Borneo’s worrying divide

Aerial mapping of Malaysian Borneo has revealed worsening carbon losses along forest edges, according to a new US study.

Researchers from Arizona State University (ASU) and Harvard University say the negative changes to forest structure following the conversion of forest to palm oil plantation has worsened over time and extended further into remnant forests than previously known.

They say data obtained by ASU’s Global Airborne Observatory also highlights changes to three important canopy traits related to a tree’s ability to capture sunlight and grow. These correspond to an average 22% decline in above-ground carbon storage along forest edges and extend more than 100 metres into the forest interior.

Consequently, even forests set aside for conservation are vulnerable to experiencing long-lasting declines in their capacity to store carbon simply if they are adjacent to plantations.

“Our study suggests a need to mitigate edge-related declines in forest carbon stocks by creating buffer zones between intensively farmed areas and forest ecosystems,” says Harvard’s Elsa Ordway, lead author of a paper in the journal Proceedings of the National Academy of Sciences.

As remnant tropical forests make up the largest terrestrial share of the global carbon budget and nearly 20% are located within 100 metres of a non-forest edge, a decrease in local carbon storage for these important ecosystems has global implications, the researchers say.