Which type of fire is sometimes set as a way to protect a forest?

Answer;

Surface fire

Explanation;Surface fires are type of forest fires that may burn primarily as a surface fire, spreading along the ground as the surface litter and undergrowth on the forest floor and is engulfed by the spreading flames.They are the easiest fires to put out and cause the least damage to the forest. Surface fires create the least amount of destruction.These fires protects the forest by releasing the nutrients that would otherwise decompose slowly, having little benefit to the ecosystem.Additionally, these fires allow more open spaces for new and different kinds of vegetation to grow and receive sunlight.

Cr(oh)3 -> cr(3+) + 3oh-