Popular science film about the biological relationship of plants, animals, insects living in the forest. The film includes macro photography and time-lapse photography, showing the biological cycles of development of plants and insects (lacewing and aphids). Landscapes of a winter forest. Spring landscapes. Buds open on trees, leaves unfold, flowers bloom. An old oak tree in a clearing. Streams are running. Young elk in the forest. Squirrel on a tree. Hedgehog in the grass. A fox under an oak tree. Roe deer run along the edge of the forest. Anthill. A spider on its web. Bear cubs frolic on a fallen tree. The bear cub climbs into the hollow for honey, eats honey. Bees are flying. Fire in the forest.