Surprises and shedding biases   Robert Leverett
  Feb 14, 2005 10:53 PST 


     Since undertaking the ENTS mission in the mid-1990s, surprises for
me have come fairly often. As I look back, oddly, some of my surprises
have come after shedding prejudices - often subconsciously acquired. For
example, I had downplayed the big tree role of the silver maple in the
flood plain regions of southern New England. Why? Well, it was partly
due to the influence of friends who didn't particularly like the
species. It lacked commercial value. While that kind of thinking didn't
enter my conscious stream of thought, it did influence me
subconsciously. I wasn't supposed to like the silver maple because it
wasn't like northern red oaks or white pines. It was a "junk" species,
so I was subconsciously programming myself to simply ignore it. Yes,
that was a silly mental process on my part, and completely my own fault,
but I have no doubt that the bias influenced me to limit the attention I
gave to the species in big tree searches. I think that I just
subconsciously wanted to give more credibility to the point of view held
by my timber-wise friends who see trees largely through a timber lens. I
subconsciously adopted their point of view.

     Well, valuable or not from a timber perspective, the silver maple
is one heck of a big tree species in the river valleys of western
Massachusetts. Of the paltry 54 silver maples in my database, 26 have
circumferences of 12 feet or more and 32 are 100 ft tall or more. The 26
big trees represent 48% of the total. To investigate the significance of
the statistic, I first appealed to the sycamore. How does the silver
maple compare to the sycamore - THE big tree of southern New England? Of
the 82 sycamores in my database, 45 are over 12 feet in circumference
for a percentage of 54%. Not too shabby - remembering that the sycamore
is our largest hardwood in New England.

     In terms of height, a total of 59% of the silver maples in my
database are over 100 feet tall. This contrasts to a whopping 77% for
the sycamore. One can more easily find the combination of large girth
and significant height in the sycamore, which is to be expected for the
species. But sycamores have a very thin distribution relative to silver
maple. The abundance of silver maple is vastly greater. So a percentage
of 48% of trees in the 12-foot circumference class assures me that there
are a lot of them out there, if I choose to look for them.

How does the silver maple compare to king cottonwood? For the
cottonwoods in my database (154 strong), only 18% are over 12 feet in
circumference. However, 90% are over 100 feet in height. Now to relative
abundance. There are lots of river bank and flood plain cottonwoods,
almost as many as there are silver maples. So, the above percentages
suggest that if I keep searching for big and/or tall specimens, I'll
encounter more 12-foot circumference silver maples than cottonwoods. The
percentages may be dramatically different.

But what do these statistics really mean? Are they measures of my
biases more than what grows out there in the bottomlands? First off,
please let me re-emphasize that my searches zero in on conspicuously
large and/or conspicuously tall trees. Obviously, I bypass thousands of
trees that hold no interest for me. I AM only looking for the
superlatives, their absolute and relative abundances, to give me a feel
for what a species can do in a region.

     In the numbers above, I have superficially compared three species
that grow in fairly similar habitats. But two are far more common that
the third. If I go on searching for big trees in the flood plains, will
the percentage domination of big silver maples over cottonwood continue
and will the height domination of tall cottonwoods over silver maples
likewise continue? I do believe that will be the case. As much as I want
to find a legitimate 20-foot circumference cottonwood in my backyard,
the odds are that I'll find a silver maple first.

            What is the prevailing perception of arborists, foresters,
ecologists, loggers, big tree hunters, forest historians, town tree
wardens, etc. about the relative abundance of big silver maples relative
to other species in southern New England? I really don't know. George
Emerson's classic 1846 edition of "Trees and Shrubs of Massachusetts"
leads one to believe that a 12-foot circumference silver maple was a
rarity in the mid-1800s, if not an extreme rarity. Has the silver maple
emerged to be the most dominant big tree in the flood plains of the
southern Connecticut River? Was George Emerson looking for big trees on
flood plains or mainly in the towns? How does the species fair on the
southern reaches of the Hudson? Darned if I know, but intend to find out
just as soon as I finish shedding my old biases. As for my new bias,
silver maples rule. They're way cool.


Robert T. Leverett
Cofounder, Eastern Native Tree Society
Hunting for records and oddities
  Feb 21, 2005 04:49 PST 

      As I write the FMTSF 2004 report to DCR, summarizing the research we have done in 2004, I search for ways to present our discoveries and conclusions to highlight the exemplary, the unusual, the startling. One bit of tall tree trivia (TTT) that I realized is that the 151.5-foot white ash in MTSF is the northern most 150-foot hardwood in the Northeast. It is located at 42.626 degrees latitude north. The two 150s in Zoar Valley (tulip at 156 and sycamore at 153) appear to be around 42.5 degrees or slighltly less.
     I wouldn't rule out a 150 slightly farther north than the Mohawk tree in the Midwest, but so far none has been confirmed by ENTS.

     The Massachusetts team is chomping at the bits to return to Trout Brook and confirm more soaring ash trees. At the least, a couple more 140s would serve to firmly establish MTSF as the center of tall tree development in the Northeast for Fraxinus americana, at least until some New York or Pennsylvania site challenges Mohawk's dominance. Will that happen? Most likely. The Catskills are a gold mine for the white ash. But for now, I can state with honesty in the 2004 report that outside of Mohawk, only two white ash trees have been measured to over 140, the Kaaterskill Falls tree bagged by Howard and the tree in Ice Glen.