PLANT ASSOCIATIONS 229 



" Ecology of Woodland Plants," by T. W. Woodhead,* 

 and " Marsh Vegetation," by Professor Yapp,f should be 

 consulted. 



In a large district, where many associations exist, the 

 limits of each type should be recorded on a map, and 

 distinguished by some definite system of colouring, as 

 in the vegetation survey-maps of Smith, Moss, Lewis 

 and Pethyridge. 



The following summary of the associations and groups 

 of associations to be dealt with is taken, with slight 

 modification, from W. G. Smith's Botanical Survey of 

 Scotland: III. and IV. Forfar and Fife : 



A. Associations with a Water-Supply comparatively 

 rich in Plant-Food. 



I. Forest. 



1. Moist soils : 



(a) Oakwood - Associations. On non- 



peaty soils at low and moderate 

 elevations (p. 269). 



(b) Oak-Birch-Heath Association. On 



dry, coarse, sandy, and dry peaty 

 soils at low elevations (p. 271). 



(c) Birch wood - Association. On non- 



calcareous soils at high elevations 

 (p. 271). 



(d) Ash-Oakwood Association. On cal- 



careous clays, marls, impure lime- 

 stones, and calcareous sandstones 

 (p. 272). 



(e) Ashwood-Association. On limestones 



(p. 272). 



(/) Beech wood -Association. On chalk 

 in the south-east of England and 

 on oolite in the Cotswold Hills 

 (p 272). 



2. Wet soils : 



Alder and Willow-Thickets (p. 243). 



* Journal of the Linnean Society : Botany, vol. xxxvii., p. 333. 

 f Annals of Botany, vol. xxiii., p. 275 ; New Phytologist, vol. vii., 

 p. 61. 



