Several years ago we planted a row of pampas grass on our property. Over time the grass had died in the center of the clump - see photo.
We are trying to tidy up this area by removing the weeds, trees and such that has taken root in the center.
My question, will the grass eventually fill in the center again? Should we just remove what is left and start over?
Any suggestions would be greatly appreciated.
Thank you!

I have had this happen to my pampas grasses that grow in moist areas with poor drainage. One of them was in a particularly moist area that never seemed to dry out and the plant finally died completely, except for a very thin ring around the outside. I just tore the whole thing down and it never returned. The ones that are up the hill a bit never did exhibit this problem.

How old is the grass? Is it a really wet area?
I don't have any experience with pampas, but many other grasses need to be dug up and divided every 3-4 years or the center will die. Division will keep it from choking itself off and reinvigorate growth. It also appears from the picture that the dead growth from previous years may be inhibiting growth.
You could just dig up what is still alive, clear out the area of debris and replant. It will possibly come back if there aren't extenuating circumstances.

Thank you for the responses!
The area is at the top of a slope. The grass was planted to slow erosion about 30 years ago. While clearing the debris we were reminded we had trimmed the grass probably 10 years ago, perhaps that caused the center to die. Also, it seems the ants decided this was a great place to live. Interesting though, two clumps in the row are unaffected, they're full and still growing.
We've decided to clear the debris and ant mounds and see what happens this growing season. If it doesn't appear promising, we will replace it next year with a native grass, perhaps indian grass.
Thanks again!

with JC any large grasses that I have ever had need to be dug up divided and replanted every 3 to 4 years to avoid dead middles. It also helps to keep the centers clear of debris. I read a few years ago to burn out the dead growth in the Spring before new growth starts which has helped quite a bit. Be careful and have water handy because they flare up quickly.
http://www.gardenguides.com/12...
http://www.youtube.com/watch?v...
Unlike this video I cut mine as short as possible before burning so that the fire is more manageable.

Best to just burn the Pampas, this gets rid of the mess and re-fertilizes the new growth.

This has been done in S. America were they still grow the grass for the plumes.