CHAPTER XXV 



MOORLAND ASSOCIATIONS 



THROTJGHOtTT the Country the term " moor " is applied 

 to ahnost any strefcoh of treeless, barren land. It may 

 be the wet peat-bogs of the uplands, the heather-clad 

 regions of hill-slopes, or the dry heaths of the lowlands. 

 The word, although used in apparently so wide a sense, 

 is, nevertheless, a good one, for all these areas have some- 

 thing in common. They aU occur on soil poor in nutri- 

 tive salts, and contain more or less humous acids. Peat 

 is present in all cases, varying in thickness from a few 

 inches on the dry grass-heath to 30 feet or more on the 

 wet cotton-grass bogs. It is the relative abundance of 

 peat which determines the character of the vegetation 

 of the moorland ; and the amount of peat in turn depends 

 upon the character of the underlying rock, the altitude, 

 and the rainfall. 



We saw in Chapter X. that vegetable remains are decom- 

 posed by bacteria, and, if the conditions are unfavourable 

 for their growth, peat will accumulate. The following 

 regions are those unsuited for the work of bacteria, and 

 it is in these places that peat is formed and moorland- 

 associations develop : 



1. In the lowlands where drainage is very bad, and 

 where the water becomes stagnant. This means a lack 

 of oxygen in the soil, whilst the evaporation from the 

 surface keeps it cold. 



2. At high altitudes where the temperature is low 

 for the greater part of the year. If this is combined with 

 a very heavy rainfall, bad drainage, and the accumula- 

 tion of stagnant water, the conditions for peat-formation 

 are intensified. It is under these circumstances that the 

 cotton-grass bog reaches its greatest development. 



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