Forests cover about 28% of the total area. Much of the forest area was destroyed during the 1940s, but the government's reforestation program planted more than 100 million trees during the 1970s and 1980s. Pine, fir, and oak are the most common trees, and resin and turpentine are the principal products. In 2000, 2,171,000 cu m (76,640,000 cu ft) of roundwood were harvested, including 1.375 million cu m (48.5 million cu ft) of firewood. Sawn wood production in 2000 totaled 137,000 cu m (4,836,000 cu ft), and wood-based panels, 563,000 cu m (19.9 million cu ft). Production of timber is insufficient to meet the domestic demand, and many forestry products are imported. Total trade in forestry products in 2000 amounted to $619.9 million imports and $71.3 million in exports.