Here's two quotations (the first by Tess Tescher, TTescher@Juno.com); the second by Alan J. Long, University of Flordia Cooperative Extension Service, (edis.ifas.ufl.edu/BODY_FR061):
Prescribed burning is a useful tool for maintaining and restoring diversity in our native grasslands. Buildups of dead plant litter can be a fire hazard, lessen the biodiversity of the area, and aid in the establishment of invader species.
Reasons We Burn: Reduction of Hazardous Fuels; Altering Vegatative Communities; Improving Wildlife and Livestock Habitat; Controlling Pest Problems; Improving Access
Surely, we can metaphorize prescribed burning in some way that will demonstrate our need for Lent practices.
Lectio Divina: Mark 8:35-36. For those who want to save their life will lose it, and those who lose their life for my sake, and for the sake of the gospel, will save it. For what will it profit them to gain the whole world and forfeit their life?