1 6 transactions of royal scottish arboricultural society. 



The Classification of Woodlands. 



We now pass on to consider more closely the types of 

 wood distinguished by the authors of the " Woodlands of 

 England." 1 The primary grouping is into three series : (i) The 

 Alder-Willow series, characterised by a very wet soil; {2) The 

 Oak and Birch series, characteristic of siliceous soils with a 

 low proportion of lime ; (3) The Beech and Ash series, character- 

 istic of soils which contain a considerable proportion of lime. 

 These three series are as a rule easily distinguished from each 

 other, but it must be understood that they may pass gradually 

 into one another. Within the second and third series the 

 woods are subdivided into other types which are called 

 " associations." 



(i) Alder-Willoiv Series. — These woods occur at low elevations 

 in valleys and where water moves slowly. At one time they 

 covered large areas in the larger vales, but as extensive 

 drainage proceeded they were converted into arable land, 

 heavy-soiled but fertile from the accumulation of deep fine 

 clays with much mineral matter. At present the best examples 

 of alder-woods are found in the Norfolk Broads, but smaller 

 fragments may be seen in many places, especially where low- 

 lying lands are liable to frequent floods. Alder and several 

 species of willow are the most frequent trees, but some oak 

 may occur, and ash is sometimes quite abundant. The 

 ground-vegetation is characterised by the taller sedges {Carex 

 paniculata and C. pendula), cuckoo flower {Cartiamine), marsh 

 marigold {Caltha palustHs), forget-me-not {Myosotis pahcstris), 

 yellow iris, queen of the meadow, tussock grass and reeds. 

 In the Cleveland district of Yorkshire, we have seen these woods 

 covering wet valley slopes on boulder clay, and there the 

 alder is encouraged and periodically coppiced as it furnishes 

 timber for clog soles and yields a good return. 



(2) Oak and Birch Series. — The distribution of woods of this 

 kind is on all siliceous {i.e. non-calcareous) soils, ranging from 

 the stiffest clays, through the various loams, to the sands and 

 gravels and soils derived from sandstones of various ages, as 

 well as on soils derived from grits, mudstones, shales, and 

 various acidic igneous rocks. As limestones and other calcareous 



' This pari is taken almost entirely from that paper, hence quotation 

 marks can be dispensed with. Only a few plants of the ground-vegetation 

 are referred to, the full lists being available in the original paper. 



