Gaines, ENTS- A sort of interesting article from about 40 years ago regarding white pines from different provenances can be found here:
http://www.fs.fed.us/ne/newtown_square/publications/research_papers/pdfs/scanned/OCR/ne_rp185.pdf Steve On Sun, Jan 3, 2010 at 5:18 PM, spruce <[email protected]> wrote: > 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]<entstrees%[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]
