Fig 1.
Characteristics of the stands comprising the study area.
Distribution of the forest stands included in the study classified into present development stages (x axis) and site types (bar fill). The development stages and site types were defined in the forest inventories conducted by the Finnish Forest Centre. ‘Young’ stands have a mean diameter at breast height of 8–16 cm, and ‘Mature’ stands a mean diameter at breast height greater than 16 cm but are not yet ready for final harvest. ‘Ready for harvest’ stands are greater than 16 or 14 m in dominant height and at least greater than 70 or 90 years in age, as defined in the current Finnish recommendations for the timing of final felling [35]. Site types are presented according to the Finnish forest classification system [36] and range from fertile mixed-species stands (herb rich) to less fertile, pine-dominated stands (dry heath).
Table 1.
The alternative management regimes applied in the forest growth simulations. For simplicity, the modified versions of ‘business-as-usual’ management have been grouped into 4 categories based on their defining features (extended rotation time, green tree retention, thinnings before final felling, or no thinnings).
Table 2.
Characteristics of planning regions.
Total number of groups of stands used as planning regions, mean number of stands in a group, and mean area of a group as defined at the different spatial scales (from Pohjanmies et al. [27]).
Fig 2.
Development of deadwood availability.
Distributions of stand-level values of deadwood availability (m3 per ha) at the beginning, halfway, and end of the 100-year simulation period when deadwood availability was maximized without a harvest income constraint (top row) and when maximal harvest income was required (bottom row). Note that the x-axis are the same in all plots, but the y-axis differ between the top and bottom row.
Fig 3.
Trade-off between harvest income and deadwood availability.
Production possibility frontiers illustrating the trade-off between harvest income and deadwood availability when forest management was optimized at different spatial scales.
Fig 4.
Differences in deadwood availability among scales.
Improvement gained from increasing the scale of management optimization from the three smaller scales to the regional scale expressed as the absolute (panel A) and relative (panel B) difference in deadwood availability.
Fig 5.
Proportion of forest area with high deadwood availability.
Proportion of forest area with deadwood availability greater than 20 m3/ha at different harvest income requirements and under forest management optimized at different spatial scales.
Table 3.
Among-stand variation in deadwood availability.
Coefficients of variation in the values of deadwood availability across stands at different harvest income requirements (90%, 70%, 50%, 30%, or 10% of its maximal value).
Fig 6.
Distributions of management regimes.
The distributions of management regimes that maximize the two objectives (‘Income’ and ‘Deadwood’) or provide the optimal outcomes at harvest income requirements of 90% and 50% when management regime allocation is optimized at different spatial scales (‘Small hold.’ for the ‘small holding’ scale and ‘Large hold.’ for the ‘large holding’ scale). For visual clarity, the 16 modified versions of ‘business-as-usual’ management (see Methods) have been grouped into 4 categories based on their defining features (extended rotation time, green tree retention, thinnings before final felling, or no thinnings). The abbreviations in the legend refer to: BAU—business-as-usual; BAU ext—business-as-usual with extended rotation time; BAU w GTR—business-as-usual with green tree retention; BAU w thin—business-as-usual with thinning before final felling; BAU wo thin—business-as-usual without thinnings; CCF—continuous cover forestry; and SA—set-aside.