I have several mature trees that have one or two roots that are protruding along the top of my yard, like the long root in the included picture. These roots make it a challenge to cut the yard each time. Therefore, I was wondering how much damage, if any, would occur if I were to cut one root off, or at least cut/shave it down far enough that I can put soil and maybe even grass over it and make it the same elevation as the surrounding terrain. I don't want anything bad to happen to the trees, but some of these roots have really taken over the yard. Any help or suggestions would be greatly appreciated.
Thanks!

 

Think of the root system as being similar to the canopy in size and complexity.

There is no guarantee answer to your question, but removing a single root like removing a single limb should not kill a tree!

 

If you really like the tree and would have remorse if it dies then just leave it. (besides removal of that tree will be expensive and you'd still have the stump as an extra expensive to remove).

Just a side note...that mounding up of dirt along side the base of the trunk, it's my understanding this is not good for trees. Although with a tree as mature as that I'm sure it makes little difference.

 

I can't see the leaves in your picture well enough to tell what type tree you have. Many oaks are very sensitive to root damage and cutting a root or two can be enough to bring down a massive oak several years later. Most other trees are more forgiving of root damage and removal. That is a pretty massive root so if you remove it I would make sure that is the only root you remove from that tree. Then in 3+ years if the tree still looks healthy you can take another root.

 

Cutting that sized root will likely kill a large segment of the tree.
For many species of tree, you can effectively map the root system to the canopy, as in, each large root feeds a specific portion of the canopy.
I worked as an arborist for several summers-, I would STRONGLY suggest just adding dirt - doesn't have to be expensive top soil, just cheap "fill dirt" e.g. subsoil, then covered with top soil and grass seed.

It's a quick way to plant trees after the 18" of nice plowed & tilled farm topsoil has been scraped off and sold. Usually a new development will have an agreement to replace trees that die in the first few years. It's actually easier for the landscaper to plant several shallow trees and then mound up dirt and mulch.
Yes, some die and have to be replaced, but that's an opportunity to up-sell the new homeowner on some landscaping...

 

Thanks for all the help. I'd rather have healthy trees so I'm going to follow some guidelines from an article someone sent me and take my time with these roots. Essentially I think I'll shave no more then 20% of a trees exposed roots that are about 2 inches or less and then wait about 2 years to verify it's health before continuing with any additional shaving. Yeah, this is going to take more time then I'd like, but I'd rather keep healthy trees. I'll also try and build up the soil around some of the offending roots to see how that works out.

On a slightly different note. As Norm201 pointed out, what's the general concensus on mulching around the base of trees? My girlfriend thought that since the trees were so "rooty" around the bases that mulching around the base would be aesthetically nice since nothing was growing around the bases and we wouldn't even be able to mow grass there if we could get it to grown there. I've seen it before in near by subdivisions, but after reading Hal_S comment, I'm a little concerned I might harming the trees. So what's the general thoughts? Keep the mulch or get rid of it and just have a bunch of gnarly raised roots at the base?

Thanks again everyone!

 

Technically you shouldn't. With the size and age of those trees you probably won't do any harm. Go for it. It would take a lot more than that to kill those trees.

The root thing. IDK. You're on your own.

 

Installing mulch around a tree is not going to do anything. If it was a problem half the trees in every neighborhood would be dead by now.

You cant pile up dirt around the trunk significantly, that will kill it.

 

Is that a public sidewalk close by the root ? I'm not a big fan of piling soil close by the crown....loose chips better.