Southeastern Surprises   Jess Riddle
  Feb 15, 2005 07:14 PST 

In some ways, my situation is a little different since I didn't have any
background, in forestry, research or other tree related disciplines, to
build off of or generated expectations prior to becoming involved with
ENTS. Consequently, many of the findings of ENTS and other knowledge
passed over the discussion list helped form my initial views. However,
some discoveries have come as real surprises even against the reference of
what we had found just a few years ago. Most recently, the discovery of
several new sites with great potential, some of them urban, has forced me
to reevaluate what we know. Even as recently as a year ago, I could look
back at a draft of Stalking the Forest Monarchs from 1997 and notice that
for most of the largest species no new record individuals had been found
and that most of the high RI sites had already been found. Since then the
recognition of Fairmont Park, Tanglewood State Park, Rock Creek National
Park and surrounding areas, and another Park outside of Raleigh NC has
opened up a wealth of new possibilities even in familiar states. Also,
the surprise comes form not from the fact that new impressive sites are
being found, but rather where they are being found. Clearly, the
Mississippi valley and adjacent areas hold great promise and are largely
unknown to ENTS, but the states along the Atlantic had been more
traditional tree hunting grounds. Consequently, this recent explosion of
new discoveries in that area has been exciting.

The disparity between the Georgia and South Carolina sections of the
southern Appalachians that the past few years of hiking have revealed was
unexpected. Rainfall, length of growing season, and overall geology are
comparable between the two regions, and SC only has a handful of
mid-elevation north facing coves. In spite of those conditions, SC
supports taller trees of most mountain species. Black cherry and yellow
buckeye, both species that grow well in mid elevation north facing coves,
are the only species that immediately come to mind that consistently grow
better in north GA. The relatively small areas of the central Brevard
Belt and Wadakoe Mountain generate much of South Carolina's advantage, but
do not account for the entire disparity. Black locust, fraser magnolia,
and cucumbertree all reach greater heights, and often diameters, at a
variety of SC sites than they are known to achieve in Georgia.

The finding that really caught me off guard was the volume of the
Middleton Oak. All of the arguments for columnar forest grown trees
having far more volume than spreading short trunked trees. Since those
climbs, I've looked at the density of branches in tree crowns more, and I
still have trouble getting my mind around how the Middle Oak with only
slightly more crown volume has so much more limb volume. Looking up form
the ground, the difference simply doesn't appear that great. However,
viewing the findings more abstractly the numbers begin to make a little
more sense. Open grown trees will typically have greater access to water,
nutrients, and light due to less competition. The greater sunlight should
allow for faster biomass accumulation, and the other resources will
support that accelerated growth. Then how would a forest grown tree
accumulate greater volume. A greater proportion of the open grown tree's
resources would go to fruit and leaves, so the annual growth rate
difference would be less than the resource difference. However, the open
grown tree would always be able to lay down as much new wood as needed,
and the greater light from the sides would allow the open grown tree to
maintain a deeper crown and hence more branch volume. Of course, this
argument is larger based on assumptions, but does give some theoretical
explanation for observed facts. The one other kink in the theory is that
the faster growth rates might lead to less fungal resistance and decreased
life spans resulting in less overall biomass accumulation. Perhaps this
finding should not have been that great of a surprise since Colby's
estimation of the Wye Oak's volume produced similar figures.

Jess Riddle