Plankton community structure in the physical environment surrounding the Prince Edward Islands (Southern Ocean)

The results are presented of a macroscale physical and biological oceanographic survey conducted during the second Marion Island Offshore Study in the upstream and downstream regions of the Prince Edward Islands in the austral autumn (April/May) 1997. Upstream of the islands, the Sub-Antarctic Front appeared to combine with the Antarctic Polar Front to form an intensive frontal feature. Closer to the islands, the fronts appeared to separate. Influenced by the shallow topography of the southwest Indian ridge, the Sub-Antarctic Front was steered northwards around the islands while the Antarctic polar front appeared to meander eastwards, where it was again encountered in the southeastern corner of the survey grid. Downstream of the islands, an intensive cold-core eddy within the Polar Frontal Zone was observed. Its exact genesis is unknown but it is possibly generated by instabilities within the meandering Antarctic polar front as its surface signature was characteristic of Antarctic surface water masses found south of the Antarctic polar front. The cold-core eddy appeared to displace the sub-Antarctic front northwards. South of the eddy, a warm patch of sub-Antarctic surface water was observed; its position appeared to be controlled by the meandering Antarctic Polar Front which lay on either side of this feature. No distinct microphytoplankton groupings could be distinguished by numerical analyses, although four distinct zooplankton groupings were identified. These corresponded to the sub-Antarctic surface waters, Antarctic surface waters and the polar frontal zone waters. The fourth grouping comprised those stations where the lowest zooplankton abundances during the entire investigation were recorded and, as a consequence, does not reflect any spatial patterns. These results suggest that the species composition and distribution of plankton in the vicinity of the islands were consistent with the prevailing oceanographic regime. Accepted: 15 March 1999     

Regional biogeography of shallow reef fish and macro-invertebrate communities in the Galapagos archipelago

Aim To delineate biogeographical patterns in Galapagos shallow‐water reef fauna at regional scales. Location Galapagos Islands. Methods Fishes and macro‐invertebrates were quantitatively censused using underwater visual techniques along more than 500 transects at defined depth strata across the Galapagos archipelago. Data were analysed using multivariate techniques to define regional patterns and identify species typical of different regions. Results Subtidal communities of fishes and macro‐invertebrates on shallow reefs differed consistently in species composition across the Galapagos archipelago, with three major biogeographical groupings: (1) the ‘far‐northern area’ containing the islands of Darwin and Wolf, (2) the ‘central/south‐eastern area’, including the east coast of Isabela, and (3) the ‘western area’, encompassing Fernandina and western Isabela. In addition, the northern islands of Pinta, Marchena and Genovesa form a separate region in the central/south‐eastern area, and Bahia Elizabeth and Canal Bolivar separate from other parts of the western area. The far‐northern bioregion is characterized by high fish species richness overall, including a high proportion of species of Indo‐Pacific origin. However, very few endemic fishes or species with distributions extending south from Ecuador (‘Peruvian’ species) are present, and the bioregion also possesses relatively low species richness of mobile macro‐invertebrate taxa. By contrast, the ‘western’ bioregion possesses disproportionately high numbers of endemic fish taxa, high numbers of cool‐temperate Peruvian fish species, and high invertebrate species richness, but very few species of Indo‐Pacific origin. The Bahia Elizabeth/Canal Bolivar bioregion possesses more endemic species and fewer species with Peruvian affinities than coasts within the western bioregion. The northern bioregion of Pinta, Marchena and Genovesa represents an overlap zone with affinities to both the far‐northern and south‐eastern islands. The south‐eastern bioregion includes species from a variety of different sources, particularly ‘Panamic’ species with distributions extending north to Central America. Main conclusions On the basis of congruent divisions for reef fish and macro‐invertebrate communities, the Galapagos archipelago can be separated into three major biogeographical areas, two of which can be further subdivided into two regions. Each of these five bioregions possesses communities characterized by a distinctive mix of species derived from Indo‐Pacific, Panamic, Peruvian and endemic source areas. The conservation significance of different regions is not reflected in counts of total species richness. The regions with the lowest overall fish species richness possess a temperate rather than tropical climate and highest levels of endemism.     

Biogeography of Indonesian snakes

The islands of eastern Indonesia occupy the major zone of contact and overlap between the reptile faunas of the Asian and Australo–Papuan regions. A survey of reptiles on twenty-eight islands in eastern Indonesia between 1988 and 1993 has documented several major range extensions and many new records of species on islands. The zoogeographic affinities of the snakes of Indonesian islands are re-examined in the light of both recent surveys and taxonomic research and coupled with that published previously. The major boundary in the snake fauna of Indonesia occurs between Sulawesi and the Lesser Sunda islands to the west and the northern and southern Maluku group of islands to the east; it corresponds to the major biogeographic boundary known as Weber's Line. The biogeographic affinities of the snakes of the Tanimbar islands are equivocal. The snake fauna of islands within the Lesser Sunda group indicate that separation between islands during the Pleistocene played a role in determining current assemblages and variation within species The islands of eastern Indonesia form biogeographic subregions that have relatively high levels of endemism and evidence of incipient speciation as a consequence of changes in sea-levels and climate during the Pleistocene.     

Mammalian endemism,range size and conservation status in the southern temperate zone

Aim To examine the taxonomic uniqueness, range sizes, endemism and conservation status of southern temperate zone mammals and how factors impacting their conservation differ across hemispheres. Location Land surfaces of all continents (with the exception of Antarctica) and continental islands with an emphasis on the southern temperate hemisphere (land south of the Tropic of Capricorn). Methods We used data from the 2008 IUCN Red List of Threatened Species to characterize conservation status, threats and range sizes to compare northern and southern temperate zone mammals. We assessed the taxonomic uniqueness of the two regions as derived from the EDGE programme. We also conducted a gap analysis by overlapping mammal ranges with protected area coverages for temperate regions. Results Southern temperate species are phylogenetically more unique than in the Northern Hemisphere. The endemics have significantly smaller range sizes and are at a significantly greater risk of extinction (about 50% greater, with 24.7% of species being threatened versus 15.6% in the Northern Hemisphere). Finally, southern temperate endemics are significantly more likely to exist outside protected areas (13.38% versus 3.65%). Main conclusions The southern temperate zone harbours a unique fauna, attributed to the long isolation from the northern temperate zone. Temperate regions are heavily exploited for human activities, especially grazing and agriculture. The Southern Hemisphere is particularly susceptible to disturbance, given the small range sizes of its species and the low degree of protected area coverage. The scenario now is one of regions with numerous endemics under high threat from human activities.     

A comparison of relict versus equilibrium models for insular mammals of the Gulf of Maine

For the mammalian faunas of 24 landbridge islands in the Gulf of Maine (0.003–279 km² in size), area accounts for 86% of variance in species richness. The slope, z , of the species-area curve is 0.247. For the seven largest islands (>10km²), the non-equilibrium hypothesis of relaxation following saturation in the post-Pleistocene is suggested by (1) elevated slope of the species-area curve (0.353), (2) correlation of species richness with island age ( r =- 0.81) and water depth to mainland ( r = -0.70), (3) highly non-random nested subsets of species ranked by island area, and (4) discontinuity with the extremely depauperate faunas of oceanic islands of the eastern North Atlantic. The alternative hypothesis of a dynamic equilibrium determined by recurrent immigration and extinction is supported by (1) documented turnover in 16 species, (2) correlation of species-area residuals with distance ( r = - 0.90), (3) distribution dependent upon vagility with reduction or absence of hibernators and other poor dispersers, (4) low levels of endemism, and (5) congruence of community structure with that of mainland fauna for both trophic level and body size.
I conclude that while some insular populations may be relictual, the faunal composition of most of these islands is dependent on recurrent colonization, much of which takes place over ice bridges. However, true equilibrium is perturbed by climatic shifts, range expansions, and human disturbance.     

叶蜂总科昆虫生物地理研究II叶蜂总科广布属的地理分布特性(膜翅目)

本文系统分析了叶蜂总科广布属的地理分布特性。叶蜂总科广布属被分为１２个主要的分布类型,其中全北界分布型６９属,可再分为６种次类型。在各分布型下列举了全部具有该类分布特征的叶蜂总科属名,并提出了一些有关起源与扩散的设想和推论。在广布型属的地理分布研究基础上,对各大生物地理界之间的关系也提出了一些看法。     

Australian barnacles (cirripedia: thoracica), distributions and biogeographical affinities

Currently, 279 barnacle species are recognized in Australia waters. The barnacle fauna of tropical Australia exhibits high species diversity (221), with a high incidence of tropical species (87 Indo-west Pacific [IWP], 16 West Pacific and 65 Indo-Malayan), a low species endemicity (8), and 44 cosmopolitan and 1 Australasian species. Conversely, that of temperate Australia shows lower species diversity (129), with a lower incidence of tropical species (26 IWP, 10 West Pacific and 25 Indo-Malayan), higher species endemicity (23), 37 cosmopolitan, 6 Australasian species, and 3 Australasian/Antarctic species. Distributions corroborate the general patterns demonstrated by the shallow-water biota of northern tropical and southern temperate Australian biogeographic provinces. Tropical and temperate provinces grade into each other in a broad overlap zone along both the western and eastern Australian coasts. This overlap zone is essentially a transitional region, with the gradual replacement of a tropical barnacle fauna in the north by a predominantly temperate barnacle fauna in the south. Both western and eastern Australian coasts are bounded by major poleward-flowing warm currents that have considerable influence on the marine flora and fauna, distributing tropical species of many taxa much farther south than could be predicted by latitude. Currently, 16 barnacle species introduced into Australian waters are identified, although this number may increase in the future due to new port developments and increased shipping arrivals.     

Patterns of diversity of the north-eastern Atlantic blenniid fish fauna (Pisces: Blenniidae)

This paper presents an analysis of the distributional patterns of blenniids (Pisces: Blenniidae) in the north‐eastern Atlantic. Two peaks of species diversity were found, both in terms of number of species and number of endemics: one in the tropical African coast and another in the Mediterranean Sea. A cluster analysis of similarity values (Jaccard coefficient) among the eastern Atlantic zoogeographical areas, revealed the following groups: a north temperate group, a tropical group formed by the tropical African coast and Mauritania, another group formed by the islands of Cape Verde, a south temperate group (South Africa), and a southern Atlantic group formed by the islands of Ascension and St Helena. Within the north temperate group, the subgroups with higher similarities were: Azores and Madeira, Canary Islands and Morocco, and the Mediterranean and the Atlantic coast of the Iberian Peninsula. Based on affinity indices, the probable directions of faunal flows were inferred. The tropical coast of Africa and the Mediterranean emerged from this analysis as probable speciation centres of the north‐eastern Atlantic blenniid fauna. The Mediterranean may have also acted as a refuge during glacial periods.     

Marine macroalgal biodiversity hotspots: why is there high species richness and endemism in southern Australian marine benthic flora?

The southern Australian marine macroalgal flora has the highest levels of species richness and endemism of any regional macroalgal flora in the world. Analyses of species composition and distributions for the southern Australian flora have identified four different floristic elements, namely the southern Australian endemic element, the widely distributed temperate element, the tropical element and a cold water element. Within the southern Australian endemic element, four species distribution patterns are apparent, thought to largely result from the Jurassic to Oligocene fragmentation of East Gondwana, the subsequent migration of Tethyan ancestors from the west Australian coast and the later invasion of high latitude Pacific species. Climatic deterioration from the late Eocene to the present is thought responsible for the replacement of the previous tropical south coast flora by an endemic temperate flora which has subsequently diversified in response to fluctuating environmental conditions, abundant rocky substrata and substantial habitat heterogeneity. High levels of endemism are attributed to Australia's long isolation and maintained, as is the high species richness, by the lack of recent mass extinction events. The warm water Leeuwin Current has had profound influence in the region since the Eocene, flowing to disperse macroalgal species onto the south coast as well as ameliorating the local environment. It is now evident that the high species richness and endemism we now observe in the southern Australian marine macroalgal flora can be attributed to a complex interaction of biogeographical, ecological and phylogenetic processes over the last 160 million years.     

Distribution of Cryptostigmata and Mesostigmata (Acari) within the litter and soil layers of two subtropical forests

Differences in the litter and soil of northern temperate and tropical and subtropical forest soil and soil faunas are noted. Analyses of the distribution and abundance of Cryptostigmata and Mesostigmata mites in the litter and soil of two Australian subtropical forests are presented. The faunal associations in the litter and soil of these forests are different. It is suggested that the litter and soil habitats of subtropical and tropical forests should be regarded as separate but connected habitats in relation to their fauna. This contrasts with the assumption, for temperate forests, that litter and soil communities are portions of a single system.     

Skate assemblage on the eastern Patagonian Shelf and Slope: structure, diversity and abundance

The eastern Patagonian Shelf and continental slope of the south-west Atlantic Ocean support a high biodiversity and abundance of skates. In this study, meso-scale differences in the assemblages, spatial and seasonal distributions of skates are revealed among six habitat zones of the eastern Patagonian Shelf characterized by distinctive oceanographic conditions. Most skates belonged to temperate fauna, and their abundance was much greater in habitats occupied by temperate waters (north-western outer shelf) or mixed waters (northern slope) than in habitats occupied by sub-Antarctic waters (SASW) (south-eastern outer shelf and southern slope). Sub-Antarctic skates were not abundant on the shelf even in habitats occupied by SASW, occurring mainly in deep areas of the lower continental slope. The majority of temperate skates migrated seasonally, shifting northward in winter and spreading southward with warming waters in summer. Most temperate species had two peaks in female maturity (mainly spring and autumn) and spawned in the same habitats where they fed. It is hypothesized that the high biodiversity and abundance of skates on the Patagonian Shelf and Slope are due to the practical absence of their natural competitors, flatfishes, which occupy similar eco-niches elsewhere.     

安徽祁门地区种子植物区系组成及特征

祁门地区位于皖南山区南端,种子植物区系组成丰富,经调查种子植物有147科731属1822种(包括亚种、变种、变型),其中17种为国家级珍稀濒危保护植物。该地区的种子植物优势科为木通科、猕猴桃科、槭树科、金缕梅科、榆科等亚热带和温带分布科。科有11种分布类型,以泛热带分布为主(占51.9%);属有14种分布类型,以北温带分布最多(占20.5%),其中温带性地理成分占55.6%;种有13种分布类型,以中国特有分布最多(占50.8%),其中温带性地理成分占33.1%,因此该区系地理成分复杂,并且具有温带区系性质。此外,该区系起源古老;替代现象和特有植物较为明显。     

The distribution of the ectoparasite fauna of Sebastes capensis from the southern hemisphere does not correspond with zoogeographical provinces of free-living marine animals

Aim We examined the ectoparasite fauna of Sebastes capensis over almost all its geographical distribution range (Chilean, Argentinean and South African coasts) to determine (1) whether the ectoparasites of this host show a zoogeographical pattern and, if so, (2) how this pattern is related to known zoogeographical patterns for free‐living organisms. Location Fish were captured from 20, 24, 30, 33, 36, 40, 45 and 52° S along the Chilean coast; 11° S on the Peruvian coast; 43° S on the Argentina coast; and 34° S on the South African coast. Methods From April to September 2003 and from April to August 2004, 626 fish were captured. The parasites were collected using standard parasitological techniques. At the component community level, zoogeographical distribution patterns were evaluated using cluster analysis. At the infra‐community level, patterns of similarity in parasite composition among localities were investigated with multivariate discriminant analyses. Results The ectoparasite fauna of S. capensis consists of six species distributed along the whole of the Chilean coast. Four other species are distributed only within the transitional zone between the northern warm temperate region (Peruvian faunistic province), extending from Peru to the northern Chilean coast up to c. 30° S, and the cold temperate region (Magellanic faunistic province). The component communities from latitudes 30 to 40° S showed higher ectoparasite species richness, while localities on the margins of the geographical range showed lower species richness. Cluster analysis indicated a grouping of localities consistent with the transitional zone. Argentina and South Africa always emerged as separate localities. Main conclusions The ectoparasite communities of S. capensis do not follow a distributional pattern concordant with the known biogeographical zones for invertebrates and/or fish along the south‐eastern Pacific. Therefore their ectoparasite fauna is not useful as a zoogeographical indicator, although it does allow us to distinguish the transitional zone of the south‐eastern Pacific. On a more extended geographical scale, it is possible to distinguish the ectoparasite communities of S. capensis in the south‐eastern Pacific (as a whole) from those of Argentina and South Africa.     

Biodiversity and biogeography of southern temperate and polar bryozoans

Aim To describe the distribution of biodiversity and endemism of bryozoans in southern temperate and polar waters. We hypothesized that we would find: (1) no strong latitudinal richness gradient; (2) striking contrasts in richness and endemism between clades and between regions; and (3) that faunal similarity of regions would cluster geographically around each southern continent. Location South Atlantic, Indian and Pacific Oceans and the Southern Ocean. Methods We constructed a data base from known literature, regional data bases and recent finds. We regionalized each southern continent, calculated levels of richness and endemism for each region and continent, and used primer 5 to perform multivariate statistical analysis. Results A third (1681) of global bryozoan species described occur south of 30° S, of which c. 87% were cheilostomes. In richness we found no latitudinal cline and change across longitude was stronger. New Zealand was richest and had the most (60%) endemic species, followed by Antarctica at 57%. There were striking contrasts in regional richness and endemism between clades but the highest levels of between‐region similarity were around Antarctica. The timing of past continent connectivity was reflected. Main conclusions Bryozoans show strong hemispherical asymmetry in richness and, like molluscs and corals, decrease away from Australasia rather than with latitude. Species endemism is much lower in Antarctic bryozoans than previously thought, and as this taxon is not particularly dispersive and is now amongst the best studied regionally, maybe Antarctic endemism in general is lower and Antarctica less cut‐off to species dispersal than previously thought. However, Antarctic generic endemism is double the level previously calculated and regional faunal similarities are much higher than around other continents – both reflecting long‐term isolation. Bryozoans, in contrast to the paradigm of Antarctic fauna, may be fairly robust to predicted climate change. Paradoxically, they may also be one of the best taxa to monitor to sensitively detect marine benthic responses.     

Antarctic, Sub-Antarctic and cold temperate echinoid database

This database includes spatial data of Antarctic, Sub-Antarctic and cold temperate echinoid distribution (Echinodermata: Echinoidea) collected during many oceanographic campaigns led in the Southern Hemisphere from 1872 to 2010. The dataset lists occurrence data of echinoid distribution south of 35°S latitude, together with information on taxonomy (from species to genus level), sampling sources (cruise ID, sampling dates, ship names) and sampling sites (geographic coordinates and depth). Echinoid occurrence data were compiled from the Antarctic Echinoid Database (David et al. 2005a), which integrates records from oceanographic cruises led in the Southern Ocean until 2003. This database has been upgraded to take into account data from oceanographic cruises led after 2003. The dataset now reaches a total of 6160 occurrence data that have been checked for systematics reliability and consistency. It constitutes today the most complete database on Antarctic and Sub-Antarctic echinoids.     

Litter and soil fauna of two Australian subtropical forests

The abundances of litter and soil fauna and some related environmental measures are given for two Australian subtropical forests, a notophyll vine forest (or rainforest) and a wet sclerophyll forest. Animals were more abundant in the wet sclerophyll forest; peak abundances were recorded in summer in both forests. Mites and Collembola accounted for 79% of the rainforest fauna and for 85% of the wet sclerophyll forest fauna. Most mites in the wet sclerophyll forest were Crypto stigmata (68%); in the rainforest both Cryptostigmata and Mesostigmata were well represented (84%). Patterns of aggregations of individuals within major faunal groups differed for the two forests. Correlations are made between the numbers of individuals of Collembola, of mites and of each order of mite and the environmental measures. Significant correlations emerged for some environmental measures in some seasons. Results are compared with those of other studies and it is concluded that poor or no humus development restricts the numbers of individuals living on tropical or subtropical forest floors. Speculations are presented to account for the difference between the faunas in the two Australian subtropical forests.     

The steppe insect fauna in the Russian Far East: Myth or reality?

The fauna of Lepidoptera in the forest-steppe zone of southern plains of the Russian Far East is analyzed. The contribution of species with the optimal distribution in the steppe and forest-steppe zones of Eurasia into the above fauna is insignificant; eastern Asian temperate species dominate in the region. The classification analysis of lists of species from local steppe and forest-steppe faunas of both Far-Eastern humid “prairies” and southern Transbaikalian region is performed. In these regions, xerophilous species constitute the essential part of the local fauna. The necessity of revision of the present zoogeographical zoning of the Far East is substantiated.     

Acari and Collembola in the litter and soil of three north Queensland rainforests

The population changes, distribution and composition of litter and soil Acari and Collembola from three north Queensland rainforests are described based on samples collected on six occasions at approximately 3-monthly intervals. Numbers of Acari and Collembola collected from litter were lower in the north Queensland rainforests than those reported from rainforests outside Australia: however, numbers of Acari and Collembola in the soil were similar to numbers in rainforest soils elsewhere. Cryptostigmata were the most abundant group of Acari in the litter and 0–4 cm soil layer, comprising 41–55% and 42–55% of the total Acari in the litter and 0–4 cm soil layers respectively. Most of the Acari and Collembola are located in the 0–4 cm soil layer at each site (53–75%), with the litter layer containing the smallest proportion (3–20%). Most of the groups of Acari and Collembola examined show little evidence of seasonal vertical migration between the litter and soil to 8 cm. Minimum numbers of Acari and Collembola in the litter occurred in the dry season and maximum numbers occurred in the wet season. Seasonal fluctuations in numbers of Cryptostigmata appear to be influenced by the periodic saturation of the soil during the wet season.