willows: their growth, use, and importance. 41 



in the nmd and sand. In sinking the mat into position stone is 

 used. This process is shown in Plate VIII, figure 2. 



Table 17 shows, as near as it is possible to obtain the figures, the 

 annual amount of willow used in revetment work. Where annual 

 figures are not available, the average amount used for several years 

 is given. Approximately 5 per cent of the amount is cottonwood 

 or other species. 



Table 17. — Amount of willow used in revetment work. 



Cords. 



Missouri to Ohio River, average of 3 years 25, 000 



Missouri River, Fort Benton to Kansas City, 1913 12, 000 



Missouri River, Kansas City to mouth, 1913 43, 580 



Mississippi River, St. Paul, Minn., to Missouri River, average of 4 years. . . . 100, 000 



Mississippi River, Cairo, 111., to White River, Ark., 1913 48, 360 



Mississippi River, White River to Warrington, Miss., 1913 51, 633 



Mississippi River, Warrington, Miss., to Head of Passes, 1913 53, 350 



Mississippi River, South and Southwest Passes, average of 4 years 23, 330 



Arkansas and White Rivers 900 



Total 358, 153 



WILLOW AS A SAND BINDER. 



One of the most important uses of willows is for binding shifting 

 sand. Along the Atlantic coast and the Great Lakes, and to a lesser 

 extent along the Pacific coast, there are large areas which are being 

 reclaimed or will be reclaimed as land becomes more valuable. On 

 the eastern shore of Lake Michigan considerable work has been done 

 and more should be undertaken, as the dunes are moving in in many 

 places and covering valuable farm land. Plate IX shows a dune 

 being reclaimed naturally by willows and an older portion where 

 poplar has followed the willows. Ordinarily it is customary to start 

 grass first in such places, but where conditions are favorable willows 

 can be started without this preliminary step. In Russia large areas 

 have been reclaimed, principally by means of the Caspian willow 

 (Solix acutifolia). The willow is very successful where brush is 

 available and can be scattered over the sand areas as a temporary 

 shelter under which it may gain a foothold before being subjected to 

 the full force of the wind. On the Pacific coast loose straw was 

 thrown on the land, and although the wind was very strong a sur- 

 prisingly large amount was not blown away. Such a planting, how- 

 ever, to be effective must begin on the lee side of a body of water or 

 strip of timber or some object that prevents the blowing of the sand 

 upon the planting to any appreciable extent. Planting begun in 

 this way can be continued out over the shifting area indefinitely 

 with little chance oi failure. It is, however, worse than useless to 

 attempt to plant up an area which has adjacent to it on the wind- 

 ward side a body of loose sand. 



