The governor of Aceh province in Sumatra, Zaini Abdullah, has executed a high court order and revoked an illegal permit to cultivate oil palms in the Tripa peat swamp forest, an area that is home to the highest-density population of Sumatran orangutans in the world.

Environmentalists have hailed the decision, which comes after a lengthy legal battle and widespread protest.

Since March, the company PT Kallista Alam has been slashing and burning Tripa to make way for oil palms. The destruction provoked international outrage and 10,000 people signed an online petition.

The patrons of the Great Apes Survival Partnership joined the protest and wrote to the Indonesian president asking him to halt the destruction of Sumatra’s rainforests and enforce laws to protect orangutans and their habitat.

Sumatran orangutans are critically endangered. There are only about 6,500 orangutans left on the island, mainly in the northern and western provinces.

The expansion permit that has now been revoked was given to PT Kallista Alam in August 2011 by the then governor of Aceh, Irwandi Yusuf.

The Administrative High Court of Medan ordered Abdullah to revoke the permit, which would have allowed PT Kallista Alam to plant oil palms on 1,605 hectares of the Tripa peat swamp.

There are five palm oil companies operating within Tripa; police and the attorney- general are investigating the slash-and-burn activities of two of them: PT Kallista Alam and PT SPS 2 (formerly PT Astra Agro Lestari).

The peat swamp forest lies within the protected Leuser ecosystem and, as such, should be off-limits for conversion.

The area was originally included in a moratorium map that indicates which areas are off-limits for conversion, but was absent from a revised version. It has now been re-declared a protected zone.

A spokesman for PT Kallista Alam said the company would accept the decision taken by the governor on the orders of the court.

The group Walhi (Friends of the Earth Indonesia) is at the forefront of the battle to save Tripa. The group has urged the Aceh governor to evaluate all plantation permits given to companies in the Tripa area and has called for all legal action being taken against companies operating in Tripa to be dealt with as a matter of urgency.

Walhi’s national executive director, Abetnego Tarigan, said the high court’s decision was a precedent for environmental conservation efforts and the enforcement of environmental law in Indonesia.

“For once, this is a decision that favours the environment and the people. It should be used as a reference point by the government. There should be a review of all forest industry licences in Indonesia.”

The executive director of Walhi Aceh, Teuku Muhammad Zulfikar, said it shouldn’t be necessary to have to resort to the courts for permits to be revoked. “If companies do not comply with the existing laws and regulations, and inflict losses for Aceh, they should be sanctioned.”

The court decision was also welcomed by the REDD+ task force. The international “Reducing Emissions from Deforestation and Forest Degradation” initiative is aimed at boosting efforts to conserve and sustainably manage forests and increase carbon stock. Developing countries are offered incentives to reduce emissions from forested lands and invest in low-carbon paths to sustainable development.

“We hope there will be no more mismanagement in the process of permit issuance,” said Mas Achmad Santosa, who chairs the task force’s legal review and law enforcement working group.

The Coalition for the Protection of Tripa said the revoking of PT Kallista Alam’s permit was an historic landmark, but was only the first step on a long road to save Tripa and the Leuser ecosystem as whole.

“Tripa shows us that moratoriums without law enforcement are meaningless. Until companies and their owners are prosecuted for illegal behaviour to the full extent of the law, they will continue to destroy Indonesia’s amazing natural and cultural heritage,” said a spokesman.

P.T Kallista Alam cannot appeal against the high court ruling. “All of the company’s activity on the 1,605-hectare plantation must stop”, said Aceh government spokesman Makmur Ibrahim. “It will be a violation of the law if it continues to operate.”Aceh’s Forestry and Plantation Agency would monitor the company to ensure that it complied with the order, he added.

This is the first time the Aceh government has revoked a palm oil permit.

The Tripa peat swamp is a UNEP/UNESCO Great Ape Survival Partnership priority site for great ape conservation.

Ian Singleton, conservation director of the Swiss-based PanEco Foundation and head of the Sumatran Orangutan Conservation Programme, says the destruction of the peat swamp is bringing the animals to the brink of extinction.

There were some 2,000 to 3,000 orangutans in the Tripa area in the 1990s, but only a few hundred at most are left today.

“We suspect that at least 100 orangutans have perished in recent forest clearing and peat burning,” Singleton said. “Another 100 orangutans are estimated to have died between 2009 and 2011 – killed either in the conversion process or because of starvation and malnutrition.”

Orangutans are not the only animals affected by the destruction of Tripa; the area has also been home to Sumatran tigers, Malayan sun bears, and other endangered and protected wildlife. It is impossible to know how many of them have perished.

Residents of villages in the Tripa area say that since PT Kallista Alam began operating there, the level of water in their wells has dropped dramatically.

Only about 12,000 hectares of the original 61,800 hectares of peat swamp forest remain. The rest has been broken up and degraded as palm oil companies drain the swamp.

In just five days in March 2012 there were no less than 87 fire hotspots (major fires detectable by satellite) in three of the oil palm concessions within Tripa (those owned by PT Kallista Alam, PT SPS 2, and PT Dua Perkasa Lestari).

This was the highest intensity of fire hotspots recorded in a 5-day period in Tripa since satellite monitoring of Indonesia’s fire hot spots began in late 2000.

At least 2,800 hectares were devastated by the March fires, and most of the hotspots occurred on the deepest peat.

Peatlands lock up huge amounts of carbon, so it is essential to conserve them. No less than ten million of Indonesia’s 22.5 million hectares of peatland have already been deforested and drained.

Tripa contains between 50 and 100 million tonnes of carbon and it should be a net carbon store. However, because of the destruction being wreaked by the palm oil companies, huge quantities of carbon are being released.

The international demand for palm oil is massive; it is present in all kinds of foodstuffs and cosmetics, and its use is now extending to biodiesel.

Indonesia is the world’s main palm oil producer. The country already has 6 million hectares of oil palm plantations, but has plans for another 4 million by 2015 dedicated to biofuel production alone.

According to the environmental organisation Greenpeace, “this phenomenal growth of the palm oil industry spells disaster for local communities, biodiversity, and climate change”.

Indonesia’s peatlands cover less than 0.1 per cent of the Earth’s surface, but, because of the way they are being destroyed, they are now responsible for 4 per cent of global greenhouse gas emissions every year.

Destruction of the Tripa peat swamp also results in reduced buffering against flooding and drought. The area was hit by a tsunami in 2004 and needs all the protection it can get.