Firewood and biodiversity - are we burning their homes to warm ours?

Cosy, sure, unless your house is on fire. sediger/Flickr

The issue of firewood management has recently attracted renewed attention in Victoria, where the State Government has changed the regulations on collecting firewood from State Forests. Firewood is cheap fuel for households, but it is also vital habitat for many species. The new regulations may put these species at threat.

New regulations make firewood collection easier

From September 1, 2011, individuals no longer need a permit to collect firewood for personal use. Some 90 sites across the state are designated as firewood collection areas.

Many Victorians, particularly in rural areas, rely heavily on firewood as a low-cost source of heating. Firewood collecting is often a family-oriented activity. Some see it as keeping the forest “tidy” while others (mistakenly) believe they are reducing the fire risk. So why should we be concerned?

In our native forests, fallen wood (“coarse woody debris”) and standing live and dead trees provide habitat for many native plant and animal species.

When people harvest firewood by cutting down trees or collecting woody debris, they directly (through resource removal) and indirectly (by habitat alteration) affect biodiversity.

Dead wood - it’s home to animals and food for forests

There are many invertebrate species that specialise in exploiting dead wood, and depend on this wood for their survival. Many of these organisms are part of co-adapted systems with fungi and plants, or they form part of complex food webs. Declines in one group can have indirect impacts on a range of other species and ecosystem processes.

The breakdown (decomposition) of dead wood is an essential process in the recycling of forest nutrients. It slowly releases essential mineral nutrients back to the soil.

A number of small mammal species rely on fallen wood for shelter, with the associated cracks and crevices and adjacent leaf litter providing a rich source of insect food.

Fallen wood provides shelter and basking sites for snakes and lizards and refuge sites for frogs.

There is mounting evidence that nearly 20 species of birds in Victoria are declining due to the effects of firewood removal.

The endangered bush-stone curlew relies on fallen wood. JJ Harrison

In our fire-prone forests, fallen wood often provides protection during fire; a temporary home from which animals can recolonise the regenerating forest.

Plant communities are also impacted by firewood collection. Direct impacts (including weed invasion) arise due to soil disturbance, while indirect effects on ecosystem function are likely through interruptions to nutrient cycling.

We know wood matters, so why are we treating it as free fuel?

The significance of these issues is well recognised. Under Victoria’s Flora and Fauna Guarantee (FFG) Act 1988, “loss of coarse woody debris from Victorian native forests and woodlands” is listed as a “Potentially Threatening Process”. There are at least 17 animal species listed under the FFG Act which are threatened by firewood collection from native forests and woodlands.

So, if we acknowledge the ecological significance of fallen wood, why do we continue to allow its removal from our native forests?

Some say the impact is small and localised. In Victoria, about 14% of firewood used for domestic purposes is collected (legally) from State Forest. Rates of illegal collection, though, are thought to be considerable.

Firewood collectors may only collect fallen wood and must leave logs with hollows and logs growing moss and fungi. Over the long term, illegal removal of live and dead trees and the repeated legal removal of undecayed fallen material means there will be no more old fallen logs. This is bad news for habitat and for nutrient cycling.

Without permits, we won’t know when ecosystems are in trouble

Has the government sent the wrong message to the community? Anecdotal evidence suggests there is considerable confusion about these recent changes to regulations. A number of callers to ABC radio thought they could now collect freely from any area of State Forest and public roadsides.

By abandoning the permit system, the Department of Sustainability and Environment can no longer monitor the impact of firewood removal on biodiversity and associated ecosystem processes.

The permit system was imprecise, but now there are no data being collected, which means no way to estimate sustainable yields of fallen timber. As existing collection areas are denuded of fallen wood, new areas will inevitably be identified. There will be serious localised depletion of this resource and subsequent flow-on effects; but we will hear no warning bells.

While our native forests may be promoted as a “cheap” (economic) source of firewood, it is time to fully appreciate the environmental costs of this activity. We must broaden the discussion to consider alternatives, such as the developing fuel-wood industry and community-based woodlots. There is definitely socio-economic value to firewood collection, but we must also acknowledge the environmental trade-offs.