Every year I have to trim small trees that grow in the south. No need for me to use a chainsaw; a reciprocating saw does wonders on trees two and four inches thick. Even cut down a five inch dead tree. Timber!
I have ornamental crepe myrtle trees and a garden of flowering hybiscus "trees". That reciprocating saw with blades for wood cutting, does wonders.
Instead of cutting a lot of grass in summer, I trim small trees in winter.