VS Mod Presentation

The ATLSS Vegetative Succession Model: 

The ATLSS Vegetative Succession Model Scott M. Duke-Sylvester ATLSS Project : University of Tennessee Project web-site : www.atlss.org E-mail : sylv@tiem.utk.edu

Overview: 

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

Purpose of the vegetative succession model: 

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: 

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 Diversity : number of species, evenness Structure : tree islands Indirectly by providing a changing habitat for other models

Model features: 

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

Model response: 

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

Model description: 

Model description Space is broken into a set of discrete cells Cell model Starts with a habitat type: H0 Set of alternative habitat types : H1 .. Hn Transition probabilities from H0 to H0 .. Hn : P0 .. Pn P0 .. Pn depend on the current environmental conditions Cell model replicated in each discrete cell

Cell Model: 

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 Determine the new habitat type for the cell

Change in cell state: 

Change in cell state H0 H1 H2 Hn P0 P1 P2 Pn …

Change in cell state: 

Change in cell state H0 H1 H2 Hn P0 P1 P2 Pn …

Change in cell state: 

Change in cell state H0 H1 H2 Hn P0 P1 P2 Pn …

Change in transition probabilities: 

Change in transition probabilities H0 H1 H2 Hn P0 P1 P2 Pn … E0

Change in transition probabilities: 

Change in transition probabilities H0 H1 H2 Hn P0 P1 P2 Pn … E0 Et

Slide14: 

Status: 

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

Availability: 

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

Collaborators: 

Collaborators Paul Wetzel Leonard Pearlstine : FGAP

Contact information: 

Contact information E-mail : sylv@tiem.utk.edu Website : www.atlss.org/~sylv