CHAP. CX11I. CONl'FERjE. y/BIE'TIN^E. 2135 



Thinning and Felling. Thinning ought to be carried on in connexion with 

 pruning; and, when large timber is to be produced, this is no less necessary 

 in the case of the vibietinae than in that of the broad-leaved trees ; though 

 the former, from their narrow conical shapes and great height, do not require 

 so much room as the latter. The advantages derived from thinning will be 

 shown in a striking manner from actual practice in Britain, when we come 

 to treat of the larch. 



The pine and fir tribe, not being trees that stole, are never cultivated as 

 coppice-wood ; and when a grove of pines is felled, the roots ought to be 

 taken up, in order to clear the way for the succeeding crop. In the German 

 and French works on the culture of the ^bietinae, there is much difference 



mode is considered the best, another point arises for discussion ; which is, 

 whether the smaller trees are to be taken out, so as to leave room for the 

 large ones to grow larger, which is called exploitation par eclaircies ; or 

 the larger ones removed to leave room for the small ones to increase in 

 size, which is called exploitation en jardinant. In the Dictionnaire des Eaux 

 et Forets, a comparative view is given of these two modes, and the preference 

 is given to the first ; but both, it is alleged, are inferior to the mode of cutting 

 down the entire grove or forest at once ; and this seems the most rational, 

 because, when the air is once let in to a grove of full-grown pines, they 

 seldom increase much in size afterwards ; doubtless, from the influence of 

 the weather on their naked trunks, which have, till then, been shaded and 

 protected by the evergreen branches of the trees that have been removed. 

 Deciduous trees, as they never receive so much protection from one another, 

 never suffer so much from thinning, whether when young, or when mature 

 and fit for felling as timber. The season for felling the Jbietinae is during 

 winter ; but in the Alps and the Pyrenees, and also in the north of Sweden 

 and Norway, where the ground is covered with snow for six or seven months 

 in the year, the trees are cut during summer. It is alleged that the wood 

 felled during the latter season, from the greater quantity of sap con- 

 tained in it, must necessarily be less durable than that felled when the sap 

 is dormant. This, however, must chiefly apply to the sap wood ; because 

 the heart wood, which alone is used for important purposes, is not pene- 

 trated by the ascending or descending sap. After the trees are felled, the 

 roots are dug up, broken into small pieces, and distilled for tar; or burned 

 in covered heaps for that product jointly with charcoal. 



In situations naturally adapted for the progress of pines and firs, the self- 

 sown seeds keep up a perpetual succession of the same species for an un- 

 known period : but when the plantation is cut down before the trees have 

 shed abundance of seeds; or where, from being an artificial plantation of 

 trees all planted at the same time, the ground is so completely shaded, 

 as to prevent the vegetation of the seeds which may have dropped on it ; 

 or where the soil is not naturally congenial to the Abietinse; in any of 

 these cases, this order ought to be succeeded by another totally different 

 from it, but at the same time suitable for the soil. Many authors have 

 observed that native woods, both in England and America, when cut down, 

 are generally succeeded by a different kind of tree (see Gard. Mag., \. 

 p. 421.); and others, that pine forests, when destroyed accidentally by fire, 

 in America, are usually succeeded by oak. M. Le Comte of Riceborough, 

 Georgia, has for upwards of thirty years paid great attention to the subject 

 of the natural succession of woods ; and the following are the results of his 

 observations respecting pine forests: "The pine lands in the southern 

 states have generally old oak grubs, which, by reason of the periodical fires, 

 are prevented from becoming trees, notwithstanding which they still continue 

 alive (see p. 1891.); and when land is turned out (that is, when the culti- 

 vation of it is relinquished), the pines, being naturally unproductive of 



