by Dr. Daniel B. Ward
reprinted from Big Trees: The Florida Register Appendix G
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Although the American Forests measurement rules permit substitution of volume in place of the formula employing circumference, height and crown spread, the inherent difficulties of the alternative technique greatly restrict its use. Following is an account (as published in The Palmetto, 1996) of the single employment thus far of volume measurement in the determination of Florida's champion trees.
Decades ago a gigantic Bald Cypress (Taxodium distichum) near Longwood, Seminole County, was recognized as perhaps the largest tree of its kind surviving in Florida. As early as the 1880s, visitors to the Sanford area are known to have waded through the surrounding swamp to view this tree. In 1927 M. O, Overstreet, a prominent citizen of Orlando (and State Senator, 1920-1924), gave lasting protection to the giant—thereafter known as the "Senator" in his honor—and an adjacent slightly smaller tree, the "Senator's Brother," by his donation of six acres to Seminole County. President Calvin Coolidge in 1929, during his last days in office, made a dedicatory speech beneath the tree, and a descriptive bronze plaque was placed on its trunk. In the mid-1930s the Work Progress Administration (WPA), to facilitate access, constructed a boardwalk from the nearby roadway to the base of the tree. But with access came vandalism; the bronze plaque and parts of an early iron fence were stolen by 1945. A sturdy replacement fence later placed at a small distance from the Senator's trunk has since effectively shielded the tree from overly affectionate visitors.
Although nearly all early reference to the Senator include statements of girth and height, as well as (unconfirmable) estimates of age, the first careful measurement to the American Forests standard was made by County Forester Mike Martin in February 1981. Mike obtained a point score of 531; this score was far above any Bald Cypress then on record, and for the moment the general assumption that the Senator was the largest Taxodium distichum in Florida seemed vindicated.
But in October 1981, Joe Corbett Mathis, a Hamilton County forester, wandered into a depression north of the Suwanee River, about four miles east of the Nobel's Ferry Bridge, and found a monstrous Bald Cypress shaped like a giant turnip, a hugely swollen base that tapered into a modest upper trunk. When the area had been logged for cypress, perhaps at the turn of the century, this tree was left because its lower portion was entirely hollow and its timber value, at that early date, wasn't worth salvaging. Joe measured the tree by the American Forests standard, which specifies the circumference be measured only at 4.5 feet, and came to a resounding 644 points. The Senator's reign was the Florida champion was over!
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In 1993, with Bob Simons, we furthered the Senator's ignominy by finding a second Hamilton County Bald Cypress, on Holton Creek, that measured 587 points. This discovery placed the Senator at third rank within the state.
Also in 1993, with Bob Simons, we remeasured the Senator, as well as the then-unmeasured Senator's Brother. The Senator had a circumference of 425 inches, a height of 118 feet, and a spread of 57 feet, giving it a point score of 557, a small improvement over Mike's 1981 score of 531, but insufficient to regain even second place. The Senator's Brother came in at 491 points, the sixth largest Bald Cypress in the state.
But Simons carried the investigation further. He used a Relaskop, a complex optical device that gives diameter measurements at intervals above the ground, and thus permits accurate calculation of trunk volume as a series of successively smaller cylinders. We accompanied him in measuring the volume of the Senator, the two Hamilton County giants, and, for good measure, an impressive tree known as "Old Methuselah" at DeLeon Springs Recreation Area, Volusia County.
The volume figures were just the inverse of the point scores. The Senator showed a volume of 3731 cubic feet. The Holton Creek tree had a volume of 2068 cubic feet. And Joe Mathis'; tree-the Florida champion by the American Forests standard-had a volume of 1872 cubic feet. (Old Methuselah, though a beautiful, symmetrical specimen, attained only 1155 cubic feet.)
So, which tree is the Florida champion? Is it the Mathis tree, larger in point total? Or is it the Senator, with the larger trunk volume? One system or the other must prevail.
Simons then called our attention to a similar controversy, in California, where trunk volume and total scores of the two largest Sequoia (Sequoiadendron giganteum) point in opposite directions. The General Sherman Sequoia is clearly larger in general appearance, with its massive cylindrical trunk, but the General Grant, which has a sizable butt and a more tapered trunk, was given a larger total point score. When volumes of the two trees were measured, the General Sherman was found to contain 52,508 cubic feet, while the General Grant contained 46,608 cubic feet. But the General Grant was scored at 1348 points, a bit ahead of the General Sherman's 1300 points.
Chaos swept the halls of American Forests! Since 1940, when American Forests began the registration of champion trees, a standard developed in 1925 by the Maryland state forester had been the agreed-upon comparator—a yardstick that permitted trees of different shapes to be matched with a single numerical scale (trunk circumference in inches, plus height in feet, plus one-fourth of the average branch spread in feet). But the tree volume, even simplified as a trunk volume, was an obviously logical alternative measure. What to do?
It took American Forests two years to decide that the standard formula was adequate, and was far easier to apply since measurement by tape and clinometer were more readily obtained that those requiring sophisticated volume measurement. But in 1992 American Forests concluded that volume measure, when available, was to be used in place of the standard formula. By this ruling, the General Sherman, at 1300 points and 52,508 cubic feet, was the National Champion Sequoia, and the general Grant, at 1348 points and 46,608 cubic feet, was relegated to the National challenger.
Applied to Taxodium in Florida, we must invert the ranking of the three largest trees. The Florida champion, once again, is the Senator at Longwood, Seminole County, with a volume of 3731 cubic feet. The Florida challenger is the tree along Holton Creek, Hamilton County, with a volume of 2068 cubic feet. And the Mathis tree, also Hamilton County, after its fifteen-year reign as Florida champion, is now moved to third place, with a volume of 1872 cubic feet. The King is deposed! Long live the King!
But let us not be quick to accept these trees as merely Florida champions. Might the largest of them also be the National champion? By American Forests records, the largest Bald Cypress is at Cat Island, West Feliciana Parish, Louisiana; it has a circumference of 644 inches and a point score of 748. But the grapevine tells us it is also a "turnip," with a swollen basal trunk but little above. It cannot be displaced, of course, without volume measurements. But it should it turn out to have a volume smaller than the measured Florida giants, then the Senator will become the National champion. We are awaiting records from American Forests, and opportunity to visit and measure the Louisiana tree. Stay tuned!
Supplemental note: Volume of the Senator was measured by R. W. Simons (aided by L. D. Harris), 19 July 1993. Procedure followed the "Smalian formula," as described in Forest Mensuration (Chapman & Meyer, 1949): Diameters were taken at 16 foot "log length" intervals (by use of a Spiegel Relaskop); calculation was made of square feet area of log ends; average was taken for each log, multiplied by the log length, and summed. (For basal log, diameter at 4.5 feet was used, rather than at 0 feet.)
for more information, see:
The Senator towers above controversy