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1.
Recent human activities and rising air temperature have increased the vulnerability of sub-Antarctic islands to alien species. At the Kerguelen Islands, the predaceous ground beetle Merizodus soledadinus is the only invasive insect originating from the southern cold temperate area (native from Patagonia, Tierra del Fuego and Falkland Islands). This austral origin raises the question of the limits of its physiological tolerance and capability to withstand (1) global change and (2) warmer climates of archipelagos where its accidental transportation could be facilitated from the Kerguelen Islands (namely Amsterdam and Saint Paul). Using gas chromatography/mass spectrometry metabolomics, we compared metabotypes of adults exposed to different temperatures (0, 4, 8, 12, 16, 20 °C). All individuals survived after 2 weeks regardless of the temperature they were exposed to. The physiological changes observed were consistent with increased metabolic rate at increased temperatures, without extreme metabotypes that are characteristic of acute stress. First cues of sublethal stress were observed after prolonged exposure to 20 °C, a warm regime unrealistic for such duration in sub-Antarctic Islands. Overall, M. soledadinus’ thermal tolerance exceeded temperatures currently experienced in nature, suggesting that climate warming may boost its invasion by eliciting its activity and broadening habitat suitability in both invaded and still pristine islands. This thermal tolerance may allow survival aboard ships and development in sub-Antarctic islands with conditions warmer than the Kerguelen Islands, such as Amsterdam and St Paul. Stringent biosecurity measures are thus needed to prevent transfer from Kerguelen to these islands. The native range of this predaceous beetle limited to the Falkland Islands and southernmost South America may be partly constrained by factors other than temperature, such as desiccation, predation or competition. 相似文献
2.
Steven L. Chown Jennifer E. Lee Justine D. Shaw 《Journal of Insect Conservation》2008,12(3-4):277-291
The Southern Ocean Islands (SOI) have an exceptionally high conservation status, and human activity on the islands is low by comparison with more tropical islands. In consequence, overexploitation, pollution and habitat destruction have had little influence on the invertebrate biotas of the islands, although overexploitation of pelagic species has the potential for an indirect influence via reduction of nutrient inputs to the terrestrial systems. By contrast, invasive alien species, the local effects of global climate change, and interactions between them are having large impacts on invertebrate populations and, as a consequence, on ecosystem functioning. Climate change is not only having direct impacts on indigenous invertebrates, but also seems to be promoting the ease of establishment of new alien invertebrate species. It is also contributing to population increases of invertebrate alien species already on the islands, sometimes with pronounced negative consequences for indigenous species and ecosystem functioning. Moreover, alien plants and mammals are also affecting indigenous invertebrate populations, often with climate change expected to exacerbate the impacts. Although the conservation requirements are reasonably well-understood for terrestrial systems, knowledge of freshwater and marine near-shore systems is inadequate. Nonetheless, what is known for terrestrial, freshwater and marine systems suggests that ongoing conservation of SOI invertebrates requires intervention from the highest political levels internationally, to slow climate change, to local improvements of quarantine measures to reduce the rates and impacts of biological invasions. 相似文献
3.
The biodiversity in the sub-Antarctic region is threatened by climatic change and biological invasions, which makes the understanding of distributions of biotas on sub-Antarctic islands essential. Although the distribution patterns of vascular plants and insects on sub-Antarctic islands are well documented, this is not always the case for microarthropods. This study provides the first quantitative assessment of the distribution and abundance of microarthropods on Prince Edward Island (PEI), one of two islands in the Prince Edward Island group. Microarthropod community structure differed significantly between PEI and nearby Marion Island, with only two invasive alien species found on PEI compared with Marion Island. Furthermore, species richness, abundance and community structure differed significantly between habitat types on both islands. This study emphasizes the importance of quarantine measures when visiting PEI to maintain its status as one of the more pristine islands in the sub-Antarctic region. 相似文献
4.
Johan Pansu Richard C. Winkworth Fran?oise Hennion Ludovic Gielly Pierre Taberlet Philippe Choler 《Biology letters》2015,11(9)
During the late nineteenth century, Europeans introduced rabbits to many of the sub-Antarctic islands, environments that prior to this had been devoid of mammalian herbivores. The impacts of rabbits on indigenous ecosystems are well studied; notably, they cause dramatic changes in plant communities and promote soil erosion. However, the responses of fungal communities to such biotic disturbances remain unexplored. We used metabarcoding of soil extracellular DNA to assess the diversity of plant and fungal communities at sites on the sub-Antarctic Kerguelen Islands with contrasting histories of disturbance by rabbits. Our results suggest that on these islands, the simplification of plant communities and increased erosion resulting from the introduction of rabbits have driven compositional changes, including diversity reductions, in indigenous soil fungal communities. Moreover, there is no indication of recovery at sites from which rabbits were removed 20 years ago. These results imply that introduced herbivores have long-lasting and multifaceted effects on fungal biodiversity as well as highlight the low resiliency of sub-Antarctic ecosystems. 相似文献
5.
D. Renault 《Polar Biology》2011,34(10):1591-1595
The alien ground beetle Merizodus soledadinus was introduced to the sub-Antarctic Kerguelen Islands in 1913. It colonized several small islands and islets of this archipelago,
without any apparent human assistance in some locations, and crossed several large rivers and alluvial plains. As aggregations
of this species on the tidal drift line are common at the Kerguelen Islands, the present work examined whether adult individuals
of M. soledadinus could disperse by flotation on the sea. Different sample sizes of ground beetles (from 1 to 10) were placed on sea water
at 8°C in plastic vials. Survival (50% lethal times) significantly increased from 2.1 ± 0.2 days for single beetles to 6.5 ± 0.3 days
for groups of 10 beetles per vial, with there being no difference in the survival duration for groups of 2, 5, and 10 beetles
per vial. Similar survival durations were found for beetles in vials with artificially agitated water and controls. In addition,
the duration of survival was twice as high under freshwater versus sea water conditions, when groups of 10 adults were used.
Finally, the survival to total submersion in freshwater was evaluated, and ranged from 3 to 4 days. This ability to survive
extended periods both floating on and/or submerged beneath salt and freshwater conditions, indicates the presence of a successful
dispersal mechanism, which may facilitate the dispersal range of M. soledadinus across the Kerguelen Islands, comprising over 300 islands and islets in total. 相似文献
6.
Four monoxenous nematodes and 1 heteroxenous cestode were found in 4 species of introduced small mammals on isolated sub-Antarctic islands of the Indian Ocean. In the Kerguelen Archipelago, Syphacia obvelata, Passalurus ambiguus (Nematoda: Oxyuridae), and Rodentolepis straminea (Cestoda: Cyclophyllidae) were respectively found in the house mouse Mus musculus, the rabbit Oryctolagus cuniculus, and the black rat Rattus rattus. One accidental nematode, Trichostrongylus sp. (Nematoda: Trichostrongylidae), was also found in a black rat on Kerguelen. On Possession Island (Crozet Archipelago), R. straminea was present in the black rat. On Amsterdam Island, the brown rat R. norvegicus harbored 2 species, R. straminea and Nippostrongylus brasiliensis (Nematoda: Heligmonellidae). The small number of founder hosts and the depauperate terrestrial communities on these remote islands explain the low diversity in the helminth communities of these introduced mammals compared with continental populations. 相似文献
7.
Philip E. Hulme 《Biological reviews of the Cambridge Philosophical Society》2017,92(3):1297-1313
A changing climate may directly or indirectly influence biological invasions by altering the likelihood of introduction or establishment, as well as modifying the geographic range, environmental impacts, economic costs or management of alien species. A comprehensive assessment of empirical and theoretical evidence identified how each of these processes is likely to be shaped by climate change for alien plants, animals and pathogens in terrestrial, freshwater and marine environments of Great Britain. The strongest contemporary evidence for the potential role of climate change in the establishment of new alien species is for terrestrial arthropods, as a result of their ectothermic physiology, often high dispersal rate and their strong association with trade as well as commensal relationships with human environments. By contrast, there is little empirical support for higher temperatures increasing the rate of alien plant establishment due to the stronger effects of residence time and propagule pressure. The magnitude of any direct climate effect on the number of new alien species will be small relative to human‐assisted introductions driven by socioeconomic factors. Casual alien species (sleepers) whose population persistence is limited by climate are expected to exhibit greater rates of establishment under climate change assuming that propagule pressure remains at least at current levels. Surveillance and management targeting sleeper pests and diseases may be the most cost‐effective option to reduce future impacts under climate change. Most established alien species will increase their distribution range in Great Britain over the next century. However, such range increases are very likely be the result of natural expansion of populations that have yet to reach equilibrium with their environment, rather than a direct consequence of climate change. To assess the potential realised range of alien species will require a spatially explicit approach that not only integrates bioclimatic suitability and population‐level demographic rates but also simulation of landscape‐level processes (e.g. dispersal, land‐use change, host/habitat distribution, non‐climatic edaphic constraints). In terms of invasive alien species that have known economic or biodiversity impacts, the taxa that are likely to be the most responsive are plant pathogens and insect pests of agricultural crops. However, the extent to which climate adaptation strategies lead to new crops, altered rotations, and different farming practices (e.g. irrigation, fertilization) will all shape the potential agricultural impacts of alien species. The greatest uncertainty in the effects of climate change on biological invasions exists with identifying the future character of new species introductions and predicting ecosystem impacts. Two complementary strategies may work under these conditions of high uncertainty: (i) prioritise ecosystems in terms of their perceived vulnerability to climate change and prevent ingress or expansion of alien species therein that may exacerbate problems; (ii) target those ecosystem already threatened by alien species and implement management to prevent the situation deteriorating under climate change. 相似文献
8.
Laparie M Larvor V Frenot Y Renault D 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2012,161(2):122-129
The relationship between nutritional requirements and the availability or quality of food is a prime parameter in determining the geographical expansion of invasive insects. At the sub-Antarctic Kerguelen Islands, the invasive ground beetle Merizodus soledadinus becomes the main invertebrate predator when it colonizes new habitats, leading to the local extinction of native fly species. Such changes in the structure of prey communities may alter the energy management (storage and expenditure) of this predator. In this species, we monitored survival and body mass during food deprivation, in addition to evaluating the effects of two distinct diets (maggots versus enchytraeids) on the consumption and restoration of body reserves (sugars and triglycerides). We found that adults can starve for more than 60 days, and feed every 3.76 days on average when food is available. We recorded higher predation rates on maggots, associated with steeper body mass variations, compared to enchytraeids. Sugars and triglycerides were significantly consumed during food deprivation and restored after refeeding, but varied similarly among individuals supplied on the distinct diets. Other parameters may determine the food preferences observed, such as salt content in prey tissues, because M. soledadinus mainly feeds in hypersaline foreshore habitats, and may limit the consumption of osmotic conformers. 相似文献
9.
Invasive aliens on tropical East Asian islands 总被引:1,自引:0,他引:1
Richard T. Corlett 《Biodiversity and Conservation》2010,19(2):411-423
Tropical East Asia (TEA) has numerous islands, both continental and oceanic. This study uses information on invasive aliens
in terrestrial habitats on these islands to test the generality of the continental-oceanic contrast in invasibility, assess
the conservation impacts of invasive species, and suggest ways to mitigate these. The continental islands of Hong Kong and
Singapore are worst-case scenarios for continental invasibility and alien species often dominate in chronically disturbed
sites, but very few have successfully invaded closed forests, with the exception of birds in Hong Kong. On other, less densely
populated, continental islands, closed-canopy forests appear to resist invasions by all taxa, with few known exceptions. Forests
on oceanic islands isolated by <100 km during the last glacial maximum appear no more susceptible to plant and invertebrate
invasions than those on continental islands, but invasions by mammals are widespread. Snake invasions may be under-recognized.
The remote oceanic Ogasawara (Bonin) Islands, >1000 km from the nearest continent, have a native biota of largely tropical
East Asian origin and are suffering from alien forest invasions across the taxonomic spectrum. These patterns of invasibility
are consistent with the idea that alien invasion is facilitated by the absence of native species in the same functional group.
Alien invasives are not yet a major conservation problem in TEA, except on remote islands, but their dominance on disturbed
sites may slow or prevent recovery of native biodiversity. Strict quarantine is impractical in TEA, although some major introduction
routes could be blocked. Management efforts should focus on early recognition and immediate control of potential problem species. 相似文献
10.
Laparie M Bical R Larvor V Vernon P Frenot Y Renault D 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2012,162(4):406-412
Metabolic fingerprinting can elucidate rearrangements of metabolic networks in organisms exposed to various environmental conditions. Maintenance of organismal performance occurs by alterations in metabolic fluxes and pathways, resulting in habitat-specific metabolic signatures. Several insects of sub-Antarctic Islands, including the wingless flies Anatalanta aptera and Calycopteryx moseleyi, are exposed to saline organic matter accumulated along littoral margins. However, C. moseleyi has long been considered restricted to a habitat of lower salinity, the Kerguelen cabbage. High C. moseleyi densities identified in saline decaying seaweeds are intriguing, and may involve osmoregulatory adjustments including accumulation of osmoprotectants. In the present work, we examined quantitative metabotypes (metabolic phenotypes) among wild C. moseleyi individuals from seaweeds versus non-saline Kerguelen cabbages. They were compared to metabotypes from wild A. aptera, a common fly on seaweed. Statistical procedures designed to magnify between-class differences failed to clearly separate C. moseleyi metabotypes from cabbage and seaweed, despite contrasted morphotypes, diets, and salinities. A. aptera exhibited higher glycerol, inositol, trehalose, and other osmoprotectants concentrations that may enhance its performance under saline environments. Seaweed may represent a secondary niche in C. moseleyi, promoted by the marked reduction in Kerguelen cabbage frequency subsequent to climate change, and herbivorous pressures caused by rabbit invasion. 相似文献
11.
Invasive alien species constitute a substantial conservation challenge in the terrestrial sub-Antarctic. Management plans,
for many of the islands in the region, call for the prevention, early detection, and management of such alien species. However,
such management may be confounded by difficulties of identification of immatures, especially of holometabolous insects. Here
we show how a DNA barcoding approach has helped to overcome such a problem associated with the likely establishment of an
alien moth species on Marion Island. The discovery of unidentifiable immatures of a noctuid moth species, 5 km from the research
station, suggested that a new moth species had colonized the island. Efforts to identify the larvae by conventional means
or by rearing to the adult stage failed. However, sequencing of 617 bp of the mitochondrial cytochrome oxidase subunit I gene,
and comparison of the sequence data with sequences on GENBANK and the barcoding of life database enabled us to identify the
species as Agrotis ipsilon (Hufnagel), a species of which adults had previously been found regularly at the research station. Discovery of immatures
of this species, some distance from the research station, suggests that a population may have established. It is recommended
that steps to be taken to eradicate the species from Marion Island. 相似文献
12.
Invasion by alien organisms is a common worldwide phenomenon, and many alien species invade native communities. Invasion by
alien species is especially likely to occur on oceanic islands. To determine how alien species become integrated into island
plant–insect associations, we analyzed the structure of tree–beetle associations using host plant records for larval feeding
by wood-feeding beetles (Coleoptera: Cerambycidae) on the oceanic Ogasawara Islands in the northwestern Pacific Ocean. The
host plant records comprised 109 associations among 28 tree (including 8 alien) and 26 cerambycid (including 5 alien) species.
Of these associations, 41.3% involved at least one alien species. Most native cerambycid species feed on host trees that have
recently died. Alien trees were used by as many native cerambycid species (but by significantly more alien cerambycid species)
as were native trees. Native cerambycid species used as many alien tree species (but significantly more native tree species)
as did alien cerambycids. Thus, we observed many types of interactions among native and alien species. A network analysis
revealed a significant nested structure in tree–cerambycid associations regardless of whether alien species were excluded
from the analysis. The original nested associations on the Ogasawara Islands may thus have accepted alien species. 相似文献
13.
Globalisation persistently fuels the establishment of non‐native species outside their natural ranges. While alien plants have been intensively studied, little is known about alien flower visitors, and especially, how they integrate into natural communities. Here, we focus on mutualistic networks from five Galápagos islands to quantify whether alien and native flower visitors differ consistently in their pairwise interactions. We find that (1) alien flower visitors have more interaction partners and larger species strengths (i.e. plants are more connected to alien insects), (2) native insects tend to have higher partner fidelity as they deviate more from random partner utilisation, and iii) the difference between native and alien flower visitors in network integration intensifies with island degradation. Thus, native and alien flower visitors are not interchangeable, and alien establishment might have yet unforeseen consequences for the pairwise dynamics between plants and flower visitors on the Galápagos – especially on the heavily disturbed islands. 相似文献
14.
Bothrometopus elongatus is one of four Ectemnorhinus-group species restricted to the epilithic biotope on the Prince Edward Islands. Here we examine the biology of this species
over a full year at Kerguelen Rise, a mid-altitude fellfield site on Marion Island. B. elongatus adults eclose from April onwards, reaching maximum densities (ca. 17 individuals m−2) in September. Females mature approximately three eggs at a time and these commence hatching in July. Larval eclosion reaches
a peak in November, during which time larval densities are also highest (ca. 153 individuals m−2). The larvae develop through six instars, which is within the range found for other Ectemnorhinus-group species. The high densities of B. elongatus in fellfield habitats, and its single, virtually discrete annual generation, make this species unusual among insects indigenous
to the sub-Antarctic. The latter generally have low densities compared to other micro-arthropods, prolonged life-cycles, and
flexible life-histories. We suggest that the diversity of life-histories found amongst the indigenous insects at Marion Island
presents considerable potential for testing environmental effects on insect life-histories. An overview of sub-Antarctic insect
life-history data suggests that the indigenous species, with generally prolonged life-cycles, are at a disadvantage relative
to introduced species that have more rapid cycles and often complete several generations per year. This is reason for concern
given rapid climate change at these islands.
Accepted: 14 November 1999 相似文献
15.
Agnès Schermann-Legionnet Françoise Hennion Philippe Vernon Anne Atlan 《Polar Biology》2007,30(9):1183-1193
The reproductive biology of Pringlea antiscorbutica R. Br. (Brassicaceae), an endemic species from the southern Indian Ocean islands, is investigated here. Controlled crosses
were performed between plants grown in a common garden on the Kerguelen Islands. Searching for potential insect pollinators,
we investigated the flying ability of all insects known from the Kerguelen Islands. We showed evidence for self-compatibility,
low pollen limitation in the absence of a biotic pollen vector and slight selfing depression in P. antiscorbutica. The insects present on the islands are mostly wingless and are not likely to be efficient pollinators of this species. Since
P. antiscorbutica shows morphological adaptations to insect pollination despite the absence of pollinators in its present range, we conclude
that this species recently evolved from insect pollination to wind and/or autonomous pollination. 相似文献
16.
Questions: Are island vegetation communities more invaded than their mainland counterparts? Is this pattern consistent among community types? Location: The coastal provinces of Catalonia and the para‐oceanic Balearic Islands, both in NE Spain. These islands were connected to the continent more than 5.35 million years ago and are now located <200 km from the coast. Methods: We compiled a database of almost 3000 phytosociological relevés from the Balearic Islands and Catalonia and compared the level of invasion by alien plants in island versus mainland communities. Twenty distinct plant community types were compared between island and mainland counterparts. Results: The percentage of plots with alien species, number, percentage and cover percentage of alien species per plot was greater in Catalonia than in the Balearic Islands in most communities. Overall, across communities, more alien species were found in the mainland (53) compared to the islands (only nine). Despite these differences, patterns of the level of invasion in communities were highly consistent between the islands and mainland. The most invaded communities were ruderal and riparian. Main conclusion: Our results indicate that para‐oceanic island communities such as the Balearic Islands are less invaded than their mainland counterparts. This difference reflects a smaller regional alien species pool in the Balearic Islands than in the adjacent mainland, probably due to differences in landscape heterogeneity and propagule pressure. 相似文献
17.
The importance of globalisation in driving the introduction and establishment of alien species in Europe
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Understanding the role of globalisation in promoting introduction and establishment of alien species is an important step towards successful management of biological invasions. We aimed to quantify the taxon‐dependent association of globalisation with the introduction and establishment of alien species in Europe. The availability of the KOF index of globalisation that measures all economic, social and political dimensions of global connectivity enables a study of this factor. Based on an extensive database of alien species, we used model selections based on the Akaike information criterion and hierarchical partitioning to identify the importance of globalisation in predicting the number of all introduced species and established species of ten mainly terrestrial taxa in countries across Europe. The association of globalisation with alien species establishment varied depending on taxon type. While the gross domestic product (GDP) of countries was a strong predictor for all but one taxon, globalisation was also found to be an important predictor for three taxa including those of high (e.g. insects) and low mobility (e.g. magnoliophyta). Globalisation explained 3.1 to 22% independently, and 5.5 to 35% jointly with other variables, of among‐country variations in the number of established alien species. The effect of globalisation on the distribution of all introduced species is not substantially different from that on the established alien species. This study highlights how globalisation among habitat availability and environmental conditions can determine the patterns of alien species introduction and establishment across Europe. The results also emphasise the varying degree of importance between different taxa. Knowledge of the relative significance of various pathways with regard to different taxa is important for correctly focusing efforts to reduce the spread of these species. 相似文献
18.
Residence time and human-mediated propagule pressure at work in the alien flora of Galapagos 总被引:1,自引:0,他引:1
Introduced species present the greatest threat to the unique terrestrial biodiversity of the Galapagos Islands. We assess
the current status of plant invasion in Galapagos, predict the likelihood of future naturalizations and invasions from the
existing introduced flora, and suggest measures to help limit future invasions. There has been a 1.46 fold increase in plant
biodiversity in Galapagos due to alien plant naturalizations, reflecting a similar trend on islands elsewhere. There are 870
alien plant species recorded in the archipelago. Of evaluated species, 34% species have naturalized. Within this group are
the invasive species (16% of evaluated) and the transformers (3.3% of evaluated). We show that, as expected, naturalized species
have been present in the archipelago longer than non-naturalized species. We also find that a higher human-mediated propagule
pressure is associated with a greater human population and with properties that have been settled longer. This, combined with
the relatively recent introduction of most species, leads us to the conclusion that Galapagos is at an early stage of plant
invasion. We predict that more species from the existing alien flora will find an opportunity to naturalize and invade as
propagule pressure increases alongside rapid human population growth associated with immigration to serve the booming tourism
industry. In order to reduce future invasion risk, we suggest reviewing inter-island quarantine measures and continuing community
education efforts to reduce human-mediated propagule pressure. 相似文献
19.
D. J. Marshall N. J. M. Gremmen L. Coetzee B. M. O’Connor P. J. A. Pugh P. D. Theron E. A. Ueckermann 《Polar Biology》1999,21(2):84-89
Sixty species of Acari are recorded from the sub-Antarctic Marion and Prince Edward Islands (the Prince Edward archipelago).
Twenty of the 45 species collected on recent expeditions are new and currently undescribed. Other new taxa include a family
of Mesostigmata, four new genera, and the first sub-Antarctic records of Cillibidae (Mesostigmata) and Eryngiopus (Prostigmata). Fifteen of the 31 species previously reported from the islands are confirmed, although eight of the previous
accounts remain doubtful. The fauna, which shows a distinction between the shoreline and terrestrial components, comprises
endemic, South Indian Ocean Province and sub-Antarctic mite species.
Accepted: 18 July 1998 相似文献
20.
Evaluating differences in the shape of native and alien plant trait distributions will bring new insights into invasions of plant communities
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Failure to quantify differences in the shape of inter‐specific trait distributions (e.g., skew, kurtosis) when comparing co‐occurring alien and native plants hinders the integration of biological invasions and plant community ecology. Within a plant community, understanding the circumstances that lead to the shape of the inter‐specific distribution of one or more functional plant traits being unimodal, bimodal, multimodal or skewed has the potential to shed new light on community vulnerability to invasion, subsequent ecosystem impacts and the selection pressures (e.g., stabilizing, directional or disruptive) acting upon native and alien species. Ignoring differences in the shape of inter‐specific trait distributions of alien and native species could miss important insights into plant invasions, including: the existence of unsaturated native plant communities, empty niches, shifting trait optima of species as a result of environmental change and incomplete colonization–extinction processes following invasion. Future comparisons of functional trait differences between native and alien species should include assessment of the shapes of inter‐specific trait distributions since these may differ even when the mean values of traits are similar for native and alien species. The infrequent application of such approaches may explain the limited generalizations regarding the drivers and consequences of plant invasions in plant communities. 相似文献