scholarly journals Is invasion success explained by the enemy release hypothesis?

2004 ◽  
Vol 7 (8) ◽  
pp. 721-733 ◽  
Author(s):  
Robert I. Colautti ◽  
Anthony Ricciardi ◽  
Igor A. Grigorovich ◽  
Hugh J. MacIsaac
2020 ◽  
pp. 1-6
Author(s):  
Elba Montes ◽  
Mónica Feriche ◽  
Esmeralda Alaminos ◽  
Juan Manuel Pleguezuelos

Abstract The key to fighting a biological invasion may lie in understanding every variable that can explain its success. The Enemy Release Hypothesis (ERH) states that when an invader arrives to a new environment, the absence of its common enemies (predators, parasites and competitors) facilitates the invasion success. The Horseshoe whip snake (Hemorrhois hippocrepis) has been recently introduced from the Iberian Peninsula to the island of Ibiza, and it is currently threatening the only endemic vertebrate, the Ibiza wall lizard (Podarcis pityusensis). We hypothesized that the snake invasion success is caused by the absence of natural predators, and we checked the ERH by relating the tail breakage rate to predation pressure. The invasive population showed a much lower incidence of tail breakage than the source population, which is in agreement with the almost absence of snake predators among the Ibizan reduced and naïve native vertebrate community. These results confirm the ERH, and support the prolongation of invasive snake trapping campaigns.


2016 ◽  
Author(s):  
Christophe Diagne ◽  
Alexis Ribas ◽  
Nathalie Charbonnel ◽  
Ambroise Dalecky ◽  
Caroline Tatard ◽  
...  

AbstractUnderstanding why some exotic species become widespread and abundant in their colonized range is a fundamental issue that still needs to be addressed. Among many hypotheses, newly established host populations may benefit from a parasite loss (“enemy release” hypothesis) through impoverishment of their original parasite communities or reduced infection levels. Moreover, the fitness of competing native hosts may be affected by the acquisition of exotic taxa from invaders (“parasite spillover”) and/or by an increased transmission risk of native parasites due to their amplification by invaders (“parasite spillback”). We focused on gastrointestinal helminth communities to determine whether these predictions could explain the ongoing invasion success of the commensal house mouse (Mus musculus domesticus) and black rat (Rattus rattus), as well as the associated drop of native Mastomys species, in Senegal. For both invasive species, our results were consistent with the predictions of the enemy release hypothesis. A decrease of helminth overall prevalence and individual species richness was observed along the invasion gradients as well as lower specific prevalence/abundance (Aspiculuris tetraptera in M. m. domesticus, Hymenolepis diminuta in R. rattus) on the invasion fronts. Conversely, we did not find strong evidence of helminth spill-over or spill-back in invasion fronts, where native and invasive rodents co-occurred. Further experimental research is needed to determine whether and how the loss of helminths and reduced infection levels along invasion routes may result in any advantageous effects on invader fitness and competitive advantage.


Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 544
Author(s):  
Lotte Korell ◽  
Martin Schädler ◽  
Roland Brandl ◽  
Susanne Schreiter ◽  
Harald Auge

The enemy-release hypothesis is one of the most popular but also most discussed hypotheses to explain invasion success. However, there is a lack of explicit, experimental tests of predictions of the enemy-release hypothesis (ERH), particularly regarding the effects of above- and belowground herbivory. Long-term studies investigating the relative effect of herbivores on invasive vs. native plant species within a community are still lacking. Here, we report on a long-term field experiment in an old-field community, invaded by Solidago canadensis s. l., with exclusion of above- and belowground insect herbivores. We monitored population dynamics of the invader and changes in the diversity and functioning of the plant community across eight years. Above- and belowground insects favoured the establishment of the invasive plant species and thereby increased biomass and decreased diversity of the plant community. Effects of invertebrate herbivores on population dynamics of S. canadensis appeared after six years and increased over time, suggesting that long-term studies are needed to understand invasion dynamics and consequences for plant community structure. We suggest that the release from co-evolved trophic linkages is of importance not only for the effect of invasive species on ecosystems, but also for the functioning of novel species assemblages arising from climate change.


Hydrobiologia ◽  
2009 ◽  
Vol 630 (1) ◽  
pp. 139-148 ◽  
Author(s):  
C. Dang ◽  
X. de Montaudouin ◽  
J. Bald ◽  
F. Jude ◽  
N. Raymond ◽  
...  

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1415 ◽  
Author(s):  
Julia J. Mlynarek

The enemy release hypothesis (ERH) predicts that the spread of (invasive) species will be facilitated by release from their enemies as they occupy new areas. However, the ERH is rarely tested on native (non-invasive, long established) species with expanding or shifting ranges. I tested the ERH for a native damselfly (Enallagma clausum) whose range has recently expanded in western Canada, with respect to its water mite and gregarine parasites. Parasitism levels (prevalence and intensity) were also compared betweenE. clausumand a closely related species,Enallagma boreale, which has long been established in the study region and whose range is not shifting. A total of 1,150 damselflies were collected at three ‘old’ sites forE. clausumin Saskatchewan, and three ‘new’ sites in Alberta. A little more than a quarter of the damselflies collected were parasitized with, on average, 18 water mite individuals, and 20% were parasitized by, on average, 10 gregarine individuals. I assessed whether the differences between levels of infection (prevalence and intensity) were due to site type or host species. The ERH was not supported:Enallagma clausumhas higher or the same levels of parasitism in new sites than old sites. However,E. borealeseems to be benefitting from the recent range expansion of a native, closely related species through ecological release from its parasites because the parasites may be choosing to infest the novel, potentially naïve, host instead of the well-established host.


2017 ◽  
Vol 98 (8) ◽  
pp. 1935-1944 ◽  
Author(s):  
Martyn Kurr ◽  
Andrew J. Davies

Invasive algae can have substantial negative impacts in their invaded ranges. One widely cited mechanism that attempts to explain how invasive plants and algae are often able to spread quickly, and even become dominant in their invaded ranges, is the Enemy Release Hypothesis. This study assessed the feeding behaviours of two species of gastropod herbivore from populations exposed to the invasive alga Sargassum muticum for different lengths of time. Feeding trials, consisting of both choice and no-choice, showed that the herbivores from older stands (35–40 years established) of S. muticum were more likely to feed upon it than those taken from younger (10–19 years established) stands. These findings provide evidence in support of the ERH, by showing that herbivores consumed less S. muticum if they were not experienced with it. These findings are in accordance with the results of other feeding-trials with S. muticum, but in contrast to research that utilizes observations of herbivore abundance and diversity to assess top-down pressure. The former tend to validate the ERH, and the latter typically reject it. The potential causes of this disparity are discussed, as are the importance of palatability, herbivore species and time-since-invasion when considering research into the ERH. This study takes an important, yet neglected, approach to the study of invasive ecology.


2021 ◽  
Author(s):  
Anna Aldorfová ◽  
Věra Hanzelková ◽  
Lucie Drtinová ◽  
Hana Pánková ◽  
Tomáš Cajthaml ◽  
...  

Abstract Purpose: To compare plant-soil feedback (PSF) of invasive Cirsium vulgare and non-invasive C. oleraceum in their native range to test a hypothesis that the invasive species is more limited by specialized pathogens in the native range and/or able to benefit more from generalist mutualists, and thus may benefit more from loss of specialized soil biota in a secondary range.Methods: We assessed changes in soil nutrients and biota following soil conditioning by each species and compared performance of plants grown in self-conditioned and control soil, from which all, some or no biota was excluded. Results: The invasive species depleted more nutrients than the non-invasive species and coped better with altered nutrient levels. The invasive species had higher seedling emergence which benefited from presence of non-specific microbes. The invasive species biomass responded less positively to specialized (self-conditioned) microbiota and more negatively to specialized larger-sized biota compared to the non-specialized control biota, suggesting the species may benefit more from enemy release and suffer less from loss of specialized mutualists when introduced to a secondary range. The invasive species showed greater ability to decrease its root-shoot ratio in presence of harmful biota and thus reduce their negative effects on its performance.Conclusions: Our study highlights the utility of detailed PSF research in the native range of species for understanding the factors that regulate performance of invasive and non-invasive species in their native range, and for pinpointing the types of biota involved in their regulation and how this changes across the plants life cycle.


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