Across Trophic Level System Simulation (ATLSS) Program for the Greater Everglades

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Goals of the ATLSS Program are to help achieve a better understanding of components of the Everglades ecosystem, to provide an integrative tool for empirical studies, and to apply these tools to an adaptive management framework.

The Science Issue and Relevance: The Florida Everglades is currently undergoing one of the nation’s largest hydrologic restoration efforts. The quantity, quality, timing, and distribution of water flow to the Greater Everglades are keys to restoring the ecosystem’s natural functions. However, the challenge for water managers and biologists is to provide the hydrologic conditions needed by communities of plants and animals, while maintaining water supplies and flood control for a large and expanding human population. An essential part of restoration planning is the development and use of ecological models to better understand the major physical processes driving the system and gain insight into expected ecological outcomes in response to specific management and restoration strategies.

Image: Florida Everglades

Methodology for Addressing the Issue: The USGS’s ATLSS (Across Trophic Level System Simulation) Program predicts the effects of alternative hydrologic scenarios on Greater Everglades species and biological communities to help restoration planners identify and select the most effective restoration strategies. It includes a collection of linked models for various physical and biological components in the Greater Everglades and is intended to provide information that can help restoration planners rank alternative strategies for water management based on ecological outcomes as predicted by the models. The longer-term goals of the ATLSS Program are to help achieve a better understanding of components of the Everglades ecosystem, to provide an integrative tool for empirical studies, and to apply these tools to an adaptive management framework.

The ATLSS Program is currently being used to address the issue of invasive plant species, such as melaleuca, in southern Florida by working to predict the effects of biocontrol on invasive plant species. USGS WARC scientists and partners are also involved in assessing freshwater fish communities needed to support wading bird colonies in the Greater Everglades, developing early warning systems to alert managers of salinity-induced changes in coastal vegetation due to sea-level rise and storm surges, and modeling changes in nutrient inputs to areas of increased water flow.

Future Steps: The ATLSS Program will continue to develop and use models to help address the Comprehensive Everglades Restoration Plan’s (CERP) need for quantitative projections of the effects of restoration scenarios on biological communities in the Greater Everglades. Data on biocontrol impacts on the invasive water hyacinth and melaleuca plant species will be used to inform models that provide insight into the spread of the species under different levels and timing of biocontrol. The ATLSS Program will also continue to help predict, understand, and prepare for the climate-related changes on the short-term dynamics of salinity in the soil and groundwater, and the long-term effects on vegetation via the model MANTRA, a process-based, dynamic vegetation model. MANTRA simulates the possible long-term effects of both gradual sea-level rise and storm surge events on the ecotone between salinity tolerant (halophytic) and salinity intolerant vegetation, by simulating competition under changing groundwater salinity and other environmental conditions. In addition, the ATLSS model GEFISH (Greater Everglades Fish Model) simulates the dynamics of the small fish community across areas of the Greater Everglades to predict prey concentrations for wading birds and other higher trophic levels. Information provided by ATLSS will be shared with the U. S. Department of Agriculture's Invasive Plant Research Laboratory, U. S. Fish and Wildlife Service, National Park Service, and other partners involved with the CERP to help inform ecosystem management and restoration strategies.