Bob,
nice topic on which we do not know so much I would guess, esp about old trees. Generally, annual radial ring width is wider towards the base of the crown and narrows as one moves down the stem until the root flare. There is a classic schematic showing this general concept. I've lost track of that reference. If I find it [or if someone else can], I'll be happy to share it. Of course, there is a certain amount of variation between species with this concept, and likely within species. Allometric equations are used to determine tree volume for species where diameter at breast height is scaled to many characteristics of trees such as crown volume, stem wood volume, aboveground biomass, etc. There are many problems with these equations, I'm sure ENTSers can understand this. Some of these issues are probably familiar: replication of trees used to make an allometric equation, the region in which the equations was created, the range of tree sizes used to create the equation [large trees are not often used. If they are only one or two large trees may be used], etc. So, there are some issues. Yet, when people skeptical of these equations cut down a tree or two to check the equation, they often are somewhat dumbfounded when their calculations fall very, very close to the original equation. I figure since volume calculation, especially of the stem, is worth money/ profit, much effort was put into these equations so they likely pay off [no pun intended..ok, i meant to write that]. So, I do not know what to make of these equations except they seem to be the best known [in a larger sense] about tree volumes without having to cutting and weighing each tree [or crawling over each tree and measuring it inch by inch]; if you don't have much time/money to investigate tree volume, they work fairly decently. Now, I guess that was tangential to the subject line of this email. I have played with a lot of tree-ring series and allometric equations; I've converted annual measurements into an estimate of diameter and then volume. When I do this, volume growth often increases through time in mature, natural forests. James [?] Hornbeck has a nice USFS publication from the early-1990s, I believe, showing something similar. There are other references as well showing similar things. I think this trend looks different in even-aged, monoculture forests less than 70 or 80 yrs old, but this is just a hypothesis. Stem volume analysis is also something done in forest science research [perhaps more in the past]. Dave LeBlanc did a nice study of red spruce in the Adirondacks undergoing decline to investigate volume growth. Basically, you make measurements every so many feet up the stem and reconstruct volume through time - very time/resource intensive; work for grad students only - it is at their pay grade. This type of analysis is not done enough, probably. Bob, did you type 'neiloid'? What the heck is a 'neiloid'? neil On Jan 14, 9:46 pm, "Edward Frank" <[email protected]> wrote: > Will, > > You are certainly right about climbing and coring. I was thinking about a > big old tree that has fallen - it would be accessible and could be measured, > cut up, and sampled extensively without harming a live tree. Perhaps an old > growth tree ... > > Ed > > Join me at the Primal Forests - Ancient Trees Community at: > http://primalforests.ning.com/ > > ----- Original Message ----- > From: Will Blozan > To: [email protected] > Sent: Wednesday, January 14, 2009 9:19 PM > Subject: [ENTS] Re: Radial versus volume growth > > Ed, > > A climber with an increment corer can do it. Important work that should be > funded. I strongly feel trees grow faster (put on more wood per year) in > their “old age”. Cambial area greatly increases and even small increments can > add up fast. BVP talks about it in his “Forest Giants” book. Misconceptions > abound, and ENTS can do great service to educate otherwise. In the face of > atmospheric carbon excess a study would be most appropriate. > > Will F. Blozan > > President, Eastern Native Tree Society > > President, Appalachian Arborists, Inc. > > --------------------------------------------------------------------------- > --- > > From: [email protected] [mailto:[email protected]] On > Behalf Of Edward Frank > Sent: Wednesday, January 14, 2009 7:04 PM > To: [email protected] > Subject: [ENTS] Re: Radial versus volume growth > > Bob, > > I do see the approach you are taking. I am considering it. The previous > notes were just ideas off the top of my head on the subject. The basic > premise you are looking at is that tree A over time will change to be the > height, girth, and form of tree B over time. (Actually it is the converse > of that arguing tree B was the same size, shape and girth as form as A at > some point in the past.) On an individual basis that is an unlikely > proposition, but as a statistical set of average trees, the arguments would > appear to be valid. If you had a big tree that was cut down. And you were > able to slice the trunk at various heights. You could determine the the > girth at a given point at a given time at a given height by counting > backwards from the outermost ring. You could determine at what age the tree > reached the height of that cut, and you could reconstruct the form of a > particular tree and its volume at any give point in time. The closer the > slices together, the more detail you would have and the better you could > reconstruct the tree in the past. > > Ed Frank > > Join me at the Primal Forests - Ancient Trees Community at: > http://primalforests.ning.com/ --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org You are subscribed to the Google Groups "ENTSTrees" group. 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