White Pine:  Genetic Diversity   Ernie Ostuno   Sep 02, 2004 18:16 PDT  Thanks Bob. I just wonder if the less than 1 percent (maybe less than one tenth of one percent) of original white pine forest (or reasonable equivalent) in Pennsylvania can be used to estimate the true potential for the upper limit of diameter/height white pine in the pre-logging era. Could it be that a favorable combination of genetics, growing conditions, and other factors resulted in some isolated groves reaching heights that were significantly above the dimensions attained by the great majority of the species elsewhere? That is, is it possible that there were some special circumstances in the vicinity of R.B. Winter State Park that allowed 200 foot tall, 6 foot dbh white pine to exist there and virtually nowhere else? Ernie RE: White Pines Present and Past   dbhg-@comcast.net   Sep 02, 2004 19:13 PDT  Ernie:    I would certainly admit to that possibility. We may have lost genetic variability in the species. I've heard arguments pro and con. Lee Frelich can speak better to the possibility, of genetic loss. Bob RE: White Pines Present and Past   Lee E. Frelich   Sep 03, 2004 06:22 PDT  Ernie: A slight chance that a handful of pines may have attained that height cannot be ruled out, but I doubt it for several reasons: 1. There is a tight relationship between maximum tree height and latitude, with taller trees in the south, and white pines in the best conditions in the Smokies rarely reach 200 feet. 2. The percentage of forest that has never been logged may only be 1 percent, but there is a lot more white pine around the landscape that still carries the original genetic heritage than that. Areas certainly exist that have been repeatedly highgraded and have nutrient depletion in the soil as well, which would shorten the trees. But there are also a number of older second-growth stands that descended directly from the original white pines (by the way exemplary examples of such stands throughout the range of each tree species should be reserved for future seed sources, like they have been doing in some eastern European countries for centuries). 3. The spatial scale of genetic variation in trees with pollen that travels miles on the wind is not small enough to allow one area of a few hundred acres to be genetically unique for a species like white pine that occurred across the landscape. Don't forget that most white pine trees are not in white pine forests; they occur in varying proportion within other forest types. Pollen coming from other stands would continuously swamp out any unique genetic structures may tend to develop. Common garden studies show that genetic variation in trees is related to a latitudinal gradient, and trees are adapted to climate conditions for 1-2 degrees latitude (75-150 miles) in either direction. 4. Given the frequency of derechos, tornadoes, hurricanes, lightning, ice storms, etc., in the eastern U.S., trees are reaching their buckling limit at much shorter heights than they do out west. Two hundred feet is really pushing it in the east--a tree that tall is not likely to stay that tall very long, and therefore there would selection against trees that are that tall, and trees that are somewhat shorter would be selected for, because they would shed their seeds on the forest floor for many more years that the supertall ones that would be shot down by various climatic forces. Lee RE: White Pines Present and Past    Bruce Allen    Sep 03, 2004 06:56 PDT  Lee, One issue you didn't address is the effect of long term exposure acid rain, SOx, NOx, and O3 on not only white pine growth but genetic diversity. I also don't necessarily discount the long term effects of high grading (particularly in the east where the duration is much longer) on genetic diversity and fast growing gene combinations. I have seen for myself that the fastest growing white pine are the most susceptible to ozone damage and expect a similar responses to SOx. The conditions that may have allowed trees to grow more rapidly in the past don't exist today. My dad made a convincing argument (in an unpublished article to the journal of forestry 1968) that white pine isn't growing as fast today as it was 150 years ago and concluded that nutrition/cation exchange capacity was the culprit.   He also sold a woodlot down wind from a coal fired power plant because the pines weren't growing and were dying prematurely. White pine is extremely genetically diverse and it is reasonable to me to expect that some of that diversity has been lost. The Smokies also have been exposed to substantial increases in ozone and SOx. Granted, the frequency of disturbance in the east limit how long a tree has to reach extreme heights, but growth rate ties into the equation. my two cents, Bruce Re: White Pines Present and Past   Joe Zorzin   Sep 03, 2004 07:42 PDT  ... Perhaps, not so much lost- as altered- such that crooked, forked, defective specimans are now FAVORED by the most powerful influence for millions of centuries on pine and other species- ferocious attacks by naked apes- who prefer to "eat" tall, straight, healthy specimans. Rasputin Zorzinovich   RE: White Pines Present and Past   Lee E. Frelich   Sep 03, 2004 12:28 PDT  Bob and Bruce: Yes, I have seen sites with nutrient deficiency that limits tree height, such as Point Beach State Forest WI, and others.   White pines on other sites with better soil mineralogy continue to do quite well. There are still areas that have not been highgraded and that don't have much impact from atmospheric deposition (or even have a positive effect on growth from atmospheric deposition) as we have on some sites in the Midwest. Given the longer growing season we have today compared with the little ice age, I expect trees on such sites to be as tall or taller today than trees that grew up under similar conditions 100-400 years ago. The landscape is a complex mosaic with patches that have been impacted by human activities to different degrees. Lee   Home