Native Grasses / Pipeline

Does anyone know the methods used to achieve the results that pipeline companies get when they seed native grasses over a pipeline? I know they do not maintain it nor do they come back and give it any assistance, yet it thrives. There has to be some sort of trick to it. I know most of us spray trying to help it establish over the weeds etc. I have an area where cows had previously grazed a young stand to the ground on pipeline before I bought it. No cows on it now and its the best looking stand I have ever seen. It's perfect for as far as I can see on the neighbors side too. Anyone know the tricks? I wouldn't think they are just getting lucky with this and its on a steeper hillside.
My experience is that switchgrass is pretty tough stuff, once it's established. I have switch on my place and the loggers I had out earlier this summer used some areas as loading areas and the switch was matted to the ground and turned brown.....I was really concerned. Here we are 2 months later and the switch is growing and green again. It didn't stand up, it looks like it simply sent up new growth. It's obviously way behind the other stuff they didn't knock down, but it sure isn't dead.....not even close. I have babied my NWSG simply because of the cost of's planting year - after that it pretty much takes care of itself. So IF you can get it to establish.....your pretty much set, at least with switchgrass.
In my electric R/W I made the deal that I would maintain it by keeping saplings out if they put up NO SPRAY signs and didn't use herbicide.They planted NWSG in there twice by using a disk machine with a broadcaster.No luck so I bought Cave-in-rock switch and drilled with my kasco versa drill and it's 6ft tall.we mow in spring and may bale or burn this year but will mow before burning to keep heat down.
Switch is one of the best NWSG for poor soil reclaims I have seen.....once a few plants establish an develop a strong crown in 2-3 years they will quickly spread their own prep, no herbicide, and intermittent grazing tolerant. Cows really like switch and you can use that to your advantage to get high animal impact to further diversify native plants and improve soil quality.