My friend claims that trees can be buried by sand dunes but still be alive and thrive.
Specifically, she showed me live oaks in Grayton Beach Florida that she was told were the tops of fully-grown oaks that are now buried in the sand and have been that way supposedly for years. What I saw looked like young oak trees–or the top branches of a really mature oak. I think it’s just that these trees get so battered by the harsh environment at the coast that they grow slowly and the wind twists them into branch-like shapes.
I searched the web and the best reference I found was an article by Frank Thone in *The Science News-Letter *(Vol. 39, No. 23, June 7, 1941, p. 367). Unfortunately, that was on JSTOR and I don’t have access (Nature Ramblings: Defiers of the Dunes on JSTOR).
I know sand dunes move and do bury trees but I didn’t think the tree could survive with 90% of it’s trunk buried. Is someone pulling her leg or am I not as smart as I thought?
Thanks for the image. Yes, I misspoke; they are probably scrub oaks, not live oaks. But I’m still wondering if they can survive if a significant portion of the tree trunk is buried in the sand for a very long time.
They may be pulling your leg, but the phenomenon certainly exists. You can see photos of it here.
There’s no particular reason why a tree should die just because the sand dune buries the lower trunk, and most trees are capable of producing adventitious roots from the trunk when it gets buried.
So provided the tree can grow faster than the sand does, and so keep its leave clear, it can theoretically survive being buried to any depth. Tamarisks seems to have actually evolved to exploit this ability. Any tree in a sand desert is prone to being buried, so most trees can’t survive in sand deserts. Additionally desert soils tend to be much less fertile than the sand itself, so tamarisks have a growth habit that actually encourages sand dunes to develop around them. That would be fatal to many trees because of the speed with which desert dunes can grow. However tamarisks can grow from the tiniest exposed branchlet and tamarisk trees have been described at the heart of dunes over 15 metres, having presumably taken root in the soil underlying the dune.
Scrub oaks LOOK like they are buried on a good day. I always thought they were buried trees when I was a kid and made forts in them on giant sand dunes.