Grazing

Q&A

Description

C. cardunculus is an erect perennial herb that can grow between 60 and 150 cm, but has been known to grow as tall as 2 m with a spread of 2 m (Weeds of Australia, 2016;Elzebroek and Wind, 2008). It has a large taproot that regenerates each year (Kelly and Pepper, 1996). The root can grow to the depth of 2 m (Parsons and Cuthbertson 2001). The stems are thick and rigid, which often branch in the upper parts, they are longitudinally ribbed and covered in a cotton down. The above-ground portion of the plant dies down each year, but off-shoots rise from the rootstock next growing season (Elzebroek and Wind, 2008).

Impact

C. cardunculus is an erect perennial herb, commonly known as cardoon or artichoke thistle. Native to southern Europe and North Africa, it has been widely introduced and is recognised as invasive in parts of Australia, the USA, Chile and Argentina. It can form dense monocultures, displacing native vegetation and degrading native plant communities. In California, it is categorized as a Most Invasive Wildland Pest Plant, category A-1, on the Californian Exotic Pest Plants of Greatest Ecological Concern. It can aggressively invade and disrupt natural habitats and has been described as a robust invasive plant that exhibits characteristics of the world’s worst weeds.

Hosts

C. cardunculus is known to be a significant agricultural pest, in particular pastoral activity (Weeds of Australia, 2016). Once established C. cardunculus can become the dominant vegetation in an area by monopolising light, moisture and nutrients from the soil. In Australia it has known to adversely affect pastures, and lucerne, by crop contamination. The prickly nature of the herb deters grazing sheep and cattle (Parsons and Cuthbertson, 2001). A thick infestation can also limit the movement of livestock (Thomsen et al., 1986).

Biological Control
<br>Biological control is not feasible as C. cardunculus has closely related cultivated species, Cynara scolymus and Cynara altilis. It is unlikely that any biological control would therefore be restricted to C. cardunculus (Thomsen et al., 1986).<br>However in the USA, the accidentally introduced artichoke fly attacks the flower head of C. cardunculus. It is not an approved biocontrol agent and does not significantly affect commercial C. scolymus crops. The fly’s affect on native thistles is still being studied, and the impact on C. cardunculus populations are not known (DiTomaso et al., 2013).

Source: cabi.org
Description

P. hysterophorus is an erect, much-branched with vigorous growth habit, aromatic, annual (or a short-lived perennial), herbaceous plant with a deep taproot. The species reproduces by seed. In its neotropical range it grows to 30-90 cm in height (Lorenzi, 1982, Kissmann and Groth, 1992), but up to 1.5 m, or even 2.5 m, in exotic situations (Haseler, 1976, Navie et al., 1996). Shortly after germination the young plant forms a basal rosette of pale green, pubescent, strongly dissected, deeply lobed leaves, 8-20 cm in length and 4-8 cm in width. The rosette stage may persist for considerable periods during unfavourable conditions (such as water or cold stress). As the stem elongates, smaller, narrower and less dissected leaves are produced alternately on the pubescent, rigid, angular, longitudinally-grooved stem, which becomes woody with age. Both leaves and stems are covered with short, soft trichomes, of which four types have been recognized and are considered to be of taxonomic importance within the genus (Kohli and Rani, 1994).;Flower heads are both terminal and axillary, pedunculate and slightly hairy, being composed of many florets formed into small white capitula, 3-5 mm in diameter. Each head consists of five fertile ray florets (sometimes six, seven or eight) and about 40 male disc florets. The first capitulum forms in the terminal leaf axil, with subsequent capitula occurring progressively down the stem on lateral branches arising from the axils of the lower leaves. Thousands of inflorescences, forming in branched clusters, may be produced at the apex of the plant during the season. Seeds (achenes) are black, flattened, about 2 mm long, each with two thin, straw-coloured, spathulate appendages (sterile florets) at the apex which act as air sacs and aid dispersal.

Hosts

P. hysterophorus is known to reduce the yield of various crops and to compete with pasture species in various countries. However, the yield loss and specific effects on the crops have not been quantified in all countries (Rubaba et al., 2017).;In Australia, the main impact of P. hysterophorus has been in the pastoral region of Queensland, where it replaces forage plants, thereby reducing the carrying capacity for grazing animals (Haseler, 1976, Chippendale and Panetta, 1994). Serious encroachment and replacement of pasture grasses has also been reported in India (Jayachandra, 1971) and in Ethiopia (Tamado, 2001, Taye, 2002). The weed is also able to invade natural ecosystems, and has caused total habitat changes in native Australian grasslands and open woodlands (McFadyen, 1992).;In India, the yield losses are reported as up to 40% in several crops and a 90% reduction of forage production (Gnanavel, 2013). P. hysterophorus is now being reported from India as a serious problem in cotton, groundnuts, potatoes and sorghum, as well as in more traditional crops such as okra (Abelmoschus esculentus), brinjal (Solanum melongena), chickpea and sesame (Kohli and Rani, 1994), and is also proving to be problematic in a range of orchard crops, including vineyards, olives, cashew, coconut, guava, mango and papaya (Tripathi et al., 1991, Mahadevappa, 1997, Gnanavel, 2013).;Similar infestations of sugarcane and sunflower plantations have recently been noted in Australia (Parsons and Cuthbertson, 1992, Navie et al., 1996), whilst in Brazil and Kenya, the principal crop affected is coffee (Njoroge, 1989, Kissmann and Groth, 1992). In Ethiopia, parthenium weed was observed to grow in maize, sorghum, cotton, finger millet (Eleusine coracana), haricot bean (Phaseolus vulgaris), tef (Eragrostis tef), vegetables (potato, tomato, onion, carrot) and fruit orchards (citrus, mango, papaya and banana) (Taye, 2002). In Pakistan, the weed has been reported from number of crops, including wheat, rice, sugarcane, sorghum, maize, squash, gourd and water melon (Shabbir 2006, Shabbir et al. 2011, Anwar et al. 2012).;In Mexico, the species is reported as a weed in cotton, rice, sugarcane, Citrus spp, beans, safflower, sunflower, lentils, corn, mango, okra, bananas, tomato, grapes, alfalfa, chili peppers, luffa, marigolds and other vegetables and fruit orchards. It is also a weed in nurseries. In Argentina is reported as a weed of tobacco fields (CONABIO, 2018).;Gnanavel (2013) also reports the following detrimental effects of P. hysterophorus on crops: it inhibits nitrogen fixing bacteria in legumes, the vast quantity of pollen it produces (ca. 624 million/plants) inhibits fruit setting, it is an alternative host for viruses that cause diseases in crop plants, and it is an alternative host for mealy bugs.

Biological Control
The use of insect and fungal pathogens and the exploitation of allelopathic plants is considered by Kaur et al. (2014) as the most economical and practical way to manage the infestations of the species. Biological control has been, and continues to be, considered the best long-term or sustainable solution to the parthenium weed problem in Australia (Haseler, 1976, McFadyen, 1992) and because of the vast areas and the socio-economics involved, this approach has also been proposed for India (Singh, 1997). South Africa was the first country in Africa to implement a biological control program against the species in 2003 (Rubaba et al., 2017). Four host-specific biocontrol agents have been released sequentially since 2010 after evaluation of their suitability, with variable establishment and spread (Strathie et al., 2016).;The use of insects as biocontrol agents had been tried in various countries (Kaur et al., 2014). Searches for, and evaluation of, coevolved natural enemies have been conducted in the neotropics since 1977. So far, nine insect species and two fungal pathogens have been introduced into Australia as classical biological control agents (Julien, 1992, McClay et al., 1995, Navie et al., 1996, Dhileepan and McFadyen, 1997, Evans, 1997a). Callander and Dhileepan (2016) report that most of these agents have become established and have proven effective in central Queensland, but that the weed is now spreading further into southern Queensland where the biocontrol agents are not present. Several of the agents are therefore now being redistributed into south and southeast Queensland.;The rust fungus, Puccinia abrupta var. partheniicola, is a prominent natural enemy in the semi-arid uplands of Mexico (Evans, 1987a, b), but since its release in Queensland in 1992, climatic conditions have been largely unfavourable (Evans, 1997a, b). It was accidentally introduced into Kenya (Evans, 1987a) and Ethiopia in mid-altitudes (1400-2500 masl) with disease incidence up to 100% in some locations (Taye et al., 2002a). Screening of another rust species (Puccinia melampodii) from Mexico was carried out (Evans, 1997b, Seier et al., 1997) and released in Australia in the summer of 1999/2000 (PAG, 2000). This fungus was later renamed Puccinia xanthii Schwein. var. parthenii-hysterophorae Seier, H.C.Evans & ç.Romero (Seier et al., 2009). Retief et al. (2013) report on specificity testing carried out in quarantine facilities in South Africa, and conclude that the fungus is suitable for release as a biological control agent of P. hysterophorus in South Africa. The authors suggest that this species has more potential for biocontrol in South Africa than Puccinia abrupta, which may have little impact in the low-altitude, high-temperature areas of the country where the weed is spreading.;In India, the mycoherbicide potential of plurivorous fungal pathogens belonging to the genera Fusarium, Colletotrichum, Curvularia,Myrothecium and Sclerotium, has and is being evaluated (Mishra et al., 1995, Evans, 1997a). Parthenium phyllody disease caused by the phytoplasma of faba bean phyllody group (FBP) was reported to reduce seed production by 85% (Taye et al., 2002b) and is being evaluated for use as a biological control agent in Ethiopia. Kaur and Aggarwal (2017) have tested an Alternaria isolate found on the weed, and report that it is worth investigating as a mycoherbicide for control of parthenium. Metabolites of Alternaria japonica and filtrates of Alternaria macrospora have caused significant damage to Parthenium (Kaur et al., 2015, Javaid et al., 2017).;Among the established insect biocontrol agents, the leaf-feeding beetle, Zygogramma bicolorata, the stem-galling moth, Epiblema strenuana, the stem-boring beetle, Listronotus setosipennis, and the seed-feeding weevil, Smicronyx lutulentus, are proving to be the most successful when climatic factors are favourable (McFadyen, 1992, Dhileepan and McFadyen, 1997, Evans, 1997a). Some control of parthenium weed has also been achieved in India with Z. bicolorata (Jayanth and Visalakshy, 1994, Singh, 1997, Sarkate and Pawar, 2006), although there has been controversy concerning its taxonomy and host specificity (Jayanth et al., 1993, Singh, 1997). Shabbir et al. (2016) reported that Z. bicolorata was most effective when applied in higher densities and at early growth stages of the weed. The distribution of this leaf beetle in South Asia was investigated by Dhileepan and Senaratne (2009), when it was present in many states in India, and in the Punjab region of Pakistan. Shrestha et al. (2011) reported that Z. bicolorata arrived in the Kathmandu Valley of Nepal in August 2010, and that by September it had spread over half of the valley areas where P. hysterophorus was present, although damage to the weed was only appreciable at one site.;Z. bicolorata has been seen attacking sunflowers in India and the use of Epiblema strenuata has not been effective, as it was found affecting Guizotia abyssinica crops (Kaur et al., 2014). More recently, Z. bicolorata and L. setosipennis have been released in South Africa and S. lutulentus is being evaluated under quarantine. Before approval as a biocontrol agent in South Africa in 2013, extensive testing suggested that Z. bicolorata would not become a pest of sunflowers in the country (McConnachie, 2015).;The use of antagonistic, competitor plants, such as Cassia spp. and Tagetes spp., has been recommended to control and replace P. hysterophorus in India (Mahadevappa and Ramaiah, 1988, Evans, 1997a, Mahadevappa, 1997, Singh, 1997). In Australia, Bowen et al. (2007) tested a number of grass and legume species against the growth of parthenium weed plants and identified further species that could suppress weed growth. Recently, Khan et al. (2013) tested a number of native and introduced pasture species and identified several of them to be suppressive against parthenium weed in both glasshouse and field conditions. The sowing of selected pasture plants in infested areas can suppress the growth of parthenium weed by as much as 80% and also provide improved fodder for stock (Adkins et al., 2012). Shabbir et al. (2013) showed that the suppressive plants and biological control agents can act synergistically to significantly reduce both the biomass and seed production of parthenium weed under field conditions. The suppressive plants strategy is easy to apply, sustainable over time, profitable under a wide range of environmental conditions and promotes native plant biodiversity. Species reported as effectively outcompeting P. hysterophorus are Cassia sericea, C. tora, C. auriculata, Croton bonplandianum, Amaranthus spinosus, Tephrosia purpurea, Hyptis suaveolens, Sida spinosa, and Mirabilis jalapa. Extracts of Imperata cylindrica, Desmostachya bipinnata, Otcantium annulatum, Sorghum halepense Dicanthium annulatum, Cenchrus pennisetiformis, Azadirachta indica, Aegle marmelos and Eucalyptus tereticornis are reported as inhibiting the germination and/or growth of P. hysterophorus (Kaur et al., 2014).

Source: cabi.org
Description

T. domingensis is a rhizomatous perennial emergent wetland macrophyte. Ramets (culms) range from 1-6 m tall (Denny, 1985b) and consist of numerous slender, linear, distichous leaves with a sheathing base that emerge vertically from a central meristem. Ramets often produce a single, erect, monoecious flowering stem consisting of a staminate spike above a pistillate spike. At maturity, ramets can collapse from wind, or under their own weight (S Hall, University of Wisconsin, USA, personal communication, 2008). Rhizomes often measure several centimeters in diameter and produce abundant adventitious roots. Smith (1967, 2000) distinguished T. domingensis from similar species primarily on the basis of pistillate spike characters. T. domingensis is characterized by: pistillate bracteoles pale to light brown, slightly exceeding pistil hairs in mature spikes;pistil hair apices colorless to orange;stigmas linear to lanceolate, slightly exceeding bracteoles in mature spikes;pistillate spikes at anthesis cinnamon to light-brown, darkening slightly at maturity;monad pollen;staminate bracteoles (scales) straw to orange-brown colored;mucilage glands present on the adaxial surface of leaf sheathes and adjacent blades. Leaves are 6-18 mm wide, mature pistillate spikes are 13-26 mm wide, and the pistillate and staminate spikes are separated by a gap of 0-8 cm. Some quantitative macroscopic characters including spike width, gap length between pistillate and staminate spikes, and leaf width are useful, but are too variable for conclusive identification, which depends on the above microscopic floral characteristics. Finlayson et al. (1985) combined measurements of the gap between male and female inflorescences with the length and diameter of the female inflorescences to distinguish T. domingensis from T. orientalis in Australia.

Impact

T. domingensis can spread prolifically by rhizomes after seedlings establish in disturbed vegetation, often forming monotypes that reduce wetland plant and animal diversity. The species thrives under eutrophic conditions and artificially stabilized hydroperiods, but in undisturbed, low-nutrient wetlands, T. domingensis often grows sparsely and does not appear to reduce diversity. T. domingensis is economically important in many regions as a weaving material, but when invasive, the species can replace other valuable plant commodities. Short-term Typha control is provided by cutting, burning, or grazing, each followed by flooding, or herbicide, but re-growth from rhizomes and a vast soil seed-bank complicate eradication.

Hosts

T. domingensis can invade the margins of rice fields and lacustrine cornfields (Sykes 1981, cited in Finlayson et al., 1983;Hall, 2008).
Host Plants and Other Plants Affected
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Plant name|Family|Context
Oryza sativa|
Zea mays subsp. mays (sweetcorn)|Poaceae
Biology and Ecology
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Genetics
T. domingensis readily hybridizes with other sympatric species of Typha. T. domingensis x latifolia has mostly abortive pollen and low seed set, while T. angustifolia x domingensis (reported in France and California) is highly fertile and can form hybrid swarms (Geze, 1912, cited in Smith, 1987;Smith, 1967). T. domingensis, T. latifolia, and T. angustifolia share n=15 chromosomes (Smith, 1967). T. domingensis shows ecotypic variation for a number of traits, including salt tolerance, germination temperature, time of flowering, height, rhizome proliferation, and rhizome number (McNaughton, 1966). Because of the worldwide distribution of T. domingensis, quantitative data presented here will likely vary widely among regional ecotypes.
Reproductive Biology
T. domingensis is protogynous, self-compatible, and does not show apomixis (Smith, 1967). Pollen requires strong winds for dispersal, and T. latifolia pollen can travel distances of at least one km (Krattinger, 1975). Despite copious pollen production, self-pollination appears to exceed outcrossing even in dense stands of T. latifolia. Some populations of T. domingensis remain in anthesis for more than a month (McNaughton, 1966). Each inflorescence can produce 600,000 fruits, or 6-17 million seeds per m 2 depending on flowering ramet density, and plants established from seed can flower by the second year (Prunster, 1940, cited in Finlayson et al., 1983;Howard-Williams, 1975). Germination can occur year-round in many climates, given adequate moisture, although germination declines below 20 ° C (Finlayson et al., 1983). In the United States, southern populations germinated at a lower temperature (13 ° C) than their northern counterparts (McNaughton, 1966). Seeds germinate under moist or submerged conditions;in an extreme case, T. domingensis germinated under 80 cm of water and survived for 8 weeks (Nicol and Ganf, 2000). Salinity reduces germination, although limited germination can occur even at 20% salinity (Beare and Zedler, 1987). High salinity prevented T. domingensis from recruiting after a lake drawdown in Malawi (Howard-Williams, 1975). Exposure to light and hypoxia increase germination (Sifton, 1959), which is low under established vegetation (Finlayson et al., 1983). In natural areas not disturbed by humans, disturbance and herbivory by animals could facilitate seedling establishment of Typha seedlings (Svengsouk and Mitsch, 2001).
Lateral rhizomes can facilitate rapid vegetative expansion after seedling establishment. Individual T. latifolia clones can span 60 m (Krattinger, 1983), and T. domingensis can spread laterally at 3-10 m/year (Parsons and Cutherbertson, 1992;Fraga and Kvet, 1993). Rhizome production is stimulated by short days and cold temperatures (McNaughton, 1966).
Physiology and Phenology
In frost-free climates, T. domingensis can produce ramets (culms) year-round, although most emerge in summer and autumn, and do not survive longer than 10 months (Finlayson et al., 1983;Parsons and Cuthbertson, 1992). In a spring-fed wetland in central Mexico, T. domingensis growing in dense stands did not produce new ramets between May and October unless disturbed by leaf harvest (Hall et al., in press). Flowering ramets differentiate by spring, and become fertile by early summer. Grace and Harrison (1986) contend that high rhizome carbohydrate supplies promote Typha ramets to flower rather than to remain vegetative. Repetitive harvesting decreased rhizome starch reserves and flowering ramet density of T. domingensis, but drought stress could promote flowering (Hall, 2008). Carbohydrate dynamics have been studied for T. latifolia. Leaf biomass is at a maximum while rhizome biomass is minimized in late summer. By autumn, leaf carbohydrates have been translocated to rhizomes, biomass increases, and rhizome starch concentrations are maximized (Linde et al., 1976). For T. domingensis in Belize, leaf turnover averages 110 days (Rejmankova et al., 1996). Fraga and Kvet (1993) report that T. domingensis in Cuba had a net primary productivity of 1500 g/m 2 /year. Litterbag experiments showed only 50% decomposition after one year, and organic matter accumulated rapidly.
In flooded conditions, oxygen is conducted to Typha ’s underwater tissues via leaf aerenchyma cells (Sale and Wetzel, 1983), allowing T. domingensis to tolerate water 2 m deep (Finlayson et al., 1983). Flooded seedlings only produced additional ramets, however, when they reached the water surface (Nicol and Ganf 2000). T. domingensis is moderately salt-tolerant, and salinities of up to 5% should not impede vegetative growth or flowering. Salinity 5% prevents growth, and salinity 25% causes leaf mortality, although rhizomes re-sprout if salinity declines (Beare and Zedler, 1987). Freshwater inflows lasting 2 months allowed T. domingensis to invade California salt marshes. T. domingensis thrives in hot climates, and grows well in water at 30 ° C (Finlayson et al., 1983). Parsons and Cuthbertson (1992) reported maximum growth at 32 ° C, declining to 50% at 18 ° C. Typha spp. show a high tolerance for soil and water contaminated by heavy metals (McNaughton et al., 1974).
Nutrition
T. domingensis thrives under high nutrient loads and stable, prolonged, hydroperiods. In the Florida Everglades, T. domingensis invasion correlated with increased phosphorus and water levels, and muck-burning fires (Urban et al., 1993;Newman et al., 1998). Typha ’s limitation by phosphorus is supported by a comparison of soil and plant tissue samples from eutrophic and un-impacted areas of the Everglades (Koch and Reddy, 1992). T. domingensis also appeared limited by phosphorus in wetlands of Mexico’s Yucatan Peninsula and Belize (Rejmankova et al., 1996). In mesocosms, elevated nutrient levels and prolonged hydroperiods increased T. domingensis biomass and tissue phosphorus concentration relative to the co-occurring Cladium jamaicense (Newman et al., 1996). Substantial peat, nitrogen, and phosphorus accumulated where T. domingensis dominated nutrient-rich areas of the Everglades (Craft and Richardson, 1993). Seedlings produced more biomass, had a greater root/shoot ratio, and contained more phosphorous when grown in burned soil than in unburned or surface-burned soil in the Everglades, suggesting that soil-burning fires promote T. domingensis by releasing phosphorus (Smith and Newman, 2001). In low-nutrient areas of the Everglades, Typha is present but does not dominate (Davis, 1994).
Nitrogen and phosphorus appeared to co-limit the congener T. latifolia when it was grown in mesocosms, whereas in the field, T. latifolia increased along a gradient of increasing phosphorus (Svengsouk and Mitsch, 2001). T. x glauca required both nitrogen and phosphorus for growth in a greenhouse experiment, but adding a higher proportion of phosphorus stimulated growth regardless of nutrient concentration (Woo and Zedler, 2002).
Associations
In disturbed and eutrophic wetlands, T. domingensis tends to form monotypes. However, T. x glauca ’s invasive growth may be dependent on anthropogenic modifications (e.g. from dams, wastewater discharge, or irrigation canals). In little-disturbed wetlands where hydroperiods fluctuate seasonally, many genera co-occur with T. domingensis. In Australian wetlands, Baumea, Eleocharis, Gahnia, Melaleuca, Muehlenbeckia, and T. orientalis co-dominate with T. domingensis where water levels fluctuate (Finlayson et al., 1983;Nicol and Ganf, 2000). In Cuba, Bidens, Cyperus, Eleocharis, Hyparrenia, Panicum, and Sagittaria can co-occur with T. domingensis in shallow water, although T. domingensis often forms temporary monotypes in deeper water (Fraga and Kvet 1993). In this system, shrubs can replace Typha because of rapid organic matter accumulation;frequent fire might reduce litter and retard succession. In Africa’s Lake Victoria, T. domingensis is less abundant than the dominant Cyperus or Miscanthidium (Kansiime et al., 2007);in Lake Chad, Vossia, Cyperus, and Phragmites dominate, while T. domingensis is rare (Denny, 1985a). Thompson (1985) ranked T. domingensis as the third most-dominant African wetland plants, behind Phragmites australis and P. mauritianus. In Belize, T. domingensis normally dominates on clay soils with low salinity, while growing sparsely with dominant Eleocharis and Cladium on marl and sandy soil with higher salinity (Rejmankova et al., 1996). T. domingensis monotypes in this region may be relics of phosphorus-rich agricultural run-off. In Iran, T. domingensis and Schoenoplectus tabernaemontani co-dominate diverse wetlands (Karami et al., 2001). In a groundwater-fed wetland in central Mexico, harvesting T. domingensis increased species richness and the recruitment of uncommon species (Hall, 2008). Here, more than 40 species co-occurred with Typha and the co-dominant Schoenoplectus americanus.
Environmental Requirements
T. domingensis tolerates a broad climatic spectrum, growing between 40 ° latitude north and south under a variety of rainfall regimes (Smith, 2000). Although T. domingensis tolerates widely variable hydroperiods, it can decline during extended drawdowns, and grows best under flooded conditions (Rejmankova et al., 1996;Palma-Silva et al., 2005). Rainfall does not appear to limit wide-scale geographic distribution, because even in seasonally dry climates (e.g. central Mexico), T. domingensis can persist in isolated springs or on lakeshores. Seedlings can tolerate anaerobic conditions, but mature plants are intolerant of anaerobic conditions created when leaves are severed below water (Sale and Wetzel, 1983).
Climate
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Climate|Status|Description|Remark
Af - Tropical rainforest climate| Preferred
60mm precipitation per month
Am - Tropical monsoon climate| Preferred
Tropical monsoon climate (60mm precipitation driest month but (100 - [total annual precipitation(mm}/25]))
As - Tropical savanna climate with dry summer| Preferred
60mm precipitation driest month (in summer) and (100 - [total annual precipitation{mm}/25])
Aw - Tropical wet and dry savanna climate| Preferred
60mm precipitation driest month (in winter) and (100 - [total annual precipitation{mm}/25])
BS - Steppe climate| Preferred
430mm and 860mm annual precipitation
BW - Desert climate| Preferred
430mm annual precipitation
C - Temperate/Mesothermal climate| Preferred
Average temp. of coldest month 0°C and 18°C, mean warmest month 10°C
Cf - Warm temperate climate, wet all year| Preferred
Warm average temp. 10°C, Cold average temp. 0°C, wet all year
Cs - Warm temperate climate with dry summer| Preferred
Warm average temp. 10°C, Cold average temp. 0°C, dry summers
Cw - Warm temperate climate with dry winter| Preferred
Warm temperate climate with dry winter (Warm average temp. 10°C, Cold average temp. 0°C, dry winters)
Latitude/Altitude Ranges
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Latitude North (°N)|Latitude South (°S)|Altitude Lower (m)|Altitude Upper (m)
40
40
0
0
Soil Tolerances
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Soil drainage
impeded
seasonally waterlogged
Soil reaction
acid
alkaline
neutral
Soil texture
heavy
light
medium
Special soil tolerances
infertile
other
saline
shallow
sodic
Notes on Natural Enemies
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Herbivory is common but variable. In Australia, kangaroos, rodents, and water birds lightly graze T. domingensis, while water buffalo can cause heavy damage (Finlayson et al., 1983). In Africa, large herbivores do not extensively feed on T. domingensis, despite its abundance (Howard-Williams and Gaudet 1985). In Costa Rica and elsewhere throughout Latin America, cattle heavily graze T. domingensis (McCoy et al., 1994). Muskrats (Ondatra zibethicus) can eliminate entire stands of Typha spp. through herbivory, at least in temperate climates (Kadlec et al., 2007). Barreto et al. (2000) mention a variety of fungal pathogens, although none have been extensively studied in the field. A variety of insects feed on T. latifolia and T. angustifolia. Lepidopteran larvae often inhabit inflorescences, while noctuid caterpillars and coleoptera attack leaves, stalks, and sometimes rhizomes (Grace and Harrison, 1986).
Means of Movement and Dispersal
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Natural Dispersal (Non-Biotic) Typha ’s tiny seeds (1 - 2 mm long) are contained in achenes attached to pistil hairs, and are often dispersed by the wind. Spikes do not shed fruits until they have dried (Krattinger, 1975), often delaying dispersal until many months after seed maturation. The entire female spike sometimes collapses in place, providing a floating platform for germination (Hall, 2008). Masses of achenes and hairs, and rhizomes, can disperse by floating on currents of water (Grace and Harrison 1986;Parsons and Cutherbertson, 1992).
Vector Transmission (Biotic)
When achenes are moistened, seeds are released, which have a pointed end that can become embedded in fish scales (Krattinger, 1975). Also, pistil hairs (with attached acenes) adhere to the clothing of fieldworkers, and could attach to animals as well (S Hall, University of Wisconsin, USA, personal communication, 2008). Mud with embedded seeds readily sticks to humans, livestock, birds, and agricultural implements (Parsons and Cuthbertson, 1992).
Intentional Introduction
Indigenous people in the Northwestern United States propagated T. latifolia using rhizome fragments (Turner and Peacock, 2005). Similar propagation of T. domingensis has not been documented.
Pathway Causes
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Cause|Notes|Long Distance|Local|References
Crop production|Seeds attach to mud on agricultural implements.| Yes
Parsons and Cuthbertson,
1992
Disturbance|Seedlings establish in disturbed vegetation.| Yes
Finlayson et al.,
1983
Hitchhiker|Achenes with hairs attach to humans and animals.| Yes
Yes
Parsons and Cuthbertson,
1992
Interbasin transfers|Achenes and rhizomes disperse with water currents.| Yes
Grace and Harrison,
1986;Parsons and Cuthbertson,
1992
Interconnected waterways|Achenes and rhizomes disperse with water currents.| Yes
Grace and Harrison,
1986;Parsons and Cuthbertson,
1992
Self-propelled|Achenes with hairs are wind-dispersed.| Yes
Krattinger,
1975
Pathway Vectors
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Vector|Notes|Long Distance|Local|References
Clothing, footwear and possessions|Achenes with hairs.| Yes
Parsons and Cuthbertson,
1992
Host and vector organisms|Achenes adhere to fish scales.| Yes
Krattinger,
1975
Water|Achenes with hairs, rhizomes.| Yes
Grace and Harrison,
1986;Parsons and Cuthbertson,
1992
Wind|Achenes with hairs.| Yes
Yes
Krattinger,
1975
Impact Summary
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Category|Impact
Economic/livelihood
Positive and negative
Environment (generally)
Positive and negative
Economic Impact
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T. domingensis can interfere with agriculture in wet areas. With the adoption of year-round rice cropping in Australia, T. domingensis invaded fields and decreased yields by 5% (Sykes 1981, cited in Finlayson et al., 1983). In central Mexico’s Lake Pátzcuaro, T. domingensis can invade low-lying cornfields. This species also tends to replace the bulrush Schoenoplectus californicus, a valuable species traditionally used to weave mats (Hall, 2008). In southern Mexico, T. domingensis invades wetlands used for horse pasture, and replaces valuable fodder (S Hall, University of Wisconsin, USA, personal communication, 2009). In lacustrine wetlands, T. domingensis can interfere with fishing and water transportation (Mitchell, 1985).


Source: cabi.org
Description

D. caricosum is a perennial, stoloniferous grass. Culms tufted at nodes of stolons, geniculately ascending, 30–60 cm tall, nodes glabrous or pubescent. Leaf sheaths compressed, keeled, shorter than internodes;leaf blades flat, 15–20 cm × 2.5–5 mm, glabrous or with a few hairs at base, margins smooth or scabrid, apex acuminate;ligule less than 1 mm, margin ciliate. Inflorescence terminal;peduncle glabrous;racemes (1–)2–4, 2.5–5 cm, with 1–3 pairs of homogamous spikelets. Sessile spikelet 3–3.5 mm;lower glume obovate-elliptic or obovate-oblong, papery, 8–12-veined, glabrous or often sparsely hirsute on lower back, slightly glossy, margins shortly ciliate, keels winged, apex rounded;upper glume ciliate above middle, apex obtuse;awn 1.5–2.5 cm, weakly geniculate. Caryopsis obovate-oblong. Pedicelled spikelet many-veined, resembling sessile (Flora of China Editorial Committee, 2015).

Impact

D. caricosum has been intentionally introduced as a perennial grazing pasture with excellent ground cover. Now, it can be found widely naturalized in tropical and subtropical regions (Cook et al., 2005;FAO, 2015). It has escaped from cultivation and has become a weed and invasive grass in Cuba, Guam, New Caledonia, and Fiji (MacKee, 1994;Oviedo Prieto et al. (2012);PIER, 2015). In Cuba, it is widespread across the islands. In Fiji, it covers large areas being very common especially in the dry zones, in pastures, canefields, waste places, and along roadsides (Smith, 1979). D. caricosum is a fast-growing gregarious grass that competes aggressively with other plants including other weeds (Cook et al., 2005).

Hosts

D. caricosum is a common weed with negative impact in pastures and sugarcane fields (Smith, 1979).


Source: cabi.org
Description

C. biflorus is a loosely tufted, annual grass, with ascending stems (culms) up to 1 m tall. Leaves alternate, simple and entire;ligule a line of hairs;blade linear, flat, 2–25(–35) cm × 2–7(–10) mm, apex filiform. Inflorescence a spike-like panicle 2–15 cm × 9–12 mm, with 1–3 spikelets enclosed by an involucre of prickly bristles;rachis angular, sinuous;involucre ovoid, 4–11 mm long with numerous spines, inner spines erect, fused at base, retrorsely hairy on the pungent, recurving apex, outer spines shorter, spreading. Spikelet lanceolate 3.5–6 mm long, acute, consisting of two glumes and usually two florets;glumes shorter than spikelet;lower floret male or sterile, its lemma as long as spikelet, membranous, upper floret bisexual, its lemma as long as spikelet, thinly leathery;stamens three, ovary superior, glabrous, with two hairy stigmas. Fruit a dorsally compressed caryopsis (grain), 2–2.5 mm × 1.5–2 mm (PROTA, 2015).

Impact

C. biflorus is an annual grass native throughout tropical Africa into Pakistan and India. It has been introduced outside of its native range into southern Africa, North America and Australia. C. biflorus is used as a forage and famine crop but more recently it has been recognised as an invasive species. The retrorsely barbed bristles are readily spread in animal fur and can seriously reduce the value of animal hides, while the barbs can damage the mouths of grazing animals. In addition to this, it is possible for this species to dominate disturbed areas and suppress the growth of native biodiversity. C. biflorus is reported as an agricultural weed in a number of countries including Niger, Nigeria, Saudi Arabia and Senegal.

Hosts

C. biflorus occurs as a weed in a wide range of crops, including Pennisetum glaucum (pearl millet) (Munde et al., 2012), Hibiscus sabdariffa (roselle) (El-Naim and Ahmed, 2010) and species of Sesamum indicum (sesame) (Chandawat, 2004).


Source: cabi.org
Description

Clayton et al. (2006) describes V. bromoides as the following

Impact


Weedy annual grasses like V. bromoides can reduce biodiversity on native grasslands, impede their restoration, and alter ecosystem processes. In pastures, V. bromoides reduces productivity, has low palatability, and its seeds can damage hides and wool of grazing animals. In annual crops like wheat, the species reduces yields (ISSG, 2012).

Hosts


In Canada, V. bromoides is one of several species named as threatening the habitat and therefore the survival of Rosy Owl-clover (Orthocarpus bracteosus) (Fairburns, 2002).


Source: cabi.org
Description

D. annulatum is a perennial grass with culms 25-100 cm tall, ascending, nodes pubescent. Sheaths lax, terete, 3-4 cm long, glabrous except finely pubescent on margins near throat;ligule a shallow membrane, approximately 1.5 mm long;blades linear-acuminate, 3-30 cm long, 2-7 mm wide, margins sparsely pubescent, apex attenuate, base subcordate. Inflorescences composed of (1) 2-15 subdigitate, short-pedunculate racemes, each raceme 3-7 cm long, peduncles glabrous;spikelet pairs subimbricate along a slender filiform axis, with 0-6 smaller homogamous spikelet pairs at base, the joints and pedicels flattened, margins setose;sessile spikelet narrowly oblong, 2-6 mm long, first glume cartilaginous, slightly concave, villous below the middle, pubescent with long bulbous-based hairs above the middle, obscurely nerved, margins inflexed, apex obtuse to subacute, second glume narrowly boat-shaped, 2-6 mm long, 3-nerved, scabrid on back of the midnerve toward apex, obscurely scaberulous over the back toward apex, hyaline, first lemma delicately hyaline, oblong-rounded, setose near tip, approximately 2 mm long, palea absent, second lemma linear, approximately 1.6 mm long, hyaline, with the central nerve excurrent as a geniculate, twisted awn 8-25 mm long;pedicellate spikelet with first glume narrowly ovate-truncate, approximately 3 mm long, 11-nerved, pectinate-setose along the back of the inflexed margins, midnerve setose on the back toward apex. Caryopsis oblong to obovate, dorsally compressed, approximately 2 mm long (Wagner et al., 1999).

Impact

D. annulatum is a perennial grass widely naturalized in tropical and subtropical regions of the world where it has been intentionally introduced. This grass species is used for grazing and for hay and silage (Barkworth et al., 2003;Cook et al., 2005;FAO, 2014). It has escaped from cultivation and has become a weed in the United States, Australia, Mexico, Central America and the West Indies (Villaseñor and Espinosa-García, 2004;Chacon and Saborío, 2012;Gonzalez-Torres et al., 2012;Randall, 2012;USDA-NRCS, 2014). D. annulatum has been intentionally introduced as a pasture grass because of its capability to establish on a wide variety of soils (including poorly drained soils), and its salinity and drought tolerance (i.e., 6- 8 months dry seasons;Cook et al., 2005). It competes aggressively with other plants and grows forming dense stands (Vibrans, 2011). D. annulatum also tolerates seasonal burning (Cook et al., 2005).

Hosts


In Australia, D. annulatum is competing aggressively with important native grasses such as the species Eriachne benthamii. In Texas (USA), this species has escaped from pastures and is outcompeting native grasses in bluestem coastal grassland communities (Queensland Department of Primary Industries and Fisheries, 2011).


Source: cabi.org
Description


Annual or very rarely biennial, herbaceous, from a stout taproot;stems 15-200 cm tall, erect, glabrous to sparsely tomentose, narrowly and discontinuously winged, the wings spinose, tomentose, branched above the lower third, branches erect to ascending. Basal leaves 6-15 cm long, oblanceolate, deeply 4-10-lobed, the base tapered;cauline leaves alternate, decurrent, sinuate to pinnately lobed, margins spinose, upper surfaces loosely tomentose, becoming glabrous, lower surfaces densely tomentose. Heads discoid (all corollas radial and salverform), 17-22 mm long, 10-20 mm wide, cylindrical to subcylindrical, sessile to stalked, solitary or 2-5 in terminal clusters. Outer phyllaries ovate-lanceolate, loosely tomentose, margins membranous, apices acuminate, terminating in a straight spine;inner phyllaries narrower, scarious. Corollas 10-14 mm long, pink to rose-purple, sometimes white. Achenes 4-6 mm long, tan to brown, sometimes shiny, transversely wrinkled, tubercled above;pappus 10-20 mm long, composed of flat, minutely barbed, white bristles. (Description slightly modified from Wilken and Hannah, 1998).

Impact

Carduus pycnocephalus is a thistle that is native to the Mediterranean region and some other countries further north or east. It has been introduced, presumably accidentally, to the USA, Australia, New Zealand and some other countries in Europe, Asia, Africa and South America. In many of the countries where it has become naturalized it is regarded as a legally-defined noxious plant or pest plant, depending on the current terminology;it also causes problems in some countries where it is considered a native species. It can form dense infestations in some places where it can smother other, smaller plants and, where it occurs in grazed pastures, can limit the access of livestock and also cause them physical damage, as well as contaminating wool. In this way it has become a problem in the USA, Australia, New Zealand, Pakistan, Iran and Europe (Pitcher and Russo, 1988).

Hosts


Pasture species can be replaced, their growth inhibited and accessibility to grazing livestock obstructed by high populations of C. pycnocephalus rosettes and flowering plants (Kelly and Popay, 1985).

Biological Control
<br>According to Picher and Russo (1988) all major parts of C. pycnocephalus are damaged by one or more insect species in southern Europe, whereas in southern California the thistles are relatively free of insect damage. The seed head weevil Rhinocyllus conicus [or Curculio conicus ] has been introduced into several countries (Canada, USA, Australia, New Zealand) for control of one or more thistle species, including C. pycnocephalus. The larvae feed on the receptacle and developing achenes of thistle species and certainly destroy many seeds, but often enough survive to maintain populations of thistles (Popay et al., 1984;Pitcher and Russo, 1988). A crown weevil (Trichosirocalus horridus [or Ceutorhynchus horridus ]) has also been introduced to several countries as a biocontrol agent for thistle species and may be effective against C. pycnocephalus.<br>The fungal rust Puccinia cardui-pycnocephali [ P. calcitrapae ], already present in many countries where C. pycnocephalus or C. tenuifolius or both are present, has also been considered as a possible biocontrol agent, but its effects seem less than lethal although more virulent strains may be more damaging (Olivieri, 1984).

Source: cabi.org
Grazing Yellows
Description

C. intestinalis is a solitary, translucent ascidian that can have a pale yellow or pale green hue. If individuals are not fouled by algae or invertebrates, ten muscle bands that run the length of the body are visible, and pale orange internal organs are seen through the translucent body. The brachial siphon has eight lobes and the atrial siphon has six lobes. Both siphons may have yellow or orange margins.

Hosts

C. intestinalis can quickly form dense aggregations, which can smother and eventually exclude other fouling species and exert heavy grazing pressure on the local phytoplankton and bacterial communities (Peterson and RiisgŒrd, 1992;Lambert and Lambert, 1998;RiisgŒrd et al., 1998;Blum et al., 2007;Petersen, 2007). In Tasmania, C. intestinalis was found to harbour the amoeba, Neoparamoeba pemaquidensis, which is responsible for amoebic gill disease in farmed salmon (Tan et al., 2002).


Source: cabi.org
Description

O. ficus-indica is a large trunk-forming segmented cactus which can attain a height of 5–7 m with a crown of over 3 m in diameter and a trunk up to 1 m in diameter. Cladodes (flat stem segments) are green to blue-green, whereas the terminal cladodes are always bright green and produce the flowers and new growth. The cladodes bear few spines to 2.5 cm or are completely spineless. Cladodes are obovate to oblong, 20–60 cm long and 10–40 cm wide, generally a half to two-thirds as broad as long. Glochids (spines) are yellow, numerous, caducous, or may not be present. Basal cladodes become woody with age. Areoles, which can number a few hundred per cladode, generally produce only one flower each. Flowers form at the apex of the cladodes, yellow or orange, cup-shaped, 6–7 cm long by 5–7 cm across. The fruit is oblong, 5–10 cm long by 4–9 cm across, green at first ripening to yellow, orange, red or purple in colour depending on the variety. The number of ovules and hence possible seeds is 150–400 (Janick and Paull, 2008).

Impact

O. ficus-indica is the most widespread and most commercially important cactus, and has been, and continues to be, widely introduced as a commercial fruit and fodder crop and more recently as part of forestry or agroforestry projects in developing countries. This has led to a large improvement to livelihoods, but has also resulted in environmental problems when the plant has become invasive. Animals disperse seed widely and vegetative propagation has made this species difficult to eradicate by mechanical and chemical means. Biological control has proved effective in some areas, but the conflict with commercial production has limited the adoption of this method in other countries.

Hosts

O. ficus-indica is not a normally a crop weed. However, in Ethiopia, infestations and hedges that surround cultivated lands are invading from the periphery, which then gradually reduce the cultivatable area and farmers have very limited means to control these invading plants from their lands. These aggressive invasions can, in time, take over entire cultivated land areas. Dense infestations also out-compete with other plants eventually leading to monospecific stands of O. ficus-indica which occurs on pastures and grazing is severely impeded, with stock forced to eat predominantly O. ficus-indica for survival.


Source: cabi.org
Grazing Ulex europaeus
Description

U. europaeus is a woody, spiny shrub that normally grows to 2-2.5 m tall in its native range (Clapham et al., 1987), but up to 7 m tall where introduced such as in New Zealand (Lee et al., 1986). It normally grows erect with ascending stems. It is densely branched in the younger outer layers, but eventually bare at the base. It can adopt a prostrate habit where grazing is heavy, or where exposed to severe wind (Clements et al., 2001). It has shallow lateral roots that are often heavily nodulated, and often has a long central taproot (Grubb et al., 1968;Richardson and Hill, 1998). Seedlings have juvenile leaves that are usually trifoliate, and these are often retained basally in the first year of growth in a form resembling a rosette. As the primary stem begins to grow, spines (modified primary branches) begin to form in the axils of reduced leaves. Secondary and tertiary spines usually form on the primary spine (Millener, 1961;Richardson and Hill, 1998). The deeply-ridged green stems are clothed with sparse hairs, and spines are alternate. Green stems have a pronounced wax layer (Zabkiewicz and Gaskin, 1978a) and normally end in a terminal spine. Leaves are reduced to insignificant scales or phyllodes at the junction of the spine and the stem. The yellow, pea-like flowers are borne singly or in small axillary clusters. The flowers are 1.5-2 cm long. Petals are enclosed by two bracteoles 2-4 mm long, and by the calyx, which is two-thirds the length of the corolla. The calyx is covered with spreading hairs. The pods are initially green and pubescent but turn black as they mature. Seeds are dark brown, dark green or black, sub-ovate (unevenly sub-spherical) and 2-4 mm long, each bearing a yellow elaiosome (aril). There are one to six seeds per pod. U. europaeus subsp. europaeus has bracteoles that are ovate, sub-acute and 2-4 mm wide, and this subspecies occurs throughout the range of the species. U. europaeus subsp. latebracteatus is native only in north-western Spain and central Portugal, mainly near the coast, and has bracteoles that are sub-orbicular, obtuse and 2-4 mm wide (Heywood and Ball, 1968).

Recognition


With the advent of modern fencing methods, it is unlikely that U. europaeus will ever be introduced to another country for this purpose, and it is also unlikely that U. europaeus would be imported in seeds for sowing because the seed is large and an obvious contaminant. However, it could be transported inadvertently in mud on vehicles, on imported animals or in imported livestock feed. It is a declared noxious weed in four states of the USA;California, Hawaii, Oregon, Washington (USDA-ARS, 2007).

Impact

U. europaeus was spread intentionally through most of the world in the 1800s and 1900s as a hedge plant, an ornamental and as a forage, although it is unlikely that it will be distributed to new areas for these purposes in future. It has large seeds and there is a threat from inadvertent introduction, but this is not high. U. europaeus was already declared a noxious weed 100 years ago in Australia and New Zealand, and is now a serious weed in many other countries, and poses a threat elsewhere where it is present but not yet invasive. It is an aggressive colonizer of disturbed habitats, and the risk from continued invasion in suitable climatic zones in countries where present is high. It is a tough, spiny, long-lived, tall shrub with a long-lived seed bank and is difficult to control. Thickets displace vegetation in grassland habitats, and outgrow and supplant tree seedlings in plantation forests. Heavy infestations modify soil and hydrological conditions, and so modify ecosystem processes. This plant poses a serious fire risk for indigenous ecosystems as well as managed habitats and human habitations.

Hosts


Although often used as a hedging plant, U. europaeus is not generally a weed of crops, but does invade pasture land, and has become a serious environmental weed in some countries.


Source: cabi.org
Description


The following paragraph is taken from Zouhar (2009, and references therein which relate largely to the USA), who notes that there exist substantial morphological variations in the species globally.
I. tinctoria is typically a biennial or short-lived usually monocarpic perennial, sometimes described as a winter annual, but this may be occasional or very localized. The plant begins as a rosette with long-petioled basal leaves usually 4-10 cm long and 0.8-4 cm wide, usually covered with simple leaves. Leaves are blue-green and slightly pubescent (Varga and Evans, 1978). Some sources suggest that around 20 stalks begin to develop from each rosette with seven or fewer maturing, while others consider that the plant usually has one main stem, simple below and branched above. Stems are erect, ranging from 35 to 120 cm tall, but mostly in the 50-90 cm range, with stem leaves, narrower than basal leaves, reducing as they rise up the stem. The plants are glabrous or hirsute. The flowers are about 6mm wide with petals about 3.5cm long. Flowers are borne in numerous, compound racemes forming a large, terminal panicle. The root system is dominated by a substantial taproot which can exceed 1.5 m in depth, with lateral roots on the upper 20-30 cm that spread laterally about 40 cm.

Recognition


Largely achieved after growth of the plant, rather than through inspection. Detection in seed, forage or similar is achievable.

Impact

Isatis tinctoria is a herbaceous dye plant which has spread, often by human intervention, widely from its area of origin in central Asia or southeast Russia. Long valued for the dye it produces, it is of pest status in alkaline soils of some western states of the United States. It is the main biotic threat to the endangered Siskiyou Mariposa Lily (Calochortus persistens) found on the California-Oregon border and also threatens the endangered Yreka phlox, Phlox hirsuta. It responds well to high inputs of fertilizer and water, but also competes well in disturbed, dry and nutrient poor conditions. Its fruits have germination-inhibiting factors and the plant produces glucosinates which may alter soil microbiological properties. It causes considerable production losses of desired plants in rangelands. Control methods are effective, but with logistical challenges, especially in more remote areas. A native rust, Micropuccinia thlaspeos, limits, but does not prevent spread. Arthropod biological control agents are being researched in Europe, but to date none are specific enough.

Hosts

I. tinctoria competes with plants of pastures, forests and rangeland and with cereal crops and alfalfa. It is most troublesome on rangeland, in disturbed non-crop sites and in undisturbed natural areas in the intermountain west (DiTomaso et al., 2013). Callihan et al. (1984) list 23 plants of rangeland, 13 of pastures and cropland and 12 of disturbed areas that were observed, collected or associated with I. tinctoria. The rangeland habitats were dominated by Artemisia tridentata (big sagebrush). I. tinctoria is reported to quickly suppress annual grasses in rangeland, but perennial grasses appear to co-exist moderately well (Callihan et al., 1984). Perennial grasses were the main native grass species in western rangeland before being replaced by introduced annual grasses (DiTomaso, 2000) which were aided by overgrazing by introduced domestic animals. These livestock tend to avoid grazing I. tinctoria (DiTomaso, 2000).


Source: cabi.org
From Wikipedia:

In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed to consume wild vegetations outdoor in order to convert grass and other forages into meat, milk, wool and other animal products, often on land unsuitable for arable farming.

Farmers may employ many different strategies of grazing for optimum production: grazing may be continuous, seasonal, or rotational within a grazing period. Longer rotations are found in ley farming, alternating arable and fodder crops; in rest rotation, deferred rotation, and mob grazing, giving grasses a longer time to recover or leaving land fallow. Patch-burn sets up a rotation of fresh grass after burning with two years of rest. Conservation grazing deliberately uses grazing animals to improve the biodiversity of a site.

Grazing has existed since the birth of agriculture; sheep and goats were domesticated by nomads before the first permanent settlements were created around 7000 BC, enabling cattle and pigs to be kept.

Grazing's ecological effects can be positive and include redistributing nutrients, keeping grasslands open or favouring a particular species over another. There can also be negative effects to the environment with overgrazing, such as soil degradation, ecological disturbance and desertification.

Feeding on standing vegetation, as by livestock or wild animals.