From Pole to Pole is the first episode of Planet Earth documentary series. Aired in 2006.
I believe observing a natural process (such as the supply chain in ecology) can be very motional and can teach more valid lessons than academics. By no means, I disrespect. However I think the lessons that academics teach are incomplete (although its our best option for knowledge,) whereas our planet is complete and represents a perfect system. My thought on this is likely to remain stable until someone can propose and design an alternative solar system. You will really feel this if you watch the documentary.
It costs around $3 at Amazon. I highly suggest taking some time to watch this documentary for fun and also drawing some lessons.
Link for purchasing it from Amazon: http://www.amazon.com/gp/product/B00321SMG8/ref=atv_feed_catalog?tag=imdb-amazonvideo-20