Spanish Heath | Erica lusitanica | Pest Rating Proposals and Final Ratings

California Pest Rating for

Spanish Heath | Erica lusitanica

Family: Ericaceae

Pest Rating: B | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

Concern about the invasiveness of Spanish heath from the land mangement along the north coast of California.

History & Status:

Background: Erica lusitanica, commonly called Spanish heath is a woody, upright, perennial evergreen shrub growing up to 10 feet tall. It can produce up to 9 million seeds per plant where it is invasive. These seeds are dispersed by wind, water, animal and human transported. It is capable of forming dense stands in forest lands, wild areas, pastureland and on right-of-ways. Leaves are light green, needle like, 3-7 mm long and arranged around the stem in groups (whorls) of three to four. Blooms are a showy mass of small, white to pink, bell (tubular) shaped flowers. Plants begin flowering in December continuing until April. It has shown quick recovery from fire and can be found in disturbed and open sandy areas. It is well adapted to acidic soils and could infest a wide range of shrub and forest habitats^1&3.

Spanish heath is native to southwest Europe and has infested large areas in northern California in Humboldt and Del -Norte counties. It is demonstrating a capacity to infest similar habitat in Oregon and Washington. In parts of Australia and New Zealand, Spanish heath is a major environmental weed that out-competes native vegetation. It impacts the parks, wildland and wildlife refuges result from the aggressive growth and competition demonstrated by this plant⁴.

Official Control: Spanish heath is under official treatment in New Zealand⁵.

California Distribution: Spanish Heath is found along waterways scattered throughout much of Coastal northern CA in Humboldt and Del Norte counties. It is also reported from Mendocino, Santa Cruz and San Francisco counties along the shoreline².

California Interceptions: Two vouchers have been submitted in the CDFA herbarium.

United States: Spanish heath is known from Oregon, and Washington.

Worldwide Distribution: Spanish heath s widely naturalized in the south-eastern parts of Australia, especially in Victoria and Tasmania. It is also reported as naturalized and as an environmental weed in UK and New Zealand⁴.

This risk Spanish Heath would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Spanish heath has established in 4 counties in California and presumably can spread to similar habitats elsewhere in the State. Therefore, there is a high risk that it can establish in California. It receives a High(3) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California. Score: 3

Low (1) not likely to establish in California; or likely to establish in very limited areas

Medium (2) may be able to establish in a larger but limited part of California

High (3) likely to establish a widespread distribution in California

2) Pest Host Range: Spanish heath does not require any one host, but grow wherever ecological conditions are favorable. It receives a High(3) in this category.

Evaluate the host range of the pest: Score : 3

Low (1) has a very limited host range

Medium (2) has a moderate host range

High (3) has a wide host range

3) Pest Dispersal Potential: Spanish heath has a very high seed production. It can spread by wind, water, animal or human activity. It receives a High(3) in this category.

Evaluate the dispersal potential of the pest: Score: 3

Low (1) does not have high reproductive or dispersal potential

Medium (2) has either high reproductive or dispersal potential

High (3) has both high reproduction and dispersal potential

4) Economic Impact: Spanish Heath only occasionally invades agricultural land. It can lower crop yields, crop value, and change cultural practices. Pasture productivity would suffer as edible forage becomes out-competed by this less desirable shrub. Right-of-way maintenance costs would increase in infested areas³. It receives a High(3) in this category.

Evaluate the economic impact of the pest to California using these criteria:

Economic Impact: A, B,C D

A. The pest could lower crop yield

B. The pest could lower crop value (includes increasing crop production costs)

C. The pest could trigger the loss of markets (includes quarantines by other states or countries)

D. The pest could negatively change normal production cultural practices

E. The pest can vector, or is vectored, by another pestiferous organism

F. The organism is injurious or poisonous to agriculturally important animals

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score (3)

-Low (1) causes 0 or 1 of these impacts

-Medium (2) causes 2 of these impacts

–High (3) causes 3 or more of these impacts

5) Environmental Impact: Spanish heath is well adapted to moist, acidic soils and could infest shrub and forest habitats along the coastal belt in California. It is commonly found growing in close association with Gorse, Scotch, French broom, and Blackberry, especially in riparian and roadside areas³.

Spanish heath can dominate open, disturbed areas, excluding other plants and lowering biodiversity and forms dense patches that could interfere with recreation activities along the coast. Its dense growth leads to competition with native vegetation and could impact sensitive species such as Humboldt milk–vetch (Astragalus agnicidus) and Abruptbeak sedge (Carex abrupta). Spanish heath receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the following criteria:

Environmental Impact: A,B,C,D,E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes

B. The pest could directly affect threatened or endangered species

C. The pest could impact threatened or endangered species by disrupting critical habitats

D. The pest could trigger additional official or private treatment programs

E. Significantly impacting cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact: Score (3)

-Low (1) causes none of the above to occur

-Medium (2) causes one of the above to occur

–High (3) causes two or more of the above to occur

Consequences of Introduction to California for Spanish heath:

Rating (Score): Add up the total score and include it here

Low = 5-8 points

Medium = 9-12 points

High = 13-15 points

Total points based on above criteria, which does not take into account the already wide distribution of this invasive plant in California: High (15).

6) Post Entry Distribution and Survey Information: Spanish heath has been found in California and receives a Medium (-2) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: (13)

Uncertainty:

As this plant is established as an invasive species in western CA, there is little uncertainty associated with this assessment.

Conclusion and Rating Justification:

Conclusions of the harm(s) associated with this pest to California using all of the evidence presented above: Proposed Rating: based on the score listed above the pest is a high risk. This would justify an “A” rating. As the plant is found in five counties in California, the pest would be best assigned a “B” rating.

References:

Brusati, E. (2011). Cal-IPC Inventory update adds eight plants. Cal-IPC News. Accessed 11-18-2016. http://www.cal-ipc.org/ip/management/plant_profiles/Erica_lusitanica.php

Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria. Berkeley, California. Accessed 11-18-2016. http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=3070

Oregon Department of Agriculture ! Noxious Weed Control Program. Accessed 11-18-2016. https://www.oregon.gov/ODA/shared/Documents/Publications/Weeds/PlantPestRiskAssessmentSpanishHeath2013.pdf

Weed of Australia, Biosecurity Queenland Edition. Accessed 11-18-2016. http://keyserver.lucidcentral.org/weeds/data/media/Html/erica_lusitanica.htm

USDA-Phytosanitary Certificate Issuance and Tracking System (PCIT) Phytosanitary Export Database ( PExD). Accessed 11-18-2016. https://pcit.aphis.usda.gov/PExD/faces/ReportFormat.jsp