Tye takes as his model the way that tree rings in the cross section of a tree trunk represent the age of the tree in years: if conditions were optimal then the number of rings in a tree trunk would be equinumerous with the years the tree has been alive.
(tree rings in the cross section of a tree trunk; represent; the age of the tree) (conditions; were; optimal) (the tree; has been; alive)
tree rings in the cross section of a tree trunk conditions the tree
represent were has been
the age of the tree
optimal
alive