Crude oil and natural gas, Algeria's main resources, were first produced in the 1950s. Algeria also has diverse minerals, including iron ore, zinc, silver, copper ore and phosphates. In the 1960s and 1970s, Algeria sought to become a manufacturing country, with investments in building materials, refined products and steel; none of these sectors is competitive in world markets. Although agriculture employs one-quarter of Algeria's work force, its importance to the economy is diminishing. State forests cover some 2% of Algeria's land. Most are brushwood, but some areas include cork oak trees, Aleppo pine, evergreen oak and cedar. Algeria has a large fishing fleet. Sardines, anchovies, tuna and shellfish are the major species caught commercially.
