110 FORESTRY [BoT. Absts., Vol. IX, 



contains 137 acres and has a complete forest cover on 97 per cent of the area, and the latter 

 contains 172 acres, of which 35 per cent is covered with forest and shrubs, 26 with willow, and 

 29 with alpine alder and spruce in meadows; 8 per cent is in meadow and 2 under cultivation. 

 Soil, vegetation, slope, elevation, springs, and all noticeable factors were considered. The 

 elevation varies from 912 to 1261 meters. On each watershed 3 rain guages were placed at 

 different elevations with a snow stake at each station. In addition, 8 snow stakes were estab- 

 lished in 1915, 4 on shaded slopes and 4 on sunny slopes. They were grouped in pairs under 

 mature conifers and hardwoods and young growth. These stakes were read- twice each week 

 at 8-9 in the morning. Temperatures were recorded at the stations of Kurzeneialp and Ried- 

 bad. Thermometers were placed on the shaded side of wooden buildings and read 3 times 

 daily. Stream flow was recorded automatically at each control station from April 16 to 

 November 30 of each year. The automatic recorders could not be depended upon during 

 freezing weather. Variations in underground drainage or supply of water are considered 

 negligible. The springs of the Rappengraben area (non-forested) are slightly stronger and 

 more constant. However, the run-off from the forested area (Sperbelgraben) was greater during 

 the dry summer periods than that of the non-forested (Rappengraben) area. The records show 

 a total of 4-5 per cent greater precipitation in the Rappengraben than in the Sperbelgraben ; 

 also, the former retained a cover of snow for 143 days, the latter only 121 days. These differ- 

 ences are attributed to the location of stations. The snow readings in the Rappengraben were 

 taken in a cove and are considered due to local conditions. Water content of the soil in the 

 Rappengraben was slightly less in summer and greater in the fall than in the Sperbelgraben. 

 The retention of water in the dry season is attributed to porosity of soil and prevention of 

 run-off due to soil looseness brought about by roots and forest animals ; and the smaller amount 

 of water in the soil of the forested area during wet seasons is attributed to the duff preventing 

 absorption after the humus and duff are wet, thereby causing greater run-off. — Individual 

 showers caused about 50 per cent more run-off on the Rappengraben than on Sperbelgraben 

 and the duration of run-off on the non-forested area was shorter. Evaporation from the forest 

 floor was 1230 cubic meters per hectare per year, and in the open 3690 per year. Transpiration 

 from the forest per year per hectare was 3000 cubic meters, from the meadow and cultivated 

 plants 1300, and from the willow areas 650. The disposition of precipitation is summed up 

 in the following tabulation: 



Sperbelgraben; Rappengraben; 



per cent of Precipitation per cent of Precipitation 



Run-off 59.3 61.9 



Evaporation from vegetation. . . 14.5 11.8 



Transpiration 18.9 8. 1 



Evaporation from ground 7.3 18.2 



100.0 100.0 



Erosion was greater in the non-forested area and the stream carried more silt. — J. V. 

 Hofmann. 



711. Gaj6n, Carlos. Una Acacia rica en tanina. [An Acacia rich in tannin.] Rev. 

 Agric. [Mexico] 5: 442-443. S fig. 1920. — A brief account is given of Acacia pycnantha 

 Benth., including botanical description, cultural directions, and analyses of the bark. — John 

 A. Stevenson. 



712. Henne, a. von. Einiges xiber den verteuerten Waldwegbau. [Concerning the cost 

 of forest road building.] Schweiz. Zeitschr. Forstw. 72: 129-140. 1921.— The cost of forest 

 road building has increased about 33 per cent during the last 25 years. Although wages have 

 increased as much as 92 per cent, transportation and other costs have increased only 23 per cent. 

 Forest roads should be built with a view to permanency, not only for the regions that they 

 traverse, but also as an outlet for adjoining regions and those farther back. Width should 

 not be sacrificed for length, although narrow roads of 2 meters width are sufficient for winter 

 sled roads. Wheel-traffic roads should be 2.5 meters wide with turnouts, or 3 meters wide. 

 Rocky and gravelly places should not be covered with rock surface except on main highways. 



