On the other hand, all of the intolerant hardwoods planted have 

 lacked this ability. With the exception of black locust stands during 

 a short period immediately after their closing, stands of these species 

 have a heavy ground cover of grass, and, consequently, no forest floor. 

 These species include white ash, white elm, white oak, catalpa, and 

 Russian mulberry. Stands of other intolerants, red oak, osage orange, 

 hickory, chestnut, black walnut, and cottonwood have not yet closed, 

 so no positive statement concerning them in this respect can be made, 

 though a small part of one sowing of black walnut on exceptionally 

 good soil shows the ground cover entirely driven out. This condition 

 will probably be temporary, as it was with black locust. Yellow poplar 

 has been planted only in mixture with white pine, so we have no 

 demonstration of what a pure stand would do. 



Bass^rood, a medium tolerant here, will probably make a better 

 showing when the stand closes. 



After making a very promising beginning, considerable portions of 

 pure stands of white elm and white ash seem to have stagnated. 



Throughout a strip immediately adjacent to a stand of black locust, 

 box elder has made excellent growth and has succeeded in eliminating 

 ground cover, though no forest floor has accumulated. This particular 

 stand furnishes a striking illustration of the beneficial effect of black 

 locust upon soil. Sugar maple is the only hardwood of high tolerance 

 planted and has run true to form in maintaining an excellent soil con- 

 dition. 



Catalpa, chestnut, and osage orange have shown conclusively that 

 they have no real place here. Russian mulberry has developed into 

 nothing more than a lot of scrubby brushes. Better soil or a mixture 

 with other species might make something out of it. 



In addition to those already listed, other species in small groups that 

 have made thrifty growth are jack and Norway pine, blue and white 

 spruce, eastern balsam, concolor fir, hemlock, honey locust, horse chest- 

 nut, buckeye, cucumber, arbor vitse, tamarack, European larch, Euro- 

 pean alder, sycamore, silver maple, white birch, and coffee tree. 



On the basis of average annual growth in height and diameter, 

 Scotch pine still leads all of the conifers with white and Austrian pine 

 a close second and Douglas fir, western yellow pine, and Norway spruce 

 in the order named. The relatively poor showing of Norway spruce 

 is largely due to its location on a poor spruce site. 



Among the hardwoods, cottonwood ranks first with sugar maple 

 second and the other species in the following order : Box elder, white 



