KALUL VILLAGE, Indonesia — Near a palm oil plantation here, bulldozers and chainsaws can be heard in what is officially “protected forest.” The hilly terrain is not ideal for large-scale agriculture, but with few areas left for expansion, the loggers are denuding the land anyway.

Aceh, the northern province on the Indonesian island of Sumatra, is a region made famous by separatist conflict and natural disasters, calamities that long held back economic development but helped preserve one of the world’s richest ecosystems. Now conservationists say the rapid clearing of virgin forest is paving the way for environmental catastrophe, turning critically endangered orangutans, tigers and elephants into refugees, and triggering landslides and flash floods.

Much of the current activity is illegal, they say, but if a land-use plan proposed by Aceh’s governor, Zaini Abdullah, is approved by the national government, currently protected forests could be rezoned as “production forests,” paving the way for logging, palm oil and mining concessions. The Aceh government argues that the change is needed to develop the local economy.

“They are very eager to build new roads and open up forests,” said Muhammad Zulfikar, of the Indonesian Forum for Environment, or Walhi, a nongovernmental organization opposed to the governor’s plan. “The government must see things not only from a political or investment point of view. What would be the point of investing if it only leads to natural disaster in the future?”