Sustaining aquatic ecosystems under global change requires scientific knowledge working in collaboration with ecosystem management and society. This session will focus on key areas of scientific knowledge and management collaboration driven forward by the career of noted aquatic ecologist Steve Carpenter. Each talk will focus on one research topic, and discuss how Carpenter’s work contributed to our current knowledge and explore key future directions for research in this area. Research areas will include: trophic cascades, aquatic food webs, freshwater fisheries management, ecosystem manipulations, eutrophication and phosphorus as a slow variable, scenario development, working with decision-makers, and resilience.

 

Note: We are requesting a longer-than-normal session to accommodate strong interest in this session and our desire to have invited speakers on particular topics while retaining space for those who wish to request to be included with contributed talks. Each talk will be 15 minutes in length.

We also have additional speakers who cannot be listed below due to limitations of the form. All are tentatively confirmed:

Garry Peterson, Stockholm Resilience Centre, Stockholm University. The Resilience of Aquatic Ecosystems: Thinking creatively about the future

Peter Leavitt, Department of Biology, University of Regina. Variance as an ecosystem property: Lessons learned from long-term data

Steve Carpenter, University of Wisconsin. Closing speaker: Models, Experiments, Scenarios and Resilience Thinking.

 

 

Lead Organizer: Elena M. Bennett, McGill University (elena.bennett@mcgill.ca)

Co-organizers:

Emily Stanley, University of Wisconsin (ehstanley@wisc.edu)

Jim Elser, Flathead Lake Biological Station, University of Montana (jim.elser@flbs.umt.edu)

Presentations

---

04:00 PM

"The Universe is made of stories" (7804)

Primary Presenter: Elena Bennett, McGill University (elena.bennett@mcgill.ca)

A foundational topic of Carpenter’s research over the past five decades has been complex systems in which uncertainty is high, nonlinear behavior abounds, values differ, and there are many possible paths forward. Building resilient communities that can navigate this type of uncertainty requires preparing for both foreseen and unforeseen changes. Adopting a long-term outlook and asking the question “what if …” can help, even if the specific changes envisioned never come to pass. In this talk, we will discuss the history and current state of scenario development featuring several sets of scenarios that were led by Carpenter and colleagues. We will discuss how these, and other scenario development projects helped transform ecological science, enhance environmental assessments, and advance many careers.

View Additional Details

---

04:15 PM

VARIANCE AS AN ECOSYSTEM PROPERTY: LESSONS LEARNED FROM LONG-TERM APPROACHES (7817)

Primary Presenter: Peter Leavitt, University of Regina (peter.leavitt@uregina.ca)

Aquatic ecology was predicated on the assumption that the variability of lakes is stable and can be partitioned into that which is known (explained) and that which is yet to be understood (unexplained or error).  However, this paradigm was disrupted in the late 1990s by the Trophic Cascade Hypothesis which envisioned variability as an intrinsic ecosystem property subject to its own controls. Whole-ecosystem experiments were subsequently used to elucidate the controls of lake variability; however, they can be difficult to interpret if their scale and magnitude are not realistic, if the trials alter fundamental lake properties, or if lake response is influenced by past conditions. Fortunately, studies spanning decades can help place large experiments into context and define the spatial and temporal variance of lakes.  These approaches include: decadal monitoring of lake properties; continuous small-scale experiments within the long-term context; repeated landscape-scale surveys; high-resolution monitoring, remotely-sensed time series, modelling and; paleolimnology. These approaches show how historical conditions alter ecosystem variability, cause abrupt state changes, and persist for decades after removal of stressors,  Similarly, long-term approaches are the main means to quantify the presence and effects of cyclic (migratory), discontinuous (catastrophe), slow (warming), or cryptic (emerging) phenomena on lakes. Comparisons among long-term approaches identifies their relative strengths and weaknesses, while forecasting the path forward for the next century.

View Additional Details

---

04:30 PM

LONG-TERM CHANGES IN SEASONAL EPILIMNETIC TEMPERATURES IN LAKE MENDOTA AND TROUT LAKE: WISCONSIN’S SENTINELS OF LAKE WARMING (7715)

Primary Presenter: Richard Lathrop, University of Wisconsin-Madison (rlathrop@wisc.edu)

Lake Mendota (40 km², 25 m deep) and Trout Lake (16 km², 36 m deep) in southern and northern Wisconsin, respectively, are Univ. Wisconsin (UW)-Madison Center for Limnology’s flagship lakes. With laboratory facilities on their shorelines, the lakes have been the focus of a rich history of limnological research. Seasonal water temperature profiles were regularly recorded in Lake Mendota in most years since 1894 (except for 1930s-1940s when city monitoring data were lost). Seasonal profiles were first recorded in Trout Lake in 1914, but profiles were not regularly recorded until the summers of 1925-1941. Following those years, profiles were only recorded sporadically in Trout Lake until 1981 when the UW’s North Temperature Lakes Long-Term Ecological Research Project began studying lakes year-round in northern Wisconsin. Lake Mendota was added to the project in 1995. High coherency in epilimnetic (0-5 m) temperatures was found between Mendota and Trout. Since 1981 when both lakes were intensively studied, spring and summer epilimnetic temperatures have not increased significantly, but a modest increase did occur in Mendota since 1894. However, fall temperatures exhibited a large upward trend (delayed cooling) in both lakes’ shorter records, but not in Mendota’s longer record. Mendota’s summer trend was due to a higher frequency of warm summers in recent decades, not from an increase in maximum temperatures. Significant air-water temperature relationships were also found. Thus, the two lakes may be used as sentinels of water temperature responses to climate change in Wisconsin.

View Additional Details

---

04:45 PM

CRADLE TO CRADLE: CYCLES OF LEARNING IN LAKES AND WATERSHEDS (7695)

Primary Presenter: Stephen Carpenter, University of Wisconsin - Madison (Steve.Carpenter@wisc.edu)

The talk is a synthesis of 51 years of projects on whole ecosystems (rivers, lakes, watersheds, a planet).  Projects were whole-ecosystem experiments, ‘what if’ studies of possible disturbances or paths of change, or ‘what happened’ assessments of responses to changes caused by people or nature. (1) Teamwork of scientists, managers and the public is essential. (2) Shared work outdoors and shared credit foster teams. (3) Use ecosystem concepts (boundaries, time frame, cycles, residence times, turnover rates, stability, resilience) to build models.  (4) Test your idea in models before you collect data. (5) If you use another team’s data then read metadata carefully, contact them about questions, and share credit. (6) To measure resilience bend it until it breaks. Consider restoration costs before experimenting.  (7) Policy is not a recipe, it’s a hypothesis to be tested. (8) Make predictions and learn when they are incorrect. (9) Expect to be surprised.   

View Additional Details