Essay: Big Tree Park, part 1
In 2013 the park initiated a big tree survey to find potential state and national champion trees, as well as to relocate and appraise the status of current champions. The principal investigator is University of South Carolina geography professor Dr. John Kupfer. The last official big tree survey at Congaree was done nearly twenty years ago by Dr. Robert Jones, then a professor at Virginia Tech. There is a high turnover rate of big trees at Congaree, and the champion tree picture can change significantly in a twenty-year period.
The National Big Tree Program was first started in 1940 by the non-profit tree advocacy organization American Forests. It has maintained a register of big trees ever since, with the latest 2015 list having 781 national champion tree species, the biggest of their kind. It should be noted that many of these champion trees are not big in the sense of a redwood or sequoia, since a lot of trees are understory species that never attain large size. At Congaree a good example is the pawpaw, one of the park’s most abundant understory trees. Any pawpaw taller than 40 feet with a diameter of six inches or greater would be considered a big tree. The current state champion pawpaw, located at Congaree, is 5.5 inches in diameter and 42 feet tall. The biggest pawpaw I’ve ever seen was a former state champion at the park, almost 9 inches in diameter and 52 feet tall. This is an impressive size for an understory tree whose diameters typically run 1-3 inches with heights of 8-18 feet, and is just as remarkable as a five-foot diameter oak or sweetgum .
Most states have big tree programs, modeled after American Forests, and a big tree state coordinator, often a forestry professor housed at the state forestry school. For South Carolina, Dr. Vic Shelburne of Clemson maintains a website and data base of more than 125 state champion trees at www.clemson.edu/public/champtree/.
The Congaree is well known as a big tree park. Few areas of equivalent size in North America can boast of the number of state and national champion trees. The number of Congaree champions waxes and wanes over the years. In the late 1970s the park had as many as nine national champion trees; at other times as few as three. More recently six national champion trees were recognized at the park – loblolly pine, sweetgum, water hickory, swamp tupelo, laurel oak, and deciduous holly – along with twenty-five state champions.
The way champion trees are scored puts many Congaree trees at a competitive disadvantage. More emphasis is put on the girth of the tree – one point per inch of circumference – than tallness, which gets one point per foot of height (the third measurement is average crown spread which receives only one point per four feet of spread). In a dense, tightly-spaced forest like Congaree, most tree growth goes into height since trees need as much sunlight as possible for photosynthesis. Trees growing in open, less-crowded places like fields, yards, and hedgerows don’t have to compete for sunlight and put much of their growth into expanding outward through circumference and crown development. To illustrate with a couple of examples: for some years Congaree had the national champion persimmon tree, growing near the banks of Cedar Creek just off the Kingsnake Trail. This wonderful tree, measuring more than seven feet in circumference and 130 feet tall, is still there, but got “dethroned” by another persimmon in Ohio that is six feet bigger in circumference but more than forty feet shorter than the Congaree tree! And not surprisingly, the national champion persimmon is growing in a cemetery, with no other trees around it. I am not trying to take away anything from the national champ – a thirteen-foot circumference persimmon is an impressive tree in anybody’s book, but then so is a persimmon that’s thirteen stories high.
American holly is another example of scoring bias against tallness. There are currently several national holly co-champions, all running about twelve to thirteen feet in circumference with heights of sixty to sixty-five feet (and again, mostly growing in open locations free of competition). The former national champion American holly at Congaree (now dead) was nearly a hundred feet tall but with a circumference of “only” eight feet.
Image: Congaree’s former national champion American holly