Living in the sand

Forest and Bird, Issue 279, 1 February 1996, Page 38

Living in the sand

or at CS Re He RR ATURAL’SAND DUNES are so Ni dry and unstable that few plants and animals are able to colonise them. Two of the more widespread and successful traditional colonisers of New Zealand’s dunelands were pingao or golden sand sedge (Desmoschoenus spiralis) and spinifex or kowhangatara (Spinifex sericeus). Not found anywhere else in the world, pingao’s tufts of coarse grass-like leaves are borne on rope-like stems trailing across the dunes. The golden colour of pingao stands out against the grey green of spinifex. Pingao is a sand binder and dune builder. Wind-blown sand is trapped among its leaves, and it accumulates and supplies nutrients to the plant. The stems continue to sprout new shoots as the sand shifts and covers them. Pingao only partially stabilises dunes, as natural dune systems are continually shifting. Today, pingao has been largely supplanted by European marram grass whose more vigorous growth habit and network of roots and stems eventually stabilises the dunes, halting their natural volatility and allowing them to be colonised by other plants. Pingao is much sought after by Maori weavers. Sun-dried, it produces a bright golden yellow and provides a vibrant contrast to the red and black dyed fibres used in tukutuku panelling, and also for the weaving of kete and whariki. With a resurgence in Maori crafts there is an increasing demand for pingao as a raw

material, but at the same time the sedge is not plentiful. Supplementary planting and careful management of established stands is now necessary. Sand dunes also support a small diverse group of specialised animals, mainly insects. These include the sand dune hopper with its peculiar sanddigging leg paddles, speckle-coated sand beetle and the nocturnal sand scarab beetle. Moths and butterflies are relatively common and some moth species are restricted to the dune environment.

Birds are not common on the dunes, unless the dunes are adjacent to lagoons or estuaries. Pipits and banded dotterels can be seen running through the sand in search of insects, and harriers sometimes nest amongst pingao. Dunes and their special plants and animals are as unique and important as the great kauri forests. But few natural dunelands remain or are adequately protected and the threat of invasion by weeds such as boxthorn, boneseed and gorse is very real.