133. 



About 90^ of the ash goes "back to the ground, or Ii;/l6 of the 

 salts in the leaves and twigs. This is a large proportion. In this 

 respect hardwoods are very good for the land. Conifers return about 1%^ 



The salts are given back to the ground regularly every ye?r, wit* 

 the leaf f.-.n. This is no fe^st and famine affnir. 



Much matter fro; fruits go to the ground, also, as with nuts, etc 

 T ey frequently are rich in nitrogen and phosphoric acid, and so give 

 the soil high grade material. Crops of fruits are repeated agnin and 



in. Begin, s^y, n,t 40 years. Then to 100 years of ag ; there may be 

 12 crops of fruit (5 year seed periods). This meaBs that loss of litter 

 in the forest is robbing the land. This is an import nnt extravagance. 



The forest protects the soil; it allows uniform chemical decom- 

 pos/ition of rocks and retards the leaching &&& of salts. 



, The forest adds organic material, aids soil life, aids the 

 water-he^, dim?; capacity of the soil, aids the production of compounds, 

 and aids chemic- 1 decomposition. 



The forest may add too much to the soil, as with Ca and clay. 

 7/hen the soil lacks lime, or when the climate is cold, as in the north- 

 west, trees may fail entirely to reproduce. 



. Forest and Soil Biology, 



The most important factors are temperature and moisture. 



ia. Boil temperature changes less in the forest than outside. 

 Forests have cool but even climates. This reduces the number of species 

 and the number of individuals, but keeps more uniform conditions than or 

 agricultural or bare land. 



b. Koist arid cool forest air favors plant and animal life in 

 the upper layer of the soil. It obviates the alternate f rests and hot 

 sun, etc. which are met with on fcare land. They are fewer but more regu- 

 lar. 



. In humid districts the soil is more moist in the forest; 

 in less humid districts the layer is less moist, perhaps because the 

 trees draw heavily on it for water supply. The forest also helps on 

 poorly drained lands, as on the verge of a swamp; it keeps them from 

 getting soggy and enables the soil to produce growth. 



cU The forest has a large body of fauna and flora above and 

 below the ground. It is inhabited by thousands of insects and fungi, etc 

 It thus bears more or less relation to the surrounding fauna and flora. 

 Log tops are breeding grounds for many species. The cleaner a forest is 

 kept the more this condition disappears. 



M) Kind and Condition of Forest in relation to Soil. 

 JL. Individual tree of scattered stand. 



a,. The seedling is of little consequence to the soil. Kinds 

 differ in importance. One seedling is not very essential in its effect. 

 A 2- year oak seedling has more effect on the soil than a 2- year spruce. 

 An oak seedling has already a big root system, and produces a tilling 

 effect, besides the leaves it drops for mulch. 



b.. Young tree J-20 feet high; There is considerable tillage 

 by the roots. Little mulch is supplied. The crown is being shaped during 



