i22 C. E. Moss, W. M. Rankin and A. G. Tanstey. 
association in a relatively dry climate, may bear a “damp” type of 
woodland in a very moist climate. 
The Classification of English Woodlands. 
We may now turn to a consideration of the main types of 
natural and semi-natural woodland that can be distinguished in this 
country. 
Three main series may he recognized, namely, (I) the Alder- 
Willow Series, (II) the Oai< and Birch Series, and (III) the 
Beech and Ash Series. The woods which belong to the first series 
are characterised by a very wet soil: those which belong to the 
second series are characteristic of siliceous soils whose proportion 
of lime is low; and those which belong to the third series are 
characteristic of soils which contain a considerable proportion of 
lime. In the bottoms of river valleys, the woods of the first series 
often pass gradually into those of the second and third series; and 
at comparatively high altitudes (300 metres), the woods of the second 
and third series exhibit a tendency to assume similar features; but, 
in general, the three series are well-defined, easily distinguished, 
and sharply marked off from each other. 
I.—Alder-Willow Series. 
From the nature of the situations in which they are found, 
woods of this series do not now cover wide tracts of country, though 
it is probable that before the extensive drainage and cultivation of 
alluvial regions they were both numerous and extensive. The 
examples of these woods which still continue here and there, always 
at low levels, as along the banks of the slow streams of the New 
Forest, in the remoter valleys and lowland peat moors of the north 
of England, and in the fens of Norfolk, furnish some idea of the 
constitution of the primitive wet woodlands of the country. 
The material for a proper understanding of the composition of 
this series is fragmentary; but what there is to hand points to the 
conclusion that the series includes at least two distinct plant 
associations. Thus the “carrs” of Norfolk, which are fed by 
alkaline and calcareous waters, harbour several woody species, 
such as Rhainnus catliarticus and Viburnum Lantana , which are 
characteristic of chalky and limestone soils; while such “ calcicole ” 
