ROTATION" OF FORESTS 



223 



bushes and gain the mastery. Sometimes the area grows 

 to poplars or birches, and people wonder why the origi- 

 nal forest trees <1<> not return; but these forest trees may 

 l)r growing unobserved here and there in the tangle, and in 

 the slow processi - 

 of time tlic poplars 

 perish fortheyare 

 short - lived and 

 the original foresl 

 may be replaced. 

 Whether one kind 

 of foresl or another 

 rel urns will depend 

 largely on the kinds 

 which arc most 

 seedfu 1 in that 

 vicinity and which, 

 t h e re t o re, have 

 s o w d themselves 

 mosl p ro f u s ely. 

 Much depends, 

 also, on the kind 

 of ii n dergro wl h 

 which firs! spriii 

 a 1 1, for some young 

 i rees can endure 





farmer i 



more or less shade than others. Pigs. 373 ami 3" I Bhow 

 two stages in the return to forest. 



364. Pasturing and mowing tend to k< <p an ana in 

 grass. This is because the grass will thrive when the lops 

 arc repeatedlj taken off, whereas trees will uot. Note 

 that the wild herbs and bushes and trees persist along the 

 fences and about old buildings, where animals and mowing 

 machines <l<> not lake them off. I sod society annus <; 

 in 1 1 or mowing. Consider Figs. 9 , 376. The tanner 



