scholarly journals Pteris multifida (spider brake).

Author(s):  
Jeanine Velez-Gavilán

Abstract Pteris multifida is a herbaceous fern native to temperate and tropical eastern Asia and naturalized on many continents as a result of being widely cultivated. Although it is an urban weed, it is not considered by most countries as an invasive or noxious weed. There is no information available on the species affecting native species or natural habitats. Although one source lists P. multifida as an invasive species in many countries outside of Africa due to it being easily dispersed by spores, there are no references or further information to support this statement. It is reported as an alien invasive species in Germany, but only as occurring in sheltered sites, growing on light-vents in cellars and walls. A species assessment for Florida, USA indicates, P. multifida is neither a weed of natural habitats nor of agriculture. The species has not been listed as an invasive plant in any state or natural areas of the USA. However, P. multifida has been assigned a Tier II Invasive Species status (defined as having moderate negative impacts on wildlife or natural communities in Louisiana), but of limited concern and/or extent in Louisiana. Pteris multifida is recorded in Cuba as potentially invasive being categorized as a species with a tendency to proliferate in some areas and capable of producing vast amounts of diaspores with high dispersal potential. No further details are given about potential invasiveness.

2021 ◽  
Vol 23 (10) ◽  
pp. 295-300
Author(s):  
F.Johnsy Mary ◽  
◽  
Dr.M.Senthil Kumar ◽  
E. Vijaykumar ◽  
G. Yadeshwaran ◽  
...  

Parthenium hysterophorus, often known as congers grass, is a noxious weed that is a member of the Asteraceae family of plants. Its natural habitats include the areas surrounding the Gulf of Mexico, Central America, Southern North America, the West Indies, and Central South America, among other places. Congress grass has risen to become one of the world’s seven most destructive and deadly weeds, according to the World Health Organization. This invasive plant is also a significant concern in India. It is responsible for a variety of illnesses and allergies in both people and animals. Aside from that, there is some potential for this plant to be used as an insecticide, herbicide, fungicide, wood preservative, anti-amoebic, and even for medicinal purposes. If any species, particularly an invasive weed, is to be evaluated for its ability to benefit living organisms, it is necessary to have a thorough understanding of both its positive and negative impacts. As a result, this review paper is an attempt to describe the present state of knowledge regarding the hazardous and helpful effects of Parthenium hysterophorus on people and animals.


Author(s):  
Lauren M. Smith-Ramesh

Abstract Allelopathy, or the process by which plants influence the growth and performance of their neighbours through the release of chemicals, may play a key role in mediating the impacts of non-native invasive species on their neighbours. The Novel Weapons Hypothesis purports that non-native invasive species are in part successful because they produce harmful allelochemicals to which resident species are particularly susceptible because residents lack a shared evolutionary history with the invader. While allelopathic non-native invaders may reduce the growth and performance of neighbours through direct phytotoxicity, they may more often exert negative impacts through disruption of biotic interactions among resident species. Allelopathy by non-native plants may disrupt mutualisms between resident plants and microbes, plant-herbivore interactions or existing competitive and facilitative interactions among resident plants. For example, several non-native plants are known to disrupt the mutualism between resident plants and mycorrhizal fungi, reducing resident plant fitness to the benefit of the invader. Allelopathic non-natives may also disrupt interactions among resident plants and their herbivores when allelochemicals also influence herbivore behaviour or fitness. Alternatively, biotic interactions can also be protective for resident species, which may be less susceptible to the impacts of non-native species when their mutualisms are intact. As we advance our understanding of allelopathy and its role in mediating the impacts of invasive plant species, we may gain new insights by viewing invasions within a network context rather than focusing on pairwise interactions.


Author(s):  
Lauren M. Smith-Ramesh ◽  

Allelopathy, or the process by which plants influence the growth and performance of their neighbours through the release of chemicals, may play a key role in mediating the impacts of non-native invasive species on their neighbours. The Novel Weapons Hypothesis purports that non-native invasive species are in part successful because they produce harmful allelochemicals to which resident species are particularly susceptible because residents lack a shared evolutionary history with the invader. While allelopathic non-native invaders may reduce the growth and performance of neighbours through direct phytotoxicity, they may more often exert negative impacts through disruption of biotic interactions among resident species. Allelopathy by non-native plants may disrupt mutualisms between resident plants and microbes, plant-herbivore interactions or existing competitive and facilitative interactions among resident plants. For example, several non-native plants are known to disrupt the mutualism between resident plants and mycorrhizal fungi, reducing resident plant fitness to the benefit of the invader. Allelopathic non-natives may also disrupt interactions among resident plants and their herbivores when allelochemicals also influence herbivore behaviour or fitness. Alternatively, biotic interactions can also be protective for resident species, which may be less susceptible to the impacts of non-native species when their mutualisms are intact. As we advance our understanding of allelopathy and its role in mediating the impacts of invasive plant species, we may gain new insights by viewing invasions within a network context rather than focusing on pairwise interactions.


Author(s):  
Jeanine Vélez-Gavilán

Abstract Anredera vesicaria is a herbaceous vine native from the south of the USA to northern South America. It is cultivated as an ornamental for its fragrant flowers, and has been introduced in the Philippines and some Caribbean islands. It is not recorded as invasive in any country but is regarded as a potential invasive species in Cuba as it has become naturalized outside its native range, has a tendency to proliferate and has a high dispersal capacity. Although A. vesicaria appears in EDDMapS for USA, it is not included as an invasive but rather for "comparison reasons" without further details given. It is also reported in the Invasive Plant Atlas, but without any information. The species is not included in the latest FLEPPC Invasive Plant List Species.


2019 ◽  
Vol 12 (4) ◽  
pp. 1484
Author(s):  
Claudio Urbano Bittencourt Pinheiro ◽  
Jairo Fernando Pereira Linhares

Uma espécie exótica invasora é definida como uma planta estranha que se propaga naturalmente em habitats naturais ou seminaturais, produzindo mudanças na composição, estrutura ou nos processos dos ecossistemas. No Brasil, os registros da dimensão do problema são deficientes, embora várias espécies já sejam consagradas como invasoras. No Maranhão, não havia nenhum estudo sobre espécies vegetais invasoras, embora registros e observações indiquem invasões em variados ambientes. Na ilha de São Luís, a invasão de áreas por um número de espécies tem se tornado aparente, com muitos pontos das áreas dos municípios invadidos por espécies vegetais introduzidas. Este estudo teve como objetivo principal levantar, identificar, quantificar e mapear as espécies invasoras vegetais na ilha de São Luís. Foram localizadas e identificadas cinco espécies invasoras principais que vêm ocupando e modificando ambientes na ilha de São Luís. São elas: 1) Leucena - Leucaena leucocephala (Lam.) de Wit. (Fabaceae); 2) Amendoeira - Terminalia cattapa L. (Combretaceae); 3) Fios de Ouro - Cuscuta racemosa Mart. (Convolvulaceae); 4) Saco de Velho - Calotropis procera (Aiton) W. T. Aiton (Apocynaceae); 5) Acácia Australiana - Acacia mangium Willd. (Fabaceae). Estas cinco espécies invasoras foram localizadas e amostradas em 420 pontos nos quatro municípios da ilha. As áreas invadidas foram amostradas com relação às espécies invasoras e também em relação às espécies acompanhantes principais. Imagem aérea da ilha de São Luís foi utilizada para localizar as formações vegetais e produzir um mapa de distribuição das espécies invasoras na ilha de São Luís.   A B S T R A C TAn alien invasive species is defined as a strange plant that propagates naturally in natural or semi-natural habitats, producing changes in the composition, structure or processes of ecosystems. In Brazil, records of the scale of the problem are deficient, although several species are already known as invasive. In Maranhão there were no studies on invasive plant species, although records and observations indicate invasions in various environments. On the island of São Luís, invasion by a number of species has become apparent, with many areas of the municipalities invaded by introduced plant species. The main objective of this study was to identify, quantify and map the invasive plant species on the island of São Luís. Five main invasive species were located and identified that have been occupying and modifying environments on the island of São Luís: 1) Leucena - Leucaena leucocephala (Lam.) De Wit. (Fabaceae); 2) Amendoeira - Terminalia cattapa L. (Combretaceae); 3) Fios de Ouro - Cuscuta racemosa Mart. (Convolvulaceae); 4) Saco de Velho - Calotropis procera (Aiton) W. T. Aiton (Apocynaceae); 5) Acacia Australiana - Acacia mangium Willd. (Fabaceae). These five invasive species were located and sampled at 420 sites in the four municipalities of the island. The invaded areas were sampled in relation to the invasive species and also in relation to the main accompanying species. An aerial image of the island of São Luís was used to locate plant formations and to produce a distribution map of the invasive species on the island of São Luís.Keywords: Invasive Species, Sampling, Mapping, São Luís, Maranhão


Genome ◽  
2019 ◽  
Vol 62 (3) ◽  
pp. 217-228
Author(s):  
Kowiyou Yessoufou ◽  
Bezeng S. Bezeng ◽  
Orou G. Gaoue ◽  
Thato Bengu ◽  
Michelle van der Bank

Alien invasive species are problematic both economically and ecologically, particularly on islands. As such, understanding how they interact with their environment is necessary to inform invasive species management. Here, we ask the following questions: What are the main functional traits that correlate with invasion success of alien plants on Robben Island? How does phylogenetic structure shape biotic interactions on the island? Using multiple approaches to explore these questions, we found that alien invasive species flower later during the year and for longer period, although flowering phenology was sensitive to alternative starting date. Additionally, we observed that alien invasive species are mostly abiotically pollinated and are generally hermaphroditic whilst their native counterparts rely on biotic pollinators, flower earlier, and are generally dioecious, suggesting that alien invasive and native species use different ecological niches. Furthermore, we found a facilitative interaction between an alien invasive legume and other invasive plants as predicted by the invasional meltdown hypothesis, but this does not influence the phylogenetic structure of plant communities. Finally, phylogenetically diverse set of native species are less receptive to alien invasive species. Collectively, our findings reveal how biotic interactions and phylogenetic relatedness structure alien invasive – native co-existence.


Koedoe ◽  
2017 ◽  
Vol 59 (1) ◽  
Author(s):  
Kudakwashe Musengi ◽  
Sally Archibald

Alien invasive species can have negative impacts on the functioning of ecosystems. Plantation species such as pines have become serious invaders in many parts of the world, but eucalypts have not been nearly as successful invaders. This is surprising considering that in their native habitat they dominate almost all vegetation types. Available theory on the qualities that characterise invasive species was used to assess the invasive potential of Eucalyptus grandis – a common plantation species globally. To determine rates of establishment of E. grandis outside plantations, we compared population demographics and reproductive traits at two locations in Mpumalanga, South Africa: one at higher elevation with more frost. Eucalyptus grandis has a short generation time. We found no evidence that establishment of E. grandis was limiting its spread into native grassland vegetation, but it does appear that recruitment is limited by frost and fire over much of its range in Mpumalanga. Populations at both study locations displayed characteristics of good recruitment. Size class distributions showed definite bottlenecks to recruitment which were more severe when exposed to frost at higher elevations. Generally, the rate of spread is low suggesting that the populations are on the establishing populations’ invasion stage. This research gives no indication that there are any factors that would prevent eucalyptus from becoming invasive in the future, and the projected increase in winter temperatures should be a cause for concern as frost is currently probably slowing recruitment of E. grandis across much of its planted range.Conservation implications: Eucalyptus plantations occur within indigenous grasslands that are of high conservation value. Frost and fire can slow recruitment where they occur, but there are no obvious factors that would prevent E. grandis from becoming invasive in the future, and monitoring of its rates of spread is recommended.


2021 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez ◽  
Charlie Riches

Abstract The erect, profusely tillering annual grass R. cochinchinensis grows up to a height of 4 m or more and is extremely competitive with annual crops, readily invading disturbed sites along roads and railways. Commonly known as itchgrass, it has brace roots near the base of the plant, a cylindrical spikelet seedhead and siliceous hairs on the leaf sheath that can penetrate and irritate the skin. Individual plants produce 2000 to 16,000 seeds that are shed as soon as they mature. A native of Indo-China, it is naturalised throughout the tropics of Asia, and is found in north-eastern Australia and savannah zones of Africa. It has been introduced into tropical America, as a potential pasture grass in the USA in the early 1900s and since the 1960s has been spread widely by contaminated rice seed, agricultural equipment and along transport routes in Central and South America, the Caribbean, and in the Gulf Coast region of the USA. An aggressive, significant weed in more than 40 countries, R. cochinchinensis is listed as a Federal Noxious Weed in the USA, and is suggested by Vibrans (2009) to be possibly the most harmful invasive plant in Mexico.


2006 ◽  
Vol 28 (1) ◽  
pp. 27 ◽  
Author(s):  
A. C. Grice

Most parts of the Australian rangelands are at risk of invasion by one or more species of non-native plants. The severity of current problems varies greatly across the rangelands with more non-native plant species in more intensively settled regions, in climatic zones that have higher and more reliable rainfall, and in wetter and more fertile parts of rangeland landscapes. Although there is quantitative evidence of impacts on either particular taxonomic groups or specific ecological processes in Australian rangelands, a comprehensive picture of responses of rangeland ecosystems to plant invasions is not available. Research has been focused on invasive species that are perceived to have important effects. This is likely to down play the significance of species that have visually less dramatic influences and ignore the possibility that some species could invade and yet have negligible consequences. It is conceivable that most of the overall impact will come from a relatively small proportion of invasive species. Impacts have most commonly been assessed in terms of plant species richness or the abundance of certain groups of vertebrates to the almost complete exclusion of other faunal groups. All scientific studies of the impacts of invasive species in Australian rangelands have focused on the effects of individual invasive species although in many situations native communities are under threat from a complex of interacting weed species. Invasion by non-native species is generally associated with declines in native plant species richness, but faunal responses are more complex and individual invasions may be associated with increase, decrease and no-change scenarios for different faunal groups. Some invasive species may remain minor components of the vegetation that they invade while others completely dominate one stratum or the vegetation overall.


Fire ◽  
2022 ◽  
Vol 5 (1) ◽  
pp. 7
Author(s):  
Leonel J. R. Nunes ◽  
Catarina I. R. Meireles ◽  
Carlos J. Pinto Gomes ◽  
Nuno M. C. Almeida Ribeiro

Invasive species are an environmental problem affecting worldwide ecosystems. In the case of Acacia dealbata Link., the negative impacts affect the productivity of the forests due to the competition established with native species while contributing to a significant increment in the available fuel load, increasing the risk of fire. In Portugal, chemical and mechanical methods are mostly used in the control of these species. However, the costs are often unsustainable in the medium term, being abandoned before completing the tasks, allowing the recovery of the invasive species. The establishment of value chains for the biomass resulting from these actions was pointed out by several authors as a solution for the sustainability of the control process, as it contributes to reducing costs. However, the problems in quantifying the biomass availability make it challenging to organize and optimize these actions. This work, which started from a dendrometrical analysis carried out in stands of A. dealbata, created a model to assess woody biomass availability. The model proved to be statistically significant for stands with trees younger than 20 years old. However, the amount of data collected and the configuration of the settlements analyzed do not allow extrapolation of the model presented to older settlements.


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