In 2000, about 45% of Slovakia was under forest cover. Forests have been severely damaged by acid rain from coal-fired power stations. Roundwood production in 2000 was 5,213,000 cu m (184 million cu ft). Slovakian forest product exports include paper, wood, and furniture. In 2000, wood pulp production amounted to 424,000 tons; paper and paperboard, 662,000 tons; and wood-based panels, 5,864,000 cu m (207 million cu ft). Slovakia's trade surplus in forestry products was nearly $176.5 million in 1997.