114 
as I have already stated, but as a very general rule, it would effect economy in water 
if dams and other receptacles for water were surrounded by a thick belt of trees. 
The question of diminution of evaporation should always be considered in cutting 
down trees from the vicinity of any stagnant or flowing water in this country. 
The- matter of shade is stated in another way when we draw attention to the 
fact that clumps of trees or forests prevent desiccation of the ground the forest 
floor. 
(e) To give shelter for stock, crops, fyc. 
This is a mechanical action of forests, and their value in that respect is so 
evident as not to be open to argument. 
Professor M. W. Harrington (op. cit., pages 23-4) says that ttie forest is to be 
considered, in its effects on climate and weather, as a special form of surface covering. 
Its effects are of the same order as those produced by a covering of sand, or sod, or 
water, but the forest effect has some peculiar features which are due to the fact that 
the covering is elevated to some extent above the soil. This imparts to the soil in 
some degree the climatic characteristics due to a topographical elevation, and also 
causes a series of wind-break effects which are not found with the other forms of surface 
covering. On account of this distinctive feature, the problem of forest climatology 
separates into two problems, which must be considered each by itself. The one relates 
to the climate of the interior of the forest, and the other to the effects of the forest 
on the climate of the country around it. The two are quite different ; the first is 
of relatively little importance, except as it relates to the second. It is the second 
which is of interest and importance, so far as relates to the suitability of a climate 
for residence and agriculture. The same authority, at page 118 (chapter "Forest, 
Wind and Storms "), speaks at greater length on the wind-break question. 
(f) The leaves of forest trees afford manure and mulch. 
This is less evident in the dry country than in the well-watered coast belt 
and coastal mountain ranges, and is of less importance in Australia, where trees are 
mainly non-deciduous as regards their leaves. But the matter is one of extent rather 
than principle, for we have debris of all kinds from living trees, consisting not only 
of leaves, but of flowers and fruit, limbs and trees, and, as regards our Eucalyptus 
forests, a large percentage of naturally shed foliaceous bark. All this serves as a 
manure and mulch to the forest floor, and thus the evaporation of the moisture is 
diminished. 
Mr. Marsh speaks of the ever-renewed and increasing vegetable mould as a 
perpetual mulch, and in reference to the humidity of forest soil he cites the following 
passage from " Etudes sur 1'Econoinie Forestiere," by Jules Clave : 
Why go so far for the proof of ;i phenomenon which is repeated every day under our own eyes, and 
of which every Parisian may convince himself without venturing beyond the. Hois do Koloj,'ne, or the forest 
of Meudon 1 Let him, after a few rainy days, pass along the Chevreuse, Road, which is bordered on the 
ri-jht by the wood and on the left by cultivated fields. The fall of water and the continuance of the rain 
have been the same on both sides ; but the ditch on the side of the forest will remain filled with water, 
