Losts of Hickory trees dying Washington,DC area

[bluepin]

I noticed a lot of hickories are dying in my area ( this is in Maryland, just south of Washington,DC ) with no obvious ( at least to my eye) cause. Full grown trees completely dry. I am hoping an arborist in the area may know exactly what and why. The issue seems very serious, I can't be the first one noticing.

Is there a blight or some known systemic disease spreading around ? Someone may have encounter this already in the daily work and may know what it is and hopefully what to do about it.
Since I have many hickory trees around my house (bitternut I think) , I am a little worried they may start to dry-out as well.

 

[ropensaddle]

http://dieoff.org/page47.htm

 

[PJM]

Hickory decline --> http://dnr.wi.gov/topic/ForestHealth/documents/HickoryMortalityFactsheet.pdf

 

[bluepin]

This is the best reply. Excellent. Thank you.

 

[Jason Douglas]

Have read about hickory decline. Often attributed to the combination of stressors including numerous aspects of pollution that can then lead to things like Ceratocystis and boring insects.
See also maple decline and oak decline.

I personally feel that anthropogenic tree declines are going to be the norm for some time.