Introduction:
European beachgrass (Ammophila arenaria)
Commonly known as marram grass, Ammophila arenaria is a beach grass native to Europe, the Mediterranean, and the coasts of the Black Sea. Widely distributed to stabilise and establish sand dunes for forestry plantings, property protection and erosion control, it can compete with and displace native vegetation communities and alter habitats with further consequences for invertebrate communities and bird species such as the ‘Endangered (EN)’ Chatham Island oystercatcher (see Haematopus chathamensis). Once established, it spreads through rigorous rhizome growth and is difficult and costly to control.
Description:
Ammophila arenaria is a coarse, perennial grass with stout culms that may reach 120 cm tall with dense, spike-like panicles and long, sharp leaf blades which may reach up to five feet. It has extensive and deep, scaly rhizomes which may give it an advantage in accessing water and nutrients.
Occurs in:
Coastland.
Habitat description:
Ammophila arenaria grows in substrates with low organic matter and free drainage, growing most vigorously in mobile or semi-stable sand dunes and thriving in wind-blown, foredune areas above the high tide line. It is highly adapted to sand
European beachgrass (Ammophila arenaria) Distribution in North America shown in green.
accretion, growing vigorously with the continued addition of fresh sand, and requiring it to avoid senescence. Burial by sand promotes elongation of the leaves and the development of adventitious roots. It tolerates a range of soil pH from 4.5 - 9.0, soil temperatures from 10 - 40°C , and salt concentrations of no more than 1 - 1.5 %. In its native range A. arenaria alone makes up the foredune plant community. Further inland, other species are able to establish when the sand movement stabilises and A. arenaria subsequently begins to senesce. In introduced habitats, A. arenaria initiates the formation of foredunes but does so differently than native plants, altering the habitat and subsequently displacing various native coastal species.
General impacts:
Ammophila arenaria is a strong competitor, capable of completely displacing native vegetation communities in some parts of its introduced range. This is attributed primarily to the ability of A. arenaria to rapidly accrete sand and survive the subsequent burial for much longer than native plant species in addition to its higher drought resistance, vigorous rhizomatous reproduction and ecological tolerance, including resistance to erosion.
It has also been suggested that A. arenaria may acculmulate local pathogens to the detriment of nearby native plants.
A. arenaria forms dense monospecific stands which can differ greatly from the sparse native coastal vegetation that are the norm for some invaded areas in the United States and New Zealand. This alters the natural dynamics of dune systems and can result in a drastically changed coastal topography or beach profile, with the creation of taller and steeper dunes than normal.
In addition to altering the impact and effect of storms and reducing the supply of sand to nearby areas, this can also reduce the nesting habitats of birds including the ‘Endangered (EN)’ Chatham Island oystercatcher (see Haematopus chathamensis in the IUCN Red List of Threatened Species) and the federally listed snowy plover, (See Charadrius alexandrinus in the IUCN
Close up of the European beachgrass (Ammophila arenaria)
Red List of Threatened Species). A. arenaria is also known to significantly alter invertebrate communities, with even small percentages of cover severely depressing arthopod populations and with dunes planted with A. arenaria having a higher Diptera abundance but lower Isopod abundance when compared to unmodified dunes.
Management information:
Physical control: Physcial control is the most effective, but also the most cost and labour intensive management option; it involves hand pulling or digging out plants with a shovel or alternatively using heavy machinery to excavate and bury or rip underground rhizomes.
Chemical Control: Glyphosate based herbicides such as Roundup and Rodeo have been found to be effective as well as haloxyfop based herbicides such as Gallant. Haloxyfop based herbicides have the advantage of being grass-specific and therefore will not kill non-target native broadleaf species like glyphosate based herbicides.
Integrated management: All chemical treatment programs will have to include a physical removal element, as regrowth is not sufficiently exposed enough for follow up herbicide use, and dead biomass needs to be manually cleared before native habitat can be restored. Futhermore, integrated management involving the use of prescribed fires (which are ineffective if used alone) followed by glyphosate-based herbicide use have shown promising and cost-effective results as an alternative to physical control techniques.
Sourced From:
