Why is amazon basin ecologically imp.

Read lots:

http://wwf.panda.org/what_we_do/where_we_work/amazon/about_the_amazon/why_amazon_important/

http://rainforests.mongabay.com/amazon/amazon_importance.htm

http://www.natureserve.org/conservation-tools/projects/endemic-species-and-ecological-systems-amazon-basin-peru-and-bolivia