AJ-
To say nothing of the classic symbiotic relationship between
Clark's nutcrackers, whitebark pines and grizzlies!
-Don
> Date: Tue, 12 Jan 2010 12:18:35 -0500
> From: [email protected]
> To: [email protected]
> Subject: Re: [ENTS] Projected heights and Jenny's wrath
>
> You and Gaines are definitely going to be sent to the "Bird Sensitivity
> Re-education Camp". Let's see, we'll make you wear aprons and hand feed
> baby bird orphans from dawn to dusk with eye droppers. It will be fun.
>
> Maybe this will help. I recall reading a theory that the acorn caching
> behavior of blue jays was responsible for rapidly pushing oak species
> north following the last major North American glaciation. Jays have
been
> documented caching acorns up to 8 miles from a source tree. They don't
> remember where they put all their acorns and are very effective at
> planting oaks. Some great studies have been published showing how
insect
> foraging bird species in Colorado ponderosa stands have an important
> role in reducing insect load on pines and thus improve the health of
the
> trees. Birds have a huge beneficial role in forest ecology.
> -AJ
>
> [email protected] wrote:
> > Andrew,
> >
> > I'm sure that you'll get kudos and credits in Jenny's avian
> > sensitivity rating system. But Gaines and I may be in trouble. We'll
> > mend our ways. At 68 1/2 I can still change. Really I can. I think I
> > can. Maybe I can.
> >
> > Bob
> >
> > ----- Original Message -----
> > From: "Andrew Joslin" <[email protected]>
> > To: [email protected]
> > Sent: Tuesday, January 12, 2010 11:15:28 AM GMT -05:00 US/Canada
Eastern
> > Subject: Re: [ENTS] Projected heights and Jenny's wrath
> >
> > That's funny! I've been a birder for more than 20 years. As a
climber I
> > frequently visit the tops of white pine. In my area in eastern
> > Massachusetts I can very confidently say that damage to tops is
> > primarily from weather. Over the years I've seen many large raptors
> > perched in white pine and have never seen them break anything.
I've even
> > seen a pair of Red-tailed Hawks mating in the top of a white pine,
you'd
> > think this rambunctious activity would do some damage but no. I can
> > imagine perching birds breaking delicate tops on smaller conifers
but on
> > mature white pine for example any branch thicker than an inch is going
> > to support Red-tailed Hawk (our largest common raptor). I have seen
> > red-tails intentionally breaking small branches off of red oak for
nest
> > material but they don't seem to go for the uppermost branches when
> > they're doing this. They need a secure perch on a thicker branch
to get
> > into position to break a small branch. I can imagine a bald eagle
easily
> > breaking out some top branches but their population densities are not
> > enough in the east to make a difference for our tall white pines.
> > -Andrew
> >
> > [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
> >
>
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