26 



PAPERS READ BEFORE THE ASSOCIATION. 



Driven oft* by retarded evaporation, the sur- 

 plus finding its way to swell the volume of 

 the great rivers. On the open . vlains the 

 rain storm descends on a surface already im- 

 tactcd by previous rains and the fervid heat; 

 of the sun. Water will not penetrate such a 

 surface, but rushes madly down its slopes to 

 swell the brooks and rivers, and instead of 

 being & blessing to the earth, is a very demon 

 in scarifying and wasting it. In reflecting 

 for a moment it is easy to see how forests are 

 a preventive of floods. Practical foresters 

 ktiow that woods generate springs, and that 

 the soil in woods is often dry when the same 

 ground in the open would be swampy. Trees 

 produce both these con trad ictofy effects by 

 means of their roots boring into the soil, and 

 so enabling water to reach lower 

 level whence springs take their 

 rise, and. again by continually 

 absorbing quantities of water by their roots, 

 they act as subsoil drains and keep the surface 

 from becoming sodden. In forest countries 

 the cbanges of temperature are greatly modi- 

 fied by the presence of timber, and the effect 

 upon water and the development of the fish 

 industries is even greater. Forests regulate 

 the flow of water as well as purify it, which 

 fact has been frequently noticed in Australia 

 whe*j streams have been polluted by the 

 wool cleansing industry. Such streams, after 

 passing through a dense forest, will appear 

 as clear as it was above the wool wash. 



The office of trees in relation to terrestrial 

 and atmospheric moisture may be summar- 

 rized as follows: 



First Tb^y help counteract the effects of 

 lonir summer droughts, by the transpira- 

 tion of water through their leaves, and by 

 their foliage and branches protect decaying 

 vegetation which acts as a mulch to the 

 earth's surface. 



Second They prevent dangerous floods by 

 holding the gentle rain in abeyance until it 

 has had time to penetrate the earth's sur- 

 face. 



Third The water thus reaching a lower 

 level by means of the boring power of the 

 roots, collects, and forms springs. 



Fourth -Some trees absorb vast quantities 

 of water, as the eucalypte, and thus act as 

 sub-soil drains. 



Fifth By preventing the accumulation of 

 bodies of water on the earth's surface the re- 

 moval of valuable soil is prevented; and, last- 

 ly, as wind breaks and shelter belts, especially 

 in large quantities, they equalize temperature, 

 both in summer and winter, and at the same 

 time add to the value of any farm so protected. 

 And this is not all, much more can be said 

 of the relation trees bear to the economy of 

 nature. Trees are intimately associated with 



the welfare of their fellow plants of the 

 lower animals and of man. There is proba- 

 bly no way in which the farmers of this 

 State could more easily or more rapidly in- 

 crease its agricultural product ihan by 

 planting shelter belts to the north and west 

 of their farms. They would, of course, be too 

 limited in extent and too widely scattered to 

 have any general influence on our 

 climate, or the flow of the water 

 courses, but as a means of direct profit it does 

 not seem unreasonable to predict that each 

 protection to our fields would increase the 

 profits of tlieir culture fully 20 per cent. 

 Orchards thus protected would have their 

 conditions measurably improved, and all 

 horticulturists know that plants generally 

 supposed to be too tender for an open, airy 

 situation will thrive when planted under the 

 protection of a wall or' among trees. What 

 garden walls are to the horticulturist these 

 plantations ought to be and would be to the 

 farmer. The subject of the proper distribu- 

 tion of fruit trees in their relation to climate 

 may well engage the attention of the agri- 

 culturist, for although in the main his suc- 

 cess depends upon the action of forces which 

 he cannot control, the distribution of 

 moisture is dependent upon conditions 

 which he may determine to a limited extent, 

 according to his will. Excess of forest in 

 some parts of our country ana. their en- 

 tire absence in others are alike unde- 

 sirable. The early explorers might well 

 call these plains the American Desert. 

 It is susceptible of proof, however, 

 that its limits are gradually receding 

 with the advance of civilization, the break- 

 ing up of the prairie soil, and the gradual 

 planting of timber trees and shrubbery. All 

 the evidence that can be obtained goes to 

 show that the grass covered area is getting 

 larger; the cactus, artemisia and buffalo grass 

 are surely disappearing. This very fact of 

 the tall grasses taking the place of the short, 

 crisp and dense buffalo grass, explains why 

 our American Desert is so rapidly disappear- 

 ing, and why grateful showers reward the 

 labors of the husbandman. Small as this 

 change in the herbage may seem to some, it 

 is not without its significance to the observer 

 of the phenomena of nature. As to general 

 climatic changes that need not concern us at 

 this moment, it is enough for us to know that 

 we can measurably ameliorate our local sur- 

 roundings by plantations of trees, and this is 

 what is most desired, that every landholder 

 mn,y protect himself and his possessions from 

 the untoward influences of wind and weather. 

 The functions that the forests perform in the 

 economy of nature are many ' and varied. 

 They are the great fertilizers of the soil,while 



