Fire and the environment

Why is fire important for the environment?

Fire is a natural part of the Australian environment and plants and animals in many ecosystems have evolved to depend on fires to provide the right conditions for their survival. Introducing fire into a landscape at the right time, helps the natural processes a range of plants and animals need such as stimulating seed germination or providing the right kind of habitat structure.

This ecological process of fire is an important tool for NPWS to use, to help conserve and manage native ecosystems. First, we assess what plants and animals need, to understand where some species or ecosystems are fire sensitive, indifferent to fire, or need fire at certain times to help them survive.

Once we know this, we can use prescribed burning to help native plants establish, improve habitat for animals or help with weed control. Depending on what we want to achieve, each burn is planned to ensure that this goal is met while protecting fire-sensitive species.

The many ways that fires have interacted with the landscape over time means that the right conditions and ecological processes needed by one species, may be quite different to those needed by another. What influences these variations is known as the fire regime.

That’s why there’s a lot of planning and assessment of species in a planned burn site, before any fires are lit, to ensure the species stay safe and the burn meets its objectives. Prescribed burns are always timed to have the least impact on native flora and fauna.

How do prescribed burns help plants and animals?

Prescribed burns aim to manage the landscape so there’s a mix of habitats available for different animals.

Before every prescribed burn, staff assess the potential impact on native animals and plants and ensure there is enough unburnt habitat in the landscape for populations to use while the burnt habitat regenerates. Animals have various strategies to survive in prescribed burn areas. Some will move ahead of the burn, while others will seek shelter in the tops of trees, in burrows or under rocks and logs.

Prescribed burns can help improve biodiversity within parks and reserves by:

• managing the landscape so that there are a mix of habitats as some native animals prefer regenerating vegetation after fire while others like long unburnt habitat
• protecting known nesting or breeding sites e.g. we might burn near an important ecological site rather than within it so that we don’t harm the targeted species, and by creating low fuel areas around it we reduce the chance of it being burnt in a large bushfire
• regenerating plant species and vegetation communities that rely on fire which means many plants will grow quickly after fire from seed germination or re-sprouting buds from under their bark or roots
• using fire as a tool to help control some weeds species.

Following a fire, the ash bed is full of nutrients which greatly enhances seedling germination. Tree trunks and roots shoot with buds capturing newly available light. The rejuvenating growth attracts wildlife that feed on the fresh shoots. Foragers explore with the easy access, digging for fungi, eating seeds and flowers. Turned soil and fresh foliage stimulates insect activity. Birds navigate through the re-emerging forest and feed freely on the cleared forest floor, while carnivorous predators take full advantage of the open area.

Plant and animal monitoring after a prescribed burn

After a prescribed burn is complete, staff monitor the site to record how plants and animals respond and use this information to improve future burns. Generally, plants and animals recover from fire over time. To help some ecosystems recover, NPWS can help with rehabilitation and regeneration through:

• controlling invading weeds
• controlling or preventing pest animals invading
• stabilising areas at risk of soil erosion and replanting them with indigenous plants
• replanting vegetation damaged by firefighting activities.

Plant and animal monitoring after a bushfire

Recovery after a bushfire is another matter. Bushfires are generally larger and more intense than a prescribed burn, and a wildlife and habitat recovery framework has been produced to help South Australia support the preservation and re-establishment of the natural environment during and following bushfires. Recovery SA also has information on helping nature recover after bushfires.

Protecting natural values

To help protect environmental values that might be affected by a bushfire, suppression activities, or by immediate post-fire threats during large and complex bushfires, a Natural Values Officer works closely with the Incident Management Team (IMT) that is managing the bushfire response.

This onsite specialist provides crucial ecological information quickly to the IMT. This information is then used to develop plans and strategies that consider these important natural values alongside life and property values at risk from the bushfire.