Collaborations Involving ATLSS

The Everglades Landscape Model (ELM) and the Across-Trophic-Level System Simulation (ATLSS) Program: Collaboration Towards Everglades Restoration

Fred H. Sklar, ELM Project Manager
Everglades Systems Research Division
South Florida Water Management District

Donald L. DeAngelis, ATLSS Project Manager
Biological Resources Division, U.S. Geological Survey
U.S. Department of Interior

Two independent Everglades landscape modeling efforts were started by Federal and State agencies in 1993 and 1992, respectively. The Federal ATLSS program was designed to create a set of integrated models to simulate the hierarchy of whole system responses across all trophic levels. The South Florida Water Management District's ELM program was designed to develop a set of integrated modules to simulate the biogeochemical processes associated with hydrology, nutrients, soil formation, and vegetation succession. Both programs were designed to evaluate designs for Everglades restoration. The differences between ATLSS and ELM include but are not limited to: 1) degree of interdependence (models vs modules); 2) boundary conditions (i.e., the size of the landscape); 3) spatial resolution (1 ha vs. 1 km); and 4) focus (i.e., upper-trophic responses vs. lower-trophic processes).

After discussion at a joint Workshop attended by researchers involved in each of these two modeling projects, it became apparent that the projects have the potential to compliment each other very well. The ATLSS is seen as most appropriate for Everglades restoration because its broad scope includes a variety of trophic components, taking a multimodeling approach to deal with interactions between vegetation components and animal populations and communities, including endangered species, taking account of interactions with hydrology. These are criteria highly valued by the public, conservationists, and our national parks. From a State and water management perspective, the ELM is appropriate for restoration because its scope revolves around plant community structure, phosphorus thresholds, sediment processes, and invasive species. These are the criteria mandated for restoration in Florida's Everglades Forever Act (EFA). The differences between these two programs are the very elements that will make collaboration scientifically feasible and beneficial for input to public policy.

  • Everglades Landscape Modeling (ELM)

    ATLSS/ELM Collaboration Sequence

    The first workshop to explore the feasibility of an ATLSS and ELM collaboration was adjourned at 1 pm, June 4, 1996 after a day and a half of discussion. We decided that collaboration was technically possible, practical, ecologically sound, and mutually desirable. We designed a three phase modeling project to link some components of the ELM to an ATLSS fish model. We expect a demonstration product to be completed by this time next year. Initially, we will limit the spatial scale to WCA-2A such that:

    Phase 1 (currently near completion) uses ELM results to drive the "fish-food" component of the ATLSS fish model (develop file sharing system; no model modifications); Phase 2 will use ELM hydrology, nutrients, and vegetation to drive the ATLSS fish model (some modification of ELM and the fish model will be necessary); and Phase 3 will develop real-time coupling of the ELM and ATLSS fish model (ELM nutrients and vegetation will include feedbacks from the ATLSS fish model).

    Other collaborative projects were discussed and it was decided that NBS and District scientists would; 1) pursue interaction on a fire disturbance model, and 2) develop general guidelines for Object-Oriented designs.

    While discussing the pros and cons of collaboration we realized that this group could serve as a forum for the evaluation of ecological data and scientific hypotheses associated with Everglades restoration. There was concern that Everglades restoration was proceeding with insufficient ecological data. To evaluate this hypothesis, our next joint meeting will include empirical scientists working in the Everglades and will focus on the significance of past and current research programs in relation to the current ELM/ATLSS modeling efforts. We also realized that, relative to the scale and cost of the engineering programs proposed for Everglades restoration, the development of models for environmental decision making is seriously underfunded. Accordingly, we discussed ways in which redundancy between ELM and ATLSS could be eliminated to compensate for funding short-falls, but it became clear that there was little overlap between the two programs. ATLSS is designed to focus on terrestrial and wetland upper trophic responses to water management while ELM is designed to focus on wetland lower trophic responses. These modeling programs complement one another rather than duplicate one another.