ES Pe eo Og SENET Ee SRR ee 
PLANT ASSOCIATIONS. - 29 
shady, and richer in humus, its undergrowth is more abundant 
In species, particularly of the bulbous and_ early-flowering 
kinds. The undergrowth of the beech is limited for two 
reasons: (1) The beech can grow in situations with much less 
light than the oak, and as it has a very thick crown when its 
leaves are fully out, it lets through very little light ; (2) its 
leaves decay slowly—not nearly as rapidly as those of the oak— 
therefore suitable soil is much more slowly formed. It follows 
that the undergrowth will consist mainly of two classes of 
plants: (a) Spring-flowering plants, which come out and 
blossom before the leaves of the beech are fully out; and 
(5) plants which live on decaying vegetable matter, and are 
therefore independent of light. The number of spring flowers 
found in a beech-wood depends on the closeness of the trees. 
Where they are crowded there is hardly anything to be found ; 
where the wood has been thinned the ground will be thickly 
covered with early spring flowers, such as Dog’s Mercury, 
Anemones, etc. In summer saprophytic plants—e.y., Bird’s- 
nest orchis—will be found in those beech-woods where the 
soil is rich in humus from the decaying leaves of several 
years (Appendix B). | 
Pasture In England, and probably in North Europe 
_ Vegetation. senerally, what is now pasture land was originally 
woodland, and if left to themselves pastures would revert 
to woods and forests. The vegetation of pasture land is 
limited in variety, and depends largely on the animals 
that are turned out to graze ; it is stated that the goat nibbles 
more closely than any other animal, and destroys every seed- 
ling that comes in its way. The herbs of a pasture are far less 
humerous than those of a meadow, especially in the case 
of a meadow given up to turf grass. A pasture is usually 
drier and higher than a meadow, and the smaller amount of 
moisture very much affects the character of the vegetation. 
Meadow Meadows are usually low-lying, often containing 
Vegetation. good deal of water, but the ground-water does 
not come so high as in a swamp or marsh, and the water flows 
more, so that a meadow is more or less drained, whilst a 
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