Dear Gaines, Thanks for keeping the White pine height debate alive. I read the white pine info at the link you referenced but didn't glean the same information that you did. First off, nowhere was there indicated a maximum height potential, regardless of site index. Second, the charts showing growth increments are for sites in the Southern Appalachians, the Southern extreme of White pine's range. The historic reports of 250+ trees are all in New England, at the center of its range. Third, site index does not take into account the micro climate and topography. We've all seen those damp, sheltered hollows and ravines where nutrients collect, the ground stays wet all through the growing season, and mosses cover everything, where trees are protected from wind and are substantially taller and healthier than those outside the area though of similar age. That's where the tallest trees are now and would have been historically. Not a lot of trees in the 250' class, just a handful scattered across the Northeast but certainly thousands of trees over 180' (our current Northeast tallest pine). Also, according to that chart, the height difference between trees growing on the poorest sites to those on the best is 60 feet, not 20. As for annual growth after 55 years being about a foot, I've felled trees in the 55-80 year old class where I've measured the annual height growth for the last three years over 30" per year. A chart for the Southern Appalachians won't necessarily apply to New England. Though the account of a 300 foot pine in Charlemont, Massachusetts may be stretched, surely some of the other 250'+ accounts must be true. They had accurate measuring devices then. Though they lacked the techno-gizmo's of today, they were not primitive. There were surveyors, builders, and others skilled in measuring then. When I measure old structures from the 1700's, they are typically within a quarter inch on a sixty foot length. A modern steel measuring tape can vary that much from winter to summer with thermal expansion. Just because we don't have them today, doesn't mean there weren't 250 footers then. Nowhere in New England are there now pines growing in an ideal spot (like that I mentioned above) where they have been undisturbed for 400 years! Jack Sobon
________________________________ From: spruce <[email protected]> To: ENTSTrees <[email protected]> Sent: Sun, January 3, 2010 5:18:59 PM Subject: [ENTS] White pine growth rates--something of interest about growth possibilities There is some research about the growth rates of white pines that may be of interest to white pine enthusiasts. For a bit of background to make the context of the research I am quoting clear: in forestry, growing sites for various eastern trees are classed by how tall a tree can grow in 50 years. This is called the "site index" for each species relative to each site. For white pine, the site indices range from 60 feet--for a rather poor site--to as much as 120 feet for the best sties. It may be possible that there are some sites with an index of over 120 feet, but if so, I assume they are very, very rare. In fact, most commonly, the best white pine sites are between 90 and 100 feet, which I commonly see quoted for most class II soils. I believe 120 feet is fairly unusual--I know of one just site, a very rich stream bottomland site that is probably a class I soil, that may have that kind of potential. OK, enough for the basic background. Here is the interesting thing I just learned: If a white pine grows 120 feet in 50 years, this same tree on this same superior growing site, after age 55, will not grow any faster than a tree growing on a relatively poor site--index 60. At age 55, both trees--the one growing on the relatively poor site, and the one growing on the very rich site, will be growing at the same rate--roughly one foot per year. So, all the difference between the height of a white pine tree growing on an excellent growing site, and the one growing on a poor site, occurs during the first 55 years. Of course this does not include any factors that may distinguish sites based on factors such as ice and wind breakage. I think this reflects on the question of how tall white pine trees can grow, in that those growing on the very best sites may not grow significantly taller than those growing on the lesser, but still very good sites. Thus, if a growing site is rated at 120 feet, over the life of a white pine tree, the final height of the tree will be just 20 feet taller than a tree growing on a site of index 100. To explain a bit more, if we want to speculate on the possibility of white pines growing to 200, or the oft quoted height of 250 feet, the idea that the 200 plus trees grew on the very best sites, and those sites are now no longer available for growing pines because they are now farmalnd, or whatever, should be less of a factor in our speculations. The difference in the ultimate height of the trees will be only 20 feet or so. So even if we want to argue that the best sites could grow pines taller than what we now see--about 175 feet max--then the potential was for 195 or so, certainly not much above 200, and certainly not 250 or anything like it. This research is summarized (with citatiion) in the USDA Forest Sefvice manual titled "Silvics of North America." The URL is: http://www.na.fs.fed.us/spfo/pubs/silvics_manual/table_of_contents.htm This is written from a forestry perspective, but contains a lot of information about tree growth, etc of interest to any tree lover. --Gaines Mcmartin -- Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected]
-- Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected]
