An experimental system of equations has been developed to simulate the atmosphere within a forest and in the atmospheric boundary layer just above the forest. The essential parts of the formulation are the equations which define the temporal variations of momentum, temperature, and vapor pressure in the forest and in the free air above (equations 1f-4f, 1-4) and those which represent the heat balance at the top of the canopy and at the earth's surface (equations 19, 20, 18f, 19f). Most of the other expressions define the various terms in these basic equations or are approximations which simplify their solution.