This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
An interesting feature of meadow vegetation is the resemblance it presents to the types of plants to be distinguished in a woodland. These consist of a tree zone, the highest, with a lower stratum of scrub, and the ground flora or lowest stratum. It is probable that the tree type, which usually has a more or less even or level upper surface, has its normal level regulated by the effect of wind, and where the wood is dense by the effect of the close grouping of the ultimate branches.
The lower zones are regulated by the influence of light, and by the adaptation of the plants to the overlying zones of tree and scrub, and, of course, the character of the soil, etc.
The same factors regulate the association of the three tiers in a meadow. The Grasses represent the tree zone, and their height may be largely said to be regulated by the influence of the wind. As a rule, the Grasses are of the same height generally, but there are giants (as amongst the trees) such as Tussock Grass, and dwarfs, as Annual Meadow Grass.
The scrub zone may be said to be represented by such plants as thistles, which (like scrub) have a more close-set spreading habit than the tree type, here the Grasses. The ground flora is made up of trailers, such as the Yellow Cinquefoil, frequent also on roadsides and banks, and rosette plants, such as the Daisy. In the case of these their close or open character is due to the effect of the two higher zones, or overcrowding and the dominance of sturdier plants, apart from main causes such as soil.
An interesting inquiry may here be set on foot as to the chief plants in each zone, and at different points vertical sections may be made from the highest to the lowest zone to show the relation of one to the others, especially in relation to the amount of light.
The types of meadow along the coast, in the lowlands and in the highlands, on nearly bare rocks or upon thick soils, may be studied in relation to height, and compared.