The fifth round of sanctions adopted by the EU on Friday over Russia's invasion of Ukraine includes import bans on wood, cement, fertilisers, seafood and liquor.
The latest sanctions will effectively stop all Russian wood exports to Finland and other EU countries.
"This will in effect end the last remaining import possibilities," said Timo Tolonen, a trade specialist at Finnish Forest Industries.
Finnish firms had, however, been reducing their reliance on Russian wood imports before the sanctions hit.
In 2021, Russian wood imports accounted for a tenth of the Finnish forest industry's raw material needs. Tolonen said Finnish forest product companies were already looking to substitute Russian wood before the war broke out.
Finnish companies are turning their gaze to domestic timber felled in the process of forest thinning, according to Tolonen, who added that forestry firms are also considering Baltic wood imports.
The latest EU sanctions package has also stopped Russian and Belarusian lorries at the Finnish border since midnight on Friday. Finnish Customs on Saturday said some three dozen trucks had been turned back at Finnish checkpoints by Saturday morning.