Heaths of North-east Yorkshire 111 



6. Midland heaths. The heaths occurring on light 

 soils in the Midlands have not been investigated. The 

 natural vegetation of the Lower Greensand of the eastern 

 Midlands appears to be essentially similar to that of 

 the Weald. Dry oakwood, degenerating into heath, and 

 extensive sub-spontaneous pinewoods are present. Some 

 of this country is however properly forested — notably the 

 Duke of Bedford's estate at Woburn. 



The vegetation of the Bunter sandstone of Sherwood 

 Forest in Nottinghamshire and Delamere Forest in 

 Cheshire also consists of oak-birch heath, grass heath 

 and Callunetum. 



7. The heaths of north-east Yorkshire. These have 

 been studied by W. Gr. Smith, whose results are still 

 unpublished. The following account is based on material 

 supplied by him. 



The heaths of this area are situated on the plateau of 

 the Oolite massif and have an average elevation of about 

 1250 feet (c. 380 m.) descending to 800 feet (c. 244 m.) 

 on the North Sea coast. They are developed on a few 

 inches of humous sand, covered by 2 or 3 inches of sandy 

 peat, and passing down into sand, derived mainly from the 

 Bstuarine sandstones, but partly from the " Calcareous 

 grit" and other sandstones of the Oolite series. The 

 greater part of this upland heath is free from glacial 

 deposits. 



These heaths, like all the upland areas dominated by 

 Calluna in the north of England and Scotland, are called 

 " moors " and are used for the preservation and shooting 

 of grouse (Lagopus scotictis), but over the warmer sandy 

 soils which cover most of the area there is rarely any 

 great extent of deep peat, so that the substratum is that 

 of the heath formation. 



The mean annual rainfall of these uplands is about 

 35 iuches (c. 90 mm.). The climate is fairly dry during 

 the growing season but decidedly damper than that of 



