WK 33

Demonstrating the First Ecosystem Simulation Models: H.T. Odum's Original Passive Electrical Analog Computers

This is a workshop to demonstrate two passive electrical analog computers constructed by H. T. Odum for early ecological simulation in the late 1950s and early 1960s.  The workshop is intended as a contribution to the 100^thanniversary celebration of ESA during the 2015 annual meetings in Baltimore, Maryland. 

One of the passive analogs is for a steady state ecosystem with batteries representing energy sources and wires and variable resistors representing carbon flow pathways.  This computer was described in an early paper by Odum (1960a) that has been recognized as a benchmark in Systems Ecology.  The other passive analog was used by Odum to describe his study of the Puerto Rican rain forest. 

The workshop will include a discussion of the design, construction and restoration of the computers with demonstrations of their use.  Odum used the units primarily for teaching elements of ecology (see Odum 1960b) and they still work effectively for this purpose based on our experiences in classrooms at the University of Maryland.  We will also include a discussion of the place of these computers in a historical context, as they represent the first examples of computer simulation in Ecology. 

Odum, H. T. 1960a. Ecological potential and analogue circuits for the ecosystem. American Scientist 48:1-8.

Odum, H. T.  1960b. Ten classroom sessions in ecology. American Biology Teacher 22:71-78.