Crown Spread Edward Frank May 01, 2005 08:40 PDT
 One of the questions I wanted to address with Will at Cook, but did not get the chance is how to measure the greatest spread, (especially with tree that may be tilted- I see a 100 foot tree tilting out over a river with a horizontal offset of 70 feet to match its 70 foot height as measured from the base). Is the longest spread measured from the base of the tree? What about trees that are slanted? I don't think it can be measured from where it diverges from the trunk, because that is an arbitrary decision especially with trees that quickly break up into multiple large braches/trunks. Attached is a small graphic. When you map a cave at each survey station you note the passage width and the passage height. What is also important is to draw a cross-section of the passage to give meaning to the numbers. When we consider in Will's formula whether to use the greatest spread or average spread, there are good points for both. The biggest advantage for longest spread is that it might actually get measured. On the other hand, I think average spread is a more meaningful number as it represents the mass of the canopy as a whole rather than just a single branch. Ed Frank