Status
Legal status
Regulated Invasive Alien Species of Union concern under the European Regulation on the prevention and management of the introduction and spread of invasive alien species [1143/2014].
Native status
Non-native
First reported in the wild
Not
present in Ireland or Northern Ireland
Invasiveness
Invasive species - risk of Medium Impact
Irish status
Absent
Introduction pathways - 1
Release in Nature
Introduction pathways subclass - 1
Other intentional release
Introduction pathways - 2
Release in Nature
Introduction pathways subclass - 2
Erosion control
NAPRA Ireland risk assessed
No
Species Biology
Identification
Ehrharta calycina is
perennial species of tussock-forming grass that expresses green to
reddish-purple leaves and inflorescence and can grow to 30-75 cm in height (Invasive
Species Ireland, 2021). The leaves are flat with leaf blades 7-20
cm in length and 2-7 mm in width (CABI, 2021). inflorescence is expressed as a contracted
to open panicle (a loose branching cluster of flowers) that is 10-15 cm long,
containing spikelet’s that are 5-8 mm long (CABI, 2021).
Ecology
Ehrharta calycina can commonly be seen growing in dense tufts and can amass large, persistent seedbanks of up to 75,000 seeds per square meter (CABI, 2021).
Impacts
Biodiversity - Ehrharta calycina has the potential to negatively impact biodiversity levels as it is highly competitive and can dominate native plant communities, ostracising them and transforming the composition of the habitat in to a grassland (Visser, 2018).
The result of the dominance exerted by Ehrharta calycina is the formation of monospecific stands which inhibit growth of other species through competitive exclusion (out-competing another species that occupies the same niche) , leading to decreased species richness and biodiversity levels (Visser, 2018).
Socio-economic - Potential costs come with controlling the invasion of Ehrharta calycina in an area, as it can be highly dominant and requires specific management aimed at its control. Additionally, due to the fire hazard that comes with this species, controlling wild fires may represent another cost related to the control of this invasive species (Visser, 2018).
Habitat
Ehrharta calycina can be
found in a variety of habitats that provide suitable growing conditions such as
sand dunes, dune scrub, coastal grasslands, maritime chaparral, oak woodlands,
disturbed road sites and heathland (CABI, 2021).
Reproduction
Ehrharta calycina can
reproduce by seed and through rhizomes but its wind dispersed seeds are the
primary method of reproduction in this species (CABI, 2021). After being moved via wind for some
distance, the seeds will settle on the surface or within the top 1-2 cm of soil
and will attempt to germinate (Smith, Bell
and Loneragan, 1999). Seeds will typically germinate after a
period of rain in winter and will grow and subsequently flower during the rainy
season, right in to early summer (CABI, 2021).
Mechanism of impact
Competition, Flammability
Management approach
As
Perennial veldt grass is listed as an Invasive Alien Species of Union concern
under the EU Regulations of Invasive Alien Species, it cannot be imported,
traded, or released to the wild. Measures must also be taken to prevent spread
of existing populations of it (European Commission, 2017).
Biosecurity
As Ehrharta calycina has the
potential to be introduced to EU countries as a contaminant of hay, all imports
should be checked and subsequently certified as free from any plant material
before they are transported (Visser and
Ray, 2018). In a similar vein, agricultural machinery from areas where Ehrharta
calycina occurs should be checked and cleaned before entering the country
in order to avoid accidental introduction of the invasive species (Visser and
Ray, 2018).
If a population of Ehrharta calycina
was recorded in Ireland, a containment zone should be quickly put up
surrounding the known plant species. This zone will encompass a 25m wide area
around the population, as this is the maximum seed dispersal distance (Visser and
Ray, 2018). The zone would then be treated with herbicides in an ongoing
management plan to eradicate the species and hopefully, prevent its spread
before it establishes itself (Visser and
Ray, 2018).
Mechanical control
Physical control methods such as grazing,
cutting or pulling of plants may only be effective with smaller populations of Ehrharta
calycina as it may not make sense from a cost benefit perspective with
larger populations (Visser and
Ray, 2018). Where physical control is feasible, cutting or pulling the plant can
be effective once the operator ensures the crown is removed. Repeated removal
over a number of years should reduce the ability of this species to spread in
an area (Visser and
Ray, 2018). Correctly disposing of plant material should be considered to reduce
chances of plants re-establishing themselves.
Grazing in a heavy stocking density may be a
highly effective method of controlling Ehrharta calycina (Visser and Ray, 2018). As this species can survive relatively
intense grazing, high stocking densities of suitable grazing species would need
to be introduced to effectively control its spread (Visser and
Ray, 2018).
Chemical control
Chemical control with compounds such as
glyphosate may be effective methods for controlling the spread of Ehrharta
calycina but there is notable data deficiency on this topic (Visser and
Ray, 2018). These herbicides can be applied through various techniques such as
broadcast treatments or spot treatments and are recommended to be used in
addition to mowing and controlled burning to increase effectiveness (Visser and
Ray, 2018). It is possible that chemical control can help to control Ehrharta
calycina but it is uncertain if it can fully eradicate the species in the
long term (Visser and
Ray, 2018).
Species group
Plant
Native region
Africa
Similar species
There
are similar looking species in the same genus such as E. erecta, which grows to a slightly lower height with smaller
leaves. E. longiflora is also similar
in appearance with leaves of around the same length but are slightly wider (CABI, 2021). Neither of these
similar species are currently present in Ireland so if Ehrharta calycina was to
become established, they could not act as confusion species.
Distribution
World distribution(GBIF)
Ehrharta calycina is native
to southern Africa but has spread to other countries such as North America,
Australia, New Zealand, Spain, Portugal and Tunisia where it has become
invasive (Invasive
Species Ireland, 2021).
Irish distribution
Not present
Native distribution
In its
native region of south Africa, Ehrharta calycina can be found in South Africa, Lesotho and
Namibia.
Temporal change
Records submitted to Data Centre in 2023
The following map is interactive. If you would prefer to view it full screen then click here.
How can you help
Report
any sightings of this species to the National Biodiversity Data Centre,
including a photograph, if possible.
Dispose
of unwanted specimens in a responsible manner that does not allow them in to
the natural environment.
Avoid
purchasing this species for ornamental purposes.
Further information
CABI Invasive Species
Compendium: https://www.cabi.org/isc/datasheet/114037
Encyclopaedia Of Life: https://eol.org/pages/1114923
GBIF: https://www.gbif.org/species/2702865
Invasive Species Ireland: http://invasivespeciesireland.com/species-accounts/potential/terrestrial/perennial-veldtgrass
References
Publications
CABI, 2021. Ehrharta calycina (perennial veldtgrass).
[online] Available at: <https://www.cabi.org/isc/datasheet/114037>
[Accessed 1 Jul. 2021].
European Commission,
2017. Invasive Alien Species of Union concern. [online] Luxembourg.
Available at:
<https://ec.europa.eu/environment/nature/pdf/IAS_brochure_species.pdf>
[Accessed 25 Jun. 2021].
Invasive Species
Ireland, 2021. Perennial veldtgrass Ehrharta calycina. [online]
Available at: <http://invasivespeciesireland.com/species-accounts/potential/terrestrial/perennial-veldtgrass>
[Accessed 1 Jul. 2021].
Smith, M.A., Bell, D.T.
and Loneragan, W.A., 1999. Comparative seed germination ecology of
Austrostipa compressa and Ehrharta calycina (Poaceae) in a Western Australian
Banksia woodland. Austral Ecology, Available at:
<https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1442-9993.1999.00944.x>
[Accessed 1 Jul. 2021].
Visser, V., 2018. Pest
risk assessment for Ehrharta calycina. [online] Available at:
<https://circabc.europa.eu/faces/jsp/extension/wai/navigation/container.jsp?FormPrincipal:_idcl=FormPrincipal:_id1&FormPrincipal_SUBMIT=1&id=10834c92-8fbf-4e68-be43-307f49654d74&javax.faces.ViewState=7J0yjkmZ1aO9y2H7wfUz2O2gkmxLKEC%2FMiGahVMPBkCxeLPsVrtGMg>
[Accessed 30 Jun. 2021].
Visser, V. and Ray,
C.A., 2018. Information on measures and related costs in relation to species
considered for inclusion on the Union list: Ehrharta calycina. [online]
Available at:
<https://circabc.europa.eu/sd/a/48b0eb45-08a5-4342-b981-9a0e310e7ba5/TSSR
Task 2018 Ehrharta calycina.pdf> [Accessed 1 Jul. 2021].