Weislander Vegetation Type Mapping
A student of mine happened upon the Weislander Vegetation Type Mapping data set while conducting some of his thesis research. This is a very great find of historical vegetation cover mapping for California. This method was well ahead of it's time (being compiled in the 1920's and 30's). This data set is now GIS enabled as a result of work conducted by UC Berkley and UC Davis. I hope you find this data set useful in your work. At least check it out. Historical photos are available as well.
My student explained to me that some of the trees in the Sierras are not as near as big now as they used to be, especially of some species.
What a great data set that is available for other ecological research!