My friend and former ASU postdoc Chris Fisher - a geoarchaeologist at Colorado State University who works mainly in the Lake Pátzcuaro Basin (Michoacán, Mexico) - was recently awarded the 2007 Gordon R. Willey Prize by the Archaeology Division of the AAA. This was for a paper based on his doctoral research research published in American Anthropologist in 2005 in which he looked at human-environment interactions in his study area. Fisher argues that contact led to a precipitous decline in indigenous population meaning that the land management system they had developed could not be maintained, thus leading to widespread landscape degradation. It's a very good paper, and you can read it as a pdf here. Congrats Chris!