The halt in Russian imports has pushed up the price of birch wood in Finland, which is in high demand for industry as well as home heating.  Due to explosive demand since late summer, some Finnish firewood vendors have doubled their prices.  "This energy crisis came as a bit of a surprise to everyone. The price of dry birch wood has doubled, and there is also pressure to increase prices further this winter," said CEO Pentti Karttunen of Maatukku, one of Finland's biggest firewood retailers, based in Vantaa.  Some Finnish wood ...