Tree islands “restore biodiversity” in oil palm farms

Environmentalists have long worried about the negative impacts of oil palm cultivation, especially on biodiversity when forests are burned and turned into plantations.

Now researchers say there is a solution that could mitigate the damage. Setting up small forest clusters or “tree islands” in large oil palm farms can help restore biodiversity and ecosystems by aiding the natural regeneration of native trees, their study suggests.

Increasing international demand for palm oil has triggered vast forest destruction in Indonesia and Malaysia – responsible for 85 per cent of global palm oil production. These plantations have been a catastrophe for endangered animals, such as tigers in Indonesia’s Sumatra. They also aggravate conflicts with local Indonesian communities over traditional land rights.

In 2023, with the production of 47 million tonnes of crude palm oil, Indonesia became the leading palm oil exporter in the world. But in the past two decades, the country has also lost 3 million hectares of natural forest areas, thanks to the spread of oil palm plantations.

Extensive conversion of forests into oil palm plantations leads to alarming loss of biodiversity
 

Published in November in the journal Science, the study says that the extensive conversion of Southeast Asian natural forests into plantations of African oil palm (Elaeis guineensis Jacq.) has led to alarming losses of biodiversity, ecosystem functioning and evolutionary history. The researchers maintain that it is essential to protect the remaining forests to conserve their rich, tropical biodiversity.

In the study, the researchers looked at how ecological restoration contributes to the recovery of biodiversity in oil palm agricultural areas in Sumatra. The researchers strategically planted trees to set up 52 tree islands of different sizes and diversity levels to find out how the restoration strategies influence biodiversity in the oil palm agricultural area.

“The main implication of our study is that it supports the use of tree islands, strategically planted patches of native vegetation within agricultural landscapes, as a viable approach to restoring plant diversity in oil palm landscapes,” says Gustavo Paterno, an author of the study and postdoctoral researcher at Göttingen University in Germany.

The researchers observed that six years after being set up, tree islands hosted a broad range of native species, including more than 2,700 woody plant species.

They say developing large and diverse tree islands is important for conserving “rare, endemic, and forest-associated” plant species in oil palm agricultural areas.

Tree islands speed up the natural revival of native trees by helping the spread of seeds by birds and wind, according to the study. This process improves biodiversity, important for developing resilient ecosystems that can resist climate change.

“Our study demonstrates the potential of tree islands to transform biodiversity-poor agricultural lands into biodiversity-enriched ecosystems, offering a promising restoration strategy for oil palm landscapes,” says Paterno. “Based on these results, we recommend the establishment of large tree islands with a high initial diversity of planted tree species to promote biodiversity recovery within conventional oil palm plantations,” he maintains.

(SciDev.Net/Sanjeet Bagcchi/wi)

Reference:

Gustavo B. Paterno et al: Diverse and larger tree islands promote native tree diversity in oil palm landscapes; Science, 14 Nov 2024, Vol 386, Issue 6723, pp. 795-802. DOI: 10.1126/science.ado1629