Oil palm cultivation linked to significant watershed disturbances

Oil palm cultivation linked to significant watershed disturbances
by Clarence Oxford
Los Angeles CA (SPX) May 03, 2024

Oil palm plantations, largely driven by the global demand for palm oil used in products ranging from instant noodles to cosmetics, are contributing to significant environmental changes, particularly in tropical regions. Recent findings from the University of Massachusetts Amherst highlight severe impacts on watershed health due to these plantations. This study, published in the Science of the Total Environment, focuses on the repercussions for watersheds, crucial for many Indigenous communities dependent on these water sources.

Researchers Briantama Asmara and Timothy Randhir from UMass Amherst investigated the Kais River watershed in West Papua, a region spanning over 1,000 square miles. The area, once a dense tropical rainforest, has seen a quarter of its land converted into oil palm plantations, leading to stark environmental changes. The researchers utilized an advanced watershed model, SWAT+, to simulate and analyze different land-use scenarios and their effects on the region's hydrology and water quality.

"The Kais River watershed, like many of the places where oil palm plantations are situated, is very remote and not particularly well studied," says Randhir.

Asmara explains the motivation behind their study: "though the palm oil companies have lots of data about what pesticides they're using, the timing of their irrigation efforts, issues with runoff, etc., that information isn't making it out to the downstream communities. I conducted this research because I wanted to get better, publicly available data to the people whose lives are being most affected."

Their research revealed that changes from forest to plantation have led to increased precipitation, runoff, and soil moisture, significantly degrading water quality. For instance, sedimentation rose by 16.9%, nitrogen levels by 78.1%, and phosphorous by 144%. Despite future scenarios predicting some moderation in pollutants, the overall environmental impact remains negative.

"The downstream Indigenous people who rely on the rivers and the streams in the watershed are highly vulnerable," Randhir notes. "They are bearing all the environmental and public health costs, while the international palm oil companies are reaping the rewards."

"And yet," Asmara adds, "our research can help. Now that we know what the oil-palm plantations are doing to the watershed, both the industry and local governments can take action." The researchers suggest implementing regulatory measures such as limiting pesticide use during floods, continuous water quality monitoring, and maintaining riparian buffers to mitigate these impacts