Forest Mensuration. Brack and Wood
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Height sticks (rods):
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Each stick is usually l.5 m long and constructed of tubular duralumin or fibreglass. A base stick is typically, l.5 m in length, and graduated in decimeters. Some sticks have a locking device which makes them safer but dearer and slower. Use of height sticks is generally confined to forests less than 25 m tall (although experienced users may successfully use sticks in forests up to 30 m). Use of height sticks is rare in native hardwood forests where the clear boles offer little support.
Only experienced people (in the use of height sticks) or persons in training should be permitted to use height sticks. Do not attempt to measure trees greater than 20 m in height until you are experienced.
Do not use height sticks in strong winds.
A crew of two persons is permissible when measuring trees less than 10 metres in height, but for trees higher than 10 m, a 3-person crew comprising a stick person, assistant and recorder is essential.
Hard hats must be worn always.
Field boots preferably should have a steel toe cap.
When many trees are being measured, protective glasses should be worn to prevent pine needles and other dislodged debris from lodging in the eye.
Proper maintenance of height sticks is important to crew safety. Sticks, particularly the ferrules, should be cleaned after each day's use and thoroughly checked each season for straightness and "smooth action".
While sticks are being hoisted, distractions such as chatting must be avoided. Concentration is essential to crew safety.
The recorder must be alert and active at all times. It is his/her duty to follow the progress of the sticks up the tree from a favourable viewing position and warn the stick person and assistant when the tip of the sticks begins to splay and when cones are dislodged. (This is apart from the recorder's other roles of recording data and ensuring parallax error is minimised.)
http://online.anu.edu.au/Forestry/mensuration/HGTSTICK.HTM
Cris.Brack@anu.edu.au
Fri, 6 Jun. 1997