8 STATE BOARD OF FORESTRY. 



Root Development. The eucalypts use a great amount of water, hence 

 they prefer a deep soil, through which the roots may penetrate to lower 

 strata in search of greater supplies of moisture. In shallow soils over- 

 lying rock or hardpan the roots are forced to spread laterally, and on 

 such situations the growth is generally stunted and slow. 



In early years root development is exceedingly rapid, that of young 

 seedlings greatly exceeding the growth of the plant above the surface. 

 During early growth most eucalypts send down a taproot as well as 

 numerous spreading laterals. The taproot of the blue gum, at least, 

 rarely penetrates to a depth greater than 6 feet, further development 

 being concentrated in the strong laterals. 



The roots exhibit a strong impulse to seek water, and to reach it some- 

 times extend over 100 feet, crossing under ditches, pavements and roads. 

 If they gain access to pipes or ditches through cracks or breaks in the 

 masonry, they send out large masses of small feeding roots. Cisterns 

 and water-pipes have been completely clogged in this manner. 



Windfirmness. The production of an extensive lateral root system 

 renders the eucalypts very windfirm. Their strong anchorage in the 

 soil, combined with the flexibility of the growing stem, renders them 

 particularly valuable for windbreak purposes, since a break which will 

 yield before the force of the wind tends to deflect the air currents 

 upward, and protects areas far to leeward, whereas an unyielding 

 barrier breaks the wind only on areas in close proximity to it. 



Reproduction. The complete adaptability of the eucalypts to Cali- 

 fornia is especially shown by their strong reproduction here by both 

 seed and sprouts. 



Sprout Reproduction. All the eucalypts planted in California sprout 

 vigorously from the stump or roots after cutting or in response to any 

 injury to the tree. The small trees in young plantations generally 

 sprout up thriftily after they have been cut back by animals or after 

 saplings have been killed to the ground by frost or fire. After fire 

 injury also, in an attempt at ref oliation, the stems generally clothe 

 themselves thickly from the ground to the top with short sprout 

 branches like fire-injured redwoods. 



Whenever it is desirable to reproduce a species which possesses cop- 

 picing qualities advantage is generally taken of tttem. With most 

 species, however, the sprouts produced after the third or fourth cutting 

 are less thrifty than those after the first or second. This tendency to 

 weaken seems absent in the eucalypts, or if present, coppicing has 

 not been practiced long enough in California to reveal it. Fuelwood 



