Influence of Shade on Plantatioris. 179 



damage, directly or indirectly. In other words, pine seedlings 

 planted in the shade of birches, black oaks, or other trees in New 

 England pastures get little more benefit from the shade than those 

 planted in patches of sweet fern ; and the latter will be free from 

 injurious shade or mechanical damage in years to come- This is, 

 of course, without considering the often compensating factor of 

 root competition of the extra expense of planting in brush. 



The Brooks plantation furnished striking corroboration of the 

 value of shade in seasons like that of 191 2. On one slope, scat- 

 tered trees or small groups of hickory (Hicoria ovata) poles, 30 

 to 50 feet in height, had been left. The slope was planted with- 

 out attention to these hickories, so that it was possible to get 

 counts on two series of plots, each series alike in site, exposure, 

 absence of low shade, ground cover, stock (2-year seedlings), 

 planting method, and time of planting; but differing in that the 

 plots of one series were shaded by these hickories at least three 

 hours daily, while the plots of the other series were unshaded and 

 more numerous. On the shaded plots, 201 out of 291 trees 

 (69%) were alive; on the unshaded plots, 181 out of 500 trees 

 (36%) were alive. The shade of the hickories had been in- 

 sufficient to cause a noticeable difference in the growth of the 

 coarse, low grass that covered the ground, but was enough to keep 

 alive two seedlings out of every three, while only about one out 

 of every three lived in the open. 



By his experiments in the sand hills at Halsey, Neb., Bates has 

 shown the great importance of root competition as a source of 

 failure in plantations where rainfall is scanty. It was not to be 

 expected, even after an unusual drouth, that its importance would 

 be as great in New England, where the soil is loamy and the 

 annual precipitation averages about 40 inches. Also no tree in 

 the Harvard plantation was without some root competition from 

 the bushes or sod that covered the old pasture, which afforded no 

 comparison like the ridges and bottoms of the Nebraska sand 

 hills. In this inspection of the Petersham plantations, root 

 competition was noted when it was obvious, from the position 

 of the tree with relation to other vegetation, that the ground 

 occupied by the roots would also have to supply moisture to 

 other plants, as when a tree had been planted at one side of a 

 hole in a thicket of sweet fern. The results for the Harvard 

 plantation are given in Table II. 



