Rolandvue,4th Week of October: Falling Pine,Cedar,Cunninghamia Leaflets

In the category of "what's that in the road? A head?".  This week is was road debris from all the evergreens or conifers in the neighborhood.  The photos show the tall white pine up Cloverlea and the pine straw on the road beneath.  All the conifers were shedding but the last picture is the Cunninghamia boughs on Rolandvue.

The immediate cause of dropping leaves was the wind last week, but it must be part of the natural process.  Conifers are both evergreen and everbivalent, constantly dropping their needles at all times of the year.  It seems heavier during this transition into winter.  The pine needles show the usual five parts typical of the white pine(white five letters,five needles).  The pine needles last about two years on the tree, bristle cone pine needles in the west can last decades.  Pine straw may help the tree compete with other trees by making the soil more acid.

Evergreens make an economic calculation, less energy to replace the leaves in the spring but some energy to protect the needles from freezing in the winter.  The needles become dehydrated and trade starch for sugar, acting as anti-freeze.  This protects the pine needles down to -5 degrees centigrade. Shedding leaves reduces the need for water during the winter, evergreen make special adaptations to preserve water and continue to bring water to the branches during frosts.  Evergreens can manage some photosynthesis on the occasional warm winter days.  Evergreens can lose branches due to snow loading.  Trade offs.

This tall white pine shows asymmetrical growth to the southeast or "flagging".  We wondered if this was growing toward the sunnier south, but it can also be due to effects of the prevailing northwest winds.  Either way the tree is somewhat a compass.

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