1310 ENCYCLOPAEDIA OF AGRICULTURE. mntxum. 



of which they can push down their roots, tarchei thrive to admiration. The geognostic character of the 

 country Irom Dunkeld to itl.ii r is primitive. At Blair If gneUs; al Dunkeld, clay ilate ; ami the inter- 

 mediate (pace is occupied by mica ilate : they lie conformably to one another. 



•>J7'i. Situation. Xne advantages resulting from planting mountain ground appear at first sight. In the 

 greater number of trees that may be supported on the acclivity of a mountain than on a surface equal to 

 it ^ bate. Trees derive nourishment from the soil Immediately around the place In which they are fixed; 



ami. a> the luperflciet of that soil must, of course, be greater on an acclivity than on the base, a greater 

 number of trees will be there supported. Practically speaking, 100 trees, at six feet apart, can be planted 

 on the hypothenusc of a right-angled triangle, whereas the base would only permit eighty at the same 

 distance. Another and a great advantage derived from planting mountain ground is, that, on an acclivity 

 the trees expose a greater surface to the influence of the sun, and air, and rain, than they ean do on a 

 level surface. That trees derive much nourishment from the air, through the instrumentality of their 

 leave., there is no doubt. The experiment of taking the bark from fifty standing larches, in May, 1811, 

 at Dunkeld. did not prevent their vegetation, and even forming wood for two years alter. The outside 

 trees in a forest are always the strongest. On an acclivity, they all possess the advantages of outside 

 trees; and at the same time, most of the shelter enjoyed by those in the interior." (Highland Soc. 

 Trims., vol. xi. p. I85.) 



B377. Nurtet were not used by the late Duke in his larch plantation. The gardener, in the Duke's 

 absence, planted some acres with a mixture of Scotch pine and larch ; but so far were the former from 

 nursing the latter, that at the end of seventeen years they had not attained a height exceeding three feet ; 

 while the larches which they were intended to nurse were from fifteen to twenty feet high. 



s-jT-v The growth of the larch. Taking the average height of an average larch, of eight years from the 

 seed, at eleven feet, it will be nearly accurate to allow sixteen inches as the annual growth, till the tree 

 i> liny years old, and after that only ten inches per annum for twenty-two years longer ; as the length of 

 the tree lessens in growth as the bulk of the wood increases. These data give a larch tree of seventy- 

 two years of age a height of ninety-three feet four inches : a fair average, agreeing with actual experi- 

 ment. The shoots of larches beyond thirty-five years of age are heavier, though they are not so long 

 as those of younger trees. The larch, like the oak, puts forth two shoots every year, the one in spring, 

 the other in autumn. The spring shoot has no lateral branches : the autumnal shoot pushes out like 

 the spring one ; but, at the time this process is going on, the spring one is throwing out lateral branches 

 which are linn and woody. 



v.'?'.'. In regard to the growth of the girth, a larch tree, on an average, will acquire an inch in girth per 

 annum, till it be twenty-four years old ; and from that time, till it has acquired the venerable age of 

 mi enty-two years, it will grow one inch and a quarter in girth every year , thus : — 

 In 24 years, it will be 2 feet in girth, at 1 inch per annum. 

 48 years more, 5 feet in girth, at l£ inch per annum. 



In 72 years, it will be 7 feet. 

 8280. The larch begins to make wood at twenty-four years of age, 

 At SO years old it will contain 26 cubic feet of wood. 

 60 — 14 ditto more. 



72 — 20 ditto more. 



In all, 60 ditto, or one load of 50 cubic feet, and 10 feet more, 

 R281. Thes; results correspond exactly with the quantities which the Duke obtained at these respective 

 ages. Larch appears to be on its greatest increase for timber from fifty-seven to seventy-two years old. 

 A larch containing fifty cubic feet, or one load of timber, is quite fit for naval purposes. At half that 

 size it is suitable for every country purpose. 



8282. Thinning larch plantations. The great object of the Duke, in planting the larch, seems to have 

 been to raise timber for naval purposes ; and, finding that larches grow to a great size at only twelve feet 

 apart, he thinned accordingly. This distance gives 380 trees to the Scotch acre, or about one tilth of the 

 2000 originally planted. " The first thinning should consistof a lightone of about one fifth of the whole, 

 by removing only those trees that are of least value or worthless. After twenty-four years from the time 

 01 planting, the spines fall off the lower branches, which are, of course, no longer useful to the soil below. 

 From twenty to thirty years old, then, the thinning is carried on so extensively, as to remove two thirds 

 of that which was left standing by the first thinning. In thinning, it is necessary to observe that all the 

 strongest and healthiest trees should be left, even if two or three of them should be closer together than 

 twelve feet. These small clumps happening to light on a favourable situation, they will thrive well, as 

 the air has access to each tree, around two thirds of its circumference. This thinning being delayed so 

 long, the trees thinned out will be valuable for a variety of purposes. One of these purposes is the pro- 

 fitable use which may be made of the bark. The la.-t thinning should be given when the trees are from 

 thirty to thirty-five years old, which will leave from 380 to 400 trees per acre." 



8283. Pruning the larch. Little or no pruning was used in the larch plantations at Dunkeld. The 380 

 trees left in the acre, it is observed, " will require a little pruning and trimming of the lower branches, 

 in order to give head room to the cattle, which are to browse on the grass below. The whole primings 

 and thinnings will cost about 5/., and their produce will fetch about 12/., leaving a profit on them of about 

 "I. an acre." (Highland Soc. Trans., vol. xi. p. 190. t 



-~jst. Thin planting the larch is recommended by the late Duke of Athol, because it allows the lower 

 branches to extend to a greater size; and on these depend the thickness of the base of the trunk of the 

 tree, and the strength of its roots. He therefore seldom planted more than 2000 plants per acre, more 

 especially in elevated regions. 



8285. The process of the thickening of the soil, and the improvement of the past are, by the larch, being very 

 important in its results, it deserves to be particularly described. The lower and stronger branches meet 

 together in six or seven years after planting, so as to form a complete matting over the ground. The air 

 and light being excluded by them, all plants that are under them die. At the same time, the annual 

 deposit of leaves from them, by means of decomposition, forms, in the course of time, a soil of con- 

 siderable depth. At the age of twenty-four, the larches lose the spines on the lower branches altogether, 

 and that is the natural mark of their being ready to be removed by thinning, to a considerable extent. 

 On the air being readmitted by the removal of the trees, the surface of the new-made soil, wherever it 

 has been formed, even among the rocks, becomes immediately covered with natural grasses, of which 

 the //oleus mollis and //. lanatus seem to predominate. These grasses continue to grow, and to thicken 

 into a sward, by the annual top-dressing which they receive from a continued deposition of leaves. The 

 Improvement of the natural surface of the ground for pasturage, by means of the larch, appears to be a 

 property peculiar to this tree. This pasturage is quite capable of improving the condition of cattle, either 

 in winter or summer. 



B286. With regard to other trees effecting a change of the ground, the following are the results of many 

 experiments made by the Duke on the subject. In oak copses, the value of the pasture is only 5s. or 6s 

 per acre for eight years only in every twenty-four years, when the copse is cut down again. Under a 

 Scotch fir plantation, the grass is not worth 6rf. more per acre than it was before it was planted. Under 

 beech and spruce it is worth less than it was before ; but the spruce affords excellent shelter to cattle, 

 either from the heat of summer or the cold of winter. Under ash the value may be 2.v. or 3s. per acre 

 more than it was in its natural state. But under larch, where the ground was not worth Is. per acre, 

 the pasture is worth from 8s. to 10& per acre, alter the first thirty years, when all the thinnings have 



