Potential natural vegetation of Poland

The Białowieża Geobotanical Station has a wonderful map of the potential natural vegetation of Poland. I looked around to see if it can be bought somewhere, but the only version I could find was as an album of 12 partial maps. Not quite what I had in mind. Fortunately, the authors have made the map available over the internet as 16 bitmap images. The obvious next step was to manually join them into one giant map, which can be found here