Biological control against parthenium weed in Australia

McFadyen, Rachel Cruttwell

doi:10.1016/0261-2194(92)90021-v

Cited by 101 publications

(14 citation statements)

References 8 publications

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“…The same method was used in this study where it was assumed that all species included in the calculations had a 'very high' impact on carrying capacity and, in-line with Van Wilgen et al (2008), reduce carrying capacity by 80% when very abundant, 20-50% when abundant and 5% when occasional. For example, P. hysterophorus impact was regarded as very high based on a study by McFadyen (1992) in Queensland Australia, who found that dense invasions reduced cattle stocking rates by up to 80%. For each weed, we applied impact estimates of Van Wilgen et al (2008) to the area with each level of abundance as in the CLIMEX models, assuming that the area indicated as suitable by the CLIMEX models is currently invaded: (1) the area environmentally unsuitable for a species was omitted from the analysis, (2) we assumed a 5% reduction in carrying capacities in areas where CLIMEX models indicated a suitability of between 1-30 for the target species, and 3) a 35% reduction in carrying capacities in areas where CLIMEX models indicated a suitability of between 30-100.…”

Section: Loss Of Livestock Derived Incomementioning

confidence: 99%

Towards estimating the economic cost of invasive alien species to African crop and livestock production

et al. 2021

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Background Invasive alien species (IAS) cause significant economic losses in all parts of the world. Although IAS are widespread in Africa and cause serious negative impacts on livelihoods as a result of yield losses and increased labour costs associated with IAS management, few data on the impacts are available in the literature and the magnitude and extent of the costs are largely unknown. We estimated the cost of IAS to agriculture, the most important economic sector in Africa. Methods Data on the monetary costs of IAS to mainland Africa as well as information about the presence and abundance of the most important IAS were collected through literature review and an online survey among a wide variety of stakeholders. Using this and additional data from publicly available sources we estimated yield losses and management costs due to IAS in agriculture for individual countries and the entire continent. Where the data allowed, the costs for selected IAS or crops were estimated separately. The estimates were extrapolated using production and distribution data and/or matching of agro-ecological zones. Results The total estimated annual cost of IAS to agriculture in Africa is USD 3.66 Tn. Yield losses, reductions in livestock derived income and IAS management costs, mainly labour costs, constitute the majority of the estimated cost (ca. 1, < 1 and 99 percent, respectively). The IAS causing the highest yield losses were Phthorimaea absoluta (USD 11.4 Bn) and Spodoptera frugiperda (USD 9.4 Bn). Conclusions This study reveals the extent and scale of the economic impacts of IAS in the agricultural sector in one of the least studied continents. Although the cost estimate presented here is significant, IAS also cause major costs to other sectors which could not be assessed due to data deficit. The results highlight the need for pre-emptive management options, such as prevention and early detection and rapid response to reduce huge potential future costs, as well as measures that contribute to large-scale control of widely established IAS at little cost to farmers and other affected land users, to reduce losses and improve livelihoods.

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Section: Loss Of Livestock Derived Incomementioning

confidence: 99%

Towards estimating the economic cost of invasive alien species to African crop and livestock production

et al. 2021

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“…In some countries such as Australia, the weed is reported to cause changes in the entire habitat in Australia grassland, open and woodlands, and river banks [37] [60]. Furthermore, [24] reported that Parthenium weed has a negative impact on the structural composition on dynamic and diversity of the plant and animals in India.…”

Section: Impacts Of Carrot-weed On Biodiversitymentioning

confidence: 99%

Carrot-Weed: A Noxious Plant That Threatens Biodiversity in Africa

Mtenga¹,

Tarimo²,

Ndakidemi³

et al. 2019

AJPS

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Carrot-weed (Parthenium hysterophorous L.) is a flowering plant of the Asteraceae family (tribe: Heliantheae). The weed became famous due to its notorious invasive role in the environment and agricultural fields. The plant has arisen as the seventh most disturbing weed globally. In Africa, the weed is spreading very fast and information on its biology, impact, and management is scarce. Therefore, this review provides general information about the carrot weed's current distribution status and its impact on agricultural crops, animals and human health in Africa. The review also highlights areas for research in managing this noxious weed in the African habitats.

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“…Parthenium hysterophorus is an annual herb native to tropical America, which has become a widespread invader of rangelands and cropping fields in at least 34 countries in Africa, Asia, Australia and the Middle East (Adkins & Shabbir 2014). The species is allelopathic, which enables it to suppress natural vegetation in a wide range of habitats (Aggarwal & Kohli 1992;Evans 1997;McFadyen 1992; Van der Laan 2006), including native grasses in the Kruger National Park (Van der Laan 2006). The weed was estimated to reduce stocking rates in Queensland, Australia, by 25% for light to medium infestations, and by as much as 80% for heavy infestations (McFadyen 1992) and by as much as 90% in India (Jayachandra 1971).…”

Section: Evidence Of Impact Of Selected Important Speciesmentioning

confidence: 99%

“…The species is allelopathic, which enables it to suppress natural vegetation in a wide range of habitats (Aggarwal & Kohli 1992;Evans 1997;McFadyen 1992; Van der Laan 2006), including native grasses in the Kruger National Park (Van der Laan 2006). The weed was estimated to reduce stocking rates in Queensland, Australia, by 25% for light to medium infestations, and by as much as 80% for heavy infestations (McFadyen 1992) and by as much as 90% in India (Jayachandra 1971). Parthenium hysterophorus also causes severe allergenic reactions (dermatitis, hay fever and asthma) in a large proportion of people who come into contact with it, as well as in livestock and wildlife (Patel 2011;Towers & Mitchell 1983).…”

Section: Evidence Of Impact Of Selected Important Speciesmentioning

confidence: 99%

“…although the exact extent of these invasions is not known, these species have taken over grasslands in other ecosystems and could exclude wildebeest from accessing critical areas in the future. (p. 168) Given that the large numbers of grazing mammals are dependent on good-quality forage, and given further that invasions by the alien plant species currently establishing in the area can reduce carrying capacities by up to 90% (Jayachandra 1971;McFadyen 1992;Ndlovu et al 2011;Yapi 2014), large impacts can be expected. For example, Ogutu et al (2009) found that the abundance of six large grazing mammal species declined markedly and persistently throughout the Masai-Mara National Reserve between 1989 and2003, and that the declines were contemporaneous with progressive habitat deterioration because of a range of factors, although invasion by alien plants was not considered.…”

Section: Potential Impacts On the Serengeti-mara Ecosystemmentioning

confidence: 99%

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A preliminary assessment of the extent and potential impacts of alien plant invasions in the Serengeti-Mara ecosystem, East Africa

Witt

Kiambi

Beale

et al. 2017

Koedoe

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This article provides a preliminary list of alien plant species in the Serengeti-Mara ecosystem in East Africa. The list is based on broad-scale roadside surveys in the area and is supplemented by more detailed surveys of tourist facilities in the Masai-Mara National Reserve and adjoining conservancies. We encountered 245 alien plant species; significantly more than previous studies, of which 62 (25%) were considered to have established self-perpetuating populations in areas away from human habitation. These included species which had either been intentionally or accidentally introduced. Of the 245 alien plants, 212 (including four species considered to be native to the region) were intentionally introduced into gardens in the National Reserve and 51 (24%) had established naturalised populations within the boundaries of these tourism facilities. Of the 51 naturalised species, 23 (11% of the 212 alien species) were recorded as being invasive within the ecosystem, outside of lodges and away from other human habitation. Currently, the Serengeti-Mara ecosystem is relatively free of widespread and abundant invasive alien plants, with a few exceptions, but there are extensive populations outside of the ecosystem, particularly to the west, from where they could spread. We address the potential impacts of six species that we consider to pose the highest risks (Parthenium hysterophorus, Opuntia stricta, Tithonia diversifolia, Lantana camara, Chromolaena odorata and Prosopis juliflora). Although invasive alien plants pose substantial threats to the integrity of the ecosystem, this has not yet been widely recognised. We predict that in the absence of efforts to contain, or reverse the spread of invasive alien plants, the condition of rangelands will deteriorate, with severe negative impacts on migrating large mammals, especially wildebeest, zebra and gazelles. This will, in turn, have a substantial negative impact on tourism, which is a major economic activity in the area.Conservation implications: Invasive alien plants pose significant threats to the integrity of the Serengeti-Mara ecosystem and steps will need to be taken to prevent these impacts. The most important of these would be the removal of alien species from tourist facilities, especially those which are known to be naturalised or invasive, the introduction of control programmes aimed at eliminating outlier invasive plant populations to slow down the spread, and the widespread use of biological control wherever possible.

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Biological control against parthenium weed in Australia

Cited by 101 publications

References 8 publications

Towards estimating the economic cost of invasive alien species to African crop and livestock production

Towards estimating the economic cost of invasive alien species to African crop and livestock production

Carrot-Weed: A Noxious Plant That Threatens Biodiversity in Africa

A preliminary assessment of the extent and potential impacts of alien plant invasions in the Serengeti-Mara ecosystem, East Africa

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