Final answer:
British Columbia started regulating forestry in the year 1975 with the Forest Act, which introduced sustainable management practices to the industry.
Step-by-step explanation:
The year that British Columbia (BC) began regulating forestry was in 1975. Prior to this, the management of forests was not as formally regulated, but with increased awareness of environmental issues and sustainable practices, the Forest Act of 1975 was established. This piece of legislation marked a significant change in how forestry was managed, with a focus on sustainability and renewability of forest resources. It also laid the groundwork for subsequent forestry policies and practices in the province, ensuring the forestry industry operated within a regulated framework.