High frequency data are increasingly available with potential to assess critical properties of aquatic ecosystems under threat from global change. Here, we review examples of quantifying stability and resilience using 1) long-term monitoring data and 2) experiments where we collected in situ high frequency data. In the first case we quantified the recovery of estuaries from hurricanes to assess stability. In the second case we quantified resilience using manipulations of lakes where thresholds were approached and crossed. For estuaries, we used long-term, high frequency measures of salinity and dissolved oxygen from the U.S. National Estuarine Research Reserve measuring disturbance and recovery in 19 estuaries impacted by hurricanes. Estuarine salinity and dissolved oxygen recovered from hurricane disturbances within 1 to 10 days. Some disturbances are longer (up to 100 days) but estuarine salinity and dissolved oxygen are typically in response to hurricanes. For lakes, we measured phytoplankton pigments and processes (dissolved oxygen and pH change) at high frequency during nutrient enrichment manipulations. Dynamic linear models provided reliable measures of loss of resilience with increases in phytoplankton from low to high biomass. Repeated transitions of phytoplankton biomass between low and high states enabled measurement of exit time – the time an ecosystem remains in a state. Our lake manipulations quantified resilience of lakes to nutrient enrichment and indicate possibilities for early warning and for comparisons among ecosystems. High frequency data that yield long-term references and frame disturbances provide opportunities to measure ecosystem stability and resilience. 

Primary Presenter: MLP Michael L. Pace, University of Virginia (mlp5fy@virginia.edu)

Authors:

Alice Besterman, Towson State University  (abesterman@towson.edu)

Cal Buelo, University of Virginia  (cbuelo10@gmail.com)

Stephen Carpenter, University of Wisconsin  (steve.carpenter@wisc.edu)

Dat Ha, University of Virginia  (dh3dv@virginia.edu)

Spencer Tassone, University of Virginia  (sjt7jc@virginia.edu)

Jonathan Walter, University of California Davis  (jawalter@ucdavis.edu)

Grace Wilkinson, University of Wisconsin  (gwilkinson@wisc.edu)