Simulating Central-European forests in the 21st century. Effects of climate change, disturbances and management on stocks, productivity and harvests

In a simulation study future development of forest resources in five Central European countries (Germany, Czechia, Slovakia, Austria, Slovenia) was explored. Initial state of 19.4 mill. ha forest was mapped at 1 × 1km resolution based on national forest inventory data, CORINE landcover types and a gap-filling algorithm. The forest ecosystem model PICUS v1.5 was employed to simulate forest resources in a set-up of management (no management, current and adaptive management) and climate scenarios (historic-current climate, three transient climate change scenarios) until 2099, including bark beetle disturbances. Particular focus was on transformation of Norway spruce forests. When temperature increases of +3-4 °C (end of 21st century) coincide with a decrease in summer precipitation volume stocks could not be maintained with current management due to reduced productivity and increased tree mortality, particularly in Norway spruce forests. In the period 2050-2099 adaptive management could reduce the loss in mean standing stock compared to continuation with current management practices by up to 585 mill. m 3 . Total harvests in the long run were moderately lower in adaptive management scenarios under climate change conditions of GWL2.6 and GWL4.1 (up to −8%). Under severe climate change (GWL4.7) adaptive management generated higher harvests than continuation with current management. The harvested volume of Norway spruce under adaptive management in 2050-2099 was reduced depending on management and climate. Losses ranged from −24.02 mill. m 3 yr −1 to −8.34 mill. m 3 yr −1 . At least partially, the lost Norway spruce harvest volume could be substituted by Douglas fir in the future.