BRITISH FOREST TREES 245 



moist soil, is suited for its growth, as the ash is, so to speak, 

 discriminating and particular in its choice ; where other 

 species fail to find a sufficiency of nutriment to stimulate 

 them to good growth, attempts with the ash may at once be 

 given up, and needless time and trouble spared. 



Its root-system requires depth and a fair degree of 

 porosity of soil for its proper development, whilst a due 

 supply of moisture is necessary both in the soil and the 

 subsoil ; but stagnating subsoil moisture is unsuited and 

 detrimental to it, unless combined with a full enjoyment of 

 genial summer warmth stimulating the foliage to increased 

 evaporation and transpiration from the leaves. Sandy soils, 

 unless moist, are in general unfavourable to it : it thrives 

 best on strong, rich, loose, mineral soil, and is altogether in 

 this respect one of the most exacting species of our forest 

 trees. 



Requirements as to Light. On the whole the ash must at 

 least be classed along with the oak with regard to its 

 demands for light, although its foliage is sparser and lighter. 

 Growing generally only on the best classes of sylvicultural 

 soils, it often appears to be more capable of bearing shade 

 than is actually the case under ordinary average circum- 

 stances. As it approaches maturity, its requirements in 

 this respect increase, although throughout the earlier stages 

 of growth it can often thrive under standards with a light 

 canopy, when such is necessary to protect it against frost. 



Attainment of Maturity and Reproductive Capacity. 

 Occurring usually as scattered individuals in forests of shade- 

 bearing species, and of beech in particular, the ash must be 

 privileged at every time of thinning, and of course rapidly 

 increases in girth and in cubic contents. Sylvicultural con- 

 siderations, however, demand its reino\al In-fore reproductive 

 measures are to be carried out for the whole forest, so that 

 it is seldom allowed to attain an age beyond eighty to 



