THR CARE OF YOUNG PLANTATIONS. 117 



endeavors to keep the soil in forests of foliageil trees 

 covered wiih tree-leaves, and in coniferous forests 

 covered with needles. The growth of grasses, moss, 

 heaths, bushes, etc., should be stopped wherever they 

 appear in forests, and precautions should be taken to 

 pretent their return. Such vegetation appears in the 

 openings of imperfect and neglected forests, and in 

 those woods that consist of light-needing trees, when the 

 foliage of the trees becomes too thin to overshadow the 

 soil. Up to within a short time it was customary to plant 

 these openings and gaps with shade-enduring trees, viz., 

 foliaged forests with oaks, beeches, maples and horn- 

 beams; and light-needing coniferous forests of pines and 

 larches with spruces and firs, by which measure the 

 grasses, weeds, etc., would be killed off, while the newly 

 planted trees under the shade of the old stock would 

 grow luxuriantly, thereby increasing the wood produc- 

 tion of the forest. All this sounds very plausible, but 

 experiments made in Germany at different experimental 

 stations during several decades show that trees planted 

 for the protection of the denuded soil use up most of the 

 plant-food in the suiface soil, and thereby damage or at 

 least keep back t he growth of the old stock of trees. It 

 may be that this observation will not coincide with 

 similar experiments yet to be made in this country, be- 

 cause our natural forests contain much more plant-food 

 than the artificial forests in the old woi-ld ; but, even in 

 Germany, intelligent foresters insist upon preserving 

 whatever is produced in the wouds that will cover the soil 

 and retain its humidity, thus preventing undue exhaus- 

 tion by surface evaporation. 



