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SUMMARY

.The vegetation of the Huddersfield district is naturally divided into three parallel zones :-

(1) The Moss Moor, a part of the Pennines ranging in altitude from 1700 to 1000 feet. Of the three zones it is the most exposed, the climatic conditions are extreme, the soil consists chiefly of deep ill-drained peat, on which Eriophorum vaginaturn dominates with very few associates. On the higher, drier ridges and moor-edges, VacciniumMyrtillus with ericnceous plants are dominant. Though now 1mxtically a treeless region, there is much evidence that forests of Betida &c. extended over a considerable part of it, and much buried timber is found at the base of the peat. At the present time Quercus dies out at 1200 feet. A characteristic vegetation of Pteris aquilina with xerophyte associates covers the hill-slopes and forms a transition region to Zone 2 .

(2) THE Millstoxe-Grit Plateau occupies the central portion of the dktrict, and the altitude ranges from 1000 t o 500 feet. In contrast to the Moss Moor, it consists of a series of fine plateilus with it general dip to the south-east. The rocks consist mainly of coarse-grained, jointed sandstones, overlaid by shallow pervious soils and i n parts by thin, reliitively dry pent. It is fully exposed to the Bun and drying east winds, and although the rainfall i8 moderately high (42 inches), water SO readily percolates or is drained off that i t is a typical, physio- logically dry area, and the vegetation is consequently xerophytic; ericxeous plants and xerophytic grasses dominating. Oak is the domiriant tree, with Birch and Pine. All the trees arc planted, but often o n the sites of primitive forest, and Oak was formerly much more abundant than a t present in this zone.

3) The Coal - Measure Area-III general the altitude ranges from 600 to 200 feet, except to the south-east, where it rises to 1200 feet. The rocks consist of fine-grained sandstones alternating with extensive deposits of shales and clays. The soils are often deep, frequently covered with much humus, and retain much water. Climatic conditions are medium, and nlthougli the rainfall is much lower (33 inches) than in Zone 2, owing to t h e nature of the soil water is more constant and the vegetation is mesophytic, except on soils over sandstone and in the higher parts, where xerophytes extend from the Gritstone Plateau.