Cornish heath (Erica vagans)

Present distribution

Scientific name:	Erica vagans L.
Common name(s):	Cornish heath

This weed is not known to be naturalised in Victoria

Habitat:

In its invasive range it occurs in cemeteries, tussock grassland, hill top (Webb et al 1988) and in frequently disturbed sites (Vera 1997). In its native range it occurs in heaths and woods (Tutin et al 1972), often not far from the coast (Underhill 1971) and is “abundant on limestone soils and montane pastures” (Obeso, Vera 1996). Usually on moist soils (compact and waterlogged), however also “in dry places on heaths in continental areas” (Nelson, Coker 1974). Can occur in very shallow soils with summer drought (Canals, Sebastia 2002) and is frost resistant to -13⁰C (Bannister, Polwart 2001).

Potential distribution

Potential distribution produced from CLIMATE modelling refined by applying suitable landuse and vegetation type overlays with CMA boundaries

Map Overlays Used

Land Use:
Forestry; horticulture perennial; pasture dryland; pasture irrigation

Ecological Vegetation Divisions
Coastal; heathland; grassy/heathy dry forest; swampy scrub; freshwater wetland (permanent); treed swampy wetland; lowland forest; foothills forest; forby forest; damp forest; riparian; wet forest; high altitude shrubland/woodland; high altitude wetland; alpine treeless; granitic hillslopes; rocky outcrop shrubland; western plains woodland; basalt grassland; alluvial plains grassland; alluvial plains woodland; ironbark/box; riverine woodland/forest; freshwater wetland (ephemeral)

Colours indicate possibility of Erica vagans infesting these areas.

In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable.

map showing the potential distribution of erica vagans

Red= Very high	Orange = Medium
Yellow = High	Green = Likely

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	Dwarf shrub (Vera 1997) – unlikely to restrict access – negligible impact	l	h
2. Reduce tourism?	Dwarf shrub (Vera 1997), red to white flowers (Webb et al 1988) – unlikely to be obvious to the average visitor	l	h
3. Injurious to people?	No effect (Vera 1997), no prickles or injuries caused	l	h
4. Damage to cultural sites?	Shallow roots (Nelson, Coker 1974) – little or negligible effect on aesthetics or structure of site	l	h
Abiotic
5. Impact flow?	Terrestrial (Canals, Sebastia 2002; Nelson, Coker 1974) – little or negligible affect on water flow	l	h
6. Impact water quality?	Terrestrial (Canals, Sebastia 2002; Nelson, Coker 1974) – no noticeable effect on dissolved oxygen or light levels	l	h
7. Increase soil erosion?	“Shrubs... trap eroded soil” (Canals, Sebastia 2002) – decrease soil erosion	l	h
8. Reduce biomass?	Established in tussock shrubland in New Zealand (Webb et al 1988) and as it is a dwarf shrub (Vera 1997) – biomass slightly decreased	mh	mh
9. Change fire regime?	The above-ground part of the plant burns to the ground in a fire (Obeso, Vera 1996), although, as it invades tussock shrubland (Webb et al 1996), it is not likely to change the frequency and intensity of fires	l	m
Community Habitat
10. Impact on composition (a) high value EVC	EVC =Riparian Forest (V); CMA = Corangamite; Bioregion = Otway Plain; VH CLIMATE potential. “Once established, the ability of many ericaceous shrubs to maximise the assimilation of nutrients and to minimise their loss makes them very competitive in nutrient poor soils... shrubs increase light extinction through the canopy.” It was found that “nitrate contents were significantly higher below the heath than away from it.” E. vagans also maintains “a large seed bank in the soil, which may potentially increase their chances of establishment” (Canals, Sebastia 2002). Invades tussock shrubland (Webb et al 1988) Major displacement of some dominant spp. Within a strata/layer	mh	h
(b) medium value EVC	EVC = Grassy Woodland (D); CMA = West Gippsland; Bioregion = Highlands – Southern Fall; VH CLIMATE potential “Once established, the ability of many ericaceous shrubs to maximise the assimilation of nutrients and to minimise their loss makes them very competitive in nutrient poor soils... shrubs increase light extinction through the canopy.” It was found that “nitrate contents were significantly higher below the heath than away from it.” E. vagans also maintains “a large seed bank in the soil, which may potentially increase their chances of establishment” (Canals, Sebastia 2002). Invades tussock shrubland (Webb et al 1988) – major displacement of some dominant spp. within different layers	mh	h
(c) low value EVC	EVC = Heathy Woodland (LC); CMA = Port Phillip and Westernport; Bioregion = Gippsland Plain; VH CLIMATE potential “Once established, the ability of many ericaceous shrubs to maximise the assimilation of nutrients and to minimise their loss makes them very competitive in nutrient poor soils... shrubs increase light extinction through the canopy.” It was found that “nitrate contents were significantly higher below the heath than away from it.” E. vagans also maintains “a large seed bank in the soil, which may potentially increase their chances of establishment” (Canals, Sebastia 2002). Invades tussock shrubland (Webb et al 1988) – major displacement of some dominant spp. within a strata/layer	mh	h
11. Impact on structure?	“Once established, the ability of many ericaceous shrubs to maximise the assimilation of nutrients and to minimise their loss makes them very competitive in nutrient poor soils... shrubs increase light extinction through the canopy.” It was found that “nitrate contents were significantly higher below the heath than away from it.” E. vagans also maintains “a large seed bank in the soil, which may potentially increase their chances of establishment” (Canals, Sebastia 2002). Invades tussock shrubland (Webb et al 1988) – likely to have a minor effect on 20-60% of the floral strata	ml	mh
12. Effect on threatened flora?	Although E. vagans is likely have some impact on vegetation structure, it’s effect on threatened flora has not been determined	mh	l
Fauna
13. Effect on threatened fauna?	Although E. vagans is likely have some impact on vegetation structure, and hence change habitat, it’s effect on threatened fauna has not been determined	mh	l
14. Effect on non-threatened fauna?	As it changes soil nutrient structure (Canals, Sebastia 2002) and invades tussock shrubland (Webb et al 1988) E. vagans is likely to change habitat dynamics – minor effects on fauna spp – reduction in habitat, food or shelter	ml	mh
15. Benefits fauna?	It is a palatable species (Canals, Sebastia 2002) and, being a low growing shrub (Vera 1997) it is likely to provide some assistance in either food or shelter to desirable species	mh	mh
16. Injurious to fauna?	No effect (Canals, Sebastia 2002)	l	h
Pest Animal
17. Food source to pests?	Rabbits sometimes feed on young Erica spp. plants (Underhill 1971) – supplies food to a serious pest, but at low levels	mh	mh
18. Provides harbour?	Rabbits burrow underneath Erica spp. plants (Underhill 1971), and due to this disturbance “activities of small mammals enhance the encroachment of Ericaceaous shrubs [with particular reference to E. vagans] in heathland patches” (Canals, Sebastia 2002) – capacity to provide harbour and permanent warrens for rabbits (and possibly foxes)	h	mh
Agriculture
19. Impact yield?	“Intact parts... drastically reduced the growth of red clover” (Ballester et al 1982). It’s allelopathic properties may result in reducing crop yields, although to what extent and what species is unknown	m	l
20. Impact quality?	It is not likely to impact on quality of yield and is not listed as an agricultural weed (Randall 2007)	l	m
21. Affect land value?	Not known to affect land value as it is not currently a weed of agriculture (Randall 2007)	l	m
22. Change land use?	As it has allelopathic properties (Ballester et al 1982), some affected crops may not longer grow adjacent to E. vagans, therefore a change of land use may be necessary – however this is not yet determined	m	l
23. Increase harvest costs?	Not known to increase harvest costs as it is not currently a weed of agriculture (Randall 2007)	l	m
24. Disease host/vector?	As it is not currently a weed of agriculture (Randall 2007) it is not known the be a disease host or vector	l	m

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	Heat and light increased germination (Valbeuna, Vera 2002) – requires natural seasonal disturbances	mh	h
2. Establishment requirements?	Occasionally found as “undergrowth in pine and oak forests, being apparently not dependent on high light intensity.” (Nelson, Coker 1974) – can establish without additional factors	h	h
3. How much disturbance is required?	In its invasive range it occurs in cemeteries, tussock grassland, hill top (Webb et al 1988) – highly disturbed natural ecosystems	ml	mh
Growth/Competitive
4. Life form?	Dwarf shrub (Vera 1997), but resprouts from underground stems after fire (Obeso, Vera 1996)	l	h
5. Allelopathic properties?	“Intact parts... drastically reduced the growth of red clover” (Ballester et al 1982)	mh	h
6. Tolerates herb pressure?	“Disappeared in those woodlands subjected to grazing” (Onaindia et al 2004). However where it occurs in the Pyrenees is grazed and is said that the late flowering allows E. vagans “to escape most herbivory when producing seed” (Canals, Sebastia 2002) – consumed, however reproduction may still be strongly inhibited if grazed when flowering	ml	h
7. Normal growth rate?	Lack “fast colonisation mechanisms” (Canals, Sebastia 2002) – less than many species of the same life form	ml	m
8. Stress tolerance to frost, drought, w/logg, sal. etc?	Frost resistant to -13˚C (Bannister, Polwart 2001) Occurs where the soil is “compact and seasonally waterlogged.” (Nelson, Coker 1974) Grows in areas that experience summer drought conditions (Canals, Sebastia 2002) Resprouts after fire, some seeds also establish (Obeso, Vera 1996)	h	h
Reproduction
9. Reproductive system	Can regenerate by seedling establishment and vegetative methods, with larger seeds having a higher germination percentage than smaller seeds (Vera 1997) – sexual and vegetative	h	h
10. Number of propagules produced?	From image (USDA 2008) – likely to produce over 2000 seeds	h	ml
11. Propagule longevity?	Seeds have a high degree of dormancy (Vera 1997) and form a “permanent seed bank” (Canals, Sebastia 2002) – likely to survive over 20 years in the soil	h	h
12. Reproductive period?	“long-lived” (Canals, Sebastia 2002) – mature plant produces viable propagules for 10 years or more	h	h
13. Time to reproductive maturity?	Unknown	m	l
Dispersal
14. Number of mechanisms?	“low wind dispersal” (Canals, Sebastia 2002)	mh	h
15. How far do they disperse?	“low wind dispersal” (Canals, Sebastia 2002) – very unlikely to disperse greater than 200 meters, most less than 20 meters	l	h

References

Ballester A, Vieitez AM, Vieitez E (1982) Allelopathic potential of Erica vagans, Calluna vulgaris, and Deaboecia cantabrica. Journal of Chemical Ecology 8(5), 851-857

Bannister P, Polwart A (2001) The frost resistance of ericoid heath plants in the British Isles in relation to their biogeography. Journal of Biogeography 28, 589-596

Canals RM, Sebastia MT (2002) Heathland dynamics in biotically disturbed areas: on the role of some features enhancing heath success. Acta Oecologica 23, 303-312

Neslon EC, Coker PD (1974) Ecology and status of Erica vagans in County Fermanagh, Ireland. Botanical Journal of the Linnean Society, 69, 153-195

Obeso JR, Vera ML (1996) Resprouting after experimental fire application and see germination in Erica vagans. Orsis 11, 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, 341-354

Randall R (2007) Erica Vagans; Global Compendium of Weeds. Available at http://www.hear.org/gcw/species/erica_vagans/ (verified 17 October 2008)

Turner D, Conran JG (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), 23-31

Tutin TG, Heywood VH, Burges NA, Moore DM, Valentine DH, Walters SM, Webb DA (eds) (1972) Flora Europaea Vol 3. Cambridge University Press.

Underhill TL (1971) Heaths and heathers; Calluna, Daboecia and Erica. David & Charles: Newton Abbot

USDA (2008) Plants profile. United States Department of Agriculture. Available at http://plants.usda.gov/java/profile?symbol=ERVA2 (verified 12 November 2008)

Vera ML (1997) Effects of altitude and seed size on germination and seedling survival of heathland plants in north Spain. Plant Ecology 133, 101-106

Webb CJ, Sykes, WR, Garrock-Jones PJ (1988) Flora of New Zealand Vol 4. Botany Division, DSIR. Christchurch, NZ.

Global present distribution data references

Global Biodiversity Information Facility (GBIF) (2008) Global biodiversity information facility, Available at http://www.gbif.org/ (verified 11 November 2008).

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