v. 1. Plant and soil responses.
v. 2. Southern forest region.
v. 3. Central forest region.
v. 4. Eastern diciduous forest region.
v. 5. Northern forest region.
v. 6. Plains grassland region.
v. 7 Mediterranean region, Western arid and semi arid region.
v. 8. Pacific Northwest and Rocky Mountain regions.
v. 9. The Alaska region.
v. 10. Index and addendum to volumes I-VIII.