Q.Why is my “Blue Dwarf Japanese Stone Pine losing it’s needles?
I planted it this spring, following directions. I have a water meter to make sure it is not too wet or too dry. The soil is alkaline. Yet it is shedding needles at the base.
Also, can I prune a few branches ?
(By the way, it was expensive )

Certified GKH Gardening Expert
Usually, they will only tolerate slightly alkaline soils. Too alkaline, and you can expect to see the symptoms that you are experiencing now. I would add a little iron sulfate to the area around the tree. That should help it out. Follow all instructions on the package for the best results.
This article will offer more information on the care of this tree: https://www.gardeningknowhow.com/ornamental/trees/pine/italian-stone-pine-information.htm