How did john smith aid the jamestown colonists’ survival?

Hello!

Anyone who would not work, would not eat. 
So they had to plant food, build shelter, and build fences for themselves. 

Hope this helps,

:)

He started a system where everyone was forced to work. If they didn't work, they would NOT eat. There is a famous quote:

“He that will not work shall not eat.”

This is what saved the people of Jamestown. 
He also arranged and established trade with the native tribes. This lead to more food and shelter for the people of Jamestown, as they were being guided by the native tribes. 

Hope I helped! Merry Christmas! :P