30 WHITE PINE TYPE 



inches as with the other two types it seldom exceeds that figure 

 as a maximum. In fact, the pineries of the Lake States have an 

 average annual precipitation of 30 inches. 



There is, however, one factor which tends to conserve the pre- 

 cipitation. That is the comparatively level topography which 

 retards rapid runoff. Generally speaking the pine type is con- 

 fined to the overwash plains formed by the streams which drained 

 from' the retreating ice sheets in the Glacial Age. These are 

 gently sloping sand or gravel beds from which the runoff is slow. 

 But the openness of the oil tends to counteract in part, at least, 

 the lack of slope. 



As a consequence the availaole moisture is .so deficient that the 

 predominating species, white pine, red pine, jack pine and pitch 

 pine, are all adapted to sites not abundantly suppHed with 

 moisture. Species which cannot endure dry sites are restricted 

 to those within the type which by reason of drainage or soil con- 

 ditions have more available moisture. Hence, hemlock and 

 hardwoods are only found in this type in deep-soiled, well-watered 

 valleys. Moreover, but few of the deciduous leafed trees charac- 

 teristic of the hardwood type just described occur in this type. 

 The important ones are white oak, chestnut, cherry or black 

 birch, gray birch and black cherry. Paper and yellow birch, 

 beech and red and white ash occur sparingly on the cooler sites 

 included within the type. 



Since the pine type is most abundant on lands which were 

 early sought for agricultural purposes, fire and clearing have had 

 profound effects upon the composition of the type. In addition 

 lumbering has played an important role in modifying the original 

 forest conditions. As a consequence there are very few stands 

 left which are representative of the type as the early settlers 

 found it. These virgin stands were either pure pine or pine 

 mixed with hemlock and tolerant hardwoods like sweet birch 

 and beech. The usual course of history after the removal of the 

 virgin stands was more or less repeated burnings. Fire was 

 used intentionally to clean up the land for cultivation or allowed 

 to run unchecked in the logging slash. As a consequence the 

 poorer sandy lands are now covered with a scrubby growth of 



