Is there anything i can do for this red oak

[limbrat]

I have a good heathy looking red oak in my yard that i would like to keep in good health. The trunk is a little over 40" at chest high and the limb tips are still small and fine. Last weekend i noticed black carpenter ants going in and out of a previously on known whole right at ground level. That tells me that the tree has some rot. It may stay good for decades more, but is there anything i can do to help it out. The tree is on a hill top with about 10"or sandy loam 4"of sand and many feet of red sand,clay gravel mix.
In the last 10yrs. i have lost 2 older oaks in the same area to blow downs. Both of those trees had rottted hearts in the first couple of feet and dead roots in the center. I say they were older because they were larger and had thick arthritic looking limb tips.

[WDH]

That doesn't sound good.......The ants are only there because the heart rot is already there.  I don't think that the ants are doing any harm.  All I can say is baby it a little bit by keeping it watered and put down a little fertilizer and it might out-live you.  Trees are like humans, they have a defined life span.  At 40", it is likely past middle age, so make it comfortable in its retirement years............................

[Phorester]

I think WDH has got it.  The ants will do the tree no harm.  They came after the rot, they do not cause it.  Sounds like you have an old tree on soil that is not so good for this species.  So you are getting the heart rot and blowdown.  Unfortunately, you own this tree at the end of its natural life.

As you say, it could be several decades before it succumbs.  But there is little you can do with a tree this old and large to help it along.  It has adjusted to the soil conditions and climate as best as it can.  Even fertilizing could be a stress, since it will upset the equilibirum the tree has developed with its growing conditions.

[WDH]

Yes, judicious is the word concerning fertilizer.  A little bit can do good.  A lot could be harmful.  Just a handful or two scattered evenly over the entire spread of the crown would be about right.

[limbrat]

Yep that's what i figured. It is an old home place built in the 30"s the shape of the trees makes it look like the woods were cut out from around them.
    Thank You Gentlemen

[ely]

my advice is be watchful of it, and if worse comes to worse, it is far better to have nice furniture in the house than a dead/rotting tree out in the yard.
waste not want not.