Ed google Marcell Experimental Forest, there's a lot of articles about this place or watch this video that explains what they are doing there, what they are testing or watching for. http://www.youtube.com/watch?v=keLBJ5Uq5Xw It's sorta surprising that they put up the tall greenhouses around some of the trees, just due to the fact that this area of Minnesota tends to get very high winds, along with tornados in the Spring and Summer.

I noticed at least 20 other webcams showing the same thing, just from different angles—really interesting to compare how it looks across all of them.