Ultimately, it's the health and wellbeing of the roots of a tree that determine whether it lives or dies. Sure, the above-ground stuff is critical to its being able to forge ahead, to live on - stuff like leaves, bark, branches.
We now have evidence of tree roots that have been alive for thousands (yes, THOUSANDS) of years, despite their above-ground growth being repeatedly harvested by generation after generation of humans.
The health of the roots determines the prospects for life in the future.
Same goes for us. Attending to our "roots" - values, faith, health, family, relationships - ultimately determines the length and quality of our lives, and of our legacies.
We each have "our own roots to water..." (Hope you enjoy the song.)