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1.
Piotr Osyczka 《Polar Biology》2010,33(8):1067-1073
The recent climate changes combined with intensified human activity in Antarctica are promoting the synanthropization process
and increasing the likelihood of alien species establishing in the native communities. Cargo items, expedition members’ equipment
and food destined for the 32nd Polish Antarctic Expedition to the “Arctowski” station in the 2007/2008 season were inspected
to determine their potential as vectors for alien lichen species. Within the cargo, packaging and foodstuffs scanned, a total
of 45 lichen specimens (24 species) were identified. Most of them had been accidentally transported with various timbers.
Cargo containers and fresh food were also found to harbour for single specimens. The majority of lichens detected are alien
to the Antarctic biota and had never been observed in the region. This paper estimates the potential risk of these lichens
establishing themselves in remote southern latitudes. The results emphasize the threat of accidental introduction of alien
organisms into Antarctica and the need for taking every precaution to prevent the importation of non-native species to this
unique environment. 相似文献
2.
Antarctic ecosystems are at risk from the introduction of invasive species. The first step in the process of invasion is the
transportation of alien species to Antarctic in a viable state. However, the effect of long-distance human-mediated dispersal,
over different timescales, on propagule viability is not well known. We assessed the viability of Poa trivialis seeds transported to Antarctica from the UK, South Africa and Australia by ship or by ship and aircraft. Following transportation
to the Antarctic Treaty area, no reduction in seed viability was found, despite journey times lasting up to 284 days and seeds
experiencing temperatures as low as −1.5°C. This work confirms that human-mediated transport may overcome the dispersal barrier
for some propagules, and highlights the need for effective pre-departure biosecurity measures. 相似文献
3.
Antarctic terrestrial ecosystems currently include very few non-native species, due to the continent’s extreme isolation from
other landmasses. However, the indigenous biota is vulnerable to human-mediated introductions of non-native species. In December
2005, four construction vehicles were imported by contractors to the British Antarctic Survey’s (BAS) Rothera Research Station
(Antarctic Peninsula) from the Falkland Islands and South Georgia (South Atlantic) on board RRS James Clark Ross. The vehicles were contaminated with >132 kg of non-Antarctic soil that contained viable non-native angiosperms, bryophytes,
micro-invertebrates, nematodes, fungi, bacteria, and c. 40,000 seeds and numerous moss propagules. The incident was a significant
contravention of BAS operating procedures, the UK Antarctic Act (1994) and the Protocol on Environmental Protection to the
Antarctic Treaty (1998), which all prohibit the introduction of non-native species to Antarctica without an appropriate permit.
The introduction of this diverse range of species poses a significant threat to local biodiversity should any of the species
become established, particularly as the biota of sub-Antarctic South Georgia is likely to include many species with appropriate
pre-adaptations facilitating the colonisation of more extreme Antarctic environments. Once the incident was discovered, the
imported soil was removed immediately from Antarctica and destroyed. Vehicle cleaning and transportation guidelines have been
revised to enhance the biosecurity of BAS operations, and to minimise the risk of similar incidents occurring. 相似文献
4.
Maria Lityńska-Zaj?c Katarzyna Chwedorzewska Maria Olech Ma?gorzata Korczak-Abshire Anna Augustyniuk-Kram 《Biodiversity and Conservation》2012,21(13):3411-3421
The aim of the project was to assess the size and species range of alien plant diaspores and phyto-remains transported into the Polish Antarctic Station during three Antarctic expeditions. Our study clearly demonstrates that many diaspores can be quite easily unintentionally transported in good conditions to the Antarctic. In the analyzed material there were present diaspores of invasive species. All identified species belong to 20 families. The most abundant were Asteraceae and Poaceae species. The most interesting finding was the presence of caryopses of Poa annua, the first alien angiosperm species which already established a stable breeding population in the Antarctic. Base on our results, we can predict that risk of establishment of anther alien plant species in the vicinity of “Arctowski” Station is very high. 相似文献
5.
Analysis of numbers of invasive species (insects, plants, plant diseases) in each of Chinese provinces and the world’s climatic
zones respectively, demonstrated positive correlations between diversity of bioinvasion and air temperature and precipitation
(the two main criteria for classifying world climate types). When the air temperature is within the range of 1–25°C, the degree
of diversity of invasive alien species increases exponentially with air temperature. However, when the air temperature falls
outside the range of 1–25°C, the diversity of harmful invasive alien species changes with air temperature in a parabolic pattern,
showing a “mid-latitude bulge”. Namely, when air temperatures are too high or too low, a lower average invasion frequency
of harmful alien species is observed. Invasion by harmful invasive alien species is more weakly related to precipitation.
Different climatic zones showed dramatic differences in resistance to the invasion of invasive alien species due to their
different characteristic climatic factors, mainly including air temperature and precipitation. 相似文献
6.
D. K. A. Barnes D. A. Hodgson P. Convey C. S. Allen A. Clarke 《Global Ecology and Biogeography》2006,15(2):121-142
Aim To investigate the major paradigms of intense isolation and little anthropogenic influence around Antarctica and to examine the timings and scales of the modification of the southern polar biota. Location Antarctica and surrounding regions. Methods First, mechanisms of and evidence for long‐term isolation are reviewed. These include continental drift, the development of a surrounding deep‐water channel and the Antarctic Circumpolar Current (ACC). They also include levels of endemism, richness and distinctiveness of assemblages. Secondly, evidence for past and modern opportunities for species transport are investigated. Comparative levels of alien establishments are also examined around the Southern Ocean. Discussion On a Cenozoic time‐scale, it is clear that Gondwana's fragmentation led to increasing geographical isolation of Antarctica and the initiation of the ACC, which restricted biota exchange to low levels while still permitting some movement of biota. On a shorter Quaternary time‐scale, the continental ice‐sheet, influenced by solar (Milankovitch) cycles, has expanded and contracted periodically, covering and exposing terrestrial and continental shelf habitats. There were probably refugia for organisms during each glacial maxima. It is also likely that new taxa were introduced into Antarctica during cycles of ice sheet and oceanic front movement. The current situation (a glacial minimum) is not ‘normal’; full interglacials represent only 10% of the last 430 ka. On short (ecological) time‐scales, many natural dispersal processes (airborne, oceanic eddy, rafting and hitch‐hiking on migrants) enable the passage of biota to and from Antarctica. In recent years, humans have become influential both directly by transporting organisms and indirectly by increasing survival and establishment prospects via climate change. Main conclusions Patterns of endemism and alien establishment are very different across taxa, land and sea, and north vs. south of the Polar Frontal Zone. Establishment conditions, as much as transport, are important in limiting alien establishment. Three time‐scales emerge as important in the modification of Antarctica's biota. The natural ‘interglacial’ process of reinvasion of Antarctica is being influenced strongly by humans. 相似文献
7.
8.
M. Lebouvier M. Laparie M. Hullé A. Marais Y. Cozic L. Lalouette P. Vernon T. Candresse Y. Frenot David Renault 《Biological invasions》2011,13(5):1195-1208
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. 相似文献
9.
Melissa Houghton Peter B. McQuillan Dana M. Bergstrom Leslie Frost John van den Hoff Justine Shaw 《Polar Biology》2016,39(1):23-33
Alien species pose an increasing threat to the biodiversity of the Antarctic region. Several alien species have established in Antarctic terrestrial communities, some representing novel functional groups such as pollinators and predators, with unknown impacts on ecosystem processes. We quantified the unintentional introduction of alien invertebrates to the Antarctic region over a 14-year period (2000–2013). To do this, probable pathways (Australian Antarctic cargo operations) and endpoints (research stations) for invertebrate introductions were searched. In addition, we undertook a stratified trapping programme targeting invertebrates on supply vessels in transit to the Antarctic region and also at cargo facilities in Australia during the 2012–2013 austral summer field season. Our results show that a diverse suite of invertebrate taxa were being introduced to the Antarctic region, with 1,376 individuals from at least 98 families observed or trapped during the sampling period. Many individuals were found alive. Diptera, Coleoptera and Lepidoptera were the most common taxa, comprising 74 % of the collection. At the family level, Phoridae (small flies) and Noctuidae (moths) were most commonly observed. Individuals from 38 different families were repeatedly introduced over the study period, sometimes in high numbers. Food and large cargo containers harboured the most individuals. These findings can assist in improving biosecurity protocols for logistic activities to Antarctica, thereby reducing the risk of invasions to the Antarctic region. 相似文献
10.
S. Schiaparelli C. Ghirardo J. Bohn M. Chiantore G. Albertelli R. Cattaneo-Vietti 《Polar Biology》2007,30(12):1545-1555
The first case of parasitic association between an eulimid mollusc (Gastropoda, Ptenoglossa) and a comatulid (Echinodermata:
Crinoidea) is reported for Antarctica. The mollusc involved in the association is Eulima
tumidula Thiele, 1912, which has now been ascribed to the genus Bathycrinicola Bouchet & Warén, 1986, never recognized before in Antarctica. This genus is present only in the NE Atlantic Ocean and the Mediterranean Sea, and
encompass species which are specific parasites of the sessile stalked crinoids of the family Bathycrinidae. However, in Antarctica,
Bathycrinicola tumidula (Thiele, 1912) exploits the endemic vagile comatulid Notocrinus virilis Mortensen, 1917, and attains the largest known dimensions (∼1 cm) for a Bathycrinicola species. The absence of suitable Bathycrinidae host in modern Antarctic benthic assemblages, as well as the long paleontological
history of the genus Notocrinus in Antarctica, suggest a possible ‘host-switch’ phenomenon. This event could reasonably have occurred when many species underwent
considerable bathymetric shifts, during the dramatic climatic changes that affected Antarctica. 相似文献
11.
Halina Galera Katarzyna J. Chwedorzewska Małgorzata Korczak-Abshire Maciej Wódkiewicz 《Biodiversity and Conservation》2018,27(8):1789-1809
Successful alien species invasion depends on many factors studied mostly in post invasion habitats, and subsequently summarized in frameworks tailored to describe the studied invasion. We used an existing expanded framework with three groups of contributing factors: habitat invisibility, system context and species invasiveness, to analyze the probability of alien species invasions in terrestrial communities of Maritime Antarctic in the future. We focused on the first two factor groups. We tested if the expanded framework could be used under a different scenario. We chose Point Thomas Oasis on King George Island to perform our analysis. Strong geographical barrier, low potential bioclimatic suitability and resource availability associated with habitat invasibility significantly reduce the likelihood of biological invasion in Antarctica. An almost full enemy release (low pressure of consumers), the high patchiness of the habitat, and the prevalence of open gaps also associated with habitat invasibility increase the possibility of invasion. The dynamics of functional connectivity, propagule pressure and spatio-temporal patterns of propagule arrival associated with human activity and climate change belonging to the system context contribute to an increase in the threat of invasions. Due to the still low land transport activity migration pathways are limited and will reduce the spread of alien terrestrial organisms by land. An effective way of preventing invasions in Antarctica seems to lie in reducing propagule pressure and eliminating alien populations as early as possible. The expanded conceptual framework opens up wider possibilities in analyzing invasions taking place in different systems and with multiple taxa. 相似文献
12.
Over the last decades, Antarctic seabird populations have been studied as bioindicators of the variability in the Southern Ocean marine ecosystem. Little information is available on the distribution and abundance of Wilson’s storm petrel (Oceanites oceanicus) in East Antarctica although the bioindicator value of this species has been investigated. Regional surveys were conducted at two coastal locations, Casey (66°S, 110°E) and Mawson (67°S, 62°E), to locate Wilson’s storm petrel nests using systematic searches in sites selected with a balanced random sampling design. Conducted in ice-free areas of similar size, searches located 553 Wilson’s storm petrel nests at Mawson and 630 at Casey. Comparable densities were observed between locations but regional estimates suggest that Wilson’s storm petrels are more abundant at Casey. Habitat preferences of Wilson’s storm petrels were investigated using resource selection functions based on Generalized Additive and Linear Models (GAMs and GLMs), which allow their ecological niche to be graphically and quantitatively described. The orientation of nests in relation to the prevailing winds was identified as a determinant of nest distribution at both locations. However, selected rock substrate types differed between Mawson and Casey. Snow was confirmed to constrain the spatial distribution of nests, especially at Casey where snow precipitations and accumulation are more common in summer, confirming the results of previous temporal surveys focusing on breeding success. At the southern edge of its geographic distribution, the Wilson’s storm petrel may be subject to more obvious climate related habitat changes in East Antarctica. Such models may provide valuable information to detect the potential effect of climate variations on this species and others, in the context of a broad Antarctic ecosystem monitoring. 相似文献
13.
Enrique Isla Dieter Gerdes Albert Palanques Núria Teixidó Wolf Arntz Pere Puig 《Polar Biology》2006,29(4):249-256
Downward particle fluxes measured by means of sediment traps to a shallow semi-closed bay (Johnson’s Dock, Livingston Island)
and to a deep basin in the western Bransfield Strait (Antarctic Peninsula) showed the important role of glaciers as sediment
carriers and suppliers to the ocean in a continent without major rivers such as Antarctica. The trap moored in Johnson’s Dock
collected coarse sediment (>1 mm mesh) not observed in the offshore traps, which mainly received fine sediment and faecal
pellets. The annual total mass flux (TMF) to the coastal zone (15 m) was 900- and three times that to mid-depth (500 m) and
near-bottom (1,000 m) traps, respectively. The fine sediment flux was especially important due to its biogenic particle contents.
Despite the differences in TMF to the coastal zone and near the bottom in the deep basin, the organic carbon (OC) flux was
similar in both environments (16 and 18 g m−2, respectively), whereas biogenic silica (BSi) flux increased three times with depth (75 and 201 g m−2, respectively). These fluxes imply that an important part of the particulate organic matter deposited in the coastal zone
is advected basinward within the fine-particle flux. Thus, benthos in deep areas depends largely on the lateral transport
of biogenic material produced in shallow environments near the coast. It is also proposed that the disintegration of Antarctic
ice shelves and the consequent increment of ice calving may produce local devastations of ecological importance not only on
the shallow but also on the rich Antarctic deep-sea benthic communities due to an increment of iceberg scouring and reduction
of the organic matter supply. 相似文献
14.
Anastasija Zaiko Maiju Lehtiniemi Aleksas Narščius Sergej Olenin 《Biological invasions》2011,13(8):1739-1765
This paper presents an overall bioinvasion impact assessment on the scale of a large marine region—the Baltic Sea, as defined
by the Helsinki Commission. The methodology is based on a classification of the abundance and distribution range of alien
species and the magnitude of their impacts on native communities, habitats and ecosystem functioning aggregated in a “Biopollution
Level” index (BPL) which ranges from ‘no impact’ (BPL = 0) to ‘massive impact’ (BPL = 4). The assessment performed for nine
Baltic sub-regions revealed that documented ecological impact is only known for 43 alien species out of 119 registered in
the Sea. The highest biopollution (BPL = 3, strong impact) occurs in coastal lagoons, inlets and gulfs, and the moderate biopollution
(BPL = 2)—in the open sea areas. The methodology was also used to classify species into alien (BPL = 0) versus ‘impacting’
species (BPL > 0), which can be divided into ‘potentially invasive’ (BPL = 1) and ‘invasive’ (BPL > 1) ones. No clear correlation
between the number of established alien and impacting species was found in the sub-regions of the Baltic Sea. The methodology,
although requiring a substantial research effort, proved to be useful for interregional comparisons and evaluating the bioinvasion
effects of individual alien species. 相似文献
15.
Alvaro T. Palma Elie Poulin Marcelo G. Silva Roberto B. San Martín Carlos A. Muñoz Angie D. Díaz 《Polar Biology》2007,30(3):343-350
One characteristic pattern found in the marine Antarctic shallow environments is the unusually high proportion of species
with protected and pelagic lecitotrophic development modes. However, species with planktotrophic development generally appear
as the most conspicuous types of organisms in these environments. The Antarctic shallow benthos is considered as one of the
most disturbed in the world, mainly due to the action of ice, thus one could hypothesize that such an environment should favor
organisms with high dispersal capability. In order to test this general hypothesis, for two consecutive summers (2004–2005)
and at two locations, we quantified the abundance and size distribution of most echinoderms present along bathymetric transects.
Our results show the predominance of broadcasters (i.e., Sterechinus neumayeri and Odontaster validus) at a location where disturbances are common, while brooders (e.g., Abatus agassizii) only occurred at shallower depths of the least disturbed location. These results not only corroborate the hypothesis that
local disturbance is an important factor generating these ecological patterns, but also suggest how ice-related disturbances
could represent a major selecting agent behind the patterns of species diversity at an evolutionary scale in Antarctica. 相似文献
16.
Reproductive failure results in many plant species becoming endangered. However, little is known of how and to what extent
pollinator shifts affect reproductive performance of endangered species as a result of the artificial introduction of alien
insects. In this study we examined breeding systems, visitor species, visiting frequency and seed set coefficients of Swertia przewalskii in two years that had different dominant pollinator species (native vs. alien). Flowers of this species were protandrous
and herkogamous and insects were needed for the production of seeds. The stigmatic receptivity of this species was shorter
than for other gentians. No significant difference in seed set coefficient was found for hand-pollinated plants between the
two years, indicating that pollinator shift only had a minor effect on this plant’s breeding system. The commonest pollinators
in 2002 were native bumblebees, alien honeybees and occasional solitary bees, however, only alien honeybees were observed
in 2004. The flower visitation rate in both years was relatively high, although the total visit frequency decreased significantly
in 2004. The control flowers without any treatment produced significantly fewer seed sets in 2004 than in 2002. In the past
decade the seed production of this species may have partly decreased due to pollination by alien honeybees, however, we suggest
that they might have acted as alternative pollinators ensuring seed production of S. przewalskii when native pollinators were unavailable. The main reason that this plant is endangered is probably the result of habitat
destruction, but changes in land use, namely intensified agricultural practice and unfavorable animal husbandry have also
contributed to its decline. We recommend that in-situ conservation, including the establishment of a protected area, is the
best way to preserve this species effectively. 相似文献
17.
Protozoan growth rates in Antarctic lakes 总被引:1,自引:0,他引:1
The growth rates of heterotrophic nanoflagellates (HNAN), mixotrophic cryptophytes, dinoflagellates and ciliates in field
assemblages from Ace Lake in the Vestfold Hills (eastern Antarctica) and Lakes Fryxell and Hoare (McMurdo Dry Valleys, western
Antarctica), were determined during the austral summers of 1996/1997 and 1997/1998. The response of the nanoflagellates to
temperature differed between lakes in eastern and western Antarctica. In Ace Lake the available bacterial food resources had
little impact on growth rate, while temperature imposed an impact, whereas in Lake Hoare increased bacterial food resources
elicited an increase in growth rate. However, the incorporation of published data from across Antarctica showed that temperature
had the greater effect, but that growth is probably controlled by a suite of factors not solely related to bacterial food
resources and temperature. Dinoflagellates had relatively high specific growth rates (0.0057–0.384 h−1), which were comparable to Antarctic lake ciliates and to dinoflagellates from warmer, lower latitude locations. Temperature
did not appear to impose any significant impact on growth rates. Mixotrophic cryptophytes in Lake Hoare had lower specific
growth rates than HNAN (0.0029–0.0059 h−1 and 0.0056–0.0127 h−1, respectively). They showed a marked seasonal variation in growth rate, which was probably related to photosynthetically
active radiation under the ice at different depths in the water column. Ciliates' growth rates showed no relationship between
food supply and mean cell volume, but did show a response to temperature. Specific growth rates ranged between 0.0033 and
0.150 h−1 for heterotrophic ciliates, 0.0143 h−1 for a mixotrophic Plagiocampa species and 0.0075 h−1 for the entirely autotrophic ciliate, Mesodinium rubrum. The data indicated that the scope for growth among planktonic Protozoa living in oligotrophic, cold extreme lake ecosystems
is limited. These organisms are likely to suffer prolonged physiological stress, which may account for the highly variable
growth rates seen within and between Antarctic lakes.
Accepted: 7 December 1999 相似文献
18.
R. H. Marrs M. G. Le Duc S. M. Smart K. J. Kirby R. G. H. Bunce P. M. Corney 《Kew Bulletin》2010,65(4):583-594
The invasion of native habitats by exotic, or alien, plant species has received considerable attention recently from policy,
research, and practical conservation management perspectives. However, a new hypothesis for species dynamics in Britain suggests
that a small number of aggressive native plant species (termed ‘thugs’) may have an equal, or greater, impact on native species
and habitats than exotic species. Here, we examine this hypothesis using multivariate techniques with field-layer cover data
collected during a country-wide survey of British woodlands. Multivariate analysis of these data identified a north-south
gradient on the first axis, and that 20 of the 25 National Vegetation Classification woodland types were sampled within the
study. The most abundant field-layer species included three of the proposed native ‘thugs’, i.e. Rubus fruticosus, Pteridium aquilinum and Hedera helix in addition to the native woodland indicator species Mercurialis perennis. Variation partitioning was used to compare the relative importance of native field-layer ‘thug’ species with invading alien
shrub and tree species relative to other environmental drivers. The variation in the field-layer data-set explained by the
three native ‘thug’ species was significant, but they explained a relatively small proportion of the variation relative to
other environmental variables (climate, soil, management factors etc.). They did, however, explain almost four times as much
variation as the three alien species that were significantly correlated with field-layer species composition (Acer pseudoplatanus, Impatiens glandulifera, Rhododendron ponticum). The results of this analysis suggest that the field-layer of British woodlands is impacted as much by native ‘thug’ species,
as it is from ‘aliens’. Concern about the impact of these native ‘thug’ species has been reported previously, but their impact
has not previously been compared to the impact of invading aliens. It is hoped that this analysis will do two things, first
to act as a sound baseline for assessing any changing balance that should occur in the future, and second, to prompt both
ecologists and conservationists to develop woodland management policies based on sound science. 相似文献
19.
Spatial and temporal variability across life's hierarchies in the terrestrial Antarctic 总被引:3,自引:0,他引:3
Chown SL Convey P 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2007,362(1488):2307-2331
Antarctica and its surrounding islands lie at one extreme of global variation in diversity. Typically, these regions are characterized as being species poor and having simple food webs. Here, we show that terrestrial systems in the region are nonetheless characterized by substantial spatial and temporal variations at virtually all of the levels of the genealogical and ecological hierarchies which have been thoroughly investigated. Spatial variation at the individual and population levels has been documented in a variety of genetic studies, and in mosses it appears that UV-B radiation might be responsible for within-clump mutagenesis. At the species level, modern molecular methods have revealed considerable endemism of the Antarctic biota, questioning ideas that small organisms are likely to be ubiquitous and the taxa to which they belong species poor. At the biogeographic level, much of the relatively small ice-free area of Antarctica remains unsurveyed making analyses difficult. Nonetheless, it is clear that a major biogeographic discontinuity separates the Antarctic Peninsula and continental Antarctica, here named the 'Gressitt Line'. Across the Southern Ocean islands, patterns are clearer, and energy availability is an important correlate of indigenous and exotic species richness, while human visitor numbers explain much of the variation in the latter too. Temporal variation at the individual level has much to do with phenotypic plasticity, and considerable life-history and physiological plasticity seems to be a characteristic of Antarctic terrestrial species. Environmental unpredictability is an important driver of this trait and has significantly influenced life histories across the region and probably throughout much of the temperate Southern Hemisphere. Rapid climate change-related alterations in the range and abundance of several Antarctic and sub-Antarctic populations have taken place over the past several decades. In many sub-Antarctic locations, these have been exacerbated by direct and indirect effects of invasive alien species. Interactions between climate change and invasion seem set to become one of the most significant conservation problems in the Antarctic. We conclude that despite the substantial body of work on the terrestrial biodiversity of the Antarctic, investigations of interactions between hierarchical levels remain scarce. Moreover, little of the available information is being integrated into terrestrial conservation planning, which lags far behind in this region by comparison with most others. 相似文献
20.
The following study was the first to describe composition and structure of the peracarid fauna systematically along a latitudinal
transect off Victoria Land (Ross Sea, Antarctica). During the 19th Antarctic expedition of the Italian research vessel “Italica”
in February 2004, macrobenthic samples were collected by means of a Rauschert dredge with a mesh size of 500 μm at depths
between 85 and 515 m. The composition of peracarid crustaceans, especially Cumacea was investigated. Peracarida contributed
63% to the total abundance of the fauna. The peracarid samples were dominated by amphipods (66%), whereas cumaceans were represented
with 7%. Previously, only 13 cumacean species were known, now the number of species recorded from the Ross Sea increased to
34. Thus, the cumacean fauna of the Ross Sea, which was regarded as the poorest in terms of species richness, has to be considered
as equivalent to that of other high Antarctic areas. Most important cumacean families concerning abundance and species richness
were Leuconidae, Nannastacidae, and Diastylidae. Cumacean diversity was lowest at the northernmost area (Cape Adare). At the
area off Coulman Island, which is characterized by muddy sediment, diversity was highest. Diversity and species number were
higher at the deeper stations and abundance increased with latitude. A review of the bathymetric distribution of the Cumacea
from the Ross Sea reveals that most species distribute across the Antarctic continental shelf and slope. So far, only few
deep-sea records justify the assumption of a shallow-water–deep-sea relationship in some species of Ross Sea Cumacea, which
is discussed from an evolutionary point of view. 相似文献