40 VEGETATION OF THE PEAK DISTRICT [cH. 
13. Birch-pine woods with B. alba; B. pubescens and Pinus 
sylvestris var. scottica sharing dominance. Local and 
confined to mid-Scotland. 
14. Pine woods with Pinus sylvestris var. scottica dominant. 
Local and confined to mid-Scotland. 
III.. AsH AND BreecH Assocrations. On calcareous soils. 
G. On deep marls or calcareous clays. 
15. Ash-oak woods with Frasinus excelsior and Quercus Robur 
sharing dominance. Abundant in the south of England. 
Usually coppiced. 
H. On shallow calcareous soils on hill slopes of the fissured limestone 
rocks. 
16. Ash woods with Frasinus excelsior dominant. Frequent in 
the west and north of England up to about 1000 feet 
(305 m.), and local on the chalk. 
17. Ash-birch woods with Fraxinus excelsior and Betula pubescens 
sharing dominance. Local on the upper slopes of hills of 
Carboniferous Limestone in the north of England. 
I. On shallow and very calcareous soils on chalk rock. 
18. Beech woods with Fagus sylvatica dominant. Frequent on 
the chalk escarpments in south-eastern England. 
WooDLAND ASSOCIATIONS OF THE SOUTHERN PENNINES 
Of the woodland associations above enumerated, two are 
well developed on the southern Pennines, and three others are 
only moderately well represented. The two former are the 
association of Quercus sessiliflora on damp, shallow, siliceous 
soils, and the association of Frazxinus excelstor on shallow 
calcareous soils; and these woods are described in some detail 
in this chapter. The woods which are only moderately well 
represented on the southern Pennines are the association of 
Quercus Robur on deep sandy soils, the association of Betula 
pubescens on damp, shallow, siliceous soils, and the alder-willow 
thickets of stream sides. Some transitional and intermediate 
‘woods also occur, and these will be referred to in the proper places. 
The relationships of these associations may be conveniently 
set out in the following form :— 
Alnus glutinosa and Salix spp. ALDER-WILLOW 
dominant THICKETS 
Quercus Robur dominant 
Woops WITH Ls sessiliflora dominant } Oak woods Oak AND 
A J BirRcH Woops 
Betula pubescens dominant Birch woods 
Fraxinus excelsior dominant ASH WOODS 
