At the end of the 18th century, forests covered around 40% of Poland. However, due to the 19th century economic exploitation during the partitions of Poland, as well as, the Nazi German and Soviet occupations between 1939–1945 with trees shipped to battle fronts across Europe, deforestation and slash and burn conditions of war shrank Polish forests to only 21% of total area of the country (as of 1946). Furthermore, rich deciduous trees were replaced with fast growing coniferous trees of lesser value meant for commerce, such as pine. After World War II, the government of Poland initiated the National Plan of Afforestation. By 1970, forests covered 29% of the country. As of 2009 – 29,1% of Poland's territory was forested, amounting to 9,088,000 hectares. It is estimated that by 2050, the total area of forested land should increase to 33%.