





1900. 



AMERICAN FORESTRY ASSOCIATION. 



303 



in the first application of scientific forestry 

 to our national lands. The Black Hills 

 Reserve, on which this examination has 

 been made, contains 1,211,680 acres. No 

 other tract of its size in this country or 

 abroad presents more favorable conditions 

 for forest management than this Reserve. 

 Markets are accessible on all sides, and 

 there is a large and steady demand for 

 timber. The forest, too, reproduces itself 

 easily and grows with great rapidity, so 

 that, although cutting and burning have 

 gone on in some places, the problem which 

 is presented is not, as in southern Cali- 

 fornia, that of fostering a scanty growth 

 and creating forest conditions, but rather 

 of utilizing and caring for an already well- 

 established forest. 



In the course of the summer's work a 

 large part of the Reserve- was examine.], 

 and on 12,000 acres exact figures were col- 

 lected regarding the si/.e and kind ,,f all 

 standing trees. From such measurements 

 estimates of the present stand and future 

 yield of timber can be compiled, and on 

 these the recommendations for the man- 

 agement of the reserve will be based. 

 ^ After leaving the Black Hills Mr. 

 Griffith and his student assistants went to 

 southern Missouri, where* they are now 

 beginning similar field work on a lar-e 

 tract of hardwood land belonging to the 

 Deering Harvester Company. This com- 

 pany, which applied for a working plan 

 last spring, has undertaken the raising of 

 timber for its own use. 



AMONG AMERICAN AND FOREIGN PERIODICALS. 



A very interesting and valuable publication 

 has just been received in the form of a reprint 

 from the Vierteljahresschrift des Bayerischcn 

 Landwirthschaftsrathcs on The Influence of 

 Plant Covet upon the tt'aterflow of Rivets, by 

 Prof. Dr. E. Wolluey in Munich. Although 

 so many observations and theories are in ex- 

 .stence on this subject, the opinions of many 

 distinguished individuals widely differ. The 

 :ause of it, sa^s Professor Wollney, is mainly 

 iue to unreliable methods of investigation. 

 Little information of value has resulted from 

 noting the changes in the rate of waterflow in 

 :onnection with the extent and nature of wooded 

 surfaces. It is clear that, owing to the many 

 r actors involved, the problem can never be thus 

 satisfactorily solved. Other factors than forest 

 :over effect the waterflow, such as the nature of 

 he soil, incline, shape of basin, waterfalls, etc. 

 [n comparing bare with forested surfaces, re- 

 gions have often been rated as naked which 

 ,vere covered with weeds and other growths. 



Professor Wollney states that in this discussion 

 single causative influences will be studied from 

 ,vhich to draw conclusions which are not abso- 

 ute data but helps in affording acquaintance 

 vith the different phenomena connected with 

 .he problem of waterflow. 



He speaks with right of the immense impor- 

 ance of the subject especially to agriculture. 



The great desideratum is to know how it may 

 )e possible to decrease floods and prevent ex- 

 reme low water. Whatever is done to ditnin- 

 sh high water fortunately acts favorably in ref- 

 :rence to low water. As a rule agriculturists 



growth keeps the soil moist since the covering 

 shades the ground and protects it from the dry- 

 ing effects of wind and sun. This is only so in 

 so far as it relates to direct evaporation by sun 

 and wind from the surface. A process of dry- 

 ing out occurs through the action of vegetation 

 so that a region covered with plants during 

 vegetative activity contains less moisture than 

 a naked soil. This is due to the large consump- 

 tion of water by plant growth. Although the 

 surface of a forest soil may be uioister, the act- 

 ual water content of a naked soil is greater. 

 The soil under a forest cover dries out down to 

 a much greater depth than bare soil. 



An unplanted soil covered with litter is during 

 dry seasons of the year much inoistcr than bare 

 ground. Utter however stimulates the gmwth 

 of trees, which causes greater demands lor moist 

 ure. The value of litter diniinislics as tin- 

 growth and transpiration increase. Kvei greens 

 transpire throughout tin- year, deciduous trees 

 for a shorter period of more intense gmwth. 

 By the year, however, tlu- conifers Iran- 

 more than deciduous species. 



In slioit, Professor \\'nllncv coin-hides th it toi 

 ests do not in any way ai-tu.illy increase the 

 amount of water in the soil hv piodneing lain or 

 by preventing evaporation ; that in fact lln-ii ben- 

 eficial influences in these mattets are mote than 

 counter-balanced by the immense amount <>l 

 water transpired by the leaves. 



Next he considers the influence of plant covei 



on the debt is earnu-e o! llo\\ in 



covered slopes assist in preventi u l>ut in 



less degree than a forest cover. Hi- concli 



1 1,., t 1.1 ;,t..o ,,f <-... ri 1i ..ii.l 1 1 >) i! i- i HI si i -i- 1 1 si ones arc 



