182 JOURNAL OF FORESTRY 



abundant. They do not, however, develop normally and soon die. 

 Earlier investigations which Hesselman has carried on for more than 

 10 years have shown that death is not due to drought, lack of light, 

 grazing, snow pressure, or competition with brush and lichens. Nu- 

 merous chemical analyses have shown that wherever the pine seedlings 

 develop normally the soil contains a noticeably higher per cent of 

 available nitrates than where they are of poor development. The con- 

 clusion, therefore, is that available nitrogen in the soil is the critical 

 factor. The presence of decaying wood or leaves when mixed with 

 the mineral soil seems to promote nitrification. Seedlings grow much 

 better near older trees, stumps, and decaying logs than in the open. 

 Experiments of 10 years' standing have shown a marked improve- 

 ment as a result of mixing sod with the soil, or even merely stirring 

 up the soil with a hoe. Similar results are often observed after logging 

 operations in which the surface layer of organic matter is mixed with 

 the soil, thus promoting nitrification. G. A. Pkarson. 



Hesselman, Henrik. Stiidicr over de iiorrldiidska tallhcdantas foryngrings- 

 villkor. Skogsvardsforeningens Tidskr., 17 :29-76. Figs. 1-16. 1919. 



Most foresters know of the success reached 

 Afforesting the in afforesting the barren heaths of Jutland. Den- 

 Barrcn Heaths mark, but few have realized the years of experi- 

 of Denmark mentation and the unflinching faith and courage 



of those who fathered this project. Though 

 several companies, which had been promoted for reforesting the dunes, 

 had failed. Enrico Dalgas became convinced that it could be done and 

 gave himself and his fortune to the work. The company which he 

 organized has successfully reforested 80,000 hectares and the Danish 

 Government 50,000 hectares. The work began about fifty years ago, 

 and at the present time only 40 per cent of the total waste area remains 

 unreclaimed. The 55-year-old stand of Norway spruce, planted where 

 nothing but worthless brush grew, yielded 3,950 cubic feet per hectare. 

 The work is done as follows : The heath is burned, then plowed and 

 disked and allowed to remain thus three years, plowed again a little 

 deeper and in a manner to break up all roots and again left for two 

 years. This process brings about aeration, bacterial life, decomposi- 

 tion, and formation of humus. In some places lime and phosphoric 

 acid is plowed under in the fall. A species of scrub pine is planted 



