386 Forestry Quarterly 



success, but when the pole wood stage is reached, the young stand 

 of pines begins to open up, single poles and groups die, the 

 openings increase, flow together, and finally a new plantation 

 becomes necessary. The reason is still hidden; insects, fungi, 

 composition and layering of soil under the plow, lowering of 

 ground water due to deforestation have been adduced as causes 

 without proof. 



The customary split planting has also been charged as cause, 

 the effect claimed being the formation of a shallow, fan-like root 

 system instead of taproot, but the author could not in many 

 hundred investigated poles find such a root formation, and al- 

 together hundreds of thousands of acres have been planted by 

 that method in other locations with entire success. 



The possibility of an inimical effect of animal manure exists at 

 least on old pastures. 



The author believes that a combination of causes may explain 

 the phenomenon, but especially a change of water conditions of 

 the soil. He cites the experience in the province of Posen, where 

 within a forested sand area there are found sinks or depressions, 

 which are fit and are used for farm purposes. In one of these 

 districts, after an extensive forest fire in 1883, when suddenly 

 several thousand acres were entirely deforested, these sinks 

 became swamps so that their cultivation had to be given up. On 

 a neighboring revir not burned, such small sinks gradually be- 

 came drier so that their former use for cabbage growing had to 

 be abandoned, and pine regeneration crept in. When the timber 

 surrounding these sinks was cut, the sinks became wet again, 

 so that alder was planted. But when the surrounding pine plan- 

 tations grew on, the water conditions changed again and the de- 

 teriorating alder had to be replaced by birch. This latter was 

 lately crowded out again by pine volunteer growth, the soil hav- 

 mg become as dry as it had been ten years before. 



The author cites a number of similar experiences, showing the 

 drying effect of the old stands. When these are removed the new 

 young plantation finds enough water, indeed the water con- 

 tents of the soil increase and the soil bears grasses and herbs 

 which usually can hardly thrive in forest soil and which use up 

 accumulated humus deposits. Our method of reforestation is 

 a jump from one extreme to the other: the open area is suddenly 

 changed into a fully stocked forest, while nature conquers the 



