Pathway risk analysis: invasive alien plants imported with live animals and unprocessed fibres from sheep and goats in New Zealand
A non-quantitative analysis of the biosecurity risks posed by the importation of live animals and fibres from sheep and goats into New Zealand has been performed using a sample of plant species known to have weedy characteristics and have dispersal mechanisms that utilize animals and animals fibres. Fruits and seeds are the primary means by which angiosperms are dispersed, and the main agents for this dispersal are wind, water and animals. Animals disperse fruits and seed either by ingesting and subsequently excreting them, or by passively transporting them once they have adhered to an external part of the body, such as the fur. This study considers a sample of the many species present in the world that could potentially be spread by animals.
These species are presented in the table below with their description, distribution and habitat, their occurrence in the EPPO region (according to DAISIE, NOBANIS and Flora Europaea), as well as their status indicated in the Global Compendium of Weeds:
Species native to the EPPO region (or at least a part of it):
|
Species
|
Description
|
Distribution and habitats
|
EPPO
|
GCW
|
|
Adonis macrocarpa (Ranunculaceae)
|
Erect, much branched annual herb which can compete strongly cereal crops and pastures. Toxic. Seeds adhere to wool and fur.
|
Native to the Mediterranean region and occurring in warm-temperate regions.
|
Widely distributed in S-Eur.
|
W, QW, NW
|
|
Chondrilla juncea (Asteraceae)
|
Erect, much branched perennial which became a major weed in cereal crops in Australia, while it is of little importance in its indigenous area. Seeds attach to wool.
|
Native from Russia, Asia Minor to the Mediterranean. Occurs in temperate, subhumid and semi-arid open scrubland.
|
Widely distributed in S-Eur.
|
W, NW, QW, EW
|
|
Dittrichia graveolens (Asteraceae)
|
Erect, much branched, aromatic annual herb up to 1 m high. When mature, the plant is not very palatable. Flower heads, when eaten by sheep can cause irritation and puncturing of digestive organs. Seeds attach to wool and fur.
|
Native to the Mediterranean region, occurs in warm-temperate and subtropical regions.
|
Widely distributed in S-Eur.
|
W, NW, EW
|
|
Heliotropium amplexicaule (Boraginaceae)
|
Hairy, summer growing annual herb. Toxic to sheep, cattle and horses. Seeds adhere to wool and fur and pass through the digestive tract unharmed.
|
Native to Central Europe, Western Asia and Northern Africa and occurring in temperate regions.
|
Widely distributed
|
W, QW, NW
|
|
Reseda lutea (Resedaceae)
|
A biennial or short lived perennial herb with a woody base and deep taproot. It competes with pastures and crops for light and nutrients but is mainly a weed of waste land. Some seed is dispersed when eaten by animals and later excreted.
|
Native to Europe, and occurring in the temperate regions, preferably with warm dry summers.
|
Widely distributed
|
W, QW, NW
|
|
Sorghum halepense (Poaceae)
|
Erect perennial grass, 0.5 to 2 m high, reproducing by seed and rhizomes. It is considered one of the worst weeds: it causes severe crop losses, it has the potential to harbour diseases and insect pests of sorghum and maize, to contaminate grain sorghum and to poison stock. Seeds stick to wool and fur of animals, and pass relatively unharmed through animal digestive tracts.
|
Native to Indo-European regions, this species occurs in subtropical and tropical regions and can invade cultivated and irrigated pastures.
|
Widely present
|
W, QW, NW, EW
|
|
Tribulus terrestris (Zygophyllaceae)
|
Prostrate summer growing annual herb. Spines of the fruit damage the feet of animals, and the plant is a nuisance in environmental and recreational areas. Fruit can get entangled in wool.
|
Large native range, occurs in almost all areas of the world.
|
Widely present
|
W, NW, NatW
|
|
Xanthium strumarium ; X. strumarium subsp. italicum (Asteraceae)
|
Erect annual herb up to 2.5 m high. The burrs are entangled in wool.
|
Native to the Americas, Europe, Asia occurs in unshaded, warm situations in temperate regions.
|
Widely present
|
W, NW, QW, NatW, EW
|
Alien species present in the EPPO region:
|
Species
|
Description
|
Distribution and habitats
|
EPPO
|
GCW
|
|
Ambrosia psilostachya (Asteraceae)
|
Erect robust perennial herb with creeping roots and forming dense colonies. It is strongly competitive, often resulting in productivity reductions in crops and pasture. Aerial growths are allelopathic and the pollen causes allergic inflammations. The fruit of this species can get entangled in wool or stick to fur.
|
Native to the Americas, occurs in semi-arid grasslands.
|
Widely distributed: BE, ES, FR, DE, GB, IT, NL, PL, SE, etc.
|
W, NW, NatW
|
|
Alternanthera pungens (Amaranthaceae)
|
Prostrate creeping perennial herb reproducing by seeds, stems producing roots at the nodes. The prickly burrs attach to animals.
|
Native to tropical America, it is found in disturbed areas.
|
ES
|
W, QW, NW
|
|
Amsinckia spp. (Boraginaceae)
|
Erect annuals very competitive with cereal crops, cause impurities in wool and are potentially toxic to stock. The fruit calyx attaches to wool, fur and hair of animals. Seeds are also believed to remain viable after passing through the digestive tract of sheep.
|
Native to the Americas, occur in temperate regions in moderately warm, unshaded situations.
|
/
|
W, NW, QW
|
|
Cenchrus incertus (Poaceae)
|
Erect annual, serious weed of maize and pastures. It produces spiny seeds containing burrs which fall at maturity and adhere to wool and fur.
|
Native to tropical America, extending from Southern USA to the Caribbean and Central America. Occurs in humid and subhumid tropical lowlands.
|
Azores (PT), ES, FR (incl. Corsica), GR, HU, IT, RO, TR
|
W, QW, NW
|
|
Cenchrus longispinus (Poaceae)
|
Annual reproducing by seeds which are contained within a burr with barbed spines which detach from the plant at maturity and adhere to wool and fur.
|
Native to North and Central America and occurs in temperate subhumid and semi-arid regions. It is a pioneer of disturbed sandy soils.
|
IT
|
W, QW, NW, NatW
|
|
Chrysanthemoides monilifera (Asteraceae)
|
Perennial shrub, 3 m high. It can invade native vegetation and coastal vegetation systems. Seeds remain viable after passing through the digestive tract of cattle, birds, and other animals.
|
Native to S and SE of South Africa, and occurs in sub humid scrubland. It prefers disturbed areas and can grow near the sea since it is tolerant of saline conditions.
|
ES, FR, Sicilia (IT)
|
W, NW, QW, NatW, EW
|
|
Cuscuta spp. (Convolvulaceae)
|
Parasitic plants affecting a wide range of broad-leaved plants which can grow in a wide range of environmental conditions. Seeds can pass through the digestive tract of animals in a viable state.
|
Many species originate from the Americas.
|
/
|
W, QW, NW,
|
|
Malvella leprosa (Malvaceae)
|
Semi-erect, deep rooted perennial, competing strongly with pasture species. Capsule can be caught in wool.
|
Native to Western North-America, occurring on canals banks and irrigated annual pastures, mainly on alkaline soils in arid and semi-arid warm-temperate regions.
|
ES
|
W, QW, NW
|
|
Nassella trichotoma (Poaceae)
|
Grass heavily reducing pasture quality. The coat of the seed and hairs at its base allow the seed to cling to wool.
|
Native to South-America. Occurs in subhumid and warm-temperate regions in open pastures and lightly timbered areas.
|
FR (incl. Corsica), IT
|
W, QW, NW, EW
|
|
Parkinsonia aculeata (Fabaceae)
|
A branching spiny shrub or small tree, 2 to 8 m high, often forming dense thickets, especially along creeks and rivers. Dispersed by birds and animals eating the seed, often enhancing germination capacity.
|
Native to Southern USA, Central America and Northern South America. It occurs in semi-arid to subhumid tropics and subtropics.
|
ES (incl. Baleares, Islas, Canarias), CY, IT
|
W, QW, NW, EW
|
|
Pennisetum villosum (Poaceae)
|
Erect grass of up to 70 cm high. Mature plants are unpalatable, stands of the plant tend to dominate the pasture. Seeds held within involucral bristles can adhere to wool and fur.
|
Native to North Africa and the Arabian Peninsula, occurs in moister semi-arid or arid subtropics.
|
Baleares (ES), FR (incl. Corsica), IT (incl. Sardinia), PT (incl. Azores, Madeira)
|
W, NW, EW
|
|
Proboscidea louisianica (Martyniaceae)
|
Erect low growing annual herb which can be strongly competitive with summer crops. Hard and woody fruits can injure stock and can attach to the feet or mouth. The hooked fruit can attach to animals, particularly sheep.
|
Native from the Americas and occurring in humid, temperate to tropical regions. Grows on disturbed sites.
|
ES, PT, RU
|
W, QW, NW, NatW
|
|
Sagittaria montevidensis (Alismataceae)
|
Emergent perennial aquatic herb. It can produce dense infestations, blocking channels and drainage ditches. While seeds spread primarily through waterways, it can also occur in mud sticking to hooves and fur.
|
Native to North and South America.
|
ES
|
W,
SW,QW, NW, EW
|
|
Sida rhombifolia (Malvaceae)
|
Erect perennial sub-shrub up to 1 m, principally a weed in moist disturbed areas. It is a serious competitor in crops and pastures in warmer regions. Seeds catch on wool and fur.
|
Native throughout the tropics, it occurs in tropical to warm-temperate savannah.
|
PT (incl. Azores, Madeira)
|
W, QW, NW, NatW
|
|
Solanum elaeagnifolium (Solanaceae – EPPO A2 List)
|
Summer growing perennial herb reducing the production of winter crops such as cereals. Fruits are eaten by animals, and seeds remain viable.
|
Native to Central and South-America, occurring in warm temperate regions.
|
AL, HR, CY, ES, FR, GR, IL, IT, RS, ME, MA, TN
|
W, QW, NW, NatW, EW
|
|
Solanum rostratum (Solanaceae)
|
Erect annual herb, poisonous and bearing numerous prickles. Burrs stick to wool.
|
Native to Mexico and the Southern United USA and occurring in semi-arid and subhumid warm-temperate regions.
|
FR, IT (incl. Sardinia), SK, TR
|
W, NW, NatW,
|
|
Sporolobus africanus (Poaceae)
|
Unpalatable perennial herb reproducing by seed. It can seriously reduce pasture production. At maturity, seeds can attach to animal fur.
|
Native to South Africa, occurs in moist areas of southern semi-arid to subhumid subtropics. It invades degraded pastures, particularly in wet or swampy areas.
|
Azores, Madeira (PT)
|
W, QW, NW, NatW, EW
|
|
Verbesina encelioides (Asteraceae – EPPO Alert List)
|
Erect branching summer-growing annual herb. It can potentially affect some cereal crop production and is toxic. Seeds have wings and fine bristles that can attach to wool and fur.
|
Native to North and South America and occurring in temperate to subtropical open scrubland.
|
DE, ES, IL, MA
|
W, NW, QW, EW
|
|
Xanthium spinosum (Asteraceae)
|
Erect annual herb up to 1 m high. Dense growth reduces pasture productivity. The burrs are entangled in wool.
|
Native to South America and occurring in exposed, moderately warm situations in temperate regions.
|
Widely present
|
W, NW, QW, EW
|
Species absent from the EPPO region:
|
Species
|
Description
|
Distribution and habitats
|
EPPO
|
GCW
|
|
Acanthospermum hispidum (Asteraceae)
|
Erect annual reproducing by seed. This herb seriously competes with several crops for water and nutrients, and impedes harvesting. Hooked spines attach to wool and fur of animals.
|
Native to South-America and present in humid and subhumid tropics.
|
Not recorded
|
W, QW, NW
|
|
Achnatherum brachychaetum (Poaceae)
|
Perennial grasses without rhizome reproducing by seeds. It can reduce yields, parti-cularly in lucerne. Fine hairs allow the seed to stick to wool.
|
Native to South-America, occurs in temperate grasslands.
|
Not recorded
|
W, QW, NW
|
|
Ambrosia confertiflora (Asteraceae)
|
Erect perennial herb forming large colonies from creeping roots. This plant is competitive and suppresses pasture species. Its burrs contaminate wool and because of hooked spines, they are not easily removed.
|
Native to the semi-arid plains of the USA and Mexico, occurring in plains of temperate regions.
|
Not recorded
|
W, NW, QW
|
|
Cyperus aromaticus (Cyperaceae)
|
Aggressive perennial reproducing by seeds and rhizomes. Unpalatable, capable of smothering many tropical pasture species. Long distance spread is mainly by seeds passing through the digestive tract of animal and birds, or being carried in mud attached to hooves and pelts.
|
Native to tropical Africa, Madagascar, Mauritius and Seychelles. Occurs in tropical pastures.
|
Not recorded
|
W, QW, NW
|
|
Gmelina asiatica (Verbenaceae)
|
Highly variable thorny shrub or small tree, 2 to 4 m high that tends to form thickets.
|
Native to Asia where it is widely distributed occurs in open deciduous or wet scrubby forests of subtropical areas.
|
Not recorded
|
W, QW, NW
|
|
Gorteria personata (Verbenaceae)
|
Spiny burrs entangle in wool and other fibrous material.
|
Native to SW Africa, occurs in undisturbed sub-tropical and warm-temperate open woodlands.
|
Not recorded
|
W, QW, NW
|
|
Homeria flaccida (Iridaceae)
|
Erect perennial reproducing from corms and seed. All parts of the plant (green or dry) are poisonous to cattle, sheep and goats. When seeds are ingested they remain viable, seeds also adhere to wool.
|
Native to South Africa. Occurs in semi-arid and subhumid subtropical scrubland.
|
Not recorded
|
W, QW, NW, NatW, EW
|
|
Hyptis capitata (Lamiaceae)
|
Erect aromatic perennial herb. The fruits adhere to wool and fur.
|
Native to Central America, occurring in the humid tropics and subtropics.
|
Not recorded
|
W, QW, NW
|
|
Hyptis suaveolens (Lamiaceae)
|
Erect branched woody-based annual herb. It is not palatable to stock. The spined burrs catch on wool and fur.
|
Native to tropical America and occurring in the subhumid or semi-arid tropics, in areas not subject to waterlogging.
|
Not recorded
|
W, QW, NW
|
|
Ibicella lutea (Martyniaceae)
|
Erect low growing annual herb which can be strongly competitive with summer crops. Hard and woody fruits can injure stock and attach to the feet or mouth. The hooked fruit can attach to animals, particularly sheep.
|
Native from the Americas and occurring in humid, temperate to tropical regions. Grows on disturbed sites.
|
Not recorded
|
W, QW, NW
|
|
Martynia annua (Martyniaceae)
|
Erect annual herb growing up to 2 m high. Seed remains in a seed pod which can catch on to animals.
|
Native to Mexico and occurring in subhumid to semi-arid scrub and steppe.
|
Not recorded
|
W, QW, NW
|
|
Pennisetum macrourum (Poaceae)
|
Erect perennial, 1 to 1.8 m high, reproducing by seed and rhizome. This plant is of low palatability. Seeds have bristles that cling to wool and hair of animals.
|
Native to South Africa.
|
Not recorded
|
W, QW, NW, EW
|
|
Physalis viscosa (Solanaceae)
|
Erect perennial herb which can compete with other vegetation for moisture and nutrients. It has an extensive root system. The fruit can be eaten by stock and it seems that germination is enhanced after seeds pass through the digestive tract.
|
Native from the America and occurring in warm-temperate regions.
|
Not recorded
|
W, QW, NW
|
|
Sclerolaena muricata (Chenopodiaceae)
|
Small erect bushy rounded shrub. Burrs contaminate wool.
|
Native to semi-arid areas of Eastern Australia.
|
Not recorded
|
W, QW, NW, NatW
|
|
Sorghum almum (Poaceae)
|
Summer growing perennial herb, 1 to 3.5 m high, reproducing by seed and rhizome. This plant has the potential to harbour diseases and insect pests of sorghum and maize, to contaminate grain sorghum and to poison stock. Seeds stick to wool and fur of animals.
|
Thought to be native to Argentina where it was widely cultivated. Occurs in subtropical and semi-arid high fertility soils.
|
Not recorded
|
W, NW
|
|
Stevia eupatoria (Asteraceae)
|
Perennial herb unpalatable and producing dense infestations limiting grazing and pasture production. Seeds attach to wool and fur.
|
Native to Mexico, occurring in subtropical to temperate mountainous woodland or grassland above 500 m.
|
Not recorded
|
W, QW, NW
|
* Abbreviations for the Global Compendium of Weeds column:
W: weed; SW: sleeper weed; NW: noxious weed; NatW: native weed; EW: environmental weed.
Sources
A Global Compendium of Weeds. http://www.hear.org/gcw/alpha_select_gcw.htm
Delivering Invasive Alien Species Inventories for Europe (DAISIE) Database. http://www.europe-aliens.org/
NOBANIS - Network on Invasive Alien Species. http://www.nobanis.org
Royal Botanic Garden Edinburgh – Flora Europaea. http://rbg-web2.rbge.org.uk/FE/fe.html
Randall J (1999) Import Risk Analysis - Importation of weed species by live animals and unprocessed fibre of sheep and goats. Ministry of Agriculture and Forestry of New Zealand. 25 p. http://www.biosecurity.govt.nz/files/regs/imports/risk/weeds-seeds-ra.pdf