390 



FORESTRY AND IRRIGATION 



sion to consider themselves as still employed 

 in the service of the Government. Brigadier 

 General Mackenzie, Chief of Engineers of the 

 Arm}', passes to the retired list, but his suc- 

 cessor in the War Department will succeed 

 him, ex-officio, on the board, while Senator 

 Allison, Congressman Ransdell, of Louis- 

 iana ; Doctor McGee, the Government's 

 chief anthropologist, and Prof. George T. 

 Swain, of the Massachusetts Institute of 

 Technology, are added members. Moreover, 

 the President has given greater consequence 

 to the Commission and prepared for the am- 

 plification of its investigations by appointing 

 and associating with it other boards on the 

 collateral projects, forests, lands, and min- 

 erals ; the quartet constituting the main sec- 

 tions of what will now be known as the 

 National Conservation Commission." 



Conservation is a National duty, and 

 we, as a people, shall fail utterly to take 

 advantage of our opportunities if we do 

 not grasp in its fullness this idea. 



5^ «« Jg 



Mountain Forests and Floods 



A WRITER in the Pacific Sportsman 

 discusses the subject of mountain 

 forests and floods. He understands that 

 forestry advocates hold that the one 

 grand object in maintaining forests on 

 mountain slopes is to "cause the snow 

 to melt slowly," and thus "preserve the 

 water supply." The position that moun- 

 tain forests do subserve these ends, he 

 then proceeds to demolish as follows : 



1. "The timber has nothing to do 

 with the water supply, but is a result of 

 the water supply. 



2. "On the contrary, the trees are a 

 detriment, because they absorb a heap 

 of water after it gets down to them 

 from the peaks. Trees in the moun- 

 tains make floods in the spring. 



3. "Snow in the timber melts too 

 fast. The timber keeps it from drift- 

 ing. The snow that falls below the 

 timber line is a positive danger rather 

 than a blessing, for the timber shades 

 it until the warm air of spring melts it 

 with a rush, and spring floods result. 



4. "The agency which maintains the 

 rivers is the snow in the huge snow 

 drifts above timber line. In the high, 

 sharp valleys of the peaks and pinna- 

 cles there are basins, steep rocky sides 

 of clififs, barren spires, smooth hillsides 



where the wind blows like all possessed 

 when a storm comes. Winter snows 

 fall deeper and oftener here than they 

 do in the timber below. The wind 

 blows the snow off the hillsides and 

 piles it into huge drifts in the basins ; 

 then the warm winds come, and the 

 rest of the snow on the hillsides above 

 the basin loosens up and comes sliding 

 down into the basin too, tons and tons 

 of it, until the basin is a basin no longer 

 but an enormous snow bank containing 

 acres of surface and anywhere from 

 ten to one hundred feet deep — mostly 

 on the north and northeast side of the 

 mountain proper and away above tim- 

 ber line, where the air is always cool 

 and where the peak shades the snow 

 bank for a good part of the day. That's 

 your reservoir that feeds the living 

 streams of summertime. 



5. "As for forest reserves, what we 

 should do is to reserve the mountains 

 above timber line from settlement, so 

 the thousands of big snow-filled basins 

 will not be polluted, and tree planting 

 should be carried on in the plains 

 country where trees are needed tor 

 fuel, lumber, and the influence they ex- 

 ert on the hot atmosphere of Kansas 

 and Texas to induce rainfall." 



til 'M 'M 



By Way of Reply 



IN THE first place, forestry people do 

 not hold that the one grand object 

 in maintaining forests on the mountain 

 slopes is "to cause the snow to melt 

 slowly" and thus "preserve the water 

 supply." They lay much stress upon 

 one factor wholly ignored by the un- 

 known writer, viz. : the rain which falls 

 upon mountain slopes. They show that 

 rain falling upon a densely forested 

 slope has its force broken by the forest 

 cover, its erosive power thus being re- 

 duced ; that, up to the point of satura- 

 tion, it is absorbed by the forest mulch, 

 passed into the underground circula- 

 tion and released slowly during the suc- 

 ceeding days, weeks, or even longer pe- 

 riods through mountain springs, grad- 

 ually to feed the streams, maintain an 

 equable flow, and serve the ends of 



