INDEX 



Acidic humus, 55, 56 

 Acidic soils, 37 

 Afforestation, 211 

 Alder, 49, 70 



Alder societies in woods, 70 

 Alder-willow thickets, 58 

 Alkaline soils, 37 

 Alluvial fen, 105 

 Alluvium, River, 10 

 Altitude, Effect of, 174 

 Altitudinal limit of aquatic plants, 154, 

 156, 159 



grassland, 103, 104 



scrub, 88 



trees, 38, 88 



trees, past and present, 88 



woodland, 44 



wheat cultivation, 205 

 Aquatic associations. Marsh and, 144 

 Aquatic plants, Altitudinal limits of, 



154, 156, 159 

 Arable land, 204 

 Ash (see also Willow), 52, 69 



Cultivation of, 67 



Germination of seeds of, 67 



Mountain, 50 

 Ash Woods, Absence of oak from, 70 



Damp places in the, 72 



Dry places in the, 72 



of Fraxinus excelsior, 65 



Ground vegetation of the, 71 



Herbaceous vegetation of the, 71 



Trees and Shrubs of the, 69 

 Aspects of associations, Seasonal, 20 

 Associations, Aquatic and Marsh, 144 



Chief, 21 



Closed, 20, 21 



Culture, 199 



Facies of, 20 



Grassland, 103 



Intermediate, 20, 125 



Mixed, 21 



Moorland, 163 



Open, 20 



Passage, 125 



Plant, 19 



Progressive, 20 



Pure, 21 



Retrogressive, 21 

 of rocks and screes, 134 

 Scrub, 88 



Seasonal aspects of, 20 

 Siliceous and calcareous soils, 133 

 Siliceous soils, 133, 215 

 Stable, 20 

 Subordinate, 21 

 Succession of, 20, 94 

 Transitional, 183, 186 

 Unstable, 20 

 Woodland, 38 

 Atmosphere, Humidity of the, 34 

 Temperature of the upper, 28 

 Upper, 27 



Bare peat, 191 



Barley, Cultivation of, 205 



Basalt, 9 



Basic soils, 37 



Beech, 49, 68, 70 



Germination of seeds of, 49 

 Betula (see Birch) 

 Betuletum pubescentis, 61 

 Bilberry, 52 



Bilberry moors, 166, 182 

 Birch, Common, 48, 70 

 Birch and Oak woods, 60 

 Birch forest. Primitive, 63 

 Birch societies in oak woods, 49 

 Birch, White, 49, 70 

 Birch woods of Betula pubescens, 59 

 Birch woods. Ground vegetation of, 62 



Scots pine in the ancient, 48, 64 

 Birdcherry, 51 

 Blackberry, 51 

 Blackthorn, 51 

 Bleaklow Hill, 104, 193 

 Bog moss (Sphagnum), 166, 184 

 Bogs (see Moors) 

 Bog xerophytes, 145, 174 

 Boulder clay, 9 

 Bracken, Requirements of, 108 

 Bramble, 51 

 Brier, 51 



British moors, 166, 220 

 British plant formations and associa- 

 tions. Summary of, 218 



15—3 



