Subject: tree deaths & pH

From: Geoff Taylor <[email-masked]>
Date: Wed, 24 Jul 1996 13:33:20 +0800

In the Eastern Pilbara of Western Australia there have been mulitiple 
tree deaths associated
with the area near Newman (approx. 4-5 million to date). Initial reports 
>from  the EPA tried to
associate the deaths with overgrazing in the area by pasturalists. 
However, although the cattle
are known to eat some of the tree species lower leaves, they cannot 
account for the lack of
foliage higher up. In addition one of the tree species seriously 
affected (white river gum)is
unpalatable and probably toxic to cattle.
The ecology of the area was seriously affected by the constrution of a 
dam across the river
Fortescue in the early 1980's by the multinational BHP mining. The river 
is only seasonal,
flowing for perhaps only five days a year and the with the construction 
of the dam the flow has
been affectively stopped with the other smaller tributaries being unable 
to accomplish the
widespread seasonal flooding associated with the area.
There have been numerous reports on the area with particular reference 
being given to one of the
properties worst affected by the problem, the cattle station Roy Hill. 
This is a pastoral lease
of about 1,000,000 acres where the owners have commented on the problem 
and the worse
degradation assoiated with the BHP owned property Ethel Creek.
The areas near the river on Roy Hill have been destocked, but the 
country is still dying despite
reasonable rainfall levels. It has been proposed that the dam at Newman 
be demolished (WA
department of Agriculture 1991). This return to the natural water regime 
was hoped to stop the
tree deaths.
However, the problem now seems to be more complex since in recent times 
the flow of water has
been such that the dam has overflowed. The water rather than solving the 
problem seems to have
contributed to even more tree deaths.
The department of agriulture has come in again and has taken soil and 
water samples from the
area near the mine and from the properties downstream. These samples 
have been inconclusive but
point to very high soil acidity (pH 2.5-4.5) in some areas. In addition 
these high soil
acidities may explain the high concentrations of heavy metals in the 
samples(Chromium,Cadmium
and Arsenic for example). The question is whether such high soil 
acidities and heavy metal
concentrations could be accounting for the tree deaths and deaths of 
perrenial grasses near the
river? Next, the mine at Newman is associated with iron ore and the open 
cast methods used in
extraction produce large amounts of dust that contaminant the dam floor. 
The question is whether
such mining could be contributing to either or both the acidity and 
heavy metal contamination?
Finally, in some of the trees trace amounts of formaldehyde have been 
found and its possible
origin is the mine, but more importantly the water from the dam is used 
as the main local water
supply and there are some reports of Newman becoming the site of a 
cancer cluster although this
is an area which needs much greater investigation. Any input on these 
maters would b appreiated
and further data can be supplied.

-- 
Regards

Geoff Taylor
======================================================================
Science department               May the groundtruth be with you"
Carine Senior High School           
CARINE 6020                 (   Aus Motto of the GLOBE program       )  
Western Australia           (Global Observations to Benefit the Earth)
======================================================================

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From: [email-masked] (BRateaver)
Date: 12 Sep 1996 05:59:17 -0400

I should think you could find plenty of info in the scientific literature
on trace minerals. I have tried to collect as much of that as I can, but
there are books I cannot afford to buy. I am sure you could get a good
deal out of any good university library, especially if you ask a reference
librarian for help.  There are so many ways now to access any bit of data
you need, on computer.

In gathering material for my Organic Method Primer Second Edition, I
collected a great deal on effects of trace minerals.

In Calif there was a big noise about selenium that accumulated and killed
so much wildlife. So these things do happen.

B. Rateaver