Three pine release experiments were begun in northern Minnesota in the 1930's. Two experiments compared the response of pines to full, moderate, and no release from competing hardwoods; the third compared only moderate and no release. Eighteen to twenty-five years later the pines responded most favorably on the full release treatments, intermediate on moderate release, and least favorably with no release. Financial aspects are briefly discussed and indicate that release, as done in these experiments is one of the better investments to be made in forestry.

Two growing-stock density experiments, one in 80-year red pine, the other in 40-year red pine, have been followed for 10 years. The third experiment, in 50-year red pine, has been followed for 5 years. Basal area growth is only slightly influenced by stand densities from 60 to 140 square feet of basal area per acre. Total height growth is not affected at all by this range of stand densities. Total cubic-foot volume and cordwood growth increase as density increases, with the increase most pronounced in the younger stands. Diameter growth of dominant and codominant trees is twice as much at 60 square feet of basal area as at 140 square feet.

Abstracts for Dec. 1954- issued in the Agricultural Research Service's series ARS-41.