In the year 2000, more than half of Indonesia’s land area was covered by some of the world’s most biologically diverse forests. Nearly 20 years later, many of these forests have been lost—causing severe, far-reaching environmental impacts that include loss of biodiversity, contamination of air and water, and emissions of climate-changing greenhouse gases.
Although Indonesia’s deforestation is a well-documented problem, up until now there has been little information about its causes. To develop effective forest conservation approaches, more information is needed about the dominant drivers of deforestation nationwide and how they change over time.
Taking advantage of new global datasets on forest loss and the growing availability of high spatial–resolution satellite images from Google Earth, my colleagues and I looked into the leading causes of deforestation in Indonesia during 2001–2016.
Our research confirmed that large-scale plantations, including oil palm and timber plantations, were an important driver of deforestation. But we were surprised to find that the role these large-scale plantations played in deforestation dropped significantly from the end of the 2000s, when they were responsible for more than half of deforestation, to 2014–2016, when they were responsible for an average of 25% of forest loss. This decline could be due to the impacts of forest conservation interventions targeting large-scale plantations, including recent corporate voluntary sustainability commitments in the palm oil industry.
We were also surprised to find that conversion of forests to grasslands was another leading cause of deforestation and is the dominant driver of deforestation in protected areas and peat forests. Grassland expansion into forests appears to correspond to dry seasons with observed spikes in fire activity, which increased dramatically in 2016 following a severe dry season.
Given that large-scale plantation expansion was a substantial driver of forest loss in Indonesia, there has been a justifiable focus among forest conservationists on counteracting these agents of change. However, we also found that small-scale agriculture and small-scale plantations contributed to almost 25% of national deforestation over the study period, suggesting the importance of designing forest management interventions that consider the values and requirements of small holder farmers.
Deforestation in Indonesia results in the loss of globally significant biodiversity and the emissions of climate change–inducing greenhouse gases. Understanding the causes of deforestation, and the social and economic conditions that set the stage for these causes, can help guide conservation programs and policies around the world.
To read our study, “What causes deforestation in Indonesia?”, visit http://iopscience.iop.org/article/10.1088/1748-9326/aaf6db.