The environment can cope with smaller fires and there is plenty of evidence to suggest that Mother Nature enjoys the benefits of frequent burning.
In a recent article on this web site titled “What would nature do if we weren’t here?“, I summarised that in many bushfire prone areas, the following would occur:
- Lightening
- Fires
- Reduced fuel
- Repeat…
We often extinguish naturally occurring fires therefore we are interfering with the natural cycle.
Bushfires and Water Quality
In the opening page of an Australian Government titled “Bushfires and Water Quality” dated November 2012, the following statement was made:
The extent to which water quality is affected by fire depends on factors such as: the size and extent of the fire; the type of surrounding vegetation, soil and erosion; the geographical features and size of the catchment; and the time period between the last fire and a significant rainfall event.
High intensity fires can cause enormous damage to water catchments by destroying ground-cover and changing hydrology, as well as altering the structure, behaviour and erosion of soil. Furthermore, the chemical reactions triggered by fire can release nutrients, metals and other toxicants stored in vegetation and soil. Post-fire rainfall has significant impacts on water quality as it often washes these contaminants into waterways and reservoirs. When this occurs, water may be unsafe for agriculture or human consumption without additional treatment or alternative sources of water. Poor water quality and loss of amenity can therefore have substantial financial implications.
Download a copy of the “Bushfires and Water Quality” document using the pdf icon below:
Water Crisis Worsens as Murray River Blue-Green Algae Spreads
A recent news media article titled “Water crisis worsens as Murray River blue-green algae spreads” dated 9th March 2016, talks about a toxic outbreak of blue-green algae that has impacted upon almost 500km of the Murray River and has claimed reservoirs, rivers, wetlands and parts of Victoria’s two biggest irrigation districts.
An EPA Victoria document titled “River Health: A Snapshot of the Effects of the 2003 Bushfires” published in June 2004 states:
The immediate impact of the fires themselves appear to be minimal, however there are several key ways in which stream ecosystems can be affected by fires. These include:
- Changes in hydrology – Flows will initially be higher following fires due to increased runoff from the cleared catchments. After several years, the regeneration of forest may result in lower flows as young forests tend to use and intercept more water than old growth forests.
- Sedimentation – Loss of vegetation coupled with changes in soil structure can lead to a build up of loose sediment and ash, that can be rapidly washed into streams during heavy rains (a sediment ‘slug’). These sediments scour and smother instream habitat, reduce dissolved oxygen and light penetration in the water column, and clog the gills of fish and other aquatic biota.
- Algal blooms – Greater amounts of sediment entering the waterways also increase the concentrations of nutrients within the system. Higher levels of nitrogen and phosphorous coupled with reduced stream shading can lead to excessive plant and algal growth.
The 2003 bushfires had a negative impact on many streams in eastern Victoria. The fires occurred towards the end of a long drought, the worst in 100 years, which may also have contributed to the decline in river health in the fire affected region. Other sites assessed by EPA in unburnt areas (such as the Latrobe, Tambo and Upper Yarra catchments) have remained in good condition despite the drought, suggesting that the bushfires are the prime cause of the changes observed in stream condition.
More than half the streams assessed did not decline in condition as a result of the fires. Given that fire and drought have been shaping the Australian landscape for millions of years, it is not surprising that aquatic systems have evolved to cope with these short-term disturbances.
Download a copy of “River Health: A Snapshot of the Effects of the 2003 Bushfires” using the pdf icon below:
Summary
There have been many big fires impacting upon the Murray River since 2003. These fires, coupled with a range of other human activities are most likely contributory factors to the poisoning of our stream and waterways.
This article is just scratching the surface of the topics relating to the potential impacts of fire upon our water and there is plenty of other information and research that suggests huge benefits to our environment with improved land management practices.
Anyone who has witnessed the devastation that is caused by large fires can appreciate how our streams and waterways are impacted upon by large fires.
Those who have seen the results of good quality / cooler burns can equally appreciate how the environment can benefit for these and other improved land management practices.
Do your own research, look at the desires and wished of the “Greener Groups” and apply some common sense. You will find that no burn policies are not the answer.
Indigenous Australians understood how to protect the environment, we seem to be wrecking the place.