Are the declining oaks all in the same area or spread out over your city/community? Anything significantly unusual about your weather over the last few years? Have you noticed any specific symptoms (mushrooms, borer damage, etc) besides general decline? Have you contacted a local extension agent for ideas?

One tree does have mushrooms they like diner plates stuck in the side of the truck.

No unusual weather around here lately.

What is an extension agent?

"The Cooperative Extension System is a nationwide, non-credit educational network. Each U.S. state and territory has a state office at its land-grant university and a network of local or regional offices. These offices are staffed by one or more experts who provide useful, practical, and research-based information to agricultural producers, small business owners, youth, consumers, and others in rural areas and communities of all sizes." - USDA

Basically, your tax money goes to pay experts in your area to help diagnose agricultural/horticultural problems, provide information and education, identify and report certain problems, etc. Sometimes, they can be very helpful. Their expertise and resources may vary from location to location. They should be familiar with conditions and issues related to your local area and be able to assist you in possibly diagnosing your tree's problems.

Here's a link to help locate your local extension service office.

Here is a link that might be useful: USDA Cooperative Extension System Locator

looking at all that cement .... the full contact urban setting... frankly .. i am amazed it has made it this far in life ....

that thing ought to be stressed based on quality of life alone ...

and if it is stressed.. simply due to location ... then it would be subject to all kinds of problems.. that might not otherwise attack a tree not so stressed ...

i mean lets be realistic here ... look at its trunk at the sidewalk.. one 5 foot square opening [based on the tree next to it] ... and no other exposed soil for what.. 100 feet anywhere???

that tree ought to have been dead decades ago.. BTW.. the sidewalk looks rather newish... if that job was done in the last 5 years.. there is the culprit ... heavy machinery .. and total disruption of the root mass ...

finally.. do they use salt on the roads??? .. just another insult to this tree ...

ken

Hey, that sidewalk does look pretty new! Are any of the other trees you mentioned located in areas where the sidewalk is relatively new? You never did really let us know about the locations of the other oaks you mentioned having problems? I think Ken's keen eye may have caught something here.

Urban street trees, planted in what some of us call 'tree coffins', don't live very long. Due to the rather inhospitable conditions, they become highly susceptible to a wide range of insect and disease problems. Add the exhaust fumes and other insults to their health, as well.

Have you contacted the City of NY Parks and Recreation Department? The Director of Forestry is James LeMyre, and he's an ISA Certified Arborist.

This particular tree is actually one of the few that are near open soil. Immediately to the right of that photo on the other side of the sidewall is an open plot with four very tall Elm's I am not sure what kind they are I can only be certain that they are not American Elms. Here's a picture of the tallest one. Note: I am one the roof of my 5 story apartment building built in 1928. I am guessing this building is about 55 Feet tall so this tree is about 70 Feet tall.
{{gwi:441763}}

I'm traveling to CA tomorrow to speak at two confs about this very issue.

Urban trees, esp on the block in the fotos above, have a hard time in the best years. Usu. their rooting volume is provided as an afterthought. One often wonders how they do it.

Dan

Ken_adrian and Brandon7. You are both right about the side walk. That side walk is relatively new say about 5 to seven years.

And the other trees are on the same side of the street along Bronx Park East. The city replaced 4 or 5 blocks worth of sidewalk.

I'd forgotten about the sidewalk repairs.

If the sidewalk is the culprit then all the Pin Oaks on the east side of Bronx Park East and north of Allerton Avenue will be dead soon. 3 have already died.