376 REPORT ON LARCH FORESTS. 



of them dying, those on the loose gravel were growing luxuri- 

 antly, making top shoots from eighteen to twenty inches annually. 

 In this case nothing evidently could produce the difference of 

 growth except the loose, open state of the gravel. Three years 

 ago the writer's attention was drawn to two plantations in 

 Morayshire, situated upon the banks of the Findhorn. The 

 one, ten years old, w^as formed partly upon the sloping bank of 

 the river, extending from south to north in the course of the 

 river, and backwards upon the table-land at top. The trees 

 upon the slope were growing vigorously, while those upon the 

 flat ground were making little progress. On examining the soil 

 and subsoil, it was found that the sloping bank consisted of a 

 loose, open sandy gravel, mixed with a little clay, while that on 

 the flat ground was similarly composed, but was firm and solid. 

 The other at the time referred to was fifteen years old. On the 

 side facing the south the trees were doing well ; while upon the 

 side facing the north they were making very little progress the 

 bark was black, and the whole trees covered with Coccus laricis. 



On taking a general look at the plantation, it was difficult to 

 account for the inferiority of growth ; but on digging up the soil 

 the cause soon appeared. The surface soil having been washed 

 and crumbled off, left almost nothing for the roots to subsist 

 upon, the subsoil being hard, compact masses of gravel and 

 moor-pan. On the opposite side of the glen the larches were 

 growing well, and will so continue till the roots enter the hard 

 subsoil, which occurrence will be greatly determined by the 

 future mode of thinning adopted. The above cases illustrate 

 the necessity of examining carefully even unsuspected soils 

 previous to planting. 



Next to moss and gravel, clay is considered the most unsuit- 

 able for the growth of larch. Drainage may render the soil dry, 

 but it does not sufficiently divide the earthy particles, so as to 

 admit the spreading of the tender roots. Another, and proba- 

 bly the most fatal result of clay soils, wet or dry, consists in 

 the premature and sudden decay of the roots. It appears that 

 the roots of larch grown upon clay soils, which grow luxuriantly 

 for several years, varying from ten to twenty-five, according to 

 circumstances, are of too soft and spongy formation to endure long; 

 hence they suddenly decay, and the tree, in consequence, withers 

 and dies. The temperature of damp clay soils is also too low 

 for the healthy development of larch, and injuriously affects it at 

 all stages of growth. It is on this account probably, more than 

 any other, that flat fertile districts are less adapted to grow 

 larch than precipitous mountain tracts. Much of the failure of 

 larch is due to it having been planted on cold clay soils. 



The comparative absence of rosin in the roots of the larch is 

 one of the chief causes of ground-rot (pumping), dry-rot, &c. 



