52 Forestry Quarterly. 



areas were deforested by fire is well taken. It would be worth while to 

 impress that fact upon the settlers. His information about the natural 

 restocking of the brush areas is too vague. We should like lo know just 

 what effect the brush has upon reproduction, whether it really aids repro- 

 duction bj' preserving soil moisture or is an unmitigated evil ; what effect 

 it has upon the reproduction of the different species, that is, whether 

 or not a stand formerly composed of pine will be changed to one of a 

 more tolerant species which can come up through the brush ; what species 

 first comes in; and the period required for natural restocking under dif- 

 ferent conditions. His recommendation about reforesting the most favor- 

 able sites first is good. 



Inter-relation Bettveen Brush and Tree Grozcth of the Crater 



National Forest, Oregon. By Harold D. Foster. Vol, VII, No. 2. 



The author has brought together a number of interesting observations 

 on the distribution, classification, and causes of brush ; also its relation 

 to reproduction. These observations tend to show that brush is caused by 

 thinning of the stand due to fire. Brush keeps the soil in condition for 

 reproduction but, he says, injures as much as it aids the reproduction. 

 On this point there is room for argument ; in the northern Sierras brush 

 is the forerunner of a second forest. His attempts to find means of 

 eradicating the brush show the impossibility of doing so except by 

 shading. 



Sitka Spruce of Alaska. By Bruce E. HofTman. Vol. VIT, 



No. 2. 



This article contains silvical observations, chiefly on the occurrence, 

 form and reproduction of Sitka spruce; illuminating details of the lum- 

 ber industry in the vicinity of the Tongass National Forest ; and definite 

 recommendations for reconnaissance, timber sales and methods of cuttine. 

 At the end is a volume table based on diameter and average merchantable 

 length. It is the first detailed information of the tree and region pub- 

 lished. The article is an example of the manner in which American 

 foresters grapple with a new problem. 



V — Ecology. 



Plant Formations and Forest Types. By F. E. Clements. Vol. 



IV, No. I. 



Professor Clements does a marked service to the profession of forestry 

 by applying the principles of ecology to forest types. In so doing he lays 

 the foundation for a thoroughly scientific study of the relation of the 

 forest to its habitat. The result is that he gives a more stable starting 

 point from whence to attack the complex problem of determining forest 

 types. The article is indispensable for a proper understanding of forest 

 types. 



The Relation of Soil Acidity to Plant Societies. By Arthur W. 



Sampson. Vol. VII, No. i. 



This article is of interest not only to ecologists but to foresters. The 

 author has investigated in a scientific manner the effect of soil aciditj' and 

 of alkalinity upon the occurrence of plant societies. His discoveries re- 



