This is the desired result of all controlled burns. It's the ecological goal of both controlled burns and naturally occurring burns. As @Rellik88 points out, many tree and plant species require this type of underbrush burn to propagate. It not only enriches the soil but it removes competing species. In turn providing a clear evolutionary advantage.

The really bad fires commonly observed in the 20th century are almost always caused by man preventing natural underbrush burns. In turn causing much large brush growth and dead material (trees and brush). Which in turn fuel massive fires which tend to kill off trees and brush which would have otherwise survived had man not interfered.