INDEX 



Pages on which illustrations appear are indicated by boldface type. 



Abies, 267, 338, 339 



balsamea, 80 



halsamea-Picea canadensis forest, 

 109 

 Absorption, selective, in soils, 179 

 Abundance, 14, 26, 30 



determination of, 30 

 Acacia, 311 

 Acarospora, 291 

 Accessory species, 52 

 Acer negundo, 102 



platanoides, 105 



psetidoplatanus, 146 



saceharum, 109, 369 

 climax forest, 333 

 Acetabularia assn., 371 

 Achillea atrata, 15 



crustata, 205 



moschaia, 15 



tomentosa, 114 

 Acid humus, 250 

 Acidifying plants, 18, 28 

 Acidity, actual, 167 



specific, 167 

 Acidophilous indicators, 28 



plants, 18, 63, 167, 170, 190, 312, 

 315 

 invasion of, 315 

 roots of, 43 

 Aconitum, 276, 277 

 Actinometer, 104 

 Actinomyces scabies, 169 

 Adaptations, genotypic, 298 

 Adenia globosa, 296 

 Adenostyles, 124 



tomentosa, 264 

 Adenostylion, 240, 250 

 AdiantetaUa, 373 



Adiantion, 373 



Adiantum capillus veneris, 109, 373 

 Adoxa moschatcllina, 90, 91 

 Adsorption in soils, 164 



phenomena, 162 

 Adsorptively saturated humus, 250 

 Aegiceras, 201 

 Aerial roots, 296 

 Aeroplankton, 76, 289, 370 

 Aestival aspect, 48, 51 

 Agapetes vulgaris, 203 

 Aggressiveness, 316 



determination of, 13 



of plants, 13 

 Agropyretum, 67 

 Agropyrum, 152, 186 



curvifolium, 158 



elongatum, 197 



glaucum, 274 



junceum, 373 

 Agrostidetum tenuis, 300 

 Agrostis alba, 283, 318 



alpina, 71, 312 



canina, 190 



rupestris, 72, 119, 365 



meadows, 267 

 Air capacity, of forest soil, reduced by 

 cutting, 283 

 of soil, 214, 227 



determination of, 231 

 and succession, 228 



content of soil, annual variations 

 of, 229 

 Aira, 280, 289 



Airplane, use of, in mapping, 357 

 Ajuga pyramidalis, 120 



reptans, 50, 69 

 Alchemilla color ata, 71 



pentaphyllea, 123 

 Alectoria nigricans, 155 



ochroleuca, 155, 292 



407 



