Today we're going to take a closer look at ecosystems -- which are communities of living organisms in an area interacting with their environment -- and how this relationship between the amount of energy a place receives and the movement of nutrients is what makes the incredible diversity of life possible. We'll also take a look at the patterns we see in the main global biomes, show you why some biomes (like tropical rainforests) are so productive, and discuss an agricultural practice some farmers have employed to help preserve their local ecosystems.