Indigenous peoples in Indonesia have relied on slash-and-burn farming techniques for subsistence farming for thousands of years. Burning these trees would be the cheapest, easiest and fastest method for clearing land, especially so when the farmers are too poor to afford alternative technologies to clear land. The resulting layer of ash from the fire serves as fertilisers for the next batch of crops. This destructive practice is repeated years after years, until the land is stripped off of all its nutrients, and could no longer support cultivation practices. These farmers will then move on to a new plot of land and continue their practice of “slash and burn”, leaving the previous land barren. This resulted in mass clearing of Indonesia’s rain forests at an alarming rate, which skyrocketed environmental and social problems.
Photo: Slash and Burn Diagram Source: https://www.e-education.psu.edu/geog030/node/141