Real peat moss, Ya or Na?

No I have not used it but I have been tempted.

i have heard that soaking it in glycerin would be one way to preserve it, or at least extend its appearance.

"Peat moss" is partially decayed organic material, largely composed of sphagnum moss.

Your picture is of real living moss, hence the reason it is green. Once dried - yes - it will turn brown. Nevertheless, many people do use this stuff for model railroad scenery. You can simply dry it, but that will leave you with a mat of brittle brown colored material. A better approach is (after drying) to preserve and color it with use of glycerin and coloring dye - do a web search on the words "how to preserve moss" for detailed instructions. You can do the same thing with lichen, which is not moss but another organism that (depending on the species) grows in a variety of different and interesting physical shapes that can be used to resemble everything from shrubs to trees on a layout.

Peat Moss is awesome.  It can be processed into many interesting textures.  My favorite way to use it is to shake it up in a jar along with some hobby acrylic paint, diluted a bit with alcohol. Various shades of green work well. Then spread it out to dry. What happens is that the moss clumps up into small granules that, when spread out on a surface makes a convincing simulation of a neglected area where low bushes have taken over. I like it because of the texture and the fact that the native brown color mixes with the green paint to give a subdued hue. It can be used in many of the situations where ground foam is typically employed, but gives a different, more natural effect, and adds variety. The acrylic is more than adequate as a preservative.

In this pic, the area below the bumper and to the right of the corral was done that way.  

Thanks for the the help and great ideas!

I use moss for my MOW muck loads as clumps of weeds or grass. I pick it from between my brick walkways, and break it into little chunks.

Don