36 A MANUAL OF FORESTRY. 



which is essential to its permanent maintenance. The 

 latter is effected by growing on it certain plants which 

 are capable of living under such conditions. Amongst 

 these the Marrum-Grass, Psamma (Ammophila) arenaria, 

 takes the first place ; it has the property that, as the 

 sand rises around it, its stalk grows higher and develops 

 numerous adventitious roots at the joints. Other 

 plants used for the same purpose are Elymus arenaritis 

 and Carex arenaria. 



The second measure, or the temporary fixation of the 

 area covered with sand behind the littoral dune, consists 

 in covering the area with various materials, such as the 

 branches of coniferous trees, heather, broom, furze, sea- 

 weed, turf, &c. ; the last, when obtainable, is best. These 

 materials (except the turf) are kept in their place either 

 by fastening them down with pegs, or by placing 

 shovelfuls of sand upon them. 



The third measure consists in stocking the tem- 

 porarily fixed area with trees, shrubs, and grasses. Of 

 trees the Scotch Pine and the Cluster Pine (Finns 

 Pinaster) are specialty adapted; seed of these may be 

 sown or transplants put in. Of other plants Psamma 

 <trenaria, Elymus arenarius, Carex arenaria, Broom (Saro- 

 thamnus scoparius), and Furze (Ulcx nana), may be 

 mentioned. It is essential to maintain the tem- 

 porary cover until it is replaced by the permanent 

 growth. 



On the west coast of France the second and third 

 measures are done simultaneously. There, a mixture 

 consisting of 98 pounds of Cluster Pine seed, 8 pounds 

 of Broom, and 3^ pounds of Psamma arenaria per acre 

 nre sown, and immediately after it the ground is covered 



