Hi, 

This looks like a leaf gall. Many trees get different galls and most of the time they are not of concern. On oaks they are typically wasps that make these. It is difficult to say for sure which gall this is because it is dried up. https://extension.psu.edu/galls-on-oak

You do not need to use a pesticide to deter the wasps  as most of the galls do not harm the tree. If the overall health of the tree seems to be fine, even though it is dropping some of the damaged leaves, the tree should push out new growth. 

If you are concerned for the trees health, fee free to send back more photos of the overall tree or some of the branches. 

Emily

Hi Brigitta, 

It can be distressing to see trees seemingly die all at once. Black locust trees look a little rough this time of year and with the lack of water Red Maple are probably struggling too. 

Many Oak trees are aging out of our communities in urban and suburban settings due to common environmental stressors and weather patterns that are seemingly due to a changing climate. You can read this article for more information: Why are Oak Trees Declining or Dying. 

Let us know if you have further questions. 

Emily

Hi, 

The first photo is a white mulberry. They can be weedy trees. The second photo we are leaning towards either an Elm or type of Cherry tree. It is difficult to see the leaf connections, and buds. You can see if it produces some seeds this year and maybe that can help ID. You can also explore this dendrology key from VTech. https://dendro.cnre.vt.edu/dendrology/leafkey1.cfm?state=&zone=6&habit=tree&leaftype=broadleaf&Phyllotaxy=alternate&leafhardwood1=simple&leafhardwood2=&leafshape=ovate1&leaflobes=unlobed&leafedges=serrate&thickness=thin

The 3rd photo we are unsure but it appears to maybe be a type of perennial. It is difficult to identify plants with out key characteristics like blooms or buds etc. 

If you end up seeing flowers, feel free to respond with a photo of one. 

Emily 

You're welcome