Ericavagans(Cornishheath) – risk assessment notes
Originates fromwestern Europe (including Britain, Ireland, France, and northern Spain)(Nelson 2011).Unlike other Erica species, E. vagans ‘does not need acidic [soil] conditions with a low pH’ (Nelson 2011).
Domestication/Cultivation
1.01.Species highly domesticated?
Yes
1.02.Naturalised where grown?
Yes (Nelson 2011)
1.03.Weedy races?No, none confirmed (Nelson 2011)
Climate and distribution
2.01. Suited to Australian climates? Yes, Tasmanian Government modelling (using source location map fromNelson (2011) and Victorian Government modelling indicates high and very high suitability to parts of Tasmania and other parts of southern Australia, especially Victoria and southern New South Wales (and ACT) (see Figures 1 and 2).E. vagans is given a score of 2 for this criterion.
2.02. Quality of climate match data?Basic (Climatch) model used by the Tasmanian Government (source location data from Nelson 2011 is very precise), and CLIMATE modelling used by the Victorian Government. Quality good. Score of 2.
2.03. Broad climate suitability?Yes. Source of origin is from as far north as Northern Ireland and south to northern Spain (Nelson 2011). It is found to an altitude of 1800 metres in the Pyrenees (Nelson 2011). Climatch indicates high to very high suitability in several distinct climate areas (under the Koppen-Geiger system) in southern Australia – SW Western Australia, South Australia, Victoria, New South Wales and Tasmania. A ‘yes’ answer to this criteria requires an indication of broad climate suitability from a climate matching program or natural occurrence in 3 or more distinct climate categories.
2.04. Native/Naturalised in regions with extended dry periods?No, inits native region (inc. northern Spain), the driest quarter of the year averages more than 50mm ofrainfall(for example even the driest quarter in Valladolid, Spain averages just over 50mm) (World Weather Online 2015).E. vagans has a tolerance for temperatures as low as -13 degrees Celcius (Bannister and Polwart 2001).
2.05. History of repeated introductions outside natural range?Yes, naturalised innorthern California, Oregon, New Zealand and Madeira (Nelson 2011). ‘Weed’ in New Zealand (Howell 2008).
Weed elsewhere
3.01. Naturalised beyond native rangeYes, naturalised in northern California, Oregon, New Zealand and Madeira (Nelson 2011).
3.02. Garden/amenity/disturbance weed?Yes. E. vagans is a ‘naturalised garden-escape even in Ireland and Britain’ (Nelson 2011).
3.03. Weed of agriculture?No, no evidence of this to date.
3.04. Environmental weed?Yes, environmental weed (Randall 2001, Randall 2012).
3.05. Congeneric weed?Yes, same genus as Spanish heath and other weedy heath species
Undesirable traits
4.01. Spines, thorns, burrs?No
4.02. Allelopathic?Yes. Intact aerial parts … drastically reduced the growth of red clover (Ballester et al 1982). Erica species are recognised as having allelopathic properties that inhibit grasses and crop plants (Rice 1984).
4.03. Parasitic?No, no documented evidence of this found.
4.04. Unpalatable to grazing animals?Yes.Although there is evidence of some level of palatabilityin Europe – ‘disappeared in these woodlands subject to grazing’ (Onaindia et al 2004), and ‘the plants of Erica vagans have a dwarfed and hummock-shaped habit due to grazing (Nelson and Coker 1974). However, in the context of Tasmanian grazing lands, though it may be browsed by livestock, the species would not be considered ‘palatable’. Hence, the response given above.
4.05. Toxic to animals?No, no evidence of this.
4.06. Host to pests and pathogens?No, no documented evidence of this found.
4.07. Toxic to humans?No, no documented evidence of this found.
4.08. Fire hazard?Yes, no documented evidence but ‘yes’ response based on related species E. baccans and other Erica sp. recorded to ‘increase fire risk’ and be ‘highly flammable’. (Blood 2001, Cancellieri et al 2005, Johansson et al 2009).
4.09. Shade tolerant?Yes, occasionally found as ‘undergrowth in pine and oak forests, being apparently not dependent on high light intensity’ (Nelson and Coker 1974).
4.10. Grows in infertile soils?Yes, ‘inhabits heathland, moors, pine and oak woodlands, and coastal dunes’ (Nelson 2011). In a study involving E. vagans, Canals and Sebastia (2002) found that ‘heathland soils [where E. vagans grows] had, on average, low nutrient pools’. Capacity to grow in infertile soils is a consistent feature of other members of the genus. ‘Ericas are capable of normal nutrition in average soils, but become mycotrophic in soils unfavourable to the direct absorption of nutrients – such as on a heather moor, where the soil is wholly humus …’ (Underhill 1971). NB E. vagans ‘does not need acidic conditions with a low pH’ (Nelson 2011). This potentially gives it capacity to establish in a broader range of landscapes as an invasive species.
4.11. Climbing or smothering habit?No, no documented evidence of this found.
4.12. Dense thickets?Yes, in its natural situation (northern Spain), it can be the ‘one of the dominant shrubs’ (Obeso and Vera 1996). Also considered for this response is that related species E. lusitanica and E. arborea are recorded to form dense thickets too (Muyt 2001, Johansson et al 2009, Nelson 2011).
Plant Type
5.01. AquaticNo
5.02. GrassNo
5.03. Nitrogen fixing woody plant?No
5.04. Geophyte?No
Reproduction
6.01. Reproductive failure in native habitat?No, no evidence found.
6.02. Viable seed?Yes,discussion of reproduction by seed in Nelson (2011), i.e. ‘seed may also be gathered and sown’ and in Vera (1997). Reproduction by seed is a common feature of this genus (for example, Erica lusitanica (Muyt 2001).
6.03. Hybridised naturally? Yes, ‘well-known natural hybrid between Erica vagans and E.tetralix, called E. X williamsii (William’s heath)’ (Nelson 2011). .
6.04. Self-compatible or apomicticUnknown
6.05. Specialist pollinators?No, no evidence found to suggest this.
6.06. Reproduces by vegetative fragmentation?No, though does resprout (Obeso and Vera 1996).
6.07. Minimum generative time? Unknown
Dispersal
7.01. Dispersed unintentionally?Yes, as with E.scoparia, seed ‘very fine and would be easily transported by water and on roadworks equipment’ (Baker 2005).
7.02. Dispersed intentionally by people?Yes, grown as an ornamental and potentially dumped in garden waste.
7.03. Produce contaminant?No, no documented evidence of this found.
7.04. Wind dispersal?Yes, (Canals and Sebastia 2002). Also, related species like E. caffra, ‘the seeds are dispersed by the wind’ (SANBI 2008). Carr et al (1992) and Blood (2001)list wind as a mechanism of dispersal for relatedE. baccans.
7.05. Propagules buoyant?Yes – based on other species such as E. baccans and E.arborea (Carr et al 1992). Light seed is likely to be buoyant in overland water flows.
7.06. Bird dispersed?No –no documented evidence of this found, but it may be possible given the sticky hairs found on this species, and recognised capacity for these to adhere to fur (Nelson 2011).
7.06. Dispersed by other animals? No, no evidence found to suggest this.
7.07. Propagules survive passage through gut?Unknown, no documented evidence of this found.
Persistence attributes
8.01. Prolific seed production (>2000/m sq.)Yes,no direct record, but very likely given prolific seed production is a common feature of Erica species. For example, the estimated 13000-20000 seeds per plant produced by E. glandulosa (Turner and Conran 2004). Also, E. baccans plantsproduce ‘many thousands of seeds… each year’ (SANBI 2010), and this level of seed production was found for E. lusitanica (DPIPWE 2015). ‘Ericaceous species … produce a large and permanent seed bank’ (Canals and Sebastia 2002).
8.02. Persistent seed bank?Yes, a persistent seed bank is a common feature of Ericas. For example, E. cinerea seed can survive 30-40 years in the soil (Turner and Conran 2004). E.baccans has a 1.6 year seed bank half-life (Holmes and Newton 2004). ‘Ericaceous species … produce a large and permanent seed bank’ (Canals and Sebastia 2002).
8.03. Well controlled by herbicides?Unknown, no documented evidence of this found for E. vagans.
8.04. Benefits from mutilation/cultivation?Unknown.
8.05. Natural enemies in Australia?Unknown, no documented evidence of this found.
Figure 1. Climatch assessment for E. vagansusing source location map from Nelson (2011). Climatch conducted by Michael Noble 24 April2015.
Figure 2. . Victorian CLIMATE assessment of potential suitability for E. vagans. Suitability - red = very high suitability, yellow = high suitability, orange = medium suitability, green = likely suitability (source DPI 2008)
References
Baker, M. (2005). Weed alerts. Tasweeds incorporating Spotter 28, pp. 10-11.
Ballester, A., Vieitez, A.M., and Vieitez, E. (1982). Allelopathic potential of Erica vagans, Calluna vulgaris, and Daboecia cantabrica. Journal of Chemical Ecology 8(5) pp. 851-857.
Bannister, P. and Polwart, A. (2001). The frost resistance of ericoid heath plants in the British Isles in relation to their biogeography. Journal of Biogeography 28, pp. 589-596.
Blood, K. (2001). Environmental weeds – a field guide for SE Australia. CH Jerram Science Publishers, Mt Waverley, Victoria.
Canals, R.M. and Sebastia M.T. (2002). Heathland dynamics in biotically disturbed areas: on the role of some features enhancing heath success. Acta Oecologica 23, pp. 303-312.
Cancellieri, D., Leoni, E. and Rossi, J.L. (2005). Kinetics of the thermal degradation of Erica arborea by DSC: Hybrid kinetic method. Thermochimica acta 438 (1), pp. 41-50.
Carr, G.W., Yugovic, J.V. and Robinson, K.E. (1992). Environmental weed invasions in Victoria – conservation and land management implications. Department of Conservation and Environment, East Melbourne, Victoria and Ecological Horticulture Pty Ltd, Clifton Hill, Victoria.
Department of Primary Industries, Victoria (DPI) (2008). Potential distribution of Erica vagans in Victoria. Unpublished report.
Department of Primary Industries, Parks, Water and Environment, Tasmania (DPIPWE) (2015). Spanish heath Erica lusitanica scoresheet. (accessed 6 February 2015).
Holmes, P.M. and Newton, R. J. (2004). Patterns of seed persistence in South African fynbos. Plant Ecology 172, pp. 143-158.
Howell, C. (2008). Consolidated list of environmental weeds in New Zealand. URL: (accessed 9 April 2015).
Johansson, M., Rooke, T., Fetene, M. and Granstrom, A. (2009). Browser selectiveity alters post-fire competition between Erica arborea and E. trimera in the sub-alpine heathlands of Ethiopia. Plant Ecology 207(1), pp. 149-160.
Muyt, A. (2001). Bush invaders of south-east Australia. R.G. and F.J. Richardson, Meredith, Victoria.
Nelson, E. C. (2011). Hardy heathers from the northern hemisphere – Calluna, Daboecia, Erica. Kew Publishing, Kew, UK.
Nelson, E.C. and Coker, P.D. (1974). Ecology and status of Erica vagans in County Fermanagh, Ireland. Botanical Journal of the Linnean Society 69, pp. 153-195.
Obeso, J. R. and Vera, M. L. (1996). Resprouting after experimental fire application and seed germination in Erica vagans.Orsis 11, pp. 155-163.
Onaindia M, Dominguez I, Albizu I, Garbisu C, Amezaga I (2004) Vegetation diversity and vertical structure as indicators of forest disturbance. Forest Ecology and Management 195, pp. 341-354.
Randall, R. (2001). Garden thugs, a national list of invasive and potentially invasive garden plants. Plant Protection Quarterly 16(4), pp. 138-171.
Randall, R.P. (2012). A global compendium of weeds (2nd Ed.). Department of Agriculture and Food, Western Australia. (accessed 6 February 2015).
Rice, E.L. (1984). Allelopathy (2nd Ed.). Academic Press Inc., Orlando, Florida.
South African National Biodiversity Institute (SANBI) (2010). Erica baccans L.. (accessed 10 February 2015).
South African National Biodiversity Institute (SANBI) (2008). Erica caffra L. (accessed 9 April 2015).
Turner, D. and Conran, J.G. (2004). The reproductive ecology of two naturalised Erica species (Ericaceae) in the Adelaide Hills: the rise and fall of two ‘would-be’ weeds? Transactions of the Royal Society of South Australia 128(1), pp. 23-31.
Underhill T.L. (1971). Heaths and heathers; Calluna, Daboecia and Erica. David & Charles, Newton Abbot, United Kingdom.
Vera M.L. (1997). Effects of altitude and seed size on germination and seedling survival of heathland plants in north Spain. Plant Ecology 133, pp. 101-106.
World Weather Online (2015).Valladolid monthly climate average, Spain. URL: 24 April 2015).