Sunday, October 3, 2010

October 3, 2010

We had tropical weather this past week, very warm and humid, and with several inches of rain, the lake is returning to it its normal level.  On Saturday it was back to +1” at the dam.  It is also nice to see the brooks flowing again.  There were some strong winds this week, but as the trees are just starting to change, the wind didn’t pull many leaves from the trees.  There is only partial color on the hills around Lake Wicwas, with peak color a good week away, but some of the smaller maples along the shore are brilliant against the dark green background.

On one warm, muggy night I went for a walk; it was so dark with the heavy cloud cover that I used an LED headlight to light the way.  It was eerie to be walking on a warm, summer-like evening, but without the summer sounds.  There are no crickets, peepers or bullfrogs making their usual nocturnal sounds this late in the year.  I was surprised to see bright light emanating from the rocks in the stone walls.  At first I thought it was fluorescence from minerals in the granite, but further investigation proved it to be emanating from lichen on the rocks.

Lichen is dual organism, formed by a symbiotic relationship between a fungus and a colony of cyanobacteria (blue-green algae, the same algae that is found in the lake during the summer).  In lichen, the fungus surrounds the algae, and absorbs water and minerals from the substrate, in this case, granite.  The algae in turn provide carbohydrates that they produce from photosynthesis.  It is the pigments in the algae that have the photonic properties that allow it to absorb light at one wavelength and emit it at another wavelength that the eye can see.  Pictures don’t do it justice – you’ll have to try it for yourself.

 And then, this weekend, fall arrived.  Temperatures were in the mid-thirties over night, and the sky was clear blue after the morning mist lifted. 

The loons are still here – I saw several on the lake – and found lots of ducks and turtles as well.  The chipmunks are getting pretty fat, and running everywhere collecting food for their winter stores.

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