19G 



INDEX. 



Meteorology, forest — Coiifinned. 



run-off intiuenced by topograiiliy, 113, 

 water capacity of soils, 144. 

 of litters, 147. 



water conductivity of soils, filtration, 148. 

 influence of grass cover upon tiltratiou, IjO. 

 of otlier covers, J 51. 

 of snow, roots of trees, 152. 

 of utMilogiiiil stratiflration, formation of 

 sinings, conditions atfectinu; tlieir flow, 153. 

 influence of forests upon surface drainage, 157. 

 retardation of water flow. l.")8, 

 J'lencb Alps experience, 159. 

 Mis.si.ssippi bad lands. I.'i9. 

 influence of forests on water How, examples 



of 1C2. 

 cft'cct of removal of forests in tbe Adirondac 



region, 165. 

 in tlie basin of tbe Schuylkill, IGC. 

 in New Hampsliire, 1G7. 

 in other States, 108. 

 Moisture, quantity of: 



returned into the atmosphere from a forest by 

 transiiiration and fvapoiation from trees 

 and soil, 16. (See Humidity.) 

 Miittrich, Dr., influence of growing forests upon 



rainfall, 113. 

 Nancy, France, results of observations on influ- 

 ence of forests upon precipitation, 108, 112. I'JG. 

 Observations on forest meteorology : France, 27, 

 108,111.126; Germany, 30, 40, 51, 61, 96, 107, 113, 

 134.146,149; Sweden, 31; Austria, 33. 

 Parks, city, value ot, 173. 

 Plains, temperature in, 83. 



Precipitation : 



over wooded and treeless districts. 111. 



Dr. I.orey's table, 113. 



influence of forests upon, 125. 



results of observations in Bohemia, 126. 



results of observations near Nancy, France, 

 126. 



results of observations in India and Brazil, 

 128. 



su pi)Osed influence of forests upon hailstorms, 

 121, 129. 



determination of the true amount of precipi- 

 tation and its bearing on theories of forest 

 influences, 175. 

 Hain, not the most satisfactory form of watcravail- 

 able for human use, 12. 



Rainfall : 



in, above, and near forests, IOC. 



Becquerel's observations. 111. 



measurements, relation of pattern and alti- 

 tude of gauge to accuracy of, 176. 



variations in geographical distiibution of 182. 



chronological variations of, 184. 



analysis of the causes of, with special relation 

 to surface conditions, 187. 



Eaingauge: 



elimination of errors of the, 135. 

 instrumental methods, 180. 

 observational methods, 181. 



Sanitary influence of forests : 



in production of oxygen and ozone, 21. 



Sanit.ary influence of forests— Continued. 



by protection against sun and wind, 21. 



by unfavorable effect upon microbes, 21. 



notes on, 171. 

 Snow : 



influence. of forests on melting of, 20, 152. 



influence on climate and weather, 23. 



influence on percolation and drainage, 152. 

 Soil conuilioiis, inflmnie of forests ujwn, 20, 4J. 

 Soil temperatures, 14,40. 



ditterences of, 87. {See Temporalure.) 

 Springs, their formation and conditions aflectiug 



their flow, 153. 

 Storms, forests, wind, and, 118. 

 Summary of conclusions as to forest influeucca, 



13. 

 Sweden : 



results of observations on forest meteorology 

 by Dr. H. E. Hauiberg, 31, 84. 

 Temperatures, air: 



under, within, and abovetree crowns, 14, 61. 



in woods, glade.*, and plains, 15, 83. 



in neighboring forest and open field stations, 

 19,51. 



mont hly range, German observations, 53. 



in deciduous and evergreen forests, 58. 



in tree crowns and above trees compared with 

 open fields, 01. " 



gradients, 68. 



above forests and near ground, ditt'erciice be- 

 tween evergreen and detiduous trees, 70. 



ditterences between tree and air, 74. 



relation to transpiration, 76. 



theoretical calculation of heat absorption, 80. 



conclusions regarding temperatures within 

 and without forests, 88. 



temperatures in wooded and treeless territo- 

 ries, 89. 



Dr. Woeikoff's conclusions, 91. 



temperatures near parallels of latitude, 92. 

 Temperatures, soil: 



in forests and open field.^, 40. 



mean annual dift'erences, tables of, 41, 44, 45. 



comparison of effect of evergreen and decidu- 

 ous ti'ees on, 47. 



influence of elevation, 48. 



ellectsoflitTer, 43,49. 



diiference under sod and bare surface, 50. 



differences inside and outside of a forest, 50. 



temperatures, tree, Geneva observations, 72. 

 Torrents in the French Alps, 159. 

 Transpiration: 



moisture returned to atmosphere by, 16, 19. 



its relation to temperature, 76. 



to evaporation, 77. 



iurtne-ice of light on, 77. 



amount of, with diflerent plants, 78. 



.imount transpired by evergreen and decidu- 

 ous trees and various species compared, 79. 



variation from day to day and with the sea- 

 sons, 80. 



beat absorbed in, 81. 



amount of water in trees, 136. 

 Trees : 



temperature in the tree crown and above 

 trees, 61. 



