1918] HUTCHINSON—FOREST TREES 
| Fagus americana 
Acer saccharum 
| Tsuga canadensis 
Abies balsamea 
Betula lutea 
Picea mariana 
Betula papyrifera 
Pinus Strobus 
(h 
(Zuercus rubr 
Populus balsamifera 
Thuja occidentalis 
Larix americana 
Fic. 5.—Forest trees: specific ranges of tolerance with 
