Zooplankton of Small Lakes and Wetland Ponds in Wisconsin - North Temperate Lakes LTER 1996

We sampled zooplankton communities from 54 small water bodies distributed throughout
Wisconsin to evaluate whether a snap-shot of zooplankton community structure during early
spring could be used for the purpose of differentiating lakes from wetlands. We collected a
single set of zooplankton and water chemistry data during a one-month time window
(synchronized from south to north across the state) from an open water site in each basin as
a means to minimize and standardize sampling effort and to minimize cascading effects
arising from predator-prey interactions with resident and immigrant aquatic insect
communities. We identified 53 taxa of zooplankton from 54 sites sampled across Wisconsin.
There was an average of 6.83 taxa per site. The zooplankton species were distributed with a
great deal of independence. We did not detect significant correlations between number of
taxa and geographic region or waterbody size. There was a significant inverse correlation
between number of taxa and the concentration of calcium ion, alkalinity and conductivity.
One pair of taxa, Lynceus brachyurus and Chaoborus americanus, showed a significant
difference in average duration of sites of their respective occurrence. All other pairs of
taxa had no significant difference in average latitude, waterbody surface area, total
phosphorus, total Kjeldahl nitrogen, alkalinity, conductivity, calcium ion, sulfate,
nitrate, silicate or chloride. Taxa were distributed at random among the sites - there were
no statistically significant pairs of taxa occurring together or avoiding each other.
Multivariate analysis of zooplankton associations showed no evidence of distinct
associations that could be used to distinguish lakes from wetlands. Zooplankton community
structure appears to be a poor tool for distinguishing between lakes and wetlands,
especially at the relatively large scale of Wisconsin (dimension of about 500 km). The data
suggest that a small body of water in Wisconsin could be classified as a wetland if it
persists in the spring and summer for only about 4 months, and if it is inhabited by Lynceus
brachyurus, Eubranchipus bundyi, and if Chaoborus americanus and Chydorus brevilabris are
absent. Schell, Jeffery M., Carlos J. Santos-Flores, Paula E. Allen, Brian M. Hunker, Scott
Kloehn, Aaron Michelson, Richard A. Lillie, and Stanley I. Dodson. 2001. Physical-chemical
influences on vernal zooplankton community structure in small lakes and wetlands of
Wisconsin, U.S.A. Hydrobiologia 445:37-50 Number of sites: 54