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Name: Eric
Status: educator
Age: 40s
Location: N/A
Country: N/A
Date: 8/5/2004
Question:
I am in need of a method to determine the age of dropped or sampled pine needles. I have been told you can count ridges along the axis of the needle but cannot find a referencable method. Can you help?

Replies:
Dear Eric,

I have not heard of the ridge-counting along axis of the needle as a measure of the age of pine needles. What I do to count the age of the needles is to look at the tree and determine the age of the adherent needles. It should be possible to count the number of years of growth before the needles drop by starting at the tip of a branch, going towards the main trunk of the tree and identifying each progressively older year's growth. The trees will produce a single flush of growth each year. Often there will be bud scale scars on the branch or the span between branch points that define a single year of growth. At some point most needles will have dropped from the growth zone of a year.

Best regards,

Jim Tokuhisa

Possibly helpful:

http://hgic.clemson.edu/factsheets/HGIC2353.htm

http://www.metla.fi/hanke/3294/index-en.htm

http://www.wsl.ch/forest/risks/projects/ntm/ntm-en.ehtml

Anthony Brach, Ph.D


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