I found a few more photos showing the discoloration of the leaves on the trees. 

I hope this helps. 

Thank you,

Allison

Hi Allison, thanks for the question.

With photo of the tree that has leaves, I was able to identify it as a hawthorn. Probably a Thornless Cockspur Hawthorn (Crataegus crus-galli (thornless form)).  The browning leaves could be insufficient water or sunscald.  These trees like moist but well-drained soil.  There could be some insect problems.  In one of the photos, you can see what appears to be a spongy moth.  Keep a lookout for aphids, scale, and mites.  Sapsuckers and woodpeckers can do a number on the trees as you have seen.  Some protection around the trunk can be helpful (see link). The tree with the missing bark could be a result of previous damage or improper pruning opening it up to disease.  Another observation is that the trees show no root flare.  Either the wood mulch is way too deep, or the trees were originally planted too deep.  This can result in problems.  If the mulch is more than 2 to 3 inches, consider spreading it thinner and totally removing it just around the trunk.  Check out the links for more information:

Crataegus crus-galli (thornless form) - Plant Finder (missouribotanicalgarden.org)

Woodpecker and Sapsucker Damage on Trees | University of Maryland Extension (umd.edu)

Dealing with Spongy Moth Around Your Home or Property - Integrated Pest Management (msu.edu)

Mulch: Just do it! - MSU Extension

Tree Owner's Manual (usda.gov)

I hope this is helpful.