News | Thursday, 4th July 2019

“Extinct” tree re-discovered by ecology student on Indonesian island

The finding of Kalappia gives new hope to conservationists

Liam Trethowan re-discovers Kalappia
Liam Trethowan re-discovers Kalappia

A rare tree has been re-discovered in a remote area of Indonesia decades after it was thought to be extinct.

Liam Trethowan, an ecology PhD student at Manchester Metropolitan University, spotted a cluster of ‘Kalappia’ trees some 200 km from where it was last seen in the 1970s while conducting fieldwork in the Indonesian rain forest as part of a research trip to the Asian nation

The discovery, near the settlements of Abuki and Kolaka on the Indonesian island of Sulawesi, raises hope among conservationists that many trees thought to be endangered or extinct may still survive in remote and under explored areas.

Trethowan published his findings in Ecology, the journal of the Ecological Society of America, entitled: An enigmatic genus on an enigmatic island: The re‐discovery of Kalappia on Sulawesi. The Kalappia tree stands 20m tall – though rumoured to reach 40m – and has bright yellow flowers that feature a unique spike, known as spurs, that are used by bees when they feed at the flower.

The bees create vibrations that cause the flower to release pollen, which they transport to other trees to allow them to reproduce.  


For years, Kalappia was exploited for its timber and used for house construction, shipbuilding and furniture manufacture.

This practice, as well as nickel mining and gas extraction, was a major contributor to deforestation and led to the International Union for Conservation of Nature categorising the species as ‘vulnerable’ in 1988.

Trethowan said: “No reports of the tree had been made since the 1970s and experts believed the tree must be extinct.

“I was really keen to go into under-explored parts of the forest whilst in Indonesia because that is where new or long since lost species can be found.

“It is also very rare to find rain forest trees in flower, which meant we could photo and closely examine this species for the very first time.”

Francis Brearley, Senior Lecturer in Ecology at Manchester Metropolitan and supervisor of the PhD research project, added: "The rediscovery of Kalappia highlights the lack of knowledge and information we have about the forests we have around us – we could be losing species that are actually just hidden in these areas.

“The failure to collect data is due to difficulties with accessibility in these areas. However, to gather baseline knowledge about rare and threatened species, exploration of remote areas is crucial and should be encouraged and, crucially, financially supported.”

Climate change

The finding of Kalappia and its close relatives in the legume family offer the chance to understand more about why plants exist in different places.

Not all these legume trees are found in the Asian rain forest, as some also exist in the arid regions of Australia. 

After closer examination of Kalappia and its relatives, Trethowan found that these species grow in harsh metal-rich environments.

He suggests that due to this, these trees might also be able to tolerate and survive in the harsh, dry environments of Australia. 

These findings may help researchers understand which plant groups will survive as the Earth’s climate changes and rain forests experience more droughts and become more difficult habitats for plants to survive in.

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