Holy Mackerel! I can't believe the way you guys keep this discussion going (and others too)! Besides that, I can't believe how much you guys write in each of your responses. How can you come with so much to say? (Hey, I'm not knocking it. I just can't believe it.) By the way, this response doesn't need to be archived on the site. I just had to say this. This discussion is like the Energizer Bunny, if you know what I mean.
--- On Thu, 1/7/10, Gaines McMartin <[email protected]> wrote: From: Gaines McMartin <[email protected]> Subject: Re: [ENTS] Re: White pine growth rates--something of interest about growth possibilities To: [email protected] Cc: [email protected] Date: Thursday, January 7, 2010, 8:40 AM Ed: All the environmental factors causing one pine tree--or group of pines--to grow taller than others I pretty much understand. As for the isolated populations: I am not sure that is what is in play in either Ontario with white pine, or in Europe with Norway spruce. The disparate results that popped up in Dr. Genys's trials were from generally forested areas, not isolated areas. And, unless I misunderstood the article about white pine in Ontario, whose summary I read, population isolation was not the issue in the variations in white pine in Ontario. I commented in that post that I was surprized that pollen drift has not eliminated that kind of variation, but apparently it has not. Maybe one more thought about provenance trials--or their interpretation. As you pointed out, after selective logging in which the best trees are cut, even if two or three times, and even if some selectiing out of the best genes has occurred, the resultant population will normally have a large enough number of trees so that they will have to compete, and thus the individuals having the best "growth" genes will dominate again, restoring the previous balance. In the same vein, provenance trials often have a short duration, and the results after 3 or 4 years are results before any competition occurs between individuals in the population being studied. And sometimes--although from my observations, not usually--the best individuals after 4 years a may not be the best over a longer period of time. Trees in a mature white pine stand and a mature Norway spruce stand will be spaced an average of at least 25 feet apart. I won't try to do any precise calculations, but these trees will be a very small fraction of the initial population. So, to get a beautiful stand of fast growing "superior" domanant trees, something like only 5% (maybe a bit more if we consider the effects of random spacing of the best trees) of the initial population need have really good growth potential. When reading the growth of seedlings in a provenance trial, a strain that produces a small number of superior trees might be missed, but might be a good strain nevertheless. Dr. Charles Maynard at SUNY Syracuse has done some work with Norway spruce, and he always emphasizes the importance of developing "land races," that is a localized genetic strain produced by planting trees from a good source, letting the trees grow to something like maturity, and then collecting the seed of the remaining dominant trees to use in subsequent plantings in the same or similar areas. He has felt that this may be more productive than doing trials of various European sources, and then selecting the best based on a simple provenance trial. The one limitation of this use of land races is sometimes a specific stand one might want to use as a source of a land race, may not have had the very basic potential of another. For example, I would much prefer to collect seed from the stand near Glady, WV than the "Rothkugel." Anyway, with the growth of the "native trees only" movement, interest in Norway spruce in this country has dropped off a cliff! Yes, I digress. Anyway, I think I have pumped myself dry on this topic. I am flat out of ideas. But I would like to see othes with some insights to chime in. In the meantime, I will enjoy watching my pine groves grow, and will be interested in finding good stands in which I--eventually maybe--or others can measure outstanding trees. White pines are wonderful even if they didn't grow to 250 feet. But that idea is so attractive, that I can understand why it is so hard for some of us to abandon. --Gaines. --------------------------------------------------------------------------------------------
