High-Carbon Primary Forests of Ontario, Canada

Ontario’s forests are changing fast under the pressure of commercial logging, coupled with the effects of climate change. The reduction of mature and old-growth primary forests negatively affects natural species habitat suitability, including woodland caribou, and reduces the long-term carbon storage. The presented dataset identifies Ontario's remaining High-Carbon Primary Forests as of 2020. We define High-Carbon Primary Forests (HCPF) as mature and old-growth, naturally regenerated forests not affected by tree canopy loss over the past 50 years, located within unfragmented landscape patches with an area of at least 1,000 ha. The HCPF mapping approach is built upon the Intact Forest Landscapes (Potapov et al., 2017) and Roadless Areas (Quinby et al., 2022) methodologies, which were modified to apply at the provincial level.  The dataset employs remote sensing data through a combination of automated processing and visual image interpretation, enabling both identification and ongoing monitoring of these high conservation value forests. This resource supports conservation planning and monitoring efforts aimed at preserving HCPF within Ontario's managed forests.