Abstract Twenty years have passed since four tenth-acre thinning plots were established in a dense stand of 15-year-old red pine (Pinus resinosa) at the Cloquet Experimental Forest, Cloquet, Minn. This progress report summarizes the results obtained thus far. It is the fifth in a series of articles appearing in the Journal (3, 4, 5, 6).
T. Schantz-Hansen (Sun,) studied this question.