500 JOURNAL OF FORESTRY 



same time most scathing and sarcastic, account of the doings of the 

 Development Commission, appearing in the Timber Trades Journal, 

 purporting to be the commission's report for the year 1950, by which 

 time every town was supposed to have secured a forest school, but 

 reforestation schemes or other use of the education were frowned 

 upon. There are now more than a dozen schools teaching forestry. 



Transactions of the Royal Scottish Arboricultural Society, January, 1917, pp. 

 1-13. 



SOIL, WATER, AND CLIMATE 



Succession from soil exhaustion implies an 

 Woodland anti-climax or going back. The ordinary direc- 



Succession from tion of succession is forward. Thus succession 

 Soil Bxlvaiistion following a forest fire is usually due to soil im- 

 provement from the reaction of the vegetation 

 itself. The direction of development in vegetation is usually toward 

 the highest type of mesophytism possible under the prevailing climatic 

 conditions. This is progressive development from bare areas to climax. 

 Clements and others have recently questioned whether regressive suc- 

 cession exists in the same sense as progressive succession. Nielsson, 

 Cajander, Cowles, Moss, and others, in their discussion of this subject, 

 infer that retrogression is usually due to local conditions bringing 

 about the destruction of a particular stage in the succession, but in 

 all cases this does not appear to be true. This destruction often occurs 

 again and again at any stage of succession in many separate places, 

 and as a result there is, over the whole area, a mosaic of the so-called 

 "regressive" areas with the progressive areas. 



Succession is fundamentally a process of development. Clements 

 contends that in the so-called regressive succession there are no proc- 

 esses of development at all. They are rather examples of the initia- 

 tion of progressive development in consequence of destruction. 



There are, no doubt, many instances of the change of a forest 

 vegetation into a lower type of vegetation. Such is the conversion of 

 the forest into scrub, heath, grass-land, or swamp. Evidence of the 

 change of forest into grass-land or heath is obtained wherever lum- 

 bering, grazing, and cultivation have been practiced for long periods. 

 There is no doubt, however, but the usual conversion of forest to 



