Project Summary Sheet

Project: Vegetative Community Succession Models for the Across Trophic Level System Simulation Program

Web Sites: ATLSS.ORG

Location (Subregions & Counties): The total system

Funding (Source): USGS Place-Based Studies

Principal Investigator(s): Louis J. Gross, The Institute for Environmental Modeling (TIEM), University of Tennessee, Knoxville, TN 37996-1610 Phone: 865-974-4295; Paul R. Wetzel, Department of Biological Sciences, East Tennessee State University, P.O. Box 70703, Johnson City, TN 37614-0703 Tel. 423/434-0830, Fax. 423/439-5958 wetzelpr@etsu.edu

Project Personnel: Donald L. DeAngelis, Phone: 305-284-1690 e-mail: ddeangelis@umiami.ir.miami.edu

Supporting Organizations: USGS/BRD, NPS, ACE, EPA

Associated / Linked Projects: Component of ATLSS Program

Overview & Status: ATLSS models in their current form all assume that vegetation will remain unchanged over the period of the model simulations. This is not likely to be true, as changes in hydrology are almost certain to result in changes in the vegetation pattern in many parts of the Everglades. The development of a set of vegetative succession models for the main vegetative types in the Everglades region is generally regarded as being essential, if scientists and managers are to be able to project the possible effects of changes in the hydrology of the region. Vegetation responds sensitively to changes in hydroperiod and limiting nutrient concentration. Furthermore, important animal species, such as wading birds, the snail kite, and the Cape Sable seaside sparrow, have specific habitat needs that are tied to particular types of vegetation. The basic goal is to develop predictive vegetation succession models for the targeted habitats, describing how they are affected by changes in hydrology and available nutrients. Disturbance regimes are the third major landscape driver that we assume is strongly coupled to succession, so fire scenarios will also be built into the models. Three basic community types will be included in the modeling. These are "pine/scrub/flatwood", "cypress forest", and "herbaceous plant communities". Note, for example, that the herbaceous plant community includes key vegetation types for a several of the animal species represented in ATLSS models. Model development will take place in Year 1; calibration and testing in Year 2.

Needs & Products: We will develop a set of vegetation succession models for analysis of the Comprehensive Everglades Restoration Plan (CERP). These models are intended to predict the responses of the main vegetation types of the area covered by the USGS's Across Trophic Level System Simulation (ATLSS) models to changes in hydrology and nutrients. Such dynamic vegetation predictions spanning multiple decades are critical to projecting (1) changes in the pattern of vegetation, (2) changes in parameters important to water flow, and (3) habitat quality for important higher trophic level species. The succession models will be linked to the spatially-explicit species index (SESI) models, and to the individual-based Cape Sable seaside sparrow and snail kite models of the ATLSS Program, because the vegetation types constitute key habitats for animal species being modeled under the ATLSS Program. This will allow the ATLSS models to be run, for the first time, for a landscape in which vegetation can undergo succession.

Application to Everglades Restoration: Predictive models of vegetation succession are essential in forecasting effects of restoration on the Everglades landscape. This project will address CESI/CERP Information Need 3050-3 and will indirectly address 3007-5 and 3007-10.