Indonesia and Malaysia lost more than 11 million hectares (42,470 square miles) of forest between 2000 and 2010, according to a study published last year in the journal Global Change Biology. The area is roughly the size of Denmark or the state of Virginia.
The bulk of forest loss occurred in lowland forests, which declined by 7.8 million hectares or 11 percent on 2000 cover. Peat swamp forests lost the highest percentage of cover, declining 19.7 percent. Lowland forests have historically been first targeted by loggers before being converted for agriculture. Peatlands are increasingly converted for industrial oil palm estates and pulp and paper plantations.
The study also broke down changes in forest cover by island. Borneo, which is shared by Malaysia, Brunei, and Indonesia, topped the list in terms of total area lost at 5 million hectares during the period, accounting for 12 percent of its 2000 cover. But forests declined at a faster rate in Sumatra, which lost 23.7 percent of its forest cover or 3.5 million hectares.
Sabah and Sarawak, which comprise Malaysian Borneo, lost more than 15 percent of their forest cover during the period.
Java was the only island to see forest recovery, with a net increase of 37,000 ha or 4 percent of 2000 cover.
Forest loss was most stark in peatlands. Sumatra lost more than 41 percent of its peatlands during the period, while Borneo lost a quarter. Malaysia lost a staggering 45.3 percent of its peat swamp forests during the decade.
The study is based on analysis of NASA Landsat data by Jukka Miettinen, Chenghua Shi and Soo Chin Liew of the Center for Remote Imaging, Sensing and Processing (CRISP) at the National University of Singapore (NUS).
Overall the researchers estimate that forest cover decreased in Indonesia by 8.8 million hectares, or 9.3 percent, during the study period. Malaysia lost 2.3 million hectares, or 13.2 percent. The results differ significantly from estimates published by the U.N. last year, which put forest cover loss at roughly 4.9 million hectares in Indonesia and 1.1-1.3 million hectares in Malaysia. The U.N. Food and Agriculture Organization (FAO) traditionally relied on self-reported data based on forest inventories, rather than satellite imagery. But that approach is now changing, with FAO releasing new satellite-based estimates.
CITATION: Jukka Miettinen, Chenghua Shi and Soo Chin Liew. Deforestation rates in insular Southeast Asia between 2000 and 2010. Global Change Biology (2011) 17, 2261–2270, doi: 10.1111/j.1365-2486.2011.02398.x