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

本研究从分布于美国威斯康星州的54个小型水体中采集浮游动物群落样本，旨在探究早春时节浮游动物群落结构的瞬时采样数据是否可用于区分湖泊与湿地。我们在为期一个月的时间窗口内（该窗口在全州范围内从南到北同步开展），从每个水体的敞水采样点采集了一套浮游动物与水化学数据，以尽可能统一采样规范、降低采样误差，并最小化因与本地及迁入的水生昆虫群落发生捕食者-猎物相互作用而产生的级联效应。本次研究共在威斯康星州的54个采样点中鉴定出53个浮游动物分类单元（taxa），每个采样点的平均分类单元数为6.83个。浮游动物物种的分布具有较强的独立性。未检测到分类单元数量与地理区域或水体规模之间存在显著相关性。分类单元数量与钙离子浓度、碱度及电导率之间存在显著的负相关关系。一对分类单元：Lynceus brachyurus与Chaoborus americanus，二者各自出现的采样点的平均存续时长存在显著差异。其余所有分类单元对在平均纬度、水体表面积、总磷、凯氏总氮、碱度、电导率、钙离子浓度、硫酸盐、硝酸盐、硅酸盐或氯化物浓度方面均无显著差异。分类单元在各采样点间呈随机分布——未发现存在显著共现或相互排斥的分类单元对。对浮游动物类群关联的多变量分析显示，不存在可用于区分湖泊与湿地的显著类群关联模式。浮游动物群落结构似乎并非区分湖泊与湿地的有效工具，尤其是在威斯康星州这样约500公里跨度的较大空间尺度下。研究数据表明，威斯康星州的小型水体若仅在春夏季存续约4个月，且栖息有Lynceus brachyurus、Eubranchipus bundyi，同时不存在Chaoborus americanus与Chydorus brevilabris，则可被归类为湿地。参考文献：Schell JM, Santos-Flores CJ, Allen PE, Hunker BM, Kloehn S, Michelson A, Lillie RA, Dodson SI. 2001. Physical-chemical influences on vernal zooplankton community structure in small lakes and wetlands of Wisconsin, U.S.A. Hydrobiologia 445:37-50 采样点数量：54