Answer:
Torres del Paine was a forest that had grown slowly over the time period of 200 years. When the forest caught fire due to a gas stove used by the natives, it burnt through the roots and took away the greenery from it.
A forest that took 200 years to completely bloom, would definitely take more time to recover from the burnt roots and barks. The new trees were planted very carefully making sure they get rid of the sediment that would hinder their growth.