(1972) Silent Running

Silent Running is a 1972 environmentally-themed American post-apocalyptic science fiction film starring Bruce Dern, featuring Cliff Potts, Ron Rifkin, and Jesse Vint. It was directed by Douglas Trumbull, who had previously worked as a special effects supervisor on science fiction films, including 2001: A Space Odyssey and The Andromeda Strain.

After the end of all botanical life on Earth, ecologist Freeman Lowell (Bruce Dern) maintains a greenhouse on a space station in order to preserve various plants for future generations. Assisted by three robots and a small human crew, Lowell rebels when he is ordered to destroy the greenhouse in favor of carrying cargo, a decision that puts him at odds with everyone but his mechanical companions. Lowell and his robots are forced to do anything necessary to keep their invaluable greenery alive.