(News-Press.com) - This was one big tree, a giant even among the giants of Corkscrew Swamp Sanctuary — the massive bald cypress tree's lowest branch was as big as a mature live oak.
Just the kind of tree Mike Knight and Ralph Arwood were looking for last week: The two men are in the first phase of an Explorers Club expedition to study giant bald cypress trees at Corkscrew, the largest old-growth bald cypress stand in the world; the sanctuary's average old-growth cypress tree is 11 to 12 feet in circumference; giant trees are 17 to 23 feet.
Knight, regional director of The Explorers Club's Florida Chapter, and Corkscrew volunteer Arwood measured the tree's circumference at 20.2 feet, which would make it about 700 years old; in other words, the tree was growing in Corkscrew during theBlack Death in Europe and when Joan of Arc was burned at the stake.
"That's a fun tree," Arwood said. "I like that tree."
Founded in 1904, The Explorers Club is an international society that promotes field research and the exploration of land, sea, air and outer space.
Explorers Club members have included Edmund Hillary, who led the first successful ascent of Mount Everest in 1953, and Apollo 11 astronauts Neil Armstrong, Buzz Aldrinand Michael Collins.
Phase one of the Corkscrew expedition is finding, mapping and measuring giant cypress trees in Corkscrew's 800-acre forest, which represents 2 percent of the cypress forest that once covered the region.
For phase two, researchers will climb some of the giants and document every living organism from the canopy to the ground.
"The reason The Explorers Club took interest in this expedition is that you can look ... on Google Earth and see the whole canopy, but you can't see the trees for the forest," Knight said. "It's possible nobody has ever walked through here. There are still blank spots on the map, and here's one of them in our own backyard."
Corkscrew's cypress forest is 5,000 years old, but the oldest trees are 700 years old because a fire burned nearly all of South Florida 700 years ago.
"There are old historical accounts about giant cypress trees out here that tower 150 high, measure 20 feet in girth and are 700 years old," Knight said. "We want to find how many there are and where they are. We're looking at a snapshot in time, a piece of old Florida that has existed for centuries."
Finding Corkscrew's giants is not easy.
When surveying an open area such as a coral reef, researchers can simply run transects, a series of straight lines, and count whatever organisms they're interested in.
But Corkscrew's cypress forest doesn't have any straight lines; it's a tangled mass of living and dead vegetation.
Instead of transects, Knight and Arwood employed the roaming- or creeping-line technique: Using GPS as a guide, they hiked through the forest looking for giant trees until their path was blocked by impenetrable vegetation or water, then changed directions and walked until their path was blocked again.
"We don't know where the trees are, so we weave through the forest in the general direction we want to go," Knight said. "When we see a tree that might be big enough, we throw a tape measure around it."
It was tough going, climbing or tripping over fallen logs, crawling under low branches, crashing through thick vegetation, banging shins on cypress knees, being scraped and cut by the thorns of Smilax vines, and being bled by mosquitoes and deer flies.
Arwood, who has been nominated for membership in The Explorers Club, and Knight zigged and zagged through the forest for six hours; they covered almost 5 miles on their nonlinear course. When they walked wearily out into Corkscrew's North Marsh, they were about one linear mile from their starting point.
For the day, they discovered six giant trees, ranging from 18.2 to 20.2 feet in circumference; to date, the project team, which includes several other volunteers who are not affiliated with The Explorers Club, has discovered 49 giant trees. About 200 acres of the sanctuary remain to be explored.
"Out here, you can get the idea of these ancient trees as an integral part of the ecological community," Knight said. "This is the remnant of a once huge, magnificent forest. It's a treasure for us, part of our cultural and ecological heritage."
Five giant trees, including one with a 23-foot circumference, can be seen from the Corkscrew Sanctuary boardwalk and are part of the sanctuary's Landmark Trees project, through which visitors can learn about each tree's history and its ecological role.
"This is pristine wilderness," Corkscrew spokeswoman Beth Preddy said. "It's an ancient forest just 30 miles from the beach, and people can experience it as an ancient forest, and get to know the awesomeness of these monumental landmark trees."