Subject
- Douglas fir47
- Soils -- Oregon21
- Industrial arts -- Study and teaching15
- Douglas fir beetle14
- Douglas fir -- Diseases and pests13
- Forest ecology12
- Stream ecology -- Oregon12
- Wood -- Bonding12
- Educational counseling11
- Forage plants -- Oregon11
- Home economics -- Study and teaching11
- Soils -- Analysis11
- Forest soils10
- Mycorrhizas10
- Plant-soil relationships10
- Bark beetles9
- Forest ecology -- Oregon9
- Germination9
- Grazing9
- Pheasants9