Sap rise in spring

Ross Koning Koning at ECSUC.CTSTATEU.EDU
Wed Oct 2 13:03:32 EST 1996

At  8:08 AM 10/2/96 +0100, Gunnar Fridborg wrote:
>Another observation:
>In the park around the main buildning of  Uppsala University they cut off
>some branches of a birch  a few meters above the ground. This was done in
>early spring. I passed the tree one or two weeks later when  winter had
>come back temporarily with several degrees below zero. From the cut
>surfaces big icicles were hanging and only from there. I took a picture
>for educational purposes and we use to discuss the phenomenon in my
>classes. Our explanation is frozen sap  and root pressure. I tasted one
>icicles but it wasn=B4t sweet. Silly enough I didn=B4t take one with me to
>analyze it further.
>Gunnar, Uppsala

In our town the utility company made a sweep through to remove
limbs near powerlines in spring.  It was sad to see the trees
all scarred and skinned up one-side.  The trees will now fall
on the houses instead of the precious wires!  That's another
story.  The interesting part was that the sap flow from those
wounds attracted bees.  It WAS sweet (red maple in particular)
and later the wounds developed fungi.  The trees are still
standing two years later, but I fear for their long-term
survival.  I didn't investigate the fungi any further, but
I hope they are not wood-rot fungi or a successional species
to wood-rot fungi.  Needless to say I was furious about the
tree damage...and still fuming over it.


Ross Koning                 | Koning at
Biology Department          |
Eastern CT State University | Phone: 860-465-5327
Willimantic, CT  06226  USA | Fax: 860-465-5213

                Plant Physiology is Phun!

 /\|___/\     //\______COOH   NH-CH2-CH=C-CH2OH  \/OH
|  |  |  |    |  |  ||       //\___     \CH3     /\|/\\/\\COOH
 \/ \/|\/|    \\/ \ /       N  ||  N            |  |
 /\ | |__|=        NH       |  || ||           //\//\
  | COOH                    \\ /\ /            O
  COOH        H2C=CH2         N  NH

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