Mueller-Solger, A. B.. University of California, Davis, abmuellersolger@ucdavis.edu
Brett, M. B.. University of Washington,
Goldman, C. R.. University of California, Davis,

 
ZOOPLANKTON EFFECTS ON LOWER TROPHIC LEVELS: A META-ANALYSIS OF ENCLOSURE STUDIES.
 
We conducted a meta-analysis with the results of 389 enclosure studies with and without zooplankton in order to find general patterns and magnitudes of the impacts of metazoan zooplankton on planktonic algae, ciliates, heterotrophic flagellates and bacteria. We found that in general, zooplankton decrease ciliate and flagellate densities by 33% each and phytoplankton density by 12%, compared to controls without zooplankton. In contrast, bacterial growth is generally slightly, but not significantly, stimulated by the presence of zooplankton (6% increase). Further investigation of sources of variation in zooplankton impacts within the four prey groups revealed significant differences in impacts related to study lake, zooplankton taxonomic group, nutrient availability and ecosystem trophic status, with greatest estimated impacts found for ciliate densities in oligotrophic systems (74% decrease over controls). We also compared results obtained with several meta-analysis metrics. With this meta-analysis we were able to combine results from independent experiments to provide general insights into connections between the classical and the microbial aquatic food webs, and pinpoint areas in need of further investigation.
 
Day: Wednesday, Feb. 3
Time: 03:45 - 04:00pm
Location: Hilton of Santa Fe
 
Code: SS20WE0345H