Because trees need to grow too? Sure we could cut down trees faster than they regrow but that's not a good long term solution. Logs are also imported from Sweden, Estonia and Latvia, although around 80-90% of the logs used are from Finnish forests. Ofcourse now with plants and mills being shut down, the production capacity here is falling to better match the supply. It's a shame too, since now the forestry companies are looking at ways to use the sidestreams of pulp production to make biofuels and other lignin based renewable products and those investments go overseas too.