Waimairi County foreshore a comprehensive landscape development Technical Report
- Author
- Challenger, S.
- Year
- 1970
- Species
- Spinifex sericeus, kowhangatara, spinifex, silvery sand grass, Ficinia spiralis, pingao, pikio, golden sand sedge, Desmoschoenus spiralis
- Summary
- Techniques for revegetation of foredunes in New Zealand were investigated using three indigenous sand-binding species: pingao, spinifex and sand tussock. Emphasis was placed on the development of guidelines from research trials designed to investigate the rehabilitation of dunes by planting nursery-raised seedlings. The aim was to promote successful techniques that will be of use to coastal managers and community-based interest groups such as Beach Care and Coast Care. Seed characteristics and methods for collection/preparation of seed are described. Pingao and sand tussock seedlings can be raised in large numbers in a nursery. Difficulties in raising spinifex seedlings at reasonable cost arise from low plant vigour and high mortality. Although transplanting of stolons and direct field seeding of spinifex are used successfully for management-scale restoration of sand dunes in New South Wales, trials in New Zealand have shown low survival rates from transplanted stolons and poor germination and growth after direct seeding. Nursery-raised seedlings of all three species established successfully in trials in several North Island coastal areas and along the beaches near Christchurch. The most favourable planting site for sand-binders was the seaward face of the mobile foredune just above high water level, providing that only moderate sand accumulation is expected. Plant growth was significantly increased by the application of a slow-release fertiliser (Magamp) at time of planting in trials on the less exposed beaches of the eastern North Island. More active sand movement on the west coast of the North Island and along the Christchurch beaches was thought to increase nutrient supply to planted seedlings, but may cause high mortality at exposed sites by burying plants. Because nursery-raised seedlings and planting-out are both expensive, consideration should be given to the alternative strategy of enhancing existing populations of sand-binding species. In either case the plants will require protection from human and animal activity. In the coastal environment, setbacks due to excessive sand accretion or erosion associated with storm events must be expected and should be rectified as soon as possible. The development of a frontal dune with a continuous cover of vigorous sandbinding vegetation is seen as an achievable objective in coastal areas with a high amenity value. The most desirable end-result for the foredune habitat would be a self-sustaining ecosystem based on indigenous species.