ANNUAL INCREMENT OF SPRUCE AND SCOTS PINE. 1 63 



growing season of these trees was probably due to the deep, 

 peaty soil in which they were growing — a soil which would 

 take some time to dry and warm in the early summer. This 

 surmise is certainly borne out by the second season's observa- 

 tions, as owing to the exceptionally warm and dry weather the 

 soil was in a condition favourable for growth fully three weeks 

 earlier than in 19 lo, and it remained in an almost equally 

 favourable condition right on until September. 



The spruce in Plantation K are under observation for the 

 first time this season, and consequently no comparison can be 

 made with a previous year. 



In Plantation D (spruce) there is a slight falling off in the 

 average increase in girth — -675 inches as compared with 

 •712 inches. No. 3 in this lot shows the largest individual 

 increase in girth (r25 inches) of any of the trees under 

 observation. The current annual increment has remained 

 practicallv stationary at 93 cub. feet per acre as compared with 

 91 cub. feet. The percentage rate of growth was 6'58 % as 

 compared with 6-98 %. 



The Scots pine in Plantation I show a marked falling off in 

 girth-increment as compared with 1910, averaging only -'260 inches 

 as against -587 inches. The current annual increment has fallen 

 from 67 cub. feet to 46 cub. feet per acre, and the percentage 

 rate of growth from 4-27 % to 2-59 %. The spruce in the same 

 plantation show a decrease in girth-increment from -687 inches 

 to "525 inches, the percentage being 3-54 % as against 4'i6 %. 



At first sight these results appear to be inconsistent with 

 those obtained in Plantation K where the warm and dry summer 

 produced increased growth. In the case of Plantation I, 

 however, it will be noticed that the crop is a thin one of 

 280 stems per acre. They are situated on a considerable slope, 

 and the soil is naturally of a rather dry nature. All these 

 conditions, but more especially the thinness of the crop and 

 the resulting want of canopy, have caused the ground to suffer 

 from a lack of moisture to a much greater extent than would 

 have otherwise been the case, The results are, as might be 

 expected, much more marked in the case of the light-demanding 

 Scots pine than in that of the heavier canopied spruce, although 

 the latter crop is also too thin. There is quite a strong growth 

 of surface vegetation below the Scots pine, while such growth 

 is almost absent below the spruce. If these deductions are 



