The film tells about the consequences of disturbing the natural balance, about the benefits of swamps, about the measures taken in the USSR to preserve natural resources. A panorama of the swamps. Sedge in the swamp. Quagmire. Berries in the swamp. The excavator bucket scoops up the quagmire. Excavator tracks. The process of draining swampy lands. The excavator is working. Wheat field in yesterday's swamp. Peat extraction: the machine is running. Traces of imbalance between man and nature: loose sands in the place of drained swamps. A team with a horse goes on loose sands. Ravines in the forest. Soil erosion marks: cracked earth. View of the Desna River (filmed from above). A rider on horseback crosses a shallow river. A type of raised bog - storage of moisture. Rain in the swamp. The man holds the moss of the raised bogs in his hands. View of a river born in raised bogs. Pointer "Source of the Volga". Swamp near the Tver village Vomoverkhovye-reserve. Wooden sculpture near the swamp. View of the swamp of the source of the Dnieper. Riders on horseback are passing by. Blueberries in the swamp. Frog in the swamp. Swans float on the water. Beavers. Boars. Reserved bogs in Lithuania. Floating laboratory house on the water. Biologists are studying the area to help wild birds. Ducks on the water. Cranberries in berry swamps. View of the cranberry reserve. A panorama of a plantation on a worked-out peat bog. Wooden sculpture in the park.