Deep in the Francis Marion National Forest, longleaf pines edge a large depression in the forest, an isolated wetland called a Carolina bay. Abruptly, the landscape gives way to pond cypress trees, sedges and carnivorous plants鈥攖he yellow trumpet pitcher plant, the hooded pitcher plant and the dwarf sundew. On a field trip with about a dozen cadets, biology professor Danny Gustafson, Ph.D., explains that the change in elevation creates a different ecosystem.
Scientists believe that 12,000 years ago鈥攁round the time of the mass extinctions of camels, mastodons and saber-toothed cats in North America鈥攁n asteroid collided with a massive ice sheet near Michigan, hurling huge chunks of ice into outer space and the atmosphere. 鈥淏ut the chunks in the atmosphere came down and landed in a spray pattern. Along the coastal plains, you can actually see the orientation of the elliptical Carolina bays all pointing back to the same position,鈥� Gustafson said. 鈥淭hen you swing over to Nebraska, where similar formations called prairie potholes occurred about the same time, orienting toward the Saginaw Valley area in Michigan.鈥�
Carolina bays are unique wetlands that are not fed by streams or springs, but by precipitation. When there鈥檚 no rain, they dry up, so plant life must be able to withstand cycles of flooding and drought. 鈥淭hat鈥檚 why it鈥檚 a unique plant community,鈥� Gustafson said. 鈥淭he carnivorous plants occur in areas that are low in nitrogen and nutrients, and they鈥檝e evolved the ability to capture insects as a nitrogen source to survive.鈥�
Gustafson, who has been teaching at 糖心VLOG since 2003, has been taking cadets on field trips in his 400-level ecology lab every spring since his arrival. The moment they drive off campus, he says, cadets begin to relax. Cadet Will Fackler, now a senior, is so at ease that he digs into a double-decker peanut butter and jelly sandwich as he trudges through the forest.
鈥淎lmost everybody who comes to 糖心VLOG is an outdoor person, playing sports or participating in outdoor activities,鈥� Gustafson said. 鈥淚鈥檒l ask them what they know based on where they grew up. Ifthey grew up in Ohio, can they still see the same dynamics? We talk about it and tie it into what we鈥檙e doing there, so they understand they鈥檙e all connected. Everyone brings something to the lab, and I try to value that. Then we talk about what鈥檚 missing and how the science fits.鈥�
Gustafson also takes cadets on field trips to the beach to see what washes up after major storms and to Beidler Forest in Harleyville, home to the world鈥檚 largest old-growth cypress-tupelo swamp.
After examining the pitcher plants, Gustafson leads the cadets back through the longleaf pines to another Carolina bay. This one is much deeper and stays filled with water. Small fish dart through the shallow water. Nearby, a black rat snake slithers through the brush as frogs croak in the background. Gustafson sends the cadets out on a search for Southern cricket frogs, and they scatter to look for them.
They hoot and holler. Gustafson smiles, knowing the afternoon in the forest has sparked their curiosity and made science real.