Ultimately, all these causes for deforestation can be attributed to the fundamental cause: Growing Population Density.
Surprisingly, Indonesia is the fourth largest country on Earth with a population of 252.8 million, an increase from 2013’s estimate of 250.6 million.
Source: http://esa.un.org/wpp/
As a result, this saw an increase in demand not just for food and water, but land area for settlement as well. The increase in consumption drove the profit-driven firms to exploit the invaluable natural resource around us, which led to massive deforestation, most of which being illegal despite government regulations that were put into place. The growing population also resulted the clearing of forested area to build more infrastructure for the settlement of the growing population. Lastly, it also led to higher levels of subsistence activity such as “Slash and Burn” as it is needed to obtain a higher quantity of agricultural products to support the growing population.
Data on population density by province in Indonesia shows strong inverse relationship with forest covers. Fraser A. I states that for every 1% increase in population, there is an approximate decrease of forest cover of 0.3%. The overall decrease of forest cover is thus 1%, which corresponds to the annual forest cover loss of 900,000 to 1 million ha, observed by FAO. This implies that as the population grows larger, the forests will deplete at a faster rate.