An ecosystem is a place where any organism lives. It can be as small as a hand full of soil or as big as the world.
self sustaining collection of organism and their physical enviorment
Steve Austin played by Lee Majors The Six Million Dollar Man.
The fact that you even ask the question shows me that you do not have the knowledge, training, or skill to rebuild a transmission. It takes training and skill to accomplish this difficult repair....
Probably millions or billions.