The director of the Oscar-winning March of the Penguins, Luc Jacquet, takes a spectacular journey with renowned French botanist and ecologist Francis Hallé into the tropical rainforests of the Peruvian Amazon and Gabon. Including beautiful animation, and drawing on extensive research, this is an expedition into into the very heart of life on earth. Once Upon a Forest is screening in the San Francisco Green Film Festival on on Saturday, May 31 and Sunday, June 1, 2014.