Growth and diversity effects of silvicultural alternatives on an old‐growth forest in Finland

Summary The study compares six silvicultural alternatives on an old-growth Norway spruce-dominated stand. Untreated forest was used as a control treatment. The wide stem distribution range was maintained by single tree and group selection. Shelterwood cuttings (pure Norway spruce, pure Scots pine and in mixtures with broadleaved species) transformed the stand into a two-storied structure, whereas diameter cutting narrowed the stem diameter distribution. Pure pine and pure spruce shelterwood cuttings gave the lowest and untreated the highest stand diversity index value and greatest volume growth. In general, there are several useful silvicultural alternatives to clearcutting in old-growth mixed stands of boreal forests.