THE NORTHERN HARDWOODS REGION 269 



trees together forming approximately sixty per cent of the forest. 

 Spruce, hemlock, and white pine are the leading conifers. There 

 is also some balsam and arborvitae. Pure coniferous stands are 

 of infrequent occurrence. 



In the original forest some areas bore more spruce than at 

 present, while other portions were originally all hardwood 

 growth. The amount of spruce in mixture with the hardwoods 

 has been decreased by cutting out the former. 



Other common hardwoods are poplar, paper birch, basswood, 

 and white ash. Red oak becomes of commercial importance in 

 the Vermont, New Hampshire, and Massachusetts sections of 

 the region. Black cherry and black birch occur mainly in the 

 southern portions. Chestnut extends up from the regions to 

 the south a little way into the northern hardwoods region in 

 suflEicient quantity to be a commercial species in the Massa- 

 chusetts section. 



Forest Types. 



As in the spruce region both permanent and temporary forest 

 types are found. Of the five types recognized two are permanent 

 and three temporary. 



Permanent forest types. 



1. Hardwood. 



2. Swamp. 



a. Hardwood swamps. 

 h. Softwood swamps. 



Temporary forest types. 



3. Birch and poplar. 



4. Old-field hardwoods. 



5. Old-field conifers. 



I. Hardwood. — This is the prominent type, far exceeding in 

 area all others combined, and being well distributed throughout 

 the region. It occurs on a variety of soil situations, but is never 

 found on swampy sites. The soils are usually of good depth 

 and fairly rich and in many cases could be used for farming. 



