1 May, 1902.] QUEENSLAND AGRICULTURAL JOURNAL. 395 
low plateau formed of alluvial sand, gravel, and pebbles. Eleven sound-holes 
were bored in 1899—six in the forest and five outside. The water level was 
found to be lower in the forest by 6 to 64 inches during the season of active 
growth. This result confirms the Russian observations, and accords with the 
known facts concerning the action of forests in drying up swamps and stagnant 
subsoil waters. 
Nevertheless, it would be a great error to jump to the conclusion that 
lains forests always and in all countries lower the level of subsoil waters. It 
as, in fact, been shown by Mr. Ribbentrop that near Trichmopoly wells, 
6 to 10 feet deep inside the forest, held water throughout the dry season, 
whilst the river beds and wells, 15 feet deep outside, were dried up. Each 
locality must be studied under its own conditions. In a general way, it may 
be said that plains forests render service of various kinds :— 
(1) They dry up swamps and malarious places—as, for instance, the 
Landes, the Sologne, the Pontine marshes, and many others. 
(2) They suck up from great depths water which is otherwise not 
utilisable, and cause it to again cireulate in the atmosphere, where 
it forms fresh rain. 
(3) They do not injure the springs, since there are none in level plains 
where man is obliged to have recourse to irrigation. They may 
lower the subsoil water level to a degree which is seldom serious 
if the rainfall is enough to be of any practical use to the crops. 
(4) They cool and moisten the air, and render showers more frequent 
during the growing season. 
Movunrain Forests. 
A rainfall chart bears a great general resemblance to a contour or relief 
map, the more the hills, the more the rain. In reality the rainfall is more 
complicated. All mountain chains show rain maxima, and these maxima are 
very generally proportionate to the elevation. There is more rain at 6,000 feet 
than at 4,000, and more at 4,000 than at 2,000, and so on. Even small eleva- 
tions suffice to attract an appreciable maximum. Wooded mountains are still 
more effective, especially in the summer months. Mountain forests are mostly 
coniferous, and conifers exercise an influence even more powerful than that of 
broad-leaved forests. A forest is always covered by a great layer of moisture 
which is there none the less, though it is not visible as mist. Whence comes 
all this vapour? Is it due to evaporation from the leaves, or is it produced 
by some action of the millions of points of the pine needles? Science cannot 
tell, but the effect is certainly not due to transpiration alone. Transpiration 1s 
indeed less active in conifers than in broad-leaved species, and it would con- 
sequently be expected that the former would give rise to a smaller layer of 
invisible mist than the latter, but the contrary is the case. The cause must 
therefore be sought in the soil or in some other unknown factor. One cause 
may be the soil, but another is surely to be found in the greater portion of the 
rainfall that is intercepted by conifer crowns. It was shown in France that in 
1876 the conifer forests intercepted and restored to the atmosphere over 100,000 
cubic feet more water per acre than the broad-leaved forests. Other years 
have given even greater differences, and there are no means of making exact 
measurements, but there is no doubt that wooded mountains attract more rain 
than bare ones. : 
In all Europe, ppain is the country that gets least rain. Notwithstanding 
the great mountain chains running up to 10,500 feet in Grenada, Murcia, &c., 
the rainfall of July and August is not half-an-inch. If these mountains were 
wooded instead of being absolutely bare, the south-east of Spain would 
not suffer so much from drought, and the country would not have had to 
deplore the disastrous floods produced in Murcia by the Segura. Spain is at 
