760 JOURNAL OF FORESTRY 



der proposed, can be made to apply to a large region, but that each 

 locality will have certain plants that indicate the character of the dif- 

 ferent sites, which may or may not be common to other localities. 

 He illustrates by discussing the vegetation under the forests in the 

 districts of Betzigau, Ottobeuren, Sachsenried, and Denklingen, which 

 is the optimum spruce region in Bavaria and possibly in all Germany, 

 with yields far above the average for Quality I. sites. Indicator plants 

 show particularly the humus conditions, i. e., whether the soils are 

 mild, with normal decomposition of humus, or whether they are be- 

 coming acid with raw humus. Such plants may be guide-plants, prac- 

 tically always found on a particular kind of soil ; accessory indicators, 

 frequently present but often missing; and regional indicators, found 

 only in certain regions. Plants indicative of mild soils are Oxalis 

 acetosella, Aspenda odorata, Impatiens noli-nie-tangere, Galium ro- 

 tundifolium, Elymus europaeus. Milium effusum, Brachypodium sil- 

 vaticum, Carex silvatica, Catharinea undulata, Mnium undulatum. 

 Hypniim spp. Indicators of beginning or continuing raw humus for- 

 mation are : Vaccinium myrtillus, Fcstuca silvatica, Lyco podium an- 

 notinum, Polytrichum formosum, Dicranum scoparium. This mat- 

 ter deserves much more attention from forest investigators, since it 

 has a very direct bearing upon silvicultural practice, especially in con- 

 nection with natural reproduction and with methods of thinning. 



W. N. S. 



Rubner, K. Forstliche Standortsgewdchse im ziVs'tUchen Mordnengebiet Bay- 

 ems. Forstwiss. Centralbl. 42 : 135-144, 1920. 



MENSURATION, FINANCE, AND MANAGEMENT 



S. H. Howard proposes to apply Von Mantel's 

 Formula for formula to selection forests as the basis for de- 

 Selcction ■ termining the cut. Shorn of all more compli- 

 Forests. cated discussions and formulae, the proposed for- 



mula, Annual cut = j^, is identical with that 

 of Von Mantel, Annual cut = i^, except that the volume in the new 

 formula is that for the last half of the rotation instead of for the entire 

 rotation. 



The erroneous but practical assumption underlying Von Mantel's 

 formula, that mean annual growth equals current annual growth in 

 each year, hence that the volume of a series of age classes is repre- 



