Sand Dunes

Horowhenua Chronicle, 29 October 1913, Page 4

Sand Dunes

FUMLAX ARTICLE JLY THE SCIENTIFIC AMERICAN.

The best example of the complete reclamation of shifting' sand j areas is in (jaseony, .on the west coast of I'Yanee. _ In the beginning of the lUth Century this" extensive plain was still a sandy deI sort, its area being UUO.UOO" hec--1 tares (hectare, acres nearly)1 This vast extent of sandy moor- ' lands was made productive ! through properly controlling the shifting , sand along the seashore, and now, through the work of Ihe French Government, it is covered will) a well-managed pine fores! which supports a large population. The success o[ the work has given assurance lhat similar results may bis attained hero, provided proper methods of planting are followed. The fixation of these sandv, barren wastes, was started by constructing a littoral dune along the sea shore. This dune was the -secret of the success in the work. ) H was simply a bank of sand ! 'f certain dimensions which senp<l as an obstruction (o the sand which came from the ocean. On lop of (his low bank of sand was erected a hurdle to check the sand in its forward movement, and in ilus way (he height of the littoral diin« was increased. When (he first hurdle was covered up smellier was put up jn its place, and still another until the dune was about 20 feel in heigh I. This dune, which was about one or Iwo hundred feet from high-waier m;uk. projected the vegetation on I he leeward side of the dime from 111 ocean winds, and made conditions favourable for the growth of trees and other vegetation. The surface of the sand was covered with brush, like shingles on the roof of a house. The brush was lied into bundles about fen inches in diameter, and these wore held in check by a shuvell'ul of sand thrown on them here and there. r J he seed of beach grass (amniophilia areuaria) was I lieu scattered among (he brush, and it soon sprouted and held the sansr in check. _ While (Ins system, was effective it had to yield to a newer, cheaper and quicker method. The formal ion of Ihe littoral dune is a vej-y slow and expensive undertaking and it lias been found that this step can f>e omitted by planting the windward side of existing dunes with beach grass or any other form of vegetation which can be made to grow in the locality. It has been conclusively proven ofter years of effort and almost endless expense, that shifting sand cannot be successfully controlled by artificial barriers such as fences of boards or brush. They serve to check for a time, hut later (hey are covered and rendered useless. l'ermaniicy of sand can only be secured by forest cover. The building of fences and covering the sand with brush or debris must be followed by the planting or sowing of grasses, and setting trees ami shrubs. Beach grass is able to stand the action of sand and wind, especially when it is planted sufficiently close together. If this is done the use of brush is unnecessary. It has rhizomes many feet long by means of which it fixes itself firmly in the sand

The grass continues to grow, and to develop now roots, and to increase in height as (ho dunes increase in height. As the sand spreads Iho grass grows through it, until the hard, dry blades form tho nucleus of thousands of tons of sand. " Tho beach grass is the host among sand-binding plants.

and is used offensively for (his purpose. The chief characteristic of this plant is that when the sand tends (o cover it up, its μ-vow-■ih is stimulated in order to keep its lip above tho sand. It is one of the principal sand-binding , plants used in Europe and on the Pacific slope of America. Other grasses suitable for planting , on (he dunes are wild rye (Elymus arenarius), bitter grass (Panicum amaruin), sea oats (tniiola paniculata), and blue joint μ-rass (Calainagrostic sp). All those grasses possess special merit as santlbiuding plants, and can be used (o advantage within fhoir region of growth. After the sand is fixed", hardy shrubs arc planted, and in the shelter of these the young pine trees are set out.