CHAP, vi.] Advantages of Mixed Woods 135 



possible, broad-leaved species of trees should be scattered, in sufficient 

 quantity and at convenient distances, throughout Spruce woods.' 



That similar drawbacks are also incidental to the formation of 

 too extensive pure crops of either cereals or roots in agricultural 

 utilization of the soil, may be seen by a reference to Fream's 

 Agriculture \ from which the following short extract may here 

 be given : 



' In other words, side by side with the excessive, or exclusive, cultiva- 

 tion of one kind of plant, the pests whether insects or fungi which 

 prey upon that plant may be expected to become more abundant, for 

 they find their victims literally crowded together, and therefore ex- 

 tremely accessible.' 



7. Natural Regeneration of Mixed Woods is on the whole 

 easier than in the case of Pure Crops. This is but of minor 

 importance compared with many of the other more substantial 

 advantages offered by mixed crops. It is due to the special 

 treatment and tending which must be bestowed on the crops 

 in order that, so far as possible, each species may be placed in 

 the natural conditions most favourable to its growth and further 

 development. With some attention given towards securing for 

 each kind of tree the soil and situation best adapted for it, 

 a healthier growth, and a richer production of seed are natural 

 results, owing to larger secretions of starchy reserves of surplus 

 nourishment. Hence regeneration from seed in small groups 

 and patches is comparatively easy, and is more likely to be 

 successful than when one single species predominates over 

 the whole woodland area notwithstanding the usually frequent 

 changes with regard to the depth of soil and the quantity of soil- 

 moisture. The species of tree which gains most in this way is 

 again the Spruce, which cannot usually be regenerated under 

 parent standards owing to danger of windfall ; but, when treated 

 thus in mixed crops, it can be reproduced without the danger 

 otherwise threatened to young seedling crops by weevils (Cur- 

 culionidae\ The natural regeneration of the other great shade- 



1 Elements of Agriculture, 4th edit. 1892, p. 333. 



