2005 World Conference on Natural Resource Modeling

POSTERS

Eileen Cashman
An Evaluation of 2-D Hydraulic Modeling for Clear Creek Restoration

Paul Mann Cunningham
A Sensitivity Analysis of an Individual-based Trout Model

 Ari Kornfeld
Kinetics and some Physiological Implications of the Gravitropic Response
in Oat Shoots (Avena sativa)

Mark Parrish
Simulating the Longitudinal Profile of Bull Creek Watershed

Catherine A. Roberts
Research Partnerships with the Regional Environmental Council, EcoTarium,
and Mass Audubon Society in Worcester MA USA

René Rodríguez Zamora
Modeling Individual Processes in Predator-Prey Interactions using UML and Multi-Agent Systems

Kacee Shryock
A Reaction-Diffusion equation modeling the invasion of the Argentine ant population,
Linepithema humile, at Jasper Ridge Biological Preserve

Robert Gerrity
Modeling Indirect Competition
Between Two Predators with a Shared Resource
Nik Hashim Nik Mustapha

Fisheries Modeling Under Open access, Steady State, and Intertemporal Limited Entry Management

Saturday, June 18

Individual-based Models Workshop
Steve Railsback

The conference will be followed by a one-day (June 18) workshop on individual-based modeling. Individual-based models (IBMs) are simulation models that represent a system's dynamics as emerging from the behavior of the system's individuals as they interact with each other and their environment. IBMs have many potential advantages for modeling populations and communities: environmental effects can be represented mechanistically and explicitly, adaptive behaviors (e.g., "trait-mediated interactions") and their consequences can be modeled, and processes acting at different (or across) spatial and temporal scales and ecological levels (e.g., individual- vs. population-level) are easily accommodated. IBMs make a wide range of new ecological and resource management problems amenable to modeling analysis.

IBMs are now widely used, but they pose unique challenges: IBMs can be very complex and difficult to understand, they often appear highly ad-hoc with little relation to theory, and computer implementation approaches that work for simpler models often doom an IBM to failure.

The workshop will be organized around three major challenges in building and using IBMs.

•Complexity: How can a model be designed so it is complex and realistic enough to solve important, real problems, while otherwise being as simple as possible? What techniques can determine which variables and processes should be included vs. excluded?

• Theoretical and conceptual bases: The essential characteristics of most IBMs cannot be described well using either traditional mathematics or conventional ecological theory. What common conceptual basis can we use instead to design and describe IBMs? What is "theory" in models that link individual and system levels? How can this theory be developed and applied?

• Software: For IBMs, software must do more than implement the model; it must also provide a laboratory in which we can observe and conduct experiments on the virtual population in the model. Software development can be a much greater effort for IBMs, but there are specialized platforms that are very helpful. What is the appropriate platform for a particular IBM, and how can modelers get started using it?

The workshop will introduce NetLogo, a widely used, high-level platform appropriate for IBMs of moderate complexity and prototypes. Also introduced will be Swarm and RePast, which are essentially programming languages specifically for IBMs. Recommendations for selecting and learning to use these platforms will be provided.

The workshop will include exercises implementing models in the NetLogo and Repast software platforms. Computers with these packages installed will be available for participants, but people who wish to use their own computers are encouraged to install the software in advance.

NetLogo 2.1 is available at:

http://ccl.northwestern.edu/netlogo/download.shtml

The Repast Suite is available at:

http://repast.sourceforge.net/download.html

Preliminary Agenda:

Time Topic

9:00 - Introductions

9:15 - What are IBMs? Why use IBMs? What are the benefits and problems of using IBMs?

9:30 - A conceptual framework for IBMs: How do we describe and design models that are not described well by traditional mathematics?

10:30 - Break

10:45 - Getting started: How to design an IBM so it is "as simple as possible, but not simpler".

11:00 - Introduction to the NetLogo modeling platform. NetLogo provides a simple programming language and graphical interface for simple IBMs and prototypes.

12:00 - Lunch

13:00 - Analyzing IBMs: What to do once your model runs. How do you do theoretical or management science with an IBM?

13:30 - Software for IBMs: Why is software a big deal? What tools are available? How do you adequately test an IBM's software?

14:00 - Introduction to Repast, a widely used programming environment for complex IBMs.

16:00 - Wrapup

16:30 - Change of habitat and biochemically facilitated discussion.

The workshop is organized by Steve Railsback (Lang, Railsback & Assoc. and Humboldt State University). Dr. Railsback has over 10 years experience managing and conducting development of IBMs and their software, and applying IBMs to natural resource management issues. He co-authored the new book Individual-based Modeling and Ecology, which provides extensive treatment of the topics covered in the workshop.

Other participants will include a representative of the Repast development team at Argonne National Laboratory; and Andrew Kanarek and Steve Jackson (current and former students in the Humboldt State environmental modeling program who are experienced users of the NetLogo and Swarm software platforms).