Example for one sampling plot where rubber plantations have been cleared for oil palm in Indonesia. (a) satellite images of the plot in 2005, (b) 2014, © 2018 and (d) the surrounding area in 2018.
Abstract
Rubber and oil palm are two main crops threatening biodiversity and natural habitats in Southeast Asia. The expansion of these crops has been transforming landscapes in the region replacing vast areas of forests and other croplands. Here, we utilize existing crop expansion time series data and tree plantation maps combined with image interpretation methods to identify rubber-associated land cover dynamics including the extent of rubber conversion to oil palm. While existing rubber plantations in 2014 had been converted from multiple land cover types including forests, we documented more rubber conversion to oil palm and other land cover types between 2014 and 2020. The percentage conversion of existing rubber plantations to oil palm was 1.9% and 2.6% for Indonesia and Malaysia, respectively. The estimated overall rate of this conversion was 10 500 ha/year. This slow readjustment of rubber and oil palm, following their competitive advantages, may reshape agricultural threats to tropical and sub-tropical environments through indirect land-use change. Continuation of this trend could lead to displacement of rubber to countries like Cambodia, Laos, and Myanmar threatening remaining natural habitats. Sustainability measures should therefore simultaneously focus on both oil palm and rubber considering their coupled transboundary displacement trends.