Complex sentence: The Waodani once believed that the entire world was a forest (and used the same word, "ömë", for both) and the Oriente's rainforest remains the essential basis of their physical and cultural survival.
Split into simpler sentences: The Waodani once believed that the entire world was a forest (and used the same word, "ömë", for both). The Oriente's rainforest remains the essential basis of their physical and cultural survival.