Albert Everett Wieslander

In the 1930s, forester A. E. Wieslander spearheaded a U. S. Forest Service survey of California vegetation, called the Vegetation Type Mapping Project. Originally, the project was slated to include detailed vegetation type maps of 220 USGS quadrangles, but the survey was halted by World War II, and only 23 maps were published. The project continued after the war under state funding, but no more quads ever saw publication. However, much of the unpublished data survives today and exists in storage at the University of California, Berkeley. The VTM dataset has been recognized as an invaluable window into the state of California flora in the early 20th century, and has provided data for several graduate theses at the University. However, the dataset's physical fragility and resultant restriction to the U. C. Berkeley campus have made it largely inaccessible to the broader scientific community. Thus, researchers at U. C. Berkeley Department of Environmental Science, Policy, and Management (ESPM), in conjunction with the Marian Koshland Bioscience and Natural Resources Library, sought funding to digitize all of the published and unpublished dataset, for use in modern geographic information systems and to facilitate its distribution via the Internet.


VTM plot data sheets over a plot map

The ultimate goal of the original VTM project was to create vegetation type maps, but in the process the surveyors collected several other kinds of data as well. In order to validate some of the broad zones of vegetation they designated from high vantage points, the surveyors also ran vegetation transects, collecting data on species composition, depth of leaf litter, and tree size, among other things. They marked the location of these plots on USGS topographic maps, which today provide us with point occurrences of the individual species they found. Addtionally, they collected sample specimens and placed them in the University Herbarium (now the Jepson Herbarium), many of which remain there today. They also took photos of many vegetatively distinct locations, and marked the locations of these photos on maps (unfortunately most of these photos maps have been lost). And finally, of course, they created vegetation maps, drawing broad zones of single or mixed stands in crayon over USGS topographic quads.


Sample of a VTM vegetation map

The VTM photo digitization has been handled by the Marian Koshland Bioscience and Natural Resources Library, and is largely complete. They maintain the photos on their own web site. The Kelly Lab in ESPM handles the plot map digitization and georeferencing, and they make these data available on this web site as they are completed. The Allen-Diaz Lab in ESPM took on the onerous task of entering all of the plot data, which the original surveyors recorded by hand, in the field, on thin sheets of paper in faint pencil. Now these data reside in a database, which is accessible through this site both through the MapBrowser, or by direct download of files in the Data section of the site. Researchers at the Information Center for the Environment at U. C. Davis have scanned all the unpublished vegetation maps and are currently working on georeferencing and digitizing the zones of vegetation.


A VTM photo