It looks like a Slash Pine. It is normal for the lowest limbs to dieback as the tree grows taller. Is that where most of the needles have come from? I really can't see much else wrong with it.

One thing that needs to be done is to rake the mulch back off the trunk. This is know as a 'mulch volcano' and it can cause the bark and bottom part of the trunk to rot or be bothered by pest because it keeps the bark too moist inside mulch. Bark works best in the air.

http://www.tlcfortrees.info/mulching_staking.htm
http://greenenergynewton.org/Parks/mulch_2003.pdf
http://www.gdnctr.com/ads/volcano_mulch.pdf

Oh cmon now that's not a mulch volcano.

Now *THESE* are mulch volcanos
{{gwi:454122}}
{{gwi:454123}}

It's mostly off the lower limbs, but definitely off the upper ones as well. All the way to the top, pretty much on each branch, there are more brown needles than I think I've seen any other year/season. I can zoom in on the upper branches if that would help.

It's just dropped so many more needles than anyone else's in the area that I'm worried about disease or bugs.

Thanks for the thoughts so far.

Yep, those are the typical size quirky, I've seen some trees covered that much before around here. It's a bad habit in many landscapes.

But...The mother of all mulch volcanoes:
{{gwi:454124}}

Sometimes pines will shed excess needles in times of drought, and then regrow them the next spring. It could also be pine beetles, but Slash pine is moderately resistant to them (compared to Loblolly pine). If it's pine beetles you will usually know by July/August. I don't think there's anything you can do except to wait for spring and see if it puts out new needles. Expect those lower limbs to continue to die off, that's natural.

The only thing worse than mulch volcanoes......mulch volcanoes with RED mulch. (Hurts my eyes.)

BTW, that is a pretty tree.

treeguy, maybe it is just a different perspective but op's photo looks to me like about an inch of pine straw. And anyone who uses pine straw on a regular basis knows it's difficult to keep away from the trunk. But it is not uncommon to see reallu high piles like 10" of pinestraw because a couple weeks later when it all settles down it will be more like 3"

To me it looks like there is about 3 or 4 inches of bark mulch or wood chips against the trunk and a thin layer of pinestraw on top of that. I just think it's a good practice not to pile any amount of mulch on the trunk of a tree, and maybe others will learn from it also.

It is probably about 3-4 inches of mulch. I was intending to remove the pine needles, but was just showing them to give an indication of how much had fallen recently.

When the builder planted these trees (and all the others in the neighborhood), the mulch was even higher, but I've gradually lowered it a bit because it didn't seem healthy to me. I've been concerned about going even lower because at least some of the roots of the tree are actually above ground level and will be exposed.

Should I just move the mulch away from the trunk, or do I need to also lower it? Will the roots go deeper?

(I'm in Houston, by the way, not much above sea level, with lots of both rain and heat, and with thick clay soil. We can actually go from drought to multiple days of standing water in the same month.)

Thanks again, everyone, for your helpful posts.

It looks a little sparse, but not too worrisome. I would agree with the others that you should pull back the mulch a bit. It doesn't have to be a lot (so that you're exposing roots), but just enough so that you can see the "root flare," where the bottom of the trunk swells outward and the roots begin. If you want the tree to be happier, I'd suggest increasing the diameter of the mulched area, and be sure you're using acidic mulch, like pine straw or pine bark nuggets. Irrigation water tends to be somewhat alkaline, and that tree prefers acidic soil. Do not fertilize - excess nitrogen can lead to problems with pitch canker, particularly with slash pine.

I don't see any sign of pine beetles. Slash pine is somewhat less susceptible to southern pine beetle than loblolly, but is as susceptible to Ips pine engravers or black turpentine beetles as other pines. But these beetles are secondary pests that infest trees that are otherwise stressed, injured, or declining.

"Should I just move the mulch away from the trunk, or do I need to also lower it?"

I'd do both; spread it out thin and wide for the greatest benefits.

"The only thing worse than mulch volcanoes......mulch volcanoes with RED mulch"

That's when they're erupting ;-)

Resin

LOL, resin!