34 Pasture Problems 



on drift usually having a slightly higher percentage of Lolium perenne 

 and Poa trivialis than their counterparts on shales, whilst Ranunculus 

 acris and Lotus major are generally included in the flora. 



It will be sufficient here to draw two main distinctions between 

 the lowland pastures (below 200'-300') on alluvia, gravel, or drift: 



(a) Permanent pastures on well-drained alluvia or on gravel. 



(b) Permanent pastures on ill-drained alluvia or on drift. 



(a) Permanent pastures (below 300') on well-drained alluvia or 

 gravel. This type is the equivalent (although much poorer) of the 

 famous grasslands of Leicestershire and Northamptonshire^ and those 

 locally met with in Somersetshire and other counties. There is httle 

 or no difference to be seen in the herbage between those 20-50 and 

 50-100 or more years down, provided they are manured and stocked 

 on a uniform plan. It is difficult therefore to decide if these should 

 be classed as natural or semi-natural. In these districts, however, 

 the evidence goes to show that when neglected they do actually alter 

 in the direction of semi-natural to natural types, that is to say in an 

 ehmination of species. 



In practice the best are seldom neglected; they are heavily grazed 

 with stock assisted with cake and manured at regular intervals — 

 consequently the husbandry becomes a predominant and constant 

 environment factor which largely counterbalances purely natural 

 tendencies and makes for a secondary stability^. The effect of this 

 constant factor of judicious husbandry is to maintain a favourable 

 ratio of desirable indigenous herbage {Lolium perenne, Poa trivialis, etc.) 

 to undesirable (Agrostis alba and weeds). In the districts under review 

 on well-tended fields the chief contributing species with their cardinal 

 figures are : 



Lolium perenne (3. 9. 22) Agrostis alba et vars. (3. 15. 25) 



Poa trivialis (1. 4. 9) Phleum pratense distributed 



P. pratensis (1. 3. 8) Alopecurus pratensis local 



Festuca rubra (2. 5. 13) Bromus mollis* et spp. local, occasion- 

 Cynosurus cristatus (6. 9. 11) ally reaches 17 



Dactylis glomerata* (2. 6. 20) Leguminosae chiefly Trifolium repeals 

 Holcus lanatus* (2. 7. 13) (8. 19. 36) 



Anthoxanthum odorafum. (2. 4. 9) Miscellaneous plants (3. 9. 17) 

 * The maximum figures are reached under meadow conditions. 



Comparison of the above synopsis with that given for permanent 

 pastures derived from heaths, shows that Agrostis alba has definitely 



^ Cf. Smith and Crampton (13), p. 4. 



