"Productive dune systems"?

I am watching 'Chased by Dino's on the Discovery channel right now, and a paticular ecosystem type has been mentioned.

'Prosuctive dune systems'

This is being described as sand dunes surrounding rainforests.

I can't get my mind around the concept.

Anyone care to help me out?

If there is enough rain for a forest, then why the surrounding desert?

You might have a little more luck over in one of the geology or ecology newsgroups.

Sure! During the Early Jurassic, in the Navajo Erg, preserved as part of the Navajo Sandstone, there were 'wet dune,' a huge dune field that for long periods of time was quite wet, the water table close to the surface and the areas between dunes small lakes or at least with vegeation. The theory is that no plant had yet evolved to cover the dunes - no grasses remember - and the dunes shifted too much, so it stayed dune, but was quite moist. The Navajo Erg did go through some very dry periods, but even during those times there were summer monsoons.

ok, now it is starting to make sense. I had been wondering exactly what those protoceratops who were covered by sand slides had been eating. I guess they just nested near the dunes and foraged in the forest.

Do you mean sand storms?

I read somewhere that it used to be thought that the fossilized protoceratops found in the Gobi desert had been killed when they were buried alive during sand storms, but that this idea had more recently been discredited when people realized that large modern animals are always able to avoid this fate, and that there was no reason to think that dinosaurs ever died this way.

Of course large animals today do die in land slides, and maybe that's what you really meant. It's just that in my mind the association is protoceratops and sand storms. (And actually if these protoceratops were living around a sort of sand dune which no longer exists today then maybe they might also die in ways that are no longer seen).

Well not necessarily forest per se, but you've got it. The interdune areas in the Navajo had lots of vegetation, and there is some precedent today; there are river and lake beds where water is pretty close to the surface in the modern Namib that support quite a bit of vegetation and the local population of Namib desert elephants. In the Navajo apparently some trees did survived during wet periods in the interdune areas, a very odd site by today's standards.

While your last point is a good one, I would simply add that likely the protoceratops died of other causes and then was buried by a sandstorm or a landslide. Perhaps disease, injury, or predators were the proximate cause, but that weather did us a favor and preserved the fossil. It would appear based on my readings that areas that in our present would be grasslands were dunes and open desert back then because a plant cover that could stabilize dunes simply hadn't evolved yet.