SREL
Reprint #2643
INVERTEBRATES
THAT AESTIVATE IN DRY BASINS OF CAROLINA BAY WETLANDS
Susan
E. Dietz-Brantley1,2, Barbara E. Taylor1,
Darold P. Batzer2,3, and Adrienne E. DeBiase1
1Savannah River Ecology Laboratory, University of Georgia,
Aiken, South Carolina USA 29802
2Department of Entomology, University of Georgia, Athens,
Georgia USA 30602
3Corresponding author
Abstract
Water levels fluctuate widely in Carolina bay wetlands and
most dry periodically. Aquatic organisms inhabiting these
wetlands have the capacity to either resist desiccation
or to recolonize newly flooded habitats. The objective of
this study was to determine which invertebrates aestivate
in the soil of dry Carolina bays and to describe how differences
in habitat affect the composition of aestivating invertebrates.
Eight Carolina bays located on the Savannah River Site (SRS)
near Aiken, South Carolina, USA were examined for this study.
Although all of the wetlands dried seasonally, three of
the wetlands were relatively wet (inundated 47-92% of the
year on average), one was intermediate, and four were relatively
dry (inundated 20% of year on average). Sections of soil
were removed from each bay during August and November when
all sites were dry, placed into tubs, flooded, and covered
with fine mesh. Invertebrates were sampled from the water
biweekly for four weeks. Invertebrate assemblages were contrasted
between naturally inundated bays and rehydrated samples,
wetter and drier bays, August and November collections,
and remnant ditches and the main basins. Common aestivating
fauna included midges, dytiscid beetles, copepods, and cladocerans.
The Jaccard's coefficient of similarity for invertebrates
emerging from dry substrate and from naturally flooded wetlands
(with both aestivators and colonizers) averaged 0.22. More
taxa emerged from rehydrated samples from wetter bays than
drier bays. Season affected which taxa emerged. Remnant
ditches supported fewer taxa than basins. Aestivating invertebrates
make up a significant component of Carolina bay fauna.
Key Words:
aestivation, rehydration, invertebrates, wetland ponds
SREL
Reprint #2643
