278 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCTETY. 
dry soil, planted on the stiffest and most tenacious of clays, while 
those that would flourish, and attain to large dimensions, on stiff 
ground are planted on the lightest of gravelly or sandy soils. 
What wonder then if, in such cases, planting should result in 
comparative failure? The nature of the soil, therefore, is the most 
important consideration when the formation of a plantation is 
contemplated. 
Another consideration of scarcely less importance is that of 
the climate, which may be influenced by the nature of the soil, 
configuration of the district, altitude, proximity to the ocean, 
exposure, aspect, etc. The effect of elevation on the growth 
of trees is very noticeable. It is well known that as we ascend in 
height the temperature gradually and regularly decreases, and trees 
thriving at the foot of a mountain will not be found at the top. 
Even in a country possessing so little variation in height as our 
own, this effect is well seen. Abundant proof of this natural 
distribution of trees is to be seen in the forest remains found 
embedded in existing peat mosses. The low fertile ground is 
seen to have been covered with oaks, while the pine, birch, and 
willow had occupied the high elevations. It is only by an 
approximation to this natural distribution that we can hope to 
attain to great success. The greatest height at which the Scots fir 
is said to grow is 2000 feet above sea-level, but it cannot be 
expected to grow to timber size at such an elevation. Probably 
700 feet is the utmost limit at which timber can be profitably 
grown within 12 miles of the sea-coast. ‘Trees are said to thrive 
at a higher elevation in Perthshire than anywhere else in Scotland. 
This is no doubt owing to the distribution of the mountain ranges, 
and the perfect immunity from sea blasts enjoyed by that county. 
Taking the county of Aberdeen as an example, it may be noticed 
that more difficulty is likely to be experienced in forming planta- 
tions at an elevation of 400 feet in the Buchan district of the 
county, than would be the case at twice that elevation in the 
western part along the hill-sides of the Dee and Don. The reason 
is obvious. Buchan is fully exposed, both on the north and east, 
to the sea blast, the damaging effect of which is noticeable at least 
12 miles inland. Owing to its situation, the western part of the 
county is not affected by the sea, the hill ranges being so situated 
as to break the force of the storm, and rob the wind of much of 
the saline matter so fatal to certain classes of trees. Hence timber 
can be grown at a much greater elevation in this part of the county. 
