Influence of Shade on Plantations. 177 



trasting the behavior of white pine stock under a variety of local 

 influences. The portion of the Harvard white pine plantation 

 occupied a gentle southerly slope near the crest of a well rounded 

 ridge. The elevation is about 1,200 feet. The soil is well 

 drained sandy loam, very stony. The area is typical of New 

 England's abandoned ridge pastures, gradually seeding in with 

 gray birch, white pine, red maple, and occasionally a black or red 

 oak. or a chestnut. There are occasional bushes of Crataegus 

 and Viburnum, and a low cover of grass, moss, sweet fern, and 

 blueberry, grouped in some places, intermingled in others. With 

 uniformity of stock, planting method, and broad site conditions, 

 this area gave opportunity for determining the influence of shade, 

 root competition, and proximity of stones. Small areas planted 

 with Scotch pine and with red oak furnished a limited comparison 

 of species. The Brooks plantation, all white pine, is on soil 

 similar in composition, but much less stony, on the lower slopes 

 and the flats of a valley at about 800 feet elevation. The area 

 was almost completely cleared of a good stand of timber in the 

 fall of 1910, and the brush burned in 191 1. This plantation, with- 

 in itself, furnished data on the influence of overhead shade and 

 root competition. Within itself, and especially when compared 

 with the Harvard plantation, it offered some data on stock. 



The benefit, and in the case of natural reproduction, the practi- 

 cal necessity of some shade for white pine seedlings has never 

 been disputed, to the knowledge of the writers. The degree of 

 the benefit of shade was undoubtedly exaggerated by the drouth 

 of 1912, in the plantations studied; but the figures for this factor 

 should be of interest as an indication of what may be expected in 

 similar dry years. In the inspection of the plantations, shade 

 from trees of all species was recorded, for the six hours in the 

 middle of a summer day, in four classes, based on duration- (See 

 table.) Most of the trees in the first class had no shade from 

 high trees whatever, although the class includes trees which re- 

 ceived shade from high trees for not over an hour each day. 

 Shade from low bushes, such as sweet fern or blueberry, or from 

 tufts of grass, was recorded in three grades, — absent, medium, 

 and heavy. To show the influence of shade, the record of three 

 year white pine transplants, not subject to the influence of root 

 competition or of nearby stones, is given in Table I. 



