Projecting future aboveground biomass and productivity of managed eastern Canadian mixedwood boreal forest in response to climate change

Eastern Canadian boreal forests are mainly influenced by natural wildfires and forest management activities. To evaluate forest dynamics under possible interactions among fire and timber harvest in a futu r e climate warming scenario (RCP 2.6, RCP 4.5 and RCP 8.5) the forest landscape model Landis II was used to simulate the dynamics of the 78000 km(2) of boreal forests in easter n Canada. Forest management intensity scenarios were modeled considering the changes in the annual harvested area (0.5%, 1%, and 2%) and the age that conifers and hard-woods can be harvested (50 and 30 years, 70 and 50 years, and 90 and 70 years). The results of the 300-year model projections implied that both forest management intensity and climatic scenarios explained most of the variability in aboveground biomass, aboveground net prima r y productivity and forest composition . Forest management seems to be the most important factor that modified the landscape in the souther n forests because there were scheduled stands with the age and composition required by each harvesting prescription to deal with the annual allowable cut volume. On the contrary, in the norther n forests there was a mixed effect of climate change and forest management because many of the areas suitable for harvesting were previously burned limiting the amount of area available for harvesting. Thus, although it is expected an increase in wildfire area burned due to climate change, the intensification of forest management seems to be the most important driver of the increase of hardwoods and mixed stands and the decrease of conifers stands on the mixedwood boreal landscape, mainly in the souther n forests. These results suggest that timber supply would be at risk in the Abitibi Plain, therefore, some strategies should be applied to adapt forest management to climate change.

Automated summary

The study indicates that forest management intensity and climate change scenarios are key factors influencing forest dynamics in the eastern Canadian boreal forests. While forest management plays a crucial role in shaping the landscape of southern forests, a mixed effect of climate change and forest management is observed in the northern forests.