Sunday, February 16, 2014
Warm-footed trees
Another dubious observation. I've noticed often that the street near trees has less snow. Obviously pine trees hold the first inch of each snowfall in their needles, and gradually drip or evaporate it. But that didn't seem to be the whole picture. Something else was going on at ground level. Maybe.
This week gave me a good test of the constants and variables. After a solid month of unrelieved below-freezing weather with occasional but not heavy snow, the ground holds a deep reservoir of cold. Several days of above-freezing air temps haven't affected the reservoir yet. Any hint of moisture or humidity forms a thin film of super-slippery ice.... EXCEPT where tree roots are near the surface of the street. Wherever the roots bump up the pavement slightly, the pavement is bone dry. Humidity doesn't condense and freeze over roots.
Are the roots directly radiating warmth? Or is there a microbial 'community' around the roots, busily metabolizing and warming the soil? Or do the roots provide an insulating layer between the air-warmed surface and the deep cold reservoir?
¶ 9:02 AM 
