The economy is tied closely to the larger French economy through subsidies and imports. Besides the French space center at Kourou (which accounts for 25% of GDP), fishing and forestry are the most important economic activities. Forest and woodland cover 90% of the country. The large reserves of tropical hardwoods, not fully exploited, support an expanding sawmill industry that provides sawn logs for export. Cultivation of crops is limited to the coastal area, where the population is largely concentrated; rice and manioc are the major crops. French Guiana is heavily dependent on imports of food and energy.