Accommodation space limits plant invasion: Ammophila arenaria survival on New Zealand beaches
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Ammophila arenaria (marram grass) may invade remote beach-dune systems by the marine dispersal of rhizomes. In New Zealand, and elsewhere, the conservation of the remaining dune systems of high conservation value would be advanced by predicting where this species might successfully establish and undertaking appropriate surveillance. This paper examines the ability of A. arenaria to sustain growth in the stressful back-beach environment.
Shoots developed from rhizomes were subjected to burial, depth, salt spray and desiccation treatments in the glasshouse. Plants were also subjected to salt water inundation. Two field populations of A. arenaria were surveyed for a period of almost 3 years, following rhizome stranding in July 2007.
Shoots were able to emerge from depths of up to 40 cm. Rhizomes failed to produce shoots when the moisture content of rhizomes was less than 18.25 %, which occurred after 3 days of drought. The survival of buried plants was significantly reduced compared to non-buried plants when burial exceeded 80 % of the plant height. No plants survived when burial exceeded 100 % of the plant height. No tillers survived without water for more than 3 weeks. Exposure to salt spray had no effect on shoot survival. Immersion in seawater significantly reduced survival—exposure to seawater, equivalent to only one high tide immersion event, was sufficient to reduce plant survival in the glasshouse.
Burial, desiccation and salt-spray may, on occasion, be responsible for either preventing the regeneration of A. arenaria rhizomes or limiting the survival of the resultant plants, but exposure to wave activity determines the viability of a population.
KeywordsMarram grass Invasion Rhizome Marine dispersal
We wish to acknowledge the following sources of funding: The George Mason Charitable Trust and the New Zealand Federation of Graduate Women.
- Bell A (1988) Alien dune plants reshape our beaches. Ecos 54:3–6Google Scholar
- Boyd RS (1992) Influence of Ammophila arenaria on foredune plant microdistributions at Point Reyes National Seashore, California. Madronio 39(1):67–76Google Scholar
- Davy AJ, Figueroa E (1993) The colonization of strandlines. In: Miles J, Walton DWH (eds) Primary succession on land. Blackwell, London, pp 113–131Google Scholar
- Hilton MJ, Konlechner TM (2011) Incipient foredunes developed from marine-dispersed rhizome of Ammophila arenaria. J Coast Res SI 64:288–292Google Scholar
- Konlechner TM, Hilton MJ (2009) The potential for marine dispersal of Ammophila arenaria (marram grass) rhizome in New Zealand. J Coast Res SI 56(1):434–437Google Scholar
- Masselink G, Hughes MG (2003) Introduction to coastal processes and geomorphology. Hodder Arnold, LondonGoogle Scholar
- Maun MA (1994) Adaptations enhancing survival and establishment of seedlings on coastal dune-systems. Vegetatio 111:59–70Google Scholar
- Maun MA (2009) The biology of coastal sand dunes. Oxford University Press, New YorkGoogle Scholar
- Owen SJ (1996) Ecological weeds on conservation land in New Zealand: a database. Department of Conservation, WellingtonGoogle Scholar
- Sykes MT, Wilson JB (1988) An experimental investigation into the response of some New Zealand sand dune species to salt spray. Ann Bot 62:159–166Google Scholar
- Wiedemann AM, Pickart AJ (2004) Temperate zone coastal dunes. In: Martinez ML, Psuty NP (eds) Coastal dunes, ecology and conservation. Springer, Berlin, pp 53–65Google Scholar
- Zar JH (1999) Biostatistical analysis. Prentice Hall International, New JerseyGoogle Scholar