The U.S. government agencies that manage federal lands in similar ecosystems of the U.S. Southwest have found the same thing. The biologists call them "fire-adapted ecosystems."

In the case of the forests especially, they've found that controlled, regular fire not only improves the ecosystem, it prevents damage from hotter fires. They call controlled fires of woodlands and grasslands "prescribed burning."

When fires aren't frequent enough, trees, undergrowth, and fallen material become too plentiful. Then when a fire does occur, it burns so hot that it kills roots, mycelium, and microorganisms in the soil, and burns up the mixed in detritus. What was soil becomes powdered rock, mere dust. Then it takes much longer for the land to recover. And in hilly and mountainous terrain, it leads to dangerous mudslides when it rains.