Fire is crucial to keep many of Australia’s ecosystems healthy, and is a huge contributor to rich biodiversity. The Wurundjeri and other indigenous mobs used fire as a tool to manage the land. The chemical properties in smoke encourage some dormant indigenous seeds to germinate in the soil and some eucalypt species to open their seed pods. Fire also burns away leaf litter and old thatch from vegetation, leaving open patches for indigenous seeds to germinate. This can become a problem when the seed bank has become weed infested.
We use spot burning for weed control in sites where hand-weeding and herbicide spraying are not appropriate. Weedy annual grasses have small root systems as they concentrate all their energy into foliage growth. This makes it easier to control patches over a couple of years of follow-up burning.
Burning at different times of year helps to achieve different outcomes: cool burns throughout winter and spring can be used for weed control, whereas hot burns at the beginning of autumn are often used for thatch removal and species rejuvenation.