﻿S BULLETIN 13, U. S. DEPARTMENT OF AGRICULTURE. 



White pine at one place or another associates with nearly every 

 other tree species native to the Northeastern and Lake States. There 

 are several species, however, with which it shows a special tendency 

 to mix throughout its range or in portions of it. On the better soils 

 hemlock, red spruce, sugar maple, beech, basswood, elm, and yellow 

 birch form with white pine characteristic forest types. Hemlock is 

 perhaps the most common associate throughout its range. Of slower 

 growth, smaller size, and more shade enduring than white pine, it often 

 forms a dense under-story of foliage beneath the pine crowns. Under 

 the heavy shade of such stands the forest floor is absolutely bare, save 

 for the thick layer of decomposing needles. In the early logging 

 operations, which removed only the best of the pine, hemlock was 

 considered valueless, except where tanbark markets existed, and was 

 left standing. Even the felled trees from which bark had been 

 removed were left to rot in the woods. With the disappearance of 

 the pine, however, hemlock lumber has steadily increased in value. 



On the deep, loamy soils where white pine associates with hemlock, 

 maple, beech, and birch the white pine reaches its best individual 

 development (PI. I). Lumbermen early removed the white pine, 

 and later in some places the hemlock from these stands, leaving the 

 hardwoods in possession of the soil. Hemlock seedlings often per- 

 sisted in the hardwood forest after the removal of the mature trees, 

 but except in large openings the young white pine succumbed to the 

 shade. 



In the Northeastern States red spruce, which itself forms immense, 

 practically pure stands, was also a common associate of white pine 

 in the original mixed hardwood forest. Both spruce and pine have 

 been largely culled, and while spruce seedlings are often abundant 

 under the hardwood crowns, pine seedlings are rare. In aspen and 

 paper birch stands, however, where the light foliage casts but little 

 shade, young white pine and other conifers often grow in abundance, 

 and eventually take the place of the short-lived birch and aspen. 



On dry, sandy soils in the East, white pine often grows mixed with 

 pitch pine, and in the West with Norway pine and jack pine. Both 

 Norway and jack pine reach their best development in the Lake 

 States and in Canada, where they form large pure stands on soils 

 too dry for white pine, associating with the latter on slightly moister 

 ones. The white and red pine mixture is especially important. 

 Typical pine forests on fresh, sandy soils in Michigan consisted of 

 white pine (45 to 55 per cent), red pine (25 to 45 per cent), with 

 scattering hemlock (10 to 15 per cent), and occasional fir and hard- 

 woods. Red-pine lumber is not much inferior to white pine, and 

 large quantities are mixed with and marketed as the latter. Jack 

 pine is so small and limby that until recent years it was considered 

 valueless. 



