INDEX 



429 



Polytrichum, sexangularc, 29, 120, 122, 



310 

 Populetum albae, 377 

 Populion albae, 377 

 Populus delloides, 141, 151 

 assn., 217 



nigra, 268 



tremula, 17 



tremuloides, 350 

 Pore volume of soil, 213, 226 

 Posidonia, 194 



Post-glacial forest, of Europe, 339, 340 

 Potametalia, 371, 374 

 Potamion eurosibiricum, 60, 364, 374 

 Potamogeton, 76 



fluitans, 374 



lucens, 60, 290 



pusillus, 290 

 Potentilla arenaria, 66, 343 



aurea, 71, 120, 365 



caulescens, 187, 373 



crantzii, 71 



puberula, 343 



visiana, 189 

 Potentilletalia, 371, 373 

 Potentillion caulescentis, 110, 373 

 Poterium spinosum, 274 

 Pozzines, 349, 350 

 Prairie, evaporation in, 142 



fires, influence of, 282 



Madagascar, 282 



vegetation, 328 

 Precipitation, 112 



annual, of Alps, 114 



contrasts in, 112 



: evaporation ratio, 143 



(See also Rainfall, Snow, Dew) 

 Preferential species, 59 

 Presence and constancy, 53 



definition of, 52 



degrees of, 53 



determination of, 53, 66 

 Preslia cervini-Heleocharis assn., 375 

 Preslion cervini, 375 

 Prevernal aspect, 47 

 Primary successions, 325 

 Primitive terminal communities, 334 

 Primula, 291 



Profiles, soil, 45, 164, 173, 189 

 Progression, sociological, 367 



Protected plants, 7, 8, 9 

 Protective colloid, 163 

 Protococcus, 109, 291 

 Province, definition of, 355 

 Prunus, 89, 318, 338 



avium, 61, 69 



mahaleb, 183 

 Psammic soils, 160 

 Psammogenous rocks, 160 

 Pseudotsuga taxifolia, 262 



forest, 267 

 Psychrometer, 132 

 Pteridium, 290 

 Pteridotherophytes, 289 

 Pteris aquilina, 105 



incisa, 203 

 Puccinia fusca, 69 

 Pulicaria dysenterica, 351 

 Putrefaction in soils, 243 



Q 



Quadrats, 28 

 of seedlings, 15 



permanent, 14, 15, 328, 329, 330 

 QuercetaUa pubescentis, 377 



ilicis, 377 

 Querceto-Betuletum, 314 



-Carpinetum, 314 

 Quercetum cocciferae, 50, 326 



iUcis, 326, 377 

 Quercion ilicis, 324, 377 

 pubescentis, 324, 377 

 roboris sessiliflorae, 324 

 Quercus borealis, 141, 217 

 cocci/era, 45, 50, 105, 130 

 assn., 282 

 garigue, 50, 51 

 scrub, 284, 326 

 garryana, 95 



ilex, 45, 86, 109, 115, 130, 174, 192, 

 245, 284 

 forest, 42, 175, 279, 284, 377 

 macchia, 115, 130, 366 

 reproduction, 175 

 maroccana forest, 133 

 mirbeckii, 74 

 forest, 133 

 pedunculata, 69, 125, 170, 351 

 -Carpinus betulus forest, 283 



