43 Studies in Forestry [CHAP. n. 



are now to be found forming pure forests in countries where 

 attention has been paid to the most recent developments of 

 scientific sylviculture ; for the tendency is now rather towards 

 the formation and maintenance of mixed woods as combining 

 important sylvicultural and financial advantages. But, if entirely 

 left to themselves, certain species of forest-trees will ultimately 

 suppress and eliminate most other kinds over tracts of soil 

 better suited to the former than to the latter. Evelyn was to 

 a certain extent aware of this more than two hundred years 

 ago, when he remarked, in one of his letters published in 

 Aubrey's Surrey, that : 



'Where goodly Oak grew, and were cut down by my grandfather 

 almost a hundred years since, is now altogether Beech ; and where my 

 brother has extirpated the Beech there rises Birch.' 



What might just be expected happens. The shade-bearing 

 and densely-shading species Beech, Spruce, Silver Fir, and in 

 a less degree Hornbeam and Black Pines assert themselves 

 over large tracts; whilst other kinds of trees of woodland 

 growth are ousted, and occur merely as subordinate clumps, 

 or groups, or patches, or as individuals scattered here and 

 there over areas and situations unsuited for the predominating 

 species, either on account of the nature of the soil or situation, 

 or for some reason connected therewith (frost, want of moisture, 

 shallowness of soil, &c.). There can, of course, never be rigid 

 lines marking off the domain of the various species ; for there 

 must always, in consequence of the various factors connected 

 with the physical conditions of soil and situation, be belts of 

 land where the advantage lies sometimes with one species and 

 sometimes with the other. At the present time on the continent 

 one has many opportunities of seeing how, in consequence of 

 bad management and of servitudes, under wru'ch the peasants 

 were entitled to rob the woodlands of their soil-protecting 

 layer of dead foliage, the domain of the Oak and the Beech 

 is being encroached on by the Pine and the Spruce, which are 

 both more easily satisfied as to soil and situation ; whilst these 



