390 



NATURE 



[January i8, 19 12 



////• >A\n.DUNES OF NEW ZEALAND.' 



^.\\l)-l)UNES originatinij from the shore occupy an 



ari'H uf 300,000 ncrcs in the North NIand and 34,000 



iifos in the South Islnnd of New Zealand. Protection 



rhoto. 



more compact turf-formem. Thus the whole dune-tract 

 id gradually converted to pat»ture. Oreat rare i* nece«- 

 sary to plant uniformly, avoiding the formation u\ trough- 

 like wind-channel* ; and " wounds " in 

 or turf must be attended to at once. 



The proper uae of dun. - 

 tracts iH, however, in l>r. 

 irockaync's opinion, for the 

 jirowth of valuabU; trees. 

 I'inut int'tgnis is stated to be 

 I he mo<,t suitable. These 

 -hould be planted from i\ 

 '<j 34 feet apart. In 

 • iermany, generally speak- 

 ing, marram grass is ooly 

 used for the foredune ; while 

 immediately in its lee the 

 planting of trees takes place 

 without any preliminary fix- 

 ing by sand-binding plants, 

 the sand being, however, 

 partially fixed by a net- 

 work of sand-fences consist- 

 ing of upright sticks. In 

 France the area behind the 

 foredune has been converted 

 to forest, not by planting, but 

 by sowing. 



Measurements of the rate 

 <>f march of a dune are 

 ilways useful. The following 

 case is given in the report. 

 The position of a wandering 

 dune in the Kaipara district, 

 Fici. 1. — Interior of I'lanuiicn on Dutic!^ New Efigbtou, chiefly y'<Vi«u <iMi]f/tu. Auckland was determined in 



.f 



.■igainst inroads of the ^iri is not 

 |)ri>>ini4 niallcr in N< \\ /,i-.il;ui(i. hut 

 protection of fertile lands from burial 

 l)y marching dunes is, and it is for 

 (lie latter purpose that the dunes have 

 10 be fixed. With this object in view, 

 ilie Sand-drift Act of 1908 was passed. 

 l\v it the Minister of Lands is 



• ■mpowered to cause operations to be 

 unil< rtaUi'ii for controlling sand-drift 

 within a proclaimed area, the cost 

 l)'ing apportioned among the owners 

 ol land within that area. The order is 

 subject to appeal to the local magis- 

 trate, the final decision resting with a 

 '>oard consisting of the magistrate and 

 !\vo assessors, one appointed by the 

 \ iovernment, the other by the local 



luthority. 

 The rainfall of New Zealand being 



• miple, it is only necessary for the 

 tirst stage of reclamation to select a 

 ]ii.'»nt which can withstand the impact 

 of driving sand and adjust itself to a 

 rising surface. The best of all is the 

 n.arrani grass {Amniophila arenaria). 

 Piactiial directions for planting are 

 jjiven in the report. This plant has 

 little value for grazing, and farmers 

 are warned that it is impossible 

 to fix the dunes by means of any 

 plant valuable for pasture. When 

 tiie dune-tract is so fixed by marram 

 grass that the sand no longer drifts, the grass dies off 

 in patches. Here pasture grasses may be sown, e.g. 

 "\ orkshire fog and clovers, to be replaced later by 



1 Report on the Iluiic-areas of New Zealand : their Geologi', Botany, and 

 Reclamation. By Dr. L. Cockayue. (Wellington, 191 1.) 



Fig. 2. — Successful planting of Marram Grass in a Wind Channel. 



Cliff-dunes south of Manukau Harbour. 



[L. Cockayne. 

 Plants rather too far apirt. 



1866. By the end of 1910 it had advanced 133 yards, 

 i.e. 9 feet per annum. 



Dr. Cockayne's valuable report contains a list of seventy- 

 four papers bearing upon the subject of the sand-dunes of 

 New Zealand. Vaugiun Cornish. 



NO. 2203, VOL. 88] 



