HR: 08:30h
AN: NB41B-01    [Abstracts]
TI: Microbial Dynamics on Decaying Leaf Litter in an Ohio Stream
AU: * Das, M
EM: mdas@kent.edu
AF: Kent State University, 256 Cunningham Hall, Kent, OH 44242 United States
AU: Royer, T V
EM: troyer@kent.edu
AF: Kent State University, 256 Cunningham Hall, Kent, OH 44242 United States
AU: Leff, L G
EM: lleff@kent.edu
AF: Kent State University, 256 Cunningham Hall, Kent, OH 44242 United States
AB: Deciduous leaf litter is an important source of energy for many streams. Fungi (aquatic hyphomycetes) and bacteria play important roles in litter processing, but the colonization dynamics of these groups across different leaf types is not well described. We examined fungal and bacterial colonization on sugar maple and white oak leaves in a hardwater stream in Northeastern Ohio from November 2003 through May 2004. Triplicate samples of each leaf type were collected from litter bags approximately monthly. The dry weight and organic content of the leaves were measured. Fungal biomass was determined from ergosterol concentrations in the samples. Image analysis of DAPI-stained cells and standard conversion factors were used to calculate bacterial biomass. On most dates, fungal biomass was similar on leaf types, and 10-fold higher than bacterial biomass. Throughout the study, bacterial numbers and biomass were greater on sugar maple than white oak. Sugar maple leaves decayed faster than oak leaves, but this was not reflected in the biomass of aquatic hyphomycetes, rather in the abundance of bacteria. Although fungi are considered the main organisms in litter breakdown, bacteria showed a greater response to leaf quality in this study, and may be more important than the biomass suggests.
DE: 9810 New fields (not classifiable under other headings)
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly