TREES ADAPTED. 113 



There are three classes of fire-lines : 



(a) Bare spaces left when planting, or cut down in existing 



plantations. 



(b} The exclusion of conifers. 

 (c) The planting (alone) of certain deciduous trees less 



inflammable than others. 



In the first case there is unnecessary waste of space, 

 and also the extra labour periodically of cutting away 

 the growth of heather or gorse which will grow freely 

 where there are no trees, and which, if left, will feed 

 the fire as well as the fir trees, and prove a danger 

 instead of a preventive. This plan, therefore, we do 

 not recommend. 



The second plan may be resorted to with success. 

 The deciduous trees may be planted the same as in 

 the rest of the area, but the nursing conifers excluded 

 or, which is still better, the third plan may be 

 adopted, viz., that of selecting certain deciduous trees 

 suitable to the soil and site, but less inflammable than 

 others. These are as follows : Maples, sycamore, 

 alder, hornbeam, walnut, ash, plane, poplars, and birch. 

 The direction and width of the lines is somewhat 

 difficult to define, and must be left to the discretion of 

 the forester or agent. They should run as far as 

 possible across the line of prevailing wind ; but, when 

 the area is narrow, they should take the direction of 

 the shortest length. 



This plan will serve to check the advance of a con- 

 flagration more completely than if the lines are taken 

 along the greatest extent. 



A further preventive will be found in good manage- 

 ment when fir plantations are carefully thinned, and 



H 



