PRELIMINARY OPERATIONS 165 



which is ultimately to cover the ground, the spaces 

 should be smaller. In places where winds or floods 

 and landslips are to be feared, and especially in wind- 

 belts, the plants should come up sufficiently dense to 

 offer a strong resistance. A poor soil will not be able 

 to raise a very dense growth, but as the soil improves 

 under cover it is better to err on the side of denseness. 

 Spacing will also depend on whether seeds or trans- 

 plants are put in. As the prospect of success is much 

 smaller with seeds than with plants, the lining should 

 be much closer for the former ; and the stronger and 

 more vigorous the transplants are the greater the 

 spacing that can be given to them. 



As it is necessary to know how many lining-pegs 

 will be required, and, later, how much seed or how 

 many plants will have to be provided according to the 

 pattern and distance between the plants selected, certain 

 formulae are employed for calculating these numbers, 

 which give very fairly satisfactory results. It is, 

 however, always good to have some reserve either of 

 seed or of plants over and above the number calculated 

 to provide for rejections in the field, for it will always 

 happen that a certain proportion of the seed will turn 

 out bad or that some of the seedlings will be misshapen 

 or injured in lifting or in transport to the field. 



Let N be the number of planting or sowing spots, 

 L the length of the piece of land to be afforested, and 

 W its width, let d represent the number of planting 

 or sowing spots in a line, and D the distance between 

 the lines. 



In the square pattern the distance between the 

 lines is the same as that between the spots in the lines, 

 i.e. d = J) and 



-(!H(^)-(< L +>)(>)-^*>- 



In the "rectangular" pattern d is not = D, and the 

 formula is, therefore : 



L,,yw ,\ LW L w 



