I really like the look of them. I can imagine happily sitting there leaning against the tree, enjoying the bark and the scent of the trees. I'd leave them alone.

I would suspect the mounds are the results of decades of piling the pine needles around the trees for mulch. Over the years the mulch breaks down and the grass took over.

Since it has been there for some times and the trees appear to be doing fine, the only problem I see is mowing around the trees.

The mounds are the root crowns that build up. There's prb'ly only a relatively thin layer of soil on them. Older trees commonly develop these root crowns.

i highly doubt the use of the term old growth ... pine are the weed trees of the forest.. they grow really fast.. they might only be as old as the house.. when was that built..

anyway.. and i will yell .... IF HERE IS NOTHING WRONG WITH THE TREE>> THEN DONT GO SCREWING WITH IT AND CREATING A PROBLEM...

crikey man... put down the shovel and walk away.. no digging around the tree.. no excavating.. no bulldozing...

just go buy a lawn chair. or 2 .... and a a cooler.. a bottle of wine for momma .. and 12 pack for the cooler .. go sit under the tree.. and hate on your neighbor like the rest of us.. lol .. start dreaming about digging in his or her yard.. lol..

and leave your gorgeous trees alone... fix a problem.. dont create problems.. and never solve what isnt a problem ...

ken