The ATLSS Vegetative Succession Model Scott M. Duke-Sylvester ATLSS Project : University of Tennessee Project web-site :

Overview  Purpose of the model  Application to restoration planning  Model description  Calibration/validation  Development/delivery schedule  Availability

Purpose of the vegetative succession model  Provide vegetative succession dynamics  Modeling changes to habitat is important for accurate modeling of higher trophic levels  A rigorous succession model would include process dynamics : Everglades Landscape Model (ELM)  The ATLSS objective is to interface with ELM, but also produce a alternative less complex succession model.

Application to restoration planning  Provides another tool for assessing the potential for change due to alternative hydrologic scenarios Directly through changes in habitat diversity and structure Directly through changes in habitat diversity and structure Diversity : number of species, evennessDiversity : number of species, evenness Structure : tree islandsStructure : tree islands Indirectly by providing a changing habitat for other models Indirectly by providing a changing habitat for other models

Model features  Time step : 1 year  Spatial scale : 500x500 meters Possibly finer if computationally feasible Possibly finer if computationally feasible  58 habitat types (FGAP 6.6)  Stochastic process influenced by local environmental processes

Model response  The model will simulate succession dynamics in response to a number of environmental processes Hydrologic disturbance : hydroperiod Hydrologic disturbance : hydroperiod Nutrient disturbance : phosphorus Nutrient disturbance : phosphorus Fire disturbance Fire disturbance  Response to disturbance is habitat type specific

Model description  Space is broken into a set of discrete cells  Cell model Starts with a habitat type: H 0 Starts with a habitat type: H 0 Set of alternative habitat types : H 1.. H n Set of alternative habitat types : H 1.. H n Transition probabilities from H 0 to H 0.. H n : P 0.. P n Transition probabilities from H 0 to H 0.. H n : P 0.. P n P 0.. P n depend on the current environmental conditions P 0.. P n depend on the current environmental conditions  Cell model replicated in each discrete cell

Cell Model  Allows for changes in cell habitat type  Allows for changes in transition probabilities in response to changing environmental conditions  Order of events: Update current transition probabilities in response to environmental change Update current transition probabilities in response to environmental change Determine the new habitat type for the cell Determine the new habitat type for the cell

Change in cell state H0H0 H1H1 H2H2 HnHn P0P0 P1P1 P2P2 PnPn …

H0H0 H1H1 H2H2 HnHn P0P0 P1P1 P2P2 PnPn …

H0H0 H1H1 H2H2 HnHn P0P0 P1P1 P2P2 PnPn …

Change in transition probabilities H0H0 H1H1 H2H2 HnHn P0P0 P1P1 P2P2 PnPn … E0E0

H0H0 H1H1 H2H2 HnHn P0P0 P1P1 P2P2 PnPn … E0E0 EtEtEtEt

Status  Currently: Estimation of model parameters is complete Estimation of model parameters is complete Paul WetzelPaul Wetzel Conceptual frame work Conceptual frame work  End year 2002: Working draft Working draft  August 2003: Model finished, results available Model finished, results available Publications Publications

Availability  Current plans Sun/Solaris environment Sun/Solaris environment C++/object oriented C++/object oriented Outputs will be posted at Outputs will be posted at Executables available to collaborating agencies Executables available to collaborating agencies

Collaborators  Paul Wetzel  Leonard Pearlstine : FGAP

Contact information   Website :