Research indicates that natural resources managed in common, resembling traditional commons such as the Swedish forest commons, could be a type of regime with the potential to stimulate successfully sustainable use conditions. This is supported by findings regarding the characteristics of Swedish forest commons, their claimed concern for the environment and relatively high proportion of old forest in two out of three regions. Swedish environmental policy is directed towards environmental quality objectives and the Sustainable Forests objective states, among other things, that biological diversity must be maintained and enhanced. Swedish National Forest Inventory data for the period 2003Á2006 were used to analyse differences between forest commons in northern Sweden and other ownership categories regarding the proportion of forestland with a large deciduous element, the proportion of forest older than 80 years with a large ( 25%) deciduous element, the volume of dead wood and the proportion of forest older than 140 years, parameters corresponding to the interim targets for enhanced biological diversity. The results show no consistent differences in indicator variables between the forest commons and other ownership categories, signifying that forests managed in common have been conducted in ways promoting biodiversity more effectively than in other ownership categories. Further studies of different ownership categories regarding driving forces and forest status are warranted.