TEMPORARY AND PERMANENT BOISEMENT, 77 



and restore to the exhausted soil, the substances withdrawn from 

 the air by their leaves [1] or from the subsoil by their roots. It 

 supplies us with one of the main instances in agriculture in which 

 time is of more value than money. With a great outlay in fertilizing 

 a poor soil, the return may be uncertain or even ruinous to the 

 cultivator. If, on the contrary, it be expended on hoisement, or plan- 

 tation of trees, where time is money, you attain your end by improv- 

 ing the fertility, and at the same time you produce the amelioration 

 by a money return. It is only in the case of very good soil that 

 time is here worth more than money. 



" Permiuient or definite boisement. — Temporary hoisement makes the 

 poor soil of Sologne produce every year, pines, rye, and buckwheat. 

 Permanent hoisement excludes agriculture, and the annual produce is 

 exclusively that of the forest. This is obtained by mixing the oak, 

 bii*ch, and chesnut, with the pine, the coppice regime of which trees 

 follows the exploitation of the last named tree. In Sologne both 

 systems have both advocates and assailants. Unfortunately, discus- 

 sion will not decide the point, and we do not as yet possess sufficient 

 data to enable us to do so. But if we look at the subject from a philan- 

 thropic point of view, the first is to be preferred, because, instead of 

 producing alone fire-wood and charcoal, it furnishes cereals, over and 

 above, to a population at pi'esent obliged to have recourse to the im- 

 portation of these from a distance. 



" Soiuings of pines along tvith other trees. — The maritime pine when 

 grown by itself is treated as has been already detailed. When 

 mixed with other trees there are no very important modifications 

 of this. It acts as a shelter to coppice woods of oak, birch, and 

 chestnut. These coppice woods continue growing while the pines 

 remain, but they do not become really productive until after the 

 exploitation of these. Instead of passing abruptly and completely 

 from the culture of the pine wood, to that of the coppice woods of 

 deciduous trees, there are sometimes left haliveaux, or standards, 

 of maritime pines. In this way we have there a coppice of oak and 

 birch under a timber forest of pines. This method is only to be 

 adopted on soil which is very favourable to the pine. 



" For mixed hoisements it does not signify whether the soil is quite 

 suited to the pine or not. The good of the trees which will per- 

 manently occupy the soil is more to be consulted. In any case, 

 where the sand is shallow, Scots firs should be preferred. 



" The trees to be mixed with pines should be, first, the red oak, on 

 stiff clay ; second, the white oak, on argilo-silicious soils ; third, the 



