The executive program and operating syntax of the forest growth model SUCSIM IV are outlined in Section A. Lists of parameters,
state variables and other quantities, and their values (if constant) are given in Section B. The remainder of the bulletin is devoted to the models used. The quantities given here reflect the state of SUCSIM IV as of summer 1978. The readers are referred to published literature for examples of SUCSIM output. Careful comparison between the text and the program code has been made, but errors (typographical and otherwise) are inevitable in a work of this scope. The authors invite notification of any and all errors and inconsistencies.