scholarly journals Argyreia nervosa (elephant creeper).

Author(s):  
Jeanine Vélez-Gavilán

Abstract A. nervosa is a liana from the tropics and sub-tropics, reported as invasive in Reunion, Hawaii (USA), Cuba, Australia, New Caledonia and Tonga, but with little information about the invasiveness of the species or its effects on habitats and native species in these countries (Oviedo Prieto et al., 2012; PIER, 2016). In Cuba it is reported as a transformer and invasive species (Oviedo Prieto et al., 2012). In Queensland, Australia it is reported as thriving around Townsville and rampaging around Cooktown. It is also reported as an environmental weed in Australia (PIER, 2016), where it is an aggressive invader of rainforest and other tropical forest communities in northern Queensland (Weeds of Australia, 2016).

2020 ◽  
Author(s):  
Jeanine Vélez-Gavilán

Abstract M. jalapa is a perennial herb in tropical and subtropical regions (Encyclopedia of Life, 2016). It is an annual in temperate climates (Dave's Garden, 2016). It has been introduced into various continents as an ornamental since the 1500's (Le Duc, 1995; Encyclopedia of Life, 2016). The species is listed as invasive in Asia (China, Indonesia, Maldives, Philippines), Africa (Kenya, Seychelles, South Africa, Uganda), South America (Chile, Ecuador) and Oceania (Cook Islands, Federated States of Micronesia, Fiji, Hawaii-USA, Kiribati, Nauru, New Caledonia, New Zealand, Niue, Pitcairn, Tonga, US Minor Outlying Islands) (BioNET-EAFRINET, 2016; Invasive Species South Africa, 2016; PIER, 2016). Oviedo Prieto et al. (2012) consider it a species with the potential of becoming invasive in Cuba. It has also been separately reported as invasive in Ethiopia, Malawi, Rwanda, Tanzania and Zambia. Although its popularity has decreased (Flora of India, 2015; Missouri Botanical Garden, 2017), the species is still popular in some countries and it is available from nurseries and over the internet worldwide (Fuentes Fiallo et al., 2001; Dave's Garden, 2016; Encyclopedia of Life, 2016). The species has a high reproductive potential as it can re-seed easily and propagate vegetatively through its tuberous roots (BioNET-EAFRINET, 2016; Invasive Species South Africa, 2016). M. jalapa is cited as not having a weed potential (PFAF, 2016), but also as an environmental weed, a "sleeper weed" or as a possible noxious weed (BioNET-EAFRINET, 2016; Dave's Garden; 2016). It can escape from gardens into nearby areas and will naturalise in disturbed areas (BioNET-EAFRINET, 2016).


2020 ◽  
Vol 637 ◽  
pp. 195-208 ◽  
Author(s):  
EM DeRoy ◽  
R Scott ◽  
NE Hussey ◽  
HJ MacIsaac

The ecological impacts of invasive species are highly variable and mediated by many factors, including both habitat and population abundance. Lionfish Pterois volitans are an invasive marine species which have high reported detrimental effects on prey populations, but whose effects relative to native predators are currently unknown for the recently colonized eastern Gulf of Mexico. We used functional response (FR) methodology to assess the ecological impact of lionfish relative to 2 functionally similar native species (red grouper Epinephelus morio and graysby grouper Cephalopholis cruentata) foraging in a heterogeneous environment. We then combined the per capita impact of each species with their field abundance to obtain a Relative Impact Potential (RIP). RIP assesses the broader ecological impact of invasive relative to native predators, the magnitude of which predicts community-level negative effects of invasive species. Lionfish FR and overall consumption rate was intermediate to that of red grouper (higher) and graysby grouper (lower). However, lionfish had the highest capture efficiency of all species, which was invariant of habitat. Much higher field abundance of lionfish resulted in high RIPs relative to both grouper species, demonstrating that the ecological impact of lionfish in this region will be driven mainly by high abundance and high predator efficiency rather than per capita effect. Our comparative study is the first empirical assessment of lionfish per capita impact and RIP in this region and is one of few such studies to quantify the FR of a marine predator.


Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 71
Author(s):  
Charalampos Dimitriadis ◽  
Ivoni Fournari-Konstantinidou ◽  
Laurent Sourbès ◽  
Drosos Koutsoubas ◽  
Stelios Katsanevakis

Understanding the interactions among invasive species, native species and marine protected areas (MPAs), and the long-term regime shifts in MPAs is receiving increased attention, since biological invasions can alter the structure and functioning of the protected ecosystems and challenge conservation efforts. Here we found evidence of marked modifications in the rocky reef associated biota in a Mediterranean MPA from 2009 to 2019 through visual census surveys, due to the presence of invasive species altering the structure of the ecosystem and triggering complex cascading effects on the long term. Low levels of the populations of native high-level predators were accompanied by the population increase and high performance of both native and invasive fish herbivores. Subsequently the overgrazing and habitat degradation resulted in cascading effects towards the diminishing of the native and invasive invertebrate grazers and omnivorous benthic species. Our study represents a good showcase of how invasive species can coexist or exclude native biota and at the same time regulate or out-compete other established invaders and native species.


2010 ◽  
Vol 26 (3) ◽  
pp. 347-350 ◽  
Author(s):  
Jannie Fries Linnebjerg ◽  
Dennis M. Hansen ◽  
Nancy Bunbury ◽  
Jens M. Olesen

Disruption of ecosystems is one of the biggest threats posed by invasive species (Mack et al. 2000). Thus, one of the most important challenges is to understand the impact of exotic species on native species and habitats (e.g. Jones 2008). The probability that entire ‘invasive communities’ will develop increases as more species establish in new areas (Bourgeois et al. 2005). For example, introduced species may act in concert, facilitating one another's invasion, and increasing the likelihood of successful establishment, spread and impact. Simberloff & Von Holle (1999) introduced the term ‘invasional meltdown’ for this process, which has received widespread attention since (e.g. O'Dowd 2003, Richardson et al. 2000, Simberloff 2006). Positive interactions among introduced species are relatively common, but few have been studied in detail (Traveset & Richardson 2006). Examples include introduced insects and birds that pollinate and disperse exotic plants, thereby facilitating the spread of these species into non-invaded habitats (Goulson 2003, Mandon-Dalger et al. 2004, Simberloff & Von Holle 1999). From a more general ecological perspective, the study of interactions involving introduced and invasive species can contribute to our knowledge of ecological processes – for example, community assembly and indirect interactions.


2014 ◽  
Vol 36 (3) ◽  
pp. 326-335 ◽  
Author(s):  
Tatiana Carvalho de Castro ◽  
Claudia Simões-Gurgel ◽  
Ivan Gonçalves Ribeiro ◽  
Marsen Garcia Pinto Coelho ◽  
Norma Albarello

The genus Cleome is widely distributed in drier areas of the tropics and subtropics. Cleome dendroides and C. rosea are Brazilian native species that occur mainly in Atlantic Forest and sandy coastal plains, respectively ecosystems negatively affected by human impacts. Cleome spinosa is frequently found in urban areas. Many Cleome species have been used in traditional medicine, as C. spinosa. In the present work, was investigated C. dendroides, C. rosea and C. spinosa germinative behavior under in vivo conditions, as well as was established suitable conditions to in vitro germination and seedling development. The in vivo germination was performed evaluating the influence of temperature, substrate and light. It was observed that only C. spinosa seeds presents physiological dormancy, which was overcome by using alternate temperatures. The substrate influenced significantly the germination of C. rosea and the seeds of C. dendroides showed the highest germination percentages in the different conditions evaluated. The post-seminal development stages under in vivo and in vitro conditions were defined. It was observed that the development was faster under in vitro than in vivo conditions. An effective methodology for in vitro germination, enabling the providing of material to experiment on plant tissue culture was established to C. dendroides and C. spinosa.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0237894
Author(s):  
Amy E. Kendig ◽  
Vida J. Svahnström ◽  
Ashish Adhikari ◽  
Philip F. Harmon ◽  
S. Luke Flory

Infectious diseases and invasive species can be strong drivers of biological systems that may interact to shift plant community composition. For example, disease can modify resource competition between invasive and native species. Invasive species tend to interact with a diversity of native species, and it is unclear how native species differ in response to disease-mediated competition with invasive species. Here, we quantified the biomass responses of three native North American grass species (Dichanthelium clandestinum, Elymus virginicus, and Eragrostis spectabilis) to disease-mediated competition with the non-native invasive grass Microstegium vimineum. The foliar fungal pathogen Bipolaris gigantea has recently emerged in Microstegium populations, causing a leaf spot disease that reduces Microstegium biomass and seed production. In a greenhouse experiment, we examined the effects of B. gigantea inoculation on two components of competitive ability for each native species: growth in the absence of competition and biomass responses to increasing densities of Microstegium. Bipolaris gigantea inoculation affected each of the three native species in unique ways, by increasing (Dichanthelium), decreasing (Elymus), or not changing (Eragrostis) their growth in the absence of competition relative to mock inoculation. Bipolaris gigantea inoculation did not, however, affect Microstegium biomass or mediate the effect of Microstegium density on native plant biomass. Thus, B. gigantea had species-specific effects on native plant competition with Microstegium through species-specific biomass responses to B. gigantea inoculation, but not through modified responses to Microstegium density. Our results suggest that disease may uniquely modify competitive interactions between invasive and native plants for different native plant species.


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