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 
