Contact:
Robert Costanza and Thomas Maxwell
Chesapeake Bological Lab
Center for Environmental and Estuarine Studies
University of Maryland
PO Box 38
Solomons, MD 20688
(I don't have a phone number).
According to a paper I have of theirs, they have linked GIS
(MIPS, MAPII, GRASS) with a general dynamic simulation package
(STELLA) on the Macintosh. (actually many Macintoshes).
Check the Journal: Ecological Modeling in 1991 for a paper of
theirs called "Spatial Ecosystem Modelling Using Parallel
Processors.