My roommate is an ecology major, and studying "how organisms affect and are affected by other members, living and non-living alike, of local and global systems" seems to be exactly what he does. In fact, he just defined it to me now as "the study of interactions of organisms with one another and with their environment." Which is pretty much what Larry said, except Larry, to quote my roommate, "went one step further and defined 'environment.'"

So... I'm pretty sure what Larry said is a very correct and modern definition of the word "ecology."