Forestry Friday … Forestry Quiz Question

Lodgepole pine, forestry

A lodgepole pine reaches for the sunshine, as we all should.

This week, Forestry Friday is a forestry quiz question. The question is about tree growth.  This question appeared on the California Professional Foresters Exam about thirty years ago.   Any junior forester or forestry student who missed this question probably failed the test and was definitely teased for it.  In California, foresters are required to pass this test in order to become a Registered Professional Forester (RPF).  It is illegal to practice forestry in the State without a license.  Now to test your forestry knowledge.

You nail a red tag on a Lodgepole pine tree at DBH.  DBH stands for Diameter at Breast Height, which is 4 1/2 feet about the ground as measured on the high side of the base or the tree.  The tree is growing in height at 2 1/2 feet per year.  In 10 years how high will the tag be above the ground?

I look forward to reading your answers Junior Foresters.  I will reveal the correct answer next week on the Forestry Friday post.

golden retriever, forestry

Blitz answers “who cares!  How high to the first stick is the real question.”

30 thoughts on “Forestry Friday … Forestry Quiz Question

  1. Just thought I’d ramble a little to pass the time 🙂

    Conducting boundary surveys over the decades, on mountains, along rivers, fertile plains, valleys, gorges, often come across shields cut in reference trees (many different types of trees) over periods 10, 30, 50, 70, 130, 150 years older, and any where in between, or up sometimes, since an original survey, all still from hip to shoulder. So a tag won’t be going far, still four and a half feet, as for the most part, trees will grow upward from the top, the extremities, with their root system doing the same, extending out from their extremities. While on the ground we stand, right where it all started, well near enough to the point of origin.

    On another thought, girth growth would be a lot harder to calculate with changing variables from year to year, and other factors though. Once came across a 110 year old reference tree on a mountain plateau, in the valleys this type of tree would probably grow about 3 to 4 feet in diameter over the time period. But up on the rock and poor soil in a dry forest of similar size Ironbarks, I could almost wrap both my hands around it. hence the girth had probably not grown much since the shield was cut into it originally.


  2. Just tied mine yesterday so you will have to ask me again in 10 years time. Mind you with all the water here the trees growing much faster than in California.. They even get thicker and the tag since yesterday still in 4 1/2.. If I remember right everytime we tied a tree to train it after a while the string cut into the tree as the tree got thicker.. I think to save you 10 years; ‘No height growth happens only at the ends of twigs. The trunk does not stretch out as the tree grows’. I just wonder what trees used to do before someone invented the internet.. I had to confirm so I get the job kindly send me the keys for my new van, I’ll bring my own dog!


  3. Pingback: Forestry Friday … Forestry Quiz Answer | THE FORESTER ARTIST

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