No matter how you feel about birds, for an entertaining time go some place and watch the seagulls come in for a landing on ice. Takeoffs are funny too. Sam
________________________________ From: "[email protected]" <[email protected]> To: [email protected] Sent: Tue, January 12, 2010 12:15:02 PM Subject: Re: [ENTS] Projected heights and Jenny's wrath Dale, Not to worry, my friend. All us veterans have special gun totting privileges. Shhh, don't let Jenny know. Bob ----- Original Message ----- From: "Dale Luthringer" <[email protected]> To: [email protected] Sent: Tuesday, January 12, 2010 11:44:36 AM GMT -05:00 US/Canada Eastern Subject: Re: [ENTS] Projected heights and Jenny's wrath That's a tought one, Bob, I've got an itchy trigger finger... On Tue, Jan 12, 2010 at 10:52 AM, <[email protected]> wrote: Gaines, > > > >Oh boy, I hope a rift doesn't develop here in ENTS. Those of us obsessed with >tree heights will naturally want to limit damage by birds perching in the >crowns, especially their highest parts. I'm definitely not suggesting anyone >get out his/her youthful slingshot, but in time the temptation could grow. >Giving this line of thinking a foothold could prompt Jennifer Dudley to >establish a bird safety patrol to keep a close eye on us measurers. Jenny's >wrath would be swift and terrible. Resist the temptation Will. Resist the >temptation Scott, John, Dale, .......... Resist. Resist. > > >Bob > > > > > >----- Original Message ----- >From: "Gaines McMartin" <[email protected]> >To: [email protected] >>Cc: [email protected] >Sent: Tuesday, January 12, 2010 10:07:42 AM GMT -05:00 US/Canada Eastern >Subject: Re: [ENTS] Projected heights > >Jess: > > I had thought about mentioning it before, but when you say that the >growth rate of a pine tree is influenced by its current height, you >bring up an important consideration. Strictly speaking it is better >>to say that growth rate is influenced by age, and it is this >relationship that the growth curves are representing. > > But the growth rate/height relationship is something that is too >often ignored. Years ago I read a report of a provenance trial of >>white oine, that said that the best way to measure results is not the >height of the trees after some set period of time, but to measure >their growth rate at various specific heights. The idea behind this, >if I remember rightly, is that different sites, including microsites >>(my term) influence the early growth of the seedlings differently, but >this influence is minimized in the data if the growth rates of trees >are compared when they are at the same heights (comparably >established, comparably developed). And this kind of measurement would >>best predict the trees’ overall growth potential over time. > > Now the data that prompted me to open the white pine growth topic >showed that the growth rate of white pine on the better sites declines >more rapidly than that of white pine growing on the poorer sites, so >>much so that after age 55, the growth rates are the same—one foot per >year. I thought this had some application in the discussion of >whether or not white pines could, or did grow to 250 feet. Thus if >the fastest growing pines maintain their relatively fast growth rate >>for only 55 years, then the best growing white pines would not grow as >much taller than white pines with more ordinary growth rates as we >might have thought. White pines 100 feet tall in 50 years is good, >but “ordinary.” Growth of 120 feet is excellent, but after gaining 20 >>feet over the more ordinary trees in 50 years, and maybe a foot or two >in the next five, no further advantage will be gained. All that made >me think 250 foot white pines, if view of the fact that none exist >today, less likely than I might have thought. > > Sorry—I said all that before. But I wanted to re-establish the context. > > Now to the height/growth rate relationship: lost is the above data >may be the fact that the trees with the most outstanding growth will, >>in spite of any decline in growth rates down to the level of other >white pine trees after age 55, still be growing faster at any specific >height. > > Of course as Will and others have pointed out, there is the risk of >>storm damage. I would add to that the damage from large bird perch. >The bird perch issue is not recognized by all foresters, but I have >observed it first hand many, many times. The tallest trees in my pine >and spruce stands are the ones usually hit. The new growth is often >>completely mashed down. If this happens early enough in the growing >season, especially with the Norway spruce, a leader can be >re-established. I can imagine that slower growing very tall old trees >would have some difficulty doing that, and the damage could >>accumulate. This would be a significant influence on the ability of >older, very tall trees to make good further progress upward. > > This relates to the ability of second growth stands to exceed the >growth of trees in the virgin forest. I will take this up in my next >>response. Enough for one post here already. > > --Gaines >
