Do not quote me either but you are correct. Prairies depend on fire as do most native forests. Many trees are dependent on fire for their off-spring to succeed (Jack Pine, Red/White Pine, Bur/Northern/Pin Oak) and to kill off invasive species (prairies). Prescribed burns are critical in maintaining these eco-systems and are an under utilized resource. They require 'perfect' conditions (temp, humidity, timing, human resources), so are rarely done correctly if done at all. Source wildland firefighter in another life.