shaped by both conquest and collapse.

Threat to wildlife

The Leuser Ecosystem — stretching across 2.6 million hectares — is one of the most biodiverse regions on the planet. It is the only place on Earth where orangutans, elephants, tigers, and rhinos still coexist in the wild. A sanctuary, yes — but one under siege. Encroaching roads, palm oil plantations, and illegal logging continue to fragment this green stronghold.

And yet, the forest endures. You just have to know where — and how — to look

Map. of Sumatra. Courtesy of Conservation international

TREES

Trees are not merely trees — they are timekeepers.
Many of Leuser’s towering dipterocarps and ironwoods have stood for hundreds of years, some even approaching a millennium. Their trunks stretch high above the canopy, straight and patient, each ring a chapter in an ecological history few of us will ever fully read.

In primary forests like this, trees grow slowly but steadily — taking up to a century just to reach 30 meters in height. Their roots anchor not just soil, but memory — of rainfall patterns, pollinators, fires, and migrations.

To lose such a tree is to erase more than biomass. It is to erase time.

Gunung Leuser National Park. PM Photo 2024

Photo 1 top left: An ancient giant rises through the canopy of Gunung Leuser — a testament to centuries of unbroken growth. Trees like this not only store carbon but shelter entire ecosystems in their folds of bark, roots, and limbs.

Photo 2 bottom left: The vertical architecture of Gunung Leuser’s rainforest—slender trunks rising in quiet competition for light. In this layered world, every level of the canopy tells a different ecological story, from soil-dwelling fungi to treetop primates.

Gunung Leuser National Park
Sumatra, Indonesia

Trees 1

2024
4K
Reel Duration: 0’50”

Gunung Leuser National Park
Sumatra, Indonesia
Trees 2

2024
4K
Reel Duration: 1’22”

A natural doorway. Some trees in the Leuser forest grow hollowed over decades, forming sculptural bodies shaped by time, decay, and resilience.

Hollowed Giant with Forest Floor Vines (SIB04563.jpg)

This is a hollow-trunked tree, possibly another fig species (Ficus macrophylla or Ficus albipila), known for their aerial roots and strangler formations.The natural arch in the trunk evokes a forest cathedral or a gate — a visual metaphor for entry into a sacred world.

Detail of fig species (Ficus macrophyllia) ,

The tangled roots in the foreground anchor the viewer back to the forest floor, balancing the vertical energy with grounded chaos.

Buttress Roots & Epiphyte Vine (SIB04520-Enhanced-NR.jpg)

This is a buttress-rooted tree, likely a fig (Ficus) or dipterocarp species. The sweeping, wing-like flanges are a classic rainforest adaptation that:

Provides stability in shallow, thin soils, typical of tropical rainforests.
Offers natural pathways for insects, amphibians, and even small mammals.
Often supports epiphytic vines, as seen climbing upward — a vertical chain of life from soil to canopy.

Gunung Leuser National Park
Sumatra, Indonesia
Hollow-trunked tree, (Ficus macrophylla or Ficus albipila)

2024
4K
Reel Duration: 1’41”

Is Gunung Leuser forest a primary forest?

Much of Gunung Leuser still qualifies as primary forest — an ecosystem shaped not by machines or chainsaws, but by time, weather, and life itself. These forests have regenerated over centuries without industrial disturbance, preserving their original canopy, native species, and deep ecological memory.

But “primary” does not mean untouched.
In Leuser, one finds storm-felled giants, scorched trunks, vines strangling the light, and hillsides reshaped by landslides.
And yet, the forest holds — evolving, adapting, and continuing the story it began long before we arrived.

These untouched ecosystems — like the one that shelters the Thomas’s leaf monkey — are shaped by centuries of natural growth.
Every tree, root, and branch is part of a complex web that has evolved without human interference — a forest still in conversation with itself.
It is in places like these that rare species thrive, hidden in the folds of time.

Towering Dipterocarp Tree (SIB04641-Enhanced-NR.jpg)

Massive emergent tree, most likely from the Dipterocarp family, which dominates the upper canopy in Southeast Asian rainforests. These giants often rise above 60 meters and are essential for:

Orangutan movement: They use these highways of branches to travel vast distances without touching the ground.

Epiphytes and mosses: Note the lush green carpets of ferns and vines coiling up the trunk — classic rainforest layering.

Symbolism: This could be a metaphor for endurance —

“a cathedral of green,” deeply rooted and reaching skyward.

Thomas’s Leaf Monkey (Presbytis thomasi), Gunung Leuser. PM Photography 2024

Sometimes called the long-tailed langur, this primate is endemic to northern Sumatra. Known for its distinctive facial markings and spiky crest, the Thomas’s leaf monkey is both elusive and social — often seen in small, agile groups leaping through the canopy.

Gunung Leuser National Park
Sumatra, Indonesia
Leaf monkey or Long Tailed langur also known as Thomas’s Leaf Monkey (Presbytis thomasi)

2024
4K
Reel Duration: 4’30”

BIODIVERSITY

Leuser is often called the lungs of Sumatra, and for good reason. The forest is home to over 130 species of mammals, more than 580 species of birds, and hundreds of amphibians, reptiles, and rare plants — many found nowhere else on Earth. Towering dipterocarp trees rise above the canopy. Hidden orchids bloom in misty glades. Leaf monkeys leap between branches. Sumatran clouded leopards stalk unseen.

Every layer of the forest — from its forest floor to its tallest emergent trees — is alive with evolutionary drama.

This biodiversity is not only vital to the planet, it is sacred to those who live with it, and impossible to replace once gone.

Cup Fungi on Decay (SIB04685.jpg) This shows a colony of bright orange cup fungi, likely from the genus Cookeina (possibly Cookeina tricholoma), growing on a decaying branch.

These fungi are: Indicators of healthy decomposition cycles in rainforests. Often found on fallen logs, playing a vital role in nutrient recycling. Their shape captures water and spores — miniature vessels of regeneration. From a filmmaker’s eye, this is the microcosm to the emergent tree’s macrocosm — a perfect pairing to visually illustrate the forest’s vertical richness, from soil to sky.

Fern frond, particularly a delicate species of epiphytic fern —meaning it grows on other plants (like tree trunks) without harming them.

These are common in humid, tropical primary forests like Leuser, where filtered light and moisture allow them to thrive even high in the canopy.
Dark green crustose or foliose lichens appears on the bark of a tree.

Lichens are not plants — they are symbiotic organisms, formed by a partnership between fungus and algae (or cyanobacteria). They don’t have roots, and they absorb everything — water, nutrients, pollutants — from the air and rain.

Fern and lichen — quiet companions of the rainforest. One grows in shadow, the other lives off air and light. Together, they speak to the stillness and purity of Leuser’s forest micro-worlds.

Gunung Leuser National Park
Sumatra, Indonesia
Ants.

2024
4K
Reel Duration: 0’40”

ANTS
Beneath the roots and between the branches, the forest marches on six legs at a time.
|In the depths of Gunung Leuser, ants are more than background noise — they are architects, hunters, farmers, and warriors. Some of them are also shockingly large.

One of the most striking is the giant forest ant (Camponotus gigas), one of the largest ants in the world, with queens reaching up to 2.5 cm in length. These ants form massive colonies and forage in coordinated lines, often seen moving silently along tree trunks or across the forest floor.

Gunung Leuser National Park
Sumatra, Indonesia
Butterfly called Neptis hylas (“The Common sailer”)

2024
4K
Reel Duration: 01’56”

Butterfly
The butterfly shown is likely from the genus Neptis — commonly referred to as “sailers.” or Neptis hylas – “the Common Sailer”

Sailers like Neptis hylas are indicators of healthy understory conditions — they thrive in dappled light and near leaf litter, where minerals and moisture are plentiful.

They share the forest floor with ants, fungi, and decomposing leaves — all part of the silent work of renewal in tropical ecosystems.

Bracket fungi or shelf mushrooms. also knowm as the Turkey Tail Mushrooms.

Forest architects. These bracket fungi are not poisonous — but they are powerful recyclers, breaking down dead wood and returning nutrients to the soil. Without fungi, there would be no rainforest floor — only layers of the dead.

Like the Cup Fungi these mushrooms are the forest decomposers.

To walk through Leuser is to feel both deep time and immediate threat — a living world now fraying at its edges.
The same roots that nourish rare orchids and shelter orangutans are increasingly exposed to chainsaws and road maps.
The battle for Leuser is no longer about conservation alone — it is about memory, identity, and the limits of our collective will.

In the Footsteps of Giants: The Ketambe Research Station

Deep in the Leuser interior, along the upper Alas River, lies the Ketambe Research Station — a place of quiet endurance and extraordinary scientific legacy. Established in 1971, Ketambe is the world’s first orangutan research center, and the birthplace of modern primate fieldwork in Sumatra.

Ketambe Research Station, and town located in Aceh Tenggara District, Northern Sumatra. Indonesia. PM Photo 2024

Gunung Leuser National Park
Ketambe research station
Sumatra, Indonesia

2024
4K
Reel Duration: 01’57”

Alas river in Aceh Tenggara District, Northern Sumatra. Indonesia. PM Photo 2024

Gunung Leuser National Park
Alas river & Aceh fisherman
Sumatra, Indonesia

2024
4K
Reel Duration: 03’50”

Here, for over five decades, researchers have tracked wild orangutans by foot through some of the harshest terrain imaginable — recording vocalizations, observing maternal bonds, mapping home ranges, and documenting tool use long before such behaviors were widely recognized.

To walk the trails of Ketambe is to follow the footsteps of giants — not only the great apes themselves, but the women and men who made their lives’ work understanding them.

Haspy Ketambe and "the professor"Ibrahim Chane. Lodge in Ketambe

Guided by Wisdom: Ibrahim, "The Professor"

Ibrahim, affectionately known as “The Professor,” is our guide through these enchanted forests. His lifelong commitment to Leuser has made him not just a caretaker but a storyteller, whose insights into the ecosystem’s wonders and woes are unmatched. Ibrahim’s deep connection to the land and its creatures offers a unique, personal perspective on the challenges and triumphs of conservation.

As he leads us through the dense forests, his passion for the land and its inhabitants is evident in every step he takes. As we walk through the lush terrain, Ibrahim stops to show us the rare flora and fauna that call this place home. With a gentle touch, he explains the delicate balance that sustains this ecosystem. “The Leuser Ecosystem is a living testament to nature’s resilience,” he says, “but it is fragile, threatened by the encroaching hand of man.”

Interview with Prof Ibrahim Chane (excerpt #1)
Gunung Leuser National Park
Sumatra, Indonesia

2024
4K
Reel Duration: 04’42”

Interview with Prof Ibrahim Chane (excerpt #2)
Gunung Leuser National Park
Sumatra, Indonesia

2024
4K
Reel Duration: 06’09”

The forest never grows in straight lines. Lianas — thick, woody vines — twist their way toward the canopy, creating bridges for primates and patterns that seem to mimic the flow of time itself.

Spiral Lianas – Vines of the Rainforest . PM Photos 2024

Eusideroxylon zwageri (Bornean Ironwood / Kayu Ulin) PM Photo 24

Ironwood — known locally as Kayu Ulin — is among the rainforest’s most enduring trees. So dense it sinks in water, its trunk resists time, rot, and flame. Often wrapped in vines or epiphytes, it becomes a silent spine of the forest — anchoring life around it.

Native to Borneo and parts of Sumatra.

Revered for its incredibly dense, rot-resistant wood.t.
In mature forms, it often has deep buttress roots and a twisting outer sheath.

Known locally as a “ghost tree” due to its resistance to decay even after deat

Under Siege: The Battle for Leuser

While parts of it are included in the UNESCO-designated Tropical Rainforest Heritage of Sumatra (inscribed in 2004), the region has been on UNESCO’s List of World Heritage in Danger since 2011 due to illegal logging, road construction, and forest fragmentation.

Known as one of the last places on Earth where orangutans, elephants, tigers, and rhinos still live together in the wild, Leuser is under constant threat from commercial exploitation — palm oil, mining, road development — and a dangerous lack of oversight.

Palm Oil field. East Kalimantan. PM Photo 2023

Since the end of local conflicts in 1998, Leuser has become a prime target for exploitation. The rainforest faces relentless pressures from palm oil magnates, loggers, and miners, threatening to tear apart this fragile ecosystem. This encroachment not only jeopardizes the wildlife but also the very air we breathe, turning rich forests into haze-filled skies that affect millions.

The Warning from the East

In East Kalimantan, across the sea in Borneo, I have walked through landscapes that once echoed with the same rainforest symphony as Leuser. But many of those forests are now gone — replaced by silent fields, felled trees, and the empty stillness of absence.

Burnt field. East Kalimantan PM Photo 2023

An excavator operating at Mr. Jumady’s palm oil concession inside the Gunung Leuser National Park, near Tenggulun village, Aceh Tamiang, Indonesia, in August 2023. Image courtesy of RAN and Montgabay..

Mine. East Kalimantan PM Photo 2023

Deforestation for palm oil. East Kalimantan PM Photo 2023

A Global Responsibilty

Beyond its wildlife, Leuser also protects human life — providing clean water, flood regulation, and carbon storage for millions living downstream.

The Leuser Ecosystem is not just Indonesia’s treasure — it is the world’s.

And yet, its fate remains in limbo. While sections of this rainforest fall under the broader UNESCO-designated Tropical Rainforest Heritage of Sumatra, the protections are incomplete, enforcement is patchy, and large swaths remain vulnerable to deforestation, mining, and road building.

Conservation is no longer the work of a few — it is a global responsibility.

International NGOs such as the World Wildlife Fund, Conservation International, Rainforest Action Network, and the Orangutan Land Trust advocate tirelessly on behalf of ecosystems like Leuser. They work in parallel with committed local allies such as HAkA, OIC, and the Sumatran Orangutan Conservation Programme, who walk the forest floor, day after day, repairing the damage and fighting for its future.

But what these forests need now, more than anything, is visibility — the kind that inspires action, funding, and protection.

That is why we came.
To tell the story of a rainforest — not as a concept, but as a living, breathing world.

There is still time. But not much.

For an in-depth look at the challenges facing Leuser and how you can help, visit Global Conservation’s dedicated project page.

Gunung Leuser National Park
Alas river and forest in morning light
Sumatra, Indonesia

2024
4K
Reel Duration: 02’40”

Female Orangutan feeding inj the tree. PM Photo 2024

✅ International Conservation Organizations

Rainforest Action Network (RAN) – involved in Leuser campaigns
📎 https://www.ran.org/campaign/leuser/
World Wildlife Fund (WWF)
General rainforest and orangutan conservation in Indonesia
📎 https://www.worldwildlife.org/places/borneo-and-sumatra
Conservation International – not focused exclusively on Leuser, but active in Indonesia
📎 https://www.conservation.org/projects/indonesia-conservation-initiatives
Orangutan Land Trust – led by Michelle Desilets; supports habitat protection
📎 https://www.orangutanlandtrust.org/

Maps by Towering Dipterocarp Tree (SIB04641-Enhanced-NR.jpg)