Fine scale variation in microarthropod communities inhabiting the keystone species <Emphasis Type="Italic">Azorella selago</Emphasis> on Marion Island

Invertebrates contribute significantly to nutrient cycling on sub-Antarctic islands and thus their distribution patterns are of considerable interest. Few studies have, however, investigated the deterministic nature of fine-scale patterns in arthropod communities. This study investigated the relationship between the fine-scale distribution and abundance of mites (Acari: Arachnida) and springtails (Collembola: Hexapoda) in Azorella selago Hook. f. (Apiaceae) on Marion Island, and plant size, isolation, within-plant variability and epiphyte load. Microarthropod abundances were significantly higher on the southern, cold, dry, less frequently wind-blown sides of plants. Abundances were also significantly higher in association with the dominant epiphyte, a likely consequence of increased resource availability. No effects of cushion size or isolation on abundance or species richness were found. This study thus demonstrates that fine-scale variation in the microarthropod community is deterministic, a likely consequence of biotic and abiotic factors, and therefore of importance in the context of rapid climate change.     

Abundance and seasonality of mid-altitude fellfield arthropods from Marion Island

Fellfield is an important habitat in both the Antarctic and sub-Antarctic. However, few studies have examined the abundance and seasonality of arthropods in sub-Antarctic fellfield habitats. Here, soil arthropod communities were sampled for over a full year in two distinct habitat components (rocky areas and Azorella selago cushions) in a mid-altitude fellfield on Marion Island. Species richness was relatively high (42 spp.) and consisted almost exclusively of indigenous species. Maximum mean annual density in the A. selago cushions was 16,000 individuals m⁻² for Eupodes minutus. In contrast, the highest density of any species in the rocky, inter-cushion areas was 700 individuals m⁻² for Halozetes fulvus. Quantitative analyses highlighted prominent differences in arthropod community structure between the two habitat components, despite the fact that most species were common to both of them. In general, arthropod abundances were lower in the fellfield compared with less extreme vegetation types in the sub-Antarctic, but were not dissimilar to those found in fellfield in the maritime Antarctic. In the Marion Island fellfield, arthropods either showed no pronounced seasonal peak in abundance, or a summer peak, although these patterns differed between habitat components within species, and between species. These data provide a firm quantitative foundation for further investigations of community patterns and seasonality in sub-Antarctic fellfield arthropods. Accepted: 10 June 2000     

Vertical distribution of collembola, lumbricidae and elateridae in alluvial soils of floodplain forests

The species composition, abundance and, vertical distribution of Collembola (53 species), Lumbricidae (6 species), and Elateridae (12 species) are estimated in alluvial soils of the middle taiga floodplain forests. The significance of individual species in the formation of invertebrates communities in different biotopes are demonstrated, species that are adapted to high humidity are revealed. Invertebrates prefer to inhabit higher elements of the floodplain relief. The effects of relative “deepening” of groups of springtails and earthworms are demonstrated in wet soils of inter-ridge depressions.     

The microarthropods of sub-Antarctic Prince Edward Island: a quantitative assessment

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.     

The biology of Bothrometopus elongatus (Coleoptera, Curculionidae) in a mid-altitude fellfield on sub-Antarctic Marion Island

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     

Human impacts, energy availability and invasion across Southern Ocean Islands

Aim Ongoing biological invasions will enhance the impacts of humans on biodiversity. Nonetheless, the effects of exotic species on diversity are idiosyncratic. Increases in diversity might be a consequence of similar responses by species to available energy, or because of positive relationships between human density, energy and propagule pressure. Here we use data from the Southern Ocean island plants and insects to investigate these issues. Location The Southern Ocean Islands ranging from Tristan da Cunha to Heard Island and South Georgia. Methods Generalized linear models are used to explore the relationships between indigenous and exotic species richness for plants and insects on two different islands. Similar models are used to examine interactions between indigenous and exotic species richness, energy availability and propagule pressure at the regional scale. Results Positive relationships were found between indigenous and exotic species richness at local scales, although for plants, the relationship was partially triangular. Across the Southern Ocean Islands, there was strong positive covariation between indigenous and exotic plant species richness and insect species richness, even taking spatial autocorrelation into account. Both exotic and indigenous plant and insect species richness covaried with energy availability, as did human visitor frequency. When two islands with almost identical numbers of human visits were contrasted, it was clear that energy availability, or perhaps differences in climate‐matching, were responsible for differences in the extent of invasion. Conclusion In plants and insects, there are positive relationships between indigenous and exotic diversity at local and regional scales across the Southern Ocean islands. These relationships are apparently a consequence of similar responses by both groups and by human occupants to available energy. When visitor frequency is held constant, energy availability is the major correlate of exotic species richness, though the exact mechanistic cause of this relationship requires clarification.     

Abiotic conditions shape the relationship between indigenous and exotic species richness in a montane biodiversity hotspot

Montane ecosystems are more prone to invasions by exotic plant species than previously thought. Besides abiotic factors, such as climate and soil properties, plant-plant interactions within communities are likely to affect the performance of potential invaders in their exotic range. The biotic resistance hypothesis predicts that high indigenous species richness hampers plant invasions. The biotic acceptance hypothesis, on the other hand, predicts a positive relationship between indigenous and exotic species richness. We tested these two hypotheses using observational data along an elevational gradient in a southern African biodiversity hotspot. Species composition data of indigenous and exotic plants were recorded in 20 road verge plots along a gradient of 1775–2775 m a.s.l. in the Drakensberg, South Africa. Plots were 2?×?50 m in size and positioned at 50 m elevational intervals. We found a negative correlation between indigenous and exotic richness for locations with poorly developed mineral soils, suggesting biotic resistance through competitive interactions. A strong positive correlation for plots with very shallow soils at high elevations indicated a lack of biotic resistance and the possibility of facilitating interactions in harsher environments. These results suggest that biotic resistance is restricted to the lower and mid elevations while biotic acceptance prevails in presence of severe abiotic stress, potentially increasing the risk of plant invasions into montane biodiversity hotspots.

     

Acclimation effects on thermal tolerances of springtails from sub-Antarctic Marion Island: indigenous and invasive species

Collembola are abundant and functionally significant arthropods in sub-Antarctic terrestrial ecosystems, and their importance has increased as a consequence of the many invasive alien species that have been introduced to the region. It has also been predicted that current and future climate change will favour alien over indigenous species as a consequence of more favourable responses to warming in the former. It is therefore surprising that little is known about the environmental physiology of sub-Antarctic springtails and that few studies have explicitly tested the hypothesis that invasive species will outperform indigenous ones under warmer conditions. Here we present thermal tolerance data on three invasive (Pogonognathellus flavescens, Isotomurus cf. palustris, Ceratophysella denticulata) and two indigenous (Cryptopygus antarcticus, Tullbergia bisetosa) species of springtails from Marion Island, explicitly testing the idea that consistent differences exist between the indigenous and invasive species both in their absolute limits and the ways in which they respond to acclimation (at temperatures from 0 to 20 degrees C). Phenotypic plasticity is the first in a series of ways in which organisms might respond to altered environments. Using a poorly explored, but highly appropriate technique, we demonstrate that in these species the crystallization temperature (Tc) is equal to the lower lethal temperature. We also show that cooling rate (1 degree C min(-1); 0.1 degrees C min(-1); 0.5 degrees C h(-1) from 5 to -1 degrees C followed by 0.1 degrees C min(-1)) has little effect on Tc. The indigenous species typically have low Tcs (c. -20 to -13 degrees C depending on the acclimation temperature), whilst those of the invasive species tend to be higher (c. -12 to -6 degrees C) at the lower acclimation temperatures. However, Ceratophysella denticulata is an exception with a low Tc (c. -20 to -18 degrees C), and in P. flavescens acclimation to 20 degrees C results in a pronounced decline in Tc. In general, the invasive and alien species do not differ substantially in acclimation effects on Tc (with the exception of the strong response in P. flavescens). Upper lethal temperatures (ULT50) are typically higher in the invasive (33-37 degrees C) than in the indigenous (30-33 degrees C) species and the response to acclimation differs among the two groups. The indigenous species show either a weak response to acclimation or ULT50 declines with increasing acclimation temperature, whereas in the invasive species ULT50 increases with acclimation temperature. These findings support the hypothesis that many invasive species will be favoured by climate change (warming and drying) at Marion Island. Moreover, manipulative field experiments have shown abundance changes in the indigenous and invasive springtail species in the direction predicted by the physiological data.     

The significance of the sub-Antarctic Kerguelen Islands for the assessment of the vulnerability of native communities to climate change,alien insect invasions and plant viruses

The suite of environments and anthropogenic modifications of sub-Antarctic islands provide key opportunities to improve our understanding of the potential consequences of climate change and biological species invasions on terrestrial ecosystems. The profound impact of human introduced invasive species on indigenous biota, and the facilitation of establishment as a result of changing thermal conditions, has been well documented on the French sub-Antarctic Kerguelen Islands (South Indian Ocean). The present study provides an overview of the vulnerability of sub-Antarctic terrestrial communities with respect to two interacting factors, namely climate change and alien insects. We present datasets assimilated by our teams on the Kerguelen Islands since 1974, coupled with a review of the literature, to evaluate the mechanism and impact of biological invasions in this region. First, we consider recent climatic trends of the Antarctic region, and its potential influence on the establishment, distribution and abundance of alien insects, using as examples one fly and one beetle species. Second, we consider to what extent limited gene pools may restrict alien species’ colonisations. Finally, we consider the vulnerability of native communities to aliens using the examples of one beetle, one fly, and five aphid species taking into consideration their additional impact as plant virus vectors. We conclude that the evidence assimilated from the sub-Antarctic islands can be applied to more complex temperate continental systems as well as further developing international guidelines to minimise the impact of alien species.     

浦东滩涂中型土壤动物群落结构及土质酸碱度生物评价分析

1999年,对上海浦东滩涂4类不同酸碱度土壤中的中型土壤动物进行了调查。应用物种丰富度,个体数多度,多样性指数和均匀度4个群落参数,并结合种类研究,讨论了土壤动物群落结构与不同酸碱度土壤的关系。结果表明,土壤中弹尾目和蜱螨目对不同酸碱度土壤反应敏感。弹尾目的3个群落参数和蜱螨目的4个参数均很好地反映与土壤反应敏感。弹尾目的3个群落参数和蜱螨目的4个参数均很好地反映与土壤pH的关系,相关系数分别在0．9以上和0．85左右,在pH相差较大的情况下,可以区分不同酸碱度的土壤。弹尾目的符Tao(Paranura sp.)可用于评价酸碱度较接近的土壤,球角Tao(Hypogastrura sp.）可用于评价酸碱度相差较大,高pH或环境条件较恶劣的土壤。     

Habitat, predation, and coexistence between invasive and native crayfishes: prioritizing lakes for invasion prevention

Conditions fostering coexistence of native species with invasive species have received little attention in invasion biology, especially for closely related invasive and native species. We used long-term datasets on multiple replicate invasions to define conditions under which native virile crayfish (Orconectes virilis) can coexist with invasive rusty crayfish (O. rusticus). We examined multiple drivers of coexistence involving habitat use and predation at between-lake and within-lake scales to derive predictions that could guide prioritization efforts to prevent future introductions of rusty crayfish and mitigate impacts of existing invasions. Lakes in which native species persisted for many years had significantly less cobble and sand habitats, and significantly more vegetated habitats compared to lakes from which native crayfish have been displaced. In the presence of rusty crayfish, virile crayfish alter their habitat use to vegetated habitats relative to habitat use in the absence of rusty crayfish. Such vegetated habitats had greater plant standing crop, plant species richness, and sediment percent organic matter compared to vegetated sites occupied by rusty crayfish. Our results suggest that low abundance of cobble habitat and altered habitat use allows native crayfish to coexist with the rusty crayfish invader. At the within-lake scale, virile crayfish persist by escaping predation in the vegetated habitats, despite suboptimal abiotic conditions. By understanding these abiotic and biotic conditions that promote coexistence, managers could enhance native crayfish persistence by targeting high cobble lakes for efforts to prevent the introduction of invasive crayfish, and targeting vegetated habitats for protection in already invaded lakes.     

Invasibility and species richness of island endemic arthropods: a general model of endemic vs. exotic species

Aim This paper has two objectives. First, we examine how a variety of biotic, abiotic and anthropogenic factors influence the endemic and introduced arthropod richness on an oceanic island. Second, we look at the relationship between the endemic and introduced arthropod richness, to ask whether areas with high levels of endemic species richness deter invasions. Location The work was carried out on a young volcanic island, Terceira, in the Azores. Methods We used standard techniques to collect data on arthropod species richness. Environmental data were obtained from the CIELO climatic model and using GIS. The explanatory value of environmental variables on a small‐scale gradient of endemic and exotic arthropod species richness was examined with generalized linear models (GLMs). In addition, the impact of both endemic and exotic species richness in the communities was assessed by entering them after the environmental variable(s) to see if they contributed significantly to the final model (the hierarchical method). Results Abiotic (climatic and geomorphological) variables gave a better explanation of the variation in endemic species richness, whereas anthropogenic variables explained most of the variation in introduced species richness. Furthermore, after accounting for all environmental variables, part of the unexplained variance in the endemic species richness is explained by the introduced species richness and vice‐versa. That is, areas with high levels of endemic species richness had many introduced species. There is evidence of a somewhat inverse spatial distribution between a group of oceanic‐type, forest‐dwelling, endemic, relict arthropods and a group of more generalist endemic arthropods that are able to survive in disturbed marginal sites particularly rich in non‐indigenous species. Main conclusions Richness of endemic species is mainly driven by abiotic factors such as a climatic axis (oceanic‐type localities with lower temperatures and summer precipitations) and a binary variable CALD (location of sites in caldeiras or ravines), whereas richness of introduced species depends on disturbance related factors. However, after factoring out these major influences, there is a correlation between endemic and introduced richness, suggesting that – independent of the environmental and geographical factors that affect the distribution of endemic or introduced species – the richest endemic assemblages are more prone to invasion, due probably to a facilitation process. Inconclusive evidence suggests that non‐indigenous species are limited to those sites under anthropogenic influence located mainly near forest edges, but the rate of expansion of those species to high‐altitude, core pristine sites has still to be tested.     

Environmental correlates of body size distributions of European springtails (Hexapoda: Collembola)

Aim Species–body size distributions (SBDs) are plots of species richness across body size classes. They have been linked to energetic constraints, speciation–extinction dynamics and to evolutionary trends. However, little is known about the spatial variation of size distributions. Here we study SBDs of European springtails (Collembola) at a continental scale and test whether minimum, average and maximum body size and the shapes of size distributions change across latitudinal and longitudinal gradients and whether SBDs of islands and mainlands differ. We also test whether the island rule and the positive body size–range size relationship of vertebrates also holds for Collembola. Location Europe. Methods We use a unique data set on the spatial distributions of 2102 species of European springtails across 52 countries and larger islands together with associated data on body size, area, climate variables, longitude and latitude. Differences in the central moments of SBDs are inferred from simultaneous spatial autoregression models. Results The SBD of the European Collembola and its largest suborder Entomobryomorpha is unimodal and symmetrical. Average, minimum and maximum body weight and the skewness of the mainland/island SBDs peaked at intermediate latitudes. We could not find simple latitudinal gradients in minimum and maximum body weight. Average and maximum body size increased with country/island area in accordance with the island rule in vertebrates, while minimum body size did not significantly differ between islands and mainlands. Finally, we found a weak but statistically significant positive correlation of range size and body size. Main conclusions We provide evidence for differences in body size distributions between islands and mainlands that are in part in line with the island rule in invertebrates. We also find evidence for an interspecific body size–range size relationship similar to that of vertebrates although the vertebrate pattern is much stronger than the springtail pattern. Our results on latitudinal gradients of maximum and average body size imply the need to account for species richness and area effects in the study of latitudinal gradients in body size. We recommend implementing sample size and area effects in the study of body size distributions on islands and mainlands.     

Nestedness of Southern Ocean island biotas: ecological perspectives on a biogeographical conundrum

Aim To use patterns of nestedness in the indigenous and non‐indigenous biotas of the Southern Ocean islands to determine the influence of dispersal ability on biogeographical patterns, and the importance of accounting for variation in dispersal ability in their subsequent interpretation, especially in the context of the Insulantarctic and multi‐regional hypotheses proposed to explain the biogeography of these islands. Location Southern Ocean islands. Methods Nestedness was determined using a new metric, d1 (a modification of discrepancy), for the indigenous and introduced seabirds, land birds, insects and vascular plants of 26 Southern Ocean islands. To assess the possible confounding effects of spatial autocorrelation on the results, islands were assigned to 11 major island groups and each group was treated as a single island in a following analysis. In addition, nestedness of the six Southern Ocean islands comprising the South Pacific Province (New Zealand islands) was analysed. All analyses were conducted for species and genera, for each of the taxa on its own, and for the complete data sets. Results Statistically significant nestedness was found in all of the taxa examined, with nestedness declining in the order seabirds > land birds > vascular plants > insects for the indigenous species. Vagility had a marked influence on nestedness and the biogeographical patterns shown by the indigenous species. This influence was borne out by additional analyses of marine taxa and small‐sized terrestrial species, both of which were more nested than the most nested group examined here, the seabirds. Assemblages of non‐indigenous species also showed nestedness, and nestedness was generally more pronounced than in the indigenous species. Surprisingly, vagility had a significant effect on nestedness in these assemblages too. Main conclusions Nestedness analyses provide a quantitative means of comparing biogeographical patterns for groups differing in vagility. These comparisons revealed that vagility has a considerable influence on biogeographical patterns and should be taken into account in analyses. Here, investigations of more vagile taxa support hypotheses for a single origin of the Southern Ocean island biota (the Insulantarctica scenario), whilst those of less mobile taxa support the more commonly held, multi‐regional hypothesis. All biogeographical analyses across the Southern Ocean (and elsewhere) will be influenced by the effects of dispersal ability, with composite analyses dominated by sedentary groups likely to favour multi‐regional scenarios, and those dominated by mobile groups favouring single origins. Mechanisms underlying nestedness in the region range from nested physiological tolerances in more mobile groups to colonization ability and patterns of speciation in less vagile taxa. Considerable nestedness in the non‐indigenous assemblages is largely a consequence of the fact that many of these species are European weedy species.     

Genetic evidence confirms the origin of the house mouse on sub-Antarctic Marion Island

Biological invasions and climate change are two of the largest threats to biodiversity, and this is especially true for island ecosystems that have largely evolved in isolation. The house mouse is considered to have been introduced to sub-Antarctic Marion Island by sealers in the early 1800s. It is currently widespread across the island and has a large impact on the indigenous biota. To date, little information is available on genetic aspects of biological invasions in the sub-Antarctic. Ten specimens of the house mouse were collected from two geographically separated localities on Marion Island. Sequences of the mitochondrial DNA control region revealed only two haplotypes, separated by a single site change. More importantly, these haplotypes are shared between the eastern and western side of Marion Island. By comparing our sequences to data available on GenBank, we provide evidence that house mice on Marion Island is Mus musculus domesticus (Rutty 1772), and most closely related to haplotypes characterizing this species from Denmark, Sweden, Finland, and northern Germany.     

Collembolan associations in natural versus improved pastures of the New England Tableland,NSW: Distribution of native and introduced species

Native Australian species of Collembola dominated natural pasture in numbers of species present and in abundance, while introduced Collembola dominated fertilized pasture sown to exotic species. Those collembolan species which were restricted to one pasture type only were mainly epigeal and hemiedaphic species of the herbage and litter. Increased grazing by sheep decreased species richness and increased uniformity of Collembola in both pasture types. The abundance of introduced Collembola was positively associated with phosphorus content of litter.     

Effects of Fragmentation and Sea-Level Changes upon Frog Communities of Land-Bridge Islands off the Southeastern Coast of Brazil

We investigate the composition of anuran communities of land-bridge islands off the southeastern coast of Brazil. These islands provide natural long-term experiments on the effects of fragmentation in the Brazilian Atlantic Forest (BAF). We hypothesize that Pleistocene sea-level changes, in combination with other abiotic variables such as area and habitat diversity, has affected anuran species richness and community composition on these islands. Data from the literature and collections databases were used to produce species lists for eight land-bridge islands and for the mainland adjacent to the islands. We assess the effects of area, number of breeding habitats and distance to the mainland upon anuran species richness on land-bridge islands. Additionally we use nestedness analysis to quantify the extent to which the species on smaller and less habitat-diverse islands correspond to subsets of those on larger and more diverse ones. We found that area has both direct and indirect effects on anuran species richness on land-bridge islands, irrespective of distance to the mainland. However, on islands with comparable sizes, differences in species richness can be attributed to the number and quality of breeding habitats. Anuran communities on these islands display a nested pattern, possibly caused by selective extinction related to habitat loss. Common lowland pond-breeders were conspicuous by their absence. In the BAF, the conservation of fragments with a high diversity of breeding habitats could compensate for the generally negative effect of small area upon species richness. We suggest that sea-level changes have an important role in shaping composition of anuran species on coastal communities.     

Ecological biogeography of southern ocean islands: the importance of considering spatial issues

Understanding patterns of among-island variation in species richness has long been an important question in ecology and biogeography. However, despite the clear spatial nature of the data used for such investigations, the spatial distribution of the different sampled locations is rarely explicitly considered, which may be critical for statistical and biological reasons. In a recent study, Chown et al. (1998) investigated the relationships between species richness of different indigenous and introduced taxonomic groups and a variety of variables characterizing Southern Ocean islands, and here, we use these data to address spatial issues. As predicted, we found spatial autocorrelation in species richness for terrestrial taxa with high dispersal ability or for terrestrial taxa that had time to disperse locally (introduced land birds and indigenous taxa) but not for taxa that had low opportunity to disperse to nearby islands (introduced plants, insects, and mammals), which suggests that colonization from nearby islands has played an important role in shaping present-day patterns of among-island variation in species richness. Interestingly, in several cases, the estimated effect of variables changed when spatial covariance was incorporated. Moreover, the absence of autocorrelation of some variables allowed us to confirm some important results of Chown et al. (1998), notably those involving the potential impact of human presence on the biodiversity of these islands. Overall, our results illustrate the importance of considering spatial structures in ecological studies. This is notably the case when dispersal processes can be expected to explain some of the observed patterns.     

Conservation of Southern Ocean Islands: invertebrates as exemplars

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.