46 



tion of a large portion of the rainfall, and second, the retardation of the flew of the re- 

 mainder towards the great reservoir and source of all, in accordance with the observation 

 of the Hebrew preacher, ' All the rivers run into the sea ; yet the sea is not full ; for 

 unto the place from whence the rivers come thither they return again.' " 



There is another operation, noticed by Becquerel, to which sufficient importance has 

 not, until very recently, been generally ascribed, namely, the mechanical action of roots 

 as conductors of the superfluous humidity of the superficial earth to lower strata. " The 

 roots of trees," says he, " often penetrate through subsoil almost impervious to water, 

 and in such cases the moisture, which would otherwise remain above the subsoil, and 

 convert the surface earth into a bog, follows the root downwards, and escapes into more 

 porous strata, or is received by subterranean canals or reservoirs. When the forest is 

 felled the roots perish and decay, the orifices opened by them are soon obstructed, and 

 the water, after having saturated the vegetable earth, stagnates on the surface and trans- 

 forms it into ponds and morasses. Thus, in La Brenne, a tract of 200,000 acres, resting 

 on an impermeable subsoil of argillaceous earth, which ten centuries ago was covered 

 with forests, interspersed with fertile and salubrious meadows, has been converted by the 

 destruction of the woods into a vast expanse of pestilential pools and marshes. In Sologne 

 the same cause has withdrawn from cultivation and human habitation not less than 

 1,100,000 acres of ground, once well-wooded, well-drained and productive." 



From the Ebpoet of John Ednie Brown, Esq., Conservator of Forests, to the 

 Parliament of South Australia: — 



That large bodies of trees have a direct influence on the atmospheric changes of a 

 district or country is, I think, in these days of so much statistical and other reliable in- 

 formation, now a recognized fact. If we look back and examine ancient, medieval, and 

 modern history, we there find many very noted examples of decrease of rains, dried up 

 rivers, extended deserts and depleted populations, simply from the clearing of extensive 

 forests ; while again, on the other hand, it has been observed that where large tracts of 

 country have been laid under a crop of trees, and which previous to this having been 

 done were designated dry and comparatively unproductive parts, small streams of water 

 have been found where none formerly existed, and the general nature of the districts 

 has been improved to such an extent that they have become highly favourable for agri- 

 cultural purposes, and hence more able to sustain an increased population." 



1. "Trees give Shelter: — In the agricultural parts of this colony, especially in the 

 northern areas, where e!xtensive tracts of most excellent country are open to every blast 

 of wind that blows, it is self-evident that the planting of belts of trees in different direc- 

 tions through them would have a most beneficial influence on the crops which are pro- 

 duced upon the ground. The direct results of such belts would be that the hot winds, 

 which at present are the very scourge of the country so far as their effects upon vegeta- 

 tion are concerned, would, if they were not in time subdued altogether, be at all events 

 considerably softened by coming in contact with the cooler atmosphere arising from the 

 damper surface of the ground shaded by trees, and therefore pass harmlessly over the 

 country ; and thus the crops would not only be more certain, but would grow more luxu- 

 riantly, and consequently the yield would be proportionately larger. Again, another 

 important result which would arise to the agricultural community from the planting of 

 trees on the plains would be, that shelter would be given to stock, both from the hot 

 winds of summer, and the storms and cold blasts of winter." 



2. " Forests Prevent Evcvporation : — It is, perhaps, almost superfluous to remark that 

 very great evaporations take place all over the colony at all seasons of the year, from the 

 thoroughly exposed character of the country generally to the full power of the sun's 

 rays. In consequence of this, what rain falls upon the ground is, ahnost as soon as it 

 reaches the ground, again taken up into the air by evaporation, without being retained 

 in the soil for the use of the crops growing upon it. Even on those parts of the country 

 which are under indigenous forests, from the scattered and generally sparse crop of trees 

 constituting these, together with the peculiarly characteristic feature of the Australian 

 trees, affording but little shade to the ground — owing to upright habit of the foliage— 



