Thanks to everyone for the overwhelming response and discussion.
 
The whole purpose of posing this question to the group revolves around what seems to be a lack of literature on the subject.  We all seem to have experiences and knowledge with vegetation signatures and historic sites, but these connections seem to only be mentioned "in passing" in the literature for the southeastern U.S.
 
I work as an archaeologist at Fort Polk in west-central Louisiana.  We have noticed over the years that many historic sites (as indicated from historic aerials and other documentation) were missed during previous surveys.  I am currently writing an article discussing the reasons behind these sites being "overlooked", which will have a section specifically on vegetation that will largely be written by the installation botanist.  He is very knowledgable on the subject, but I'm trying to help him find any previous work done for the area or comparable resources.  We would like to, as was mentioned in one of the previous emails, develop a list of trees/shrubs/plants that almost certainly indicate a homestead (due to them having to be planted and/or not spreading heavily) as well as a list of those that are suspicious enough to justify surveyors briefly veering from their transects to further investigate.  This will help ensure that future surveyors
 can be briefed beforehand with respect to types of vegetation to "be on the lookout for".
 
Many thanks,
Brad Laffitte