During colonial times the Portuguese built several projects to make the rivers more reliable for commerce. On the Limpopo, they erected a dam to deepen the river, control its flow, and provide irrigation for the valley's farms. The dam was completed in 1974. The vegetation of lowland Mozambique is predominantly light forest and grassland, while on the coast mangroves grow in the swamps and palms line the beaches. Tropical rain forests once stood south of the Zambezi Delta, but they have all been cut down.
Forests become denser in the higher elevations, particularly along the border with Zimbabwe.
Until recent times, Mozambique supported a large and varied animal population. Elephants, water buffaloes, hippopotamuses, crocodiles, baboons, giraffes, lions, cobras, adders, flamingos, herons, buzzards, and other animals thrived throughout much of the region. However, much of the country's animal habitat has been destroyed by decades of human encroachment and by civil warfare. The reserves and game parks established by the Portuguese suffered nearly complete losses of habitat during the civil war in the 1980s. The coasts, however, were less affected and remain relatively unpolluted, and the islands offshore continue to shelter a rich variety of marine life.