Insights on community dynamics from large-scale, long-term data: time series for zooplankton and environmental variates from 35 North American lakes

The NCEAS Community
Dynamics Working Group brought together theoretical and
empirical ecologists to evaluate the relative importance of
intrinsic and extrinsic sources of variability in natural
communities. We focused on zooplankton community dynamics, in
part because we had access to extensive time series data on
zooplankton community structure from 35 North American lakes.
Thirty-four of the lakes were concentrated at 5 sites: the North
Temperate Lakes LTER site in Wisconsin; the University of Notre
Dame Environmental Research Center in Michigan; the Dorset
Environmental Research Centre, the Experimental Lakes Area, and
the Sudbury region, all in Ontario. We also have data for saline
Mono Lake in California. Our database has many strengths,
including the length of the time series (5-21 years); consistent
sampling methodologies, particularly for zooplankton; and the
availability of information on environmental factors, including
phytoplankton, physical parameters, and water chemistry. Another
unique aspect of our dataset is that it includes data from both
undisturbed reference lakes and experimentally manipulated
lakes. The whole-lake experiments include food web
manipulations, nutrient enrichments, acidifications and limings,
and an unplanned invasion of an exotic species. Some of the
experimental manipulations are even replicated within and among
sites, providing a unique opportunity to explore the extent to
which responses to a particular perturbation are consistent
across lakes. In addition to determining how manipulations
change the dynamics of zooplankton communities, we are using the
data from the reference lakes to establish bounds on normal ranges of variability and to explore how this variability differs among lakes at a site vs. between sites. Thus, our joint database is facilitating extensive comparisons of zooplankton community dynamics at the scale of whole lakes.