Spring Break in the Okefenokee Swamp

Dr. Shear took a four-day trip over spring break to collect millipedes for his MITS grant research in southeast Georgia. Included in visits were the Okefenokee and Cumberland Island Wildlife Refuges and Crooked River State Park. Canoeing through the Okefenokee for six hours resulted in observations of many birds, such as wood storks, egrets and herons, and abundant sightings of alligators basking on the mudflats. An unusual habitat at Crooked River is the Maritime Deciduous Forest, isolated here by wide expanses of Longleaf Pine Forest. The MDF, very likely a primary forest at this site, consists of live oak, hickory and cherry, with an understory of holly, turkey oak and buckeye. The trees were immense, the largest hickories we have ever seen. The forest grows on a huge shell midden–a pile of oyster shells that accumulated over the 4000-year-long occupation of the island by the Timucua tribe. On Cumberland Island, the Maritime Forest has a different expression, consisting almost entirely of live oak, but dwarfed by the constant winds from the sea and salt spray. The trees are only about 20-30 feet tall but their interlocking horizontal branches spread out more than twice that. In both forests, the litter layer is very sparse due to the rapid biological turnover in this warm climate, consisting of just a skim of leathery live oak leaves over sandy, black, organic-rich soil.

Not a particularly good habitat for millipedes, but two rare species were collected and preserved for transcriptome and DNA-barcoding work: Stelgipus serratus and Dicellarius okefenokensis. Both have very narrow distributions centering on SE Georgia and adjacent Florida.