On Saturday 28 September 2019 a staunch dozen or so folks turned up to help plant 3,000 spinifex and 500 pīngao plants near the north track to the beach off Reay Mackay Grove.
The Horowhenua District Council very kindly make the plants available, at a total cost of around $5,000. Because volunteers pitch in to help with the planting they can spend available funds on more plants.
Three Council workers joined in, spending their own weekend time to help out. Many thanks to Ann Clark, Ben Wood and Craig.
The planting began with a demo from Ben about how best to put the plants in the ground so they’ll succeed. Bury the blade of a shovel in the sand and wiggle it around to make a hole. Bury the plant deep so its roots are in the cool, damp sand. Then fill in the hole. Pīngao and Spinifex are naturally covered by drifting sand, so it’s better to bury them deep and allow some of the tops to be covered by sand.
We didn’t manage to plant everything, but some folks turned out again on Sunday to get some more in the ground. The Council will take any other left-over plants away and use them in other projects.
It’s a great feeling to help build the beach and add value to the community in this way.
Our residents and visitors mostly take great care of our beach, picking up rubbish, restoring broken fences on the dunes, and doing other quiet work to enhance our environment.
Pīngao and Spinifex (and marram)
The greatest threat to pīkao is considered to be marram grass which was introduced at the turn of the 20th century to stabilise areas that had been protected by pīkao but had been burnt from around the 1880s onwards. Marram’s nitrogen fixing companion plant, the yellow tree lupin, arrived around the same time. Together they literally smother the smaller and far less competitive pīkao.
Source. The document goes on to say:
Pīkao is found only in New Zealand and is one of our major native dune builders, stabilising sandy areas by trapping wind-blown sand. It does this between its leaves, around the plant’s base and with the long rope-like rhizomes or runners it sends out.
By allowing or encouraging sand dunes to form, pīkao creates an environment in which other native coastal species can establish and flourish. Naturally occuring pīkao is a good indicator of biodiversity in a coastal environment.
The native sand-binding grass spinifex has distinctive runners carrying tufts of floppy grey-green leaves and ball-like seed heads. Spinifex plants are single-sexed, bearing either male or female flowers. … When the wind blows, the seed heads roll along the beach until they become lodged against some obstacle, and release their seeds.
Ammophila arenaria is a species of grass that is native to the coastlines of Europe and North Africa where it grows in the sands of beach dunes. It is now established in New Zealand where it has been widely planted for the purpose of sand stabilisation.
Though not classed as a pest plant it has adverse effects on natural coastal systems. Its ability to accumulate sand effectively means that it gives rise to higher, steeper dunes than native dune vegetation. Due to the changes, it has caused in dune profiles it now outcompetes the native Spinifex sericeus (Spinifex) and Ficinia spiralis (Pingao).
All these plants are vulnerable to damage by being walked on or driven over. Be sure to keep all vehicles off the dunes and to stick to the marked tracks.