Essay: Big Tree Park, part 2

Because we are built close to the ground, relative to a tree, our attention is drawn to the tree’s girth. The tree’s height is hard to visualize, especially in a closed-in forest where it’s hard to get a complete view of the tree when standing back from it. This makes it harder for us to appreciate the most striking fact of Congaree’s big trees – their height. When Jim Elder and I first started exploring the swamp, searching for big trees, we needed tree height, along with circumference and crown spread, to submit the tree as a potential record. Without having any equipment to measure tallness, we had to resort to the “Boy Scout method.” One of us would hold an outstretched arm at a 45º angle, verified by the second person standing to the side, and step back until the arm pointed to the top of the tree. This now meant, according to trigonomic law, that the distance paced off to the base of the tree was the same as its height. Admittedly crude, some of the heights we came up with were so far off the charts that we knew they had to be too high. Imagine our surprise, however, when foresters later came behind us with clinometers and other height-measuring devices and found some of our heights to be under-reported!

Forest ecologist Dr. Robert Jones was one of the first to report on the remarkable heights of Congaree’s hardwoods. In a 1990s cooperative research report with the National Park Service, Jones indicated that Congaree had “perhaps the world’s greatest concentration of super-tall, temperate deciduous trees.” More than a third of his measured large trees, for example, were over 130 feet tall. They included a water hickory 148 feet high; a persimmon more than 130 feet tall; a green ash 140 feet high; and the tallest hardwoods he measured were a sweetgum and a cherrybark oak nearly 160 feet high.

The Native Tree Society (NTS) is a dedicated group of tall tree enthusiasts that come from all walks of life. Some are professional foresters and forest scientists, arborists, botanists and biologists; others run the gamut from business to teaching. They all have a passion for locating and studying the tallest trees in America. Their dedication extends to determining the precise height of trees, down to tenths of a foot, and they use sophisticated measuring devices, including laser rangefinders, to do this. If there is any doubt or question, they will actually climb the tree and determine its height with a tape measure.

Over the years NTS President Will Blozan, an arborist from Asheville, North Carolina, and his colleagues have made several trips to Congaree. They have recorded some impressive tree heights: a 58.8-foot tall pawpaw, a sycamore nearly 154 feet high, a Shumard oak more than 157 feet tall, and an American holly nearly 100 feet tall. Of all of Congaree’s hardwoods, the tallest they’ve found was a 160-foot cherrybark oak, now dead. This was also the tallest oak tree ever measured in North America. In fact, of the seven species of oaks that occur regularly in the Congaree floodplain, five are the tallest recorded for their species: cherrybark oak (160.1 ft.), Shumard oak (157.6 ft.), overcup oak (142.4 ft.), swamp chestnut oak (140.3 ft.), and swamp laurel oak (130.1 ft.).

In 2001 the father and son team of Doug and Jess Riddle, both avid tall tree hunters, discovered and measured Congaree’s well-known national champion loblolly pine growing on the banks of Big Tupelo Gut. This tree was first measured to be 167 feet tall. Since then it has been climbed at least twice by Blozan and NTS members to get a precise measurement using a tape drop. The latest measurement, in 2010, puts it at 171.2 feet.

Earlier, in 2000, Jess Riddle had actually found a Congaree loblolly pine, now dead, that was even taller than the champion – 172.3 feet. But the pine was a couple of feet smaller in circumference and didn’t have enough points to be a champion. This was the tallest tree ever measured in South Carolina until a few years ago when the NTS folks found a yellow poplar in Oconee County that was 177 feet.

Experience has led us to a pretty good idea about the maximum sizes attainable for the circumferences of Congaree’s big trees — but not so much for their maximum heights. The canopy of the national champion loblolly pine, for example, has not flattened out yet, as many conifers do in old age, and is still growing upward. Will it make it to 175 feet? Or even 180? The fact that we are even having a discussion of a tree that rarely exceeds heights of 100-120 feet anywhere else is remarkable testimony to some of the most remarkable trees anywhere on the planet.

Image by Robert Askins