PRELIMINARY REPORT OF EXPERIMENTS IN PENNSYLVANIA 305 



and two adjoining small tracts were planted with 8,000 2-year white- 

 pine seedlings. The planted trees established themselves satisfactorily, 

 but thrived for only a few years, because the sprout growth which fol- 

 lowed in the wake of the lumbering operation grew rapidly and became 

 very dense in spite of the omnipresent chestnut blight. In 191 5 it be- 

 came quite evident that the plantation could not succeed unless liber- 

 ated. Plans were immediately prepared which covered not only the 

 liberation of the planted trees, but also a series of experiments which 

 embraced two adjoining small areas in addition to the lumbered tract. 

 One of the adjoining areas was practically free from any existing 

 growth and the other was occupied by a 68-year-old stand of almost 

 pure chestnut, with a .8 density. Both of the adjoining areas were 

 planted at the same time as the lumbered tract and with similar planting 

 stock. 



The plans for the experiment called for a division of the aggregate 

 area into the five following plots : 



Plot I. Practically no existing tree growth present at the time of the establish- 

 ment of the plantation, which consequenth- has been developing un- 

 hindered. 



Plot II. Occupied by a 6S-year-old stand of almost pure chestnut, with a .8 

 density and no subsequent cutting. 



Plot III. Comprises a small part of the lumbered area upon which the resulting 

 sprout growth has not been removed. 



Plot IV. Comprises almost half of the lumbered area upon which a complete re- 

 moval of all the native growth which followed the lumbering opera- 

 tion took place during July and August, 1915 — that is. after the sea- 

 son's growth was completed. 



Plot V. Comprises about half of the lumbered area upon which an incomplete 

 removal of the natural growth which followed the lumbering opera- 

 tion took place during July and August, 1915. A small number of 

 the best sprouts, usually one to three on each stump, were left uncut. 

 The contemplated probable benefits to be derived from such a pro- 

 cedure were : 



1. The remaining sprouts would shelter the young white-pine 



trees. 



2. The transition from a dense shade to a partially sheltered con- 



dition would be less extreme than in the case of a complete 

 recut. 



3. The continuous development of the favored sprouts would re- 



tard the origin and development of a second generation of 

 sprouts which always follows. 



4. In case of the necessity for a subsequent recut, the favored 



first generation sprouts might have reached a marketable 

 size, while no returns could be procured from second-gen- 

 eration material. 



