>Date: Wed, 29 Nov 2000 19:38:39 +1100
>From: Andrew Fildes <afildes@xxxxxxxxxxxxxx>
>Subject: Re: [OM] Huon Pines [was: I love my 16mm
>OK - I cheated a bit - see why here -
>but note the 43,000years+ date on the Lomatia tasmanica! :-)
>Huon Pine is a bit special - it doesn't rot. A fallen log was carbon dated
>at over 22,000 years since death and it was still millable. Unbelievable
>timber. So valuable now that they've logged them under water with air
>driven saws in dam drowned vallies
Underwater logging is fast becoming a huge business. Here in the 'states,
just as in many other places in the world, logs were floated down river to a
mill. Well, many of them sank....and they were all old growth prime timber.
If the water is deep enough and cold enough, most anything will not rot, so
there is much of this going on in Lake Superior and in Canada. Rot resistant
speices like Cypress are being logged underwater in the southeast US. In
Brazil, they are logging underwater in a valley where a dam was built. They
are pulling up old growth tropical timber from the lake bottom caused by the
dam. All of this timber commands premium prices, since second and third
growth timber is not as high quality.
The science of tree ring research is called dendrochronology. A good web site
about this is at: http://web.utk.edu/~grissino/ The information gleaned from
tree rings tells many stories, including rainfall, weather patterns, etc.
Taking core samples from very old trees allows us to see what the weather was
like 5,000 years ago before there was the WeatherChannel....it's also been
instrumental in determining the amount of global warming and greenhouse gases
in the far past. These are the main reasons that scientists are keenly
interested in preserving and finding very old living trees. For example, the
bristlecone pine, once thought to be the oldest trees, grow up to the tree
line on mountains in the western US. So, they took a core sample from some of
them, then they noticed that there were dead trees above the tree line. The
tree line is the highest elevation that trees can grow. Finding dead trees
above the tree line means that the climate was once warmer and wetter in that
area at one time. So, they took core samples from the dead trees, then laid
the two samples next to each other to match them up. Fortunately, the dead
trees extended further back into time than the live ones. But the interesting
part is that they can find an approximate date at which the climate changed
based on when the higher elevation tree died. I think there are many things
left to be understood about climate.
Another example is that in Canada, where there are glaciers receeding due to
melting, the melting glaciers are uncovering tree stumps! What does that tell
you? So, there is much still to be learned about this process we are
experiencing.....who knows, maybe Texas will become a complete desert within
the next couple of years (one can only hope! <g>).....
Be Seeing You.
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