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Post-bushfire impacts on aquatic ecosystems - Coggle Diagram
Post-bushfire impacts on aquatic ecosystems
2019/20 bushfires - extent and severity unprecedented in NSW - perhaps could mention 3 billion terrestrial animals lost but little has been mentioned about impacts on water dwelling biota.
Farm dams - act as sinks for bushfire debris and can be used as a proxy to assess potential impacts across wider landscape
So why should we care? Climate change expected to exacerbate frequency of bushfires
Give example of Mt Nardi/Nightcap National Park bushfire in subtropical NSW in Nov/Dec 2019/20
(Show map wide view ie, full burn area with circle around Mt Nardi/Nightcap National Park)
Issue : high intensity rainfall after bushfire = erosion
Transports post-fire debris into water bodies
Give examples of rainfall in Jan/Feb 2020 - show as graph
Lack of data in subtropics. Most studies previously undertaken have been in South-eastern Aust in temperate regions.
While biota such as fish and amphibians (maybe list others) can find refuge during fire in water bodies, longer term impacts on water quality can cause prolonged issues
Partial to full combustion of leaves and soil can release heavy metals, nutrients and other pollutants into surrounding landscape
Can lead to heavy metals being bioaccumulated or biomagnified through the food chain
Can lead to enhanced eutrophication with increased risk of toxic algal blooms
Both of the above issues can result in a shift in biotic community structure
State aim and objectives + hypothesis of this study (refer to proposal)
Discuss methods
Sediment samples
Analysing for heavy metals + redox potential
Water samples + hydro lab
Analysing for heavy metals, nutrients, pH, DO, EC, etc
Leaf/soil collection - undertaking BOD5 experiments to assess effects of pyrogenic leaf and soil matter on oxygen demand in aquatic systems
Using burnt material collected in field
Also using green material collected from field that has been burnt in a muffle furnace at a range of burn temps (200 - 700 deg C) to simulate different burn intensity experienced across vertical and horizontal stratum during bushfire
Will compare Biological Oxygen Demand from burnt material collected in field to controlled burn material.
Macroinvertebrates
Using Signal 2 Biplots (Chessman, 2003 method), identified to order, to assess for pollution impacts on water quality
Benthic gastropods - analysing for heavy metal uptake from sediments
Results so far - explain them
Sediment samples (currently with EAL)
Water parameters recorded with probes (initial) vs Hydro lab - make note of differences
BOD5 (currently burning leaves - will start BOD experiments shortly)
Macroinvertebrate - give Signal 2 Biplots and what they mean for each dam
Conclusion
Remind audience of aim/objectives/hypothesis of study, then give summary of what have found so far and whether any preliminary conclusions can be drawn
Reiterate why important to know this information, ie, to inform mgt strategies to minimise impacts from bushfire + perhaps touch back on climate change. Ensure clear concise final message!
Have strong title page and ensure topic made clear. Start with a clear, memorable statement - perhaps a quote re the devastation of the 2019/20 fire season (also refer back to paper Bill provided re aspects to include in good presentation).