[Aqualist] 11th International Paleolimnology Symposium - special estuarine session: Some ideas re bushfire ash and burnt leaf deposits

[Barrie Pittock]

 Dear Krystyna and all in AQUA,

As you may or may not know, I am a retired climatologist who headed the
CSIRO Climate Impacts Group in the 1990s. I have just finished writing an
updated book on climate change as below, which might be useful as a tertiary
textbook. But that advertisement aside, my purpose in writing is to alert
you all to the phenomenon observed by me, and no doubt others, following the
recent bushfires in Victoria.

This is that there are extensive layers of ash and partly burnt/scorched
leaves washed up on beaches and deposited in inlets many km from the fires.
I have just returned from a brief holiday at Lakes Entrance and observed
extensive deposits in Lake Bunga (just east of LE) and Lake Tyers (a bit
further east), and also on the coastal beaches and in the sand dunes in the
lee of tufts of grass. I have some photos which I can send people if
interested, when I get them off my camera. My supposition is that these are
from the widespread fires in Victoria in the last four weeks. Probably first
from the fires in southern Gippsland mainland, and later from Wilson's Prom.
The ash and leaves would have been carried by the wind and deposited in the
sea, then washed up on the beaches by the waves, and either deposited in the
inlets or dried out in the wind and blown into the sand dunes where they
collected in the lee of shelter. I saw the latter happening on the Thursday
5 March, with deposits at high watermark, and a strong south-westerly wind
blowing them along the beach and into the dunes (I have some samples).

The point is that we need a longer history of large-scale fires in Australia
and this may be one way of getting it, if we can find areas where such
deposits are not extensively reworked. It also has policy implications.

My unpublished speculation is that as the climate is changing, getting drier
and warmer in SE Australia, large scale fires are becoming more frequent. I
would go as far as to say that nature tends to make large-scale changes via
extreme events and fire is one of these. So what we are seeing is that
nature is changing the land cover/ecosystems to match the changed climate,
via extreme events of fire, and this has severe implications for management.
The more we resist the changes the more vulnerable we will be to the extreme
event that is severe enough to overwhelm our defences. We need to either
stop the climate changes or accept that the land cover will change and
accommodate it. In Victoria we have now had three major wide-area fire
outbreaks in the last few years, 2003, 2006-7 and 2009. Where these burn the
same areas repeatedly we are likely to see major changes in ecosystems as
saplings and seed beds are destroyed. 

There are I think quite a few reconstructions of fire frequency in the past,
mainly from North America (e.g., recent analysis by Westerling et al in
Science, vol.313, pp.940-943, 18 August 2006), and some of these suggest
fire is most frequent when climate change is happening. I would appreciate
any references and discussion of these ideas. If warranted there might be a
paper to be written and a submission made to the rapidly approaching Royal
Commission into the recent Victorian fires. I may not be the person to do
that, but welcome discussion. I have a lot of other things on my plate like
articles to finish and grand-children to visit, so I have not done a
literature search and may not want to be too involved later, but there is
the idea for someone to pick up on.

Best regards to all,

Barrie.



Barrie Pittock
33 Bourneville Avenue, Brighton East Vic 3187
Ph: 03) 9592 1907, email: bpittock at bigpond.com 

Recent books:
 Climate Change: An Australian Guide to the Science and Potential Impacts,
ed. Barrie Pittock (1.4Mb): free from
http://greenhouse.gov.au/science/guide/index.html 
Climate Change: Science, Impacts and Solutions (2nd. edition), Barrie
Pittock, in press, 2009: see http://www.publish.csiro.au/pid/6010.htm. 


-----Original Message-----
From: aqualist-bounces at anu.edu.au [mailto:aqualist-bounces at anu.edu.au] On
Behalf Of Krystyna Saunders
Sent: Friday, 13 March 2009 12:53 PM
To: aqualist at anu.edu.au
Subject: [Aqualist] 11th International Paleolimnology Symposium - special
estuarine session

Dear Colleagues,

We would like to draw your attention to the following session at the 11th
International Paleolimnology Symposium, to be held 23-26 June 2009 in
Guadalajara, Mexico: 
"Paleolimnological applications in estuarine and coastal environments".

Abstracts will be accepted until May 20, but please note that early
registration ends March 20.
For further details on the conference, see
<http://www.geofisica.unam.mx/paleolimnologia>.Best regards,

Kathryn Taffs (kathryn.taffs at scu.edu.au) Krystyna Saunders
(saunderk at utas.edu.au) Kaarina Weckstrom (kaarina.weckstrom at helsinki.fi)


Session description: Increasing population and concentration of urban
development in coastal zones has resulted in environmental degradation of
estuarine environments globally. Establishing benchmarks and ranges of
natural variability to improve the management of estuaries is now critical,
whether the aim is for conservation, restoration or 'sustainable wise use'.
Paleolimnological techniques have rapidly improved during the past decade,
particularly with advances in methods that allow high-resolution
quantitative assessments of environmental change. This allows pre-impact
conditions, the rate, extent and direction of changes, and range of natural
variability to be determined. These techniques have been applied very
effectively in freshwater environments, but their use in estuaries has been
more limited. There is an urgent need to share studies that have been
conducted successfully in estuaries, examine the use of techniques in
estuarine environments and discuss options for the modification of methods
to be more applicable within estuarine environments. We invite submissions
that deal with paleolimnological studies in estuarine environments,
particularly those that have assisted environmental management strategies.
-----

Dr Krystyna Saunders
Institute of Antarctic & Southern Ocean Studies University of Tasmania
Private Bag 77 Hobart TAS 7001 Australia 

email: saunderk at utas.edu.au




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