Carbon stocks in Ontario’s managed forests and harvested wood products, 2021–2100

We used the forest carbon budget model FORCARB-ON2 to project carbon stocks in a forest ecosystem and harvested wood products (HWP) in the six ecoregions of Ontario’s managed forests. Carbon stock levels were predicted from 2021–2100 for three management scenarios with a constant harvesting level throughout the simulation horizon and for two natural development scenarios. Harvesting levels in three management scenarios reflected actual harvest volumes from 2011–2020 and 2001–2020 and planned harvest volumes (i.e., maximum harvest volume allowed in forest management plans) from 2011–2020. Natural development scenarios assumed no harvesting and either pre-suppression era or modern natural disturbance cycles. The results indicate that keeping harvest volumes at the historical levels (either 2011– 2020 or 2001–2020) would increase carbon stocks in forests and HWP by the end of the century. However, increasing harvesting to the maximum planned level would reduce stocks in both forest and combined forest–HWP pools. The analyzed management scenarios suggest there is room to increase harvest volumes to a level between historical and maximum planned, while maintaining various carbon stock indicators at 2021 levels. The results assume that forest growth, successional changes, and natural disturbance remain constant throughout this century. Changes to the above rates caused by climate change or widespread natural disturbances would affect future forest conditions and may alter predicted forest carbon stocks.