CLIMATE AND TREE GROWTH 105 



during the first twenty years or so. But after that stage 

 persistent wind, a clouded sky, and the absence of intense 

 insolation tend to check the height, growth, and develop- 

 ment of most species, and the result is a diminutive yield 

 of timber per acre, in a rotation of eighty or a hundred 

 years, compared with that obtained in continental 

 forests. On cold soils and exposed situations this diminu- 

 tion is most marked, while in sheltered valleys and warm 

 soils it may disappear altogether. But the average 

 growth of a large number of plantations will certainly show 

 it if carefully observed, whatever may be the numerous 

 theories held on this subject by various authorities. 



To the planter of trees, no doubt, the British climate is 

 decidedly favourable. Cold and wet springs and summers, 

 though not universal, are certainly common enough 

 to give the planter a fair measure of success, provided 

 he takes reasonable precautions, and avoids the common 

 mistake of planting trees, which, through root exposure 

 and other causes, are practically dead already. Mild 

 Avinters induce root action to proceed more or less from 

 October to March, and the absence of long spells of dry, 

 cold wind prevent the withering process to which plants 

 are liable when their root systems have been interfered 

 with. The planting season in Britain, therefore, is not 

 only long, but is carried on under more favourable con- 

 ditions than in many parts of Europe. Possibly its 

 favourable character in this respect is responsible for that 

 general carelessness which seems to permeate nursery and 

 planting work in this country. Liberties are taken in the 

 lifting, handling, packing, transit, and replanting of trees 

 which can only be attributed to ignorance on the one 

 hand, or to a great confidence in luck on the other, but 

 these matters will be more fully dealt with elsewhere. 

 The general absence of snow and frost for long periods 

 enables planting operations to be carried on from October 



