Changes in the fish fauna associated with a sub-Antarctic <Emphasis Type="Italic">Macrocystis pyrifera</Emphasis> kelp forest in response to canopy removal

The fish fauna associated with a Macrocystis pyrifera forest and the effects of the canopy removal on this fauna were studied in the Beagle Channel, Tierra del Fuego. Seasonal changes and differences in the fish communities that inhabit the canopy and the holdfast were also studied. Two patches of kelp forest separated by 200 m were selected. In one, the canopy was removed periodically while the other was used as a control. Samples were collected seasonally, from autumn 1999 to 2001. Fish fauna in the water column was sampled using trammel nets and holdfast fish fauna was sampled by removing the complete holdfast. Different assemblages of fish species were captured in the water column (surface and bottom) and in the holdfast. In the former there were mainly pelagic and benthopelagic species and the latter predominantly demersal species. The principal effect of the canopy removal was a drop in the abundance (and total weight) of Paranotothenia magellanica (doradito), the species with the strongest relationship with the canopy, principally at the surface of the treated patch probably due to a reduction in the availability of refuges. A high degree of seasonality was observed for fish species’ total weight, abundance and diversity, with higher values in summer and autumn. Taking into account our data and available data on kelp growth in the same locality, we suggest of cutting the kelp forest (preferably those farther away from the coast) once a year in winter or early spring, in order to minimize impact on the fish community.     

Methods for biological monitoring: Biological interactions in communities of subtidal sediments

Predation has been demonstrated to be of fundamental importance in structuring benthic communities in the intertidal zone. The aim of the present investigation was to elucidate some of the effects of predation on structuring communities in unvegetated subtidal sediments. Field manipulative cage experiments were performed on sediment in the inner part of the Oslofjord (Norway), where the species composition was typical for a moderately organically enriched sediment. Sediment from this area was transferred to an area not suspected a priori to be seriously affected by organic pollution, and the effect of predation on the fauna was evaluated. Predation effects were not observed in the Oslofjord experiments partially because of extensive obstruction of recruitment to the sediment by settlement ofPolydora antennata on the cage; however, further experiments are in progress in this area. No such settling was observed in the unpolluted area. Here 63 taxonomic groups were identified, 57 in the control and 50 in the cages; 43 taxonomic groups were found in both the cage and the control. The total number of individuals was significantly higher in the cage (4779) than in the control (2849). The fauna recruited to the sediment in the cage responded to decreased predation by macropredators by a significant reduction in diversity. Of the 10 most abundant groups 3 (Tellinacea, Syllidae andPholoë minuta) were significantly more abundant in the cage than in the control; 3 others (Prionospio malmgreni, Microphthalmus abberans and Paraonidea) were significantly more abundant in the control. It is concluded that in an unpolluted area predation is an important factor in controlling numbers of at least some of the most abundant species. However, the effect of predation does not seem to be of the same importance in the subtidal as has previously been recognized for unvegetated intertidal mudflats.     

Biodiversity, host specificity, and dominance by eusocial species among sponge-dwelling alpheid shrimp on the Belize Barrier Reef

Alpheid shrimp represent an abundant and diverse, but poorly characterized, component of the cryptic biodiversity of coral reefs worldwide. Sponge‐inhabiting alpheids provide a promising model system for exploring patterns of cryptic reef biodiversity because their habitats (hosts) are discrete and qualitatively distinct units. We tabulated data from 14 years of collections at Carrie Bow Cay, Belize to quantify patterns of diversity, host specificity, and dominance among sponge‐dwelling shrimp (Synalpheus), with special attention to eusocial species. From > 600 sampled sponges of 17 species, we recognized at least 36 Synalpheus shrimp species. Of these, 15 (42%) were new to science. Species accumulation curves suggest that we have sampled most of the Synalpheus diversity at Carrie Bow Cay. Diversity of sponge‐dwelling Synalpheus was slightly higher in shallow water, probably because of greater habitat diversity, than in deep water. Host specificity was surprisingly high, with > 50% of all shrimp species found in only a single sponge species each, although some shrimp species used as many as six hosts. Cohabitation of individual sponges by multiple shrimp species was rarer than expected by chance, supporting previous distributional and behavioural evidence that competition for hosts is strong and moulds patterns of host association. The fauna of most well‐sampled sponge species was dominated, both in numbers of individuals and in frequency of occurrence, by eusocial species. Eusocial shrimp species also inhabited a significantly greater number of sponge species than did non‐social shrimp. Consequently, > 65% of shrimp in our quantitative samples belonged to the four eusocial species, and on a per‐species basis, eusocial species were 17 times as abundant as non‐social species. Our data suggest that the highly diverse sponge‐dwelling shrimp assemblage of the Belize Barrier Reef is structured by competition, and that eusociality has allowed a small number of species to dominate the sponge resource.     

The ecology of ostracodes (Ostracoda,Crustacea) in western Mongolia

Aquatic biota in Central Asia witnesses and faces a changing environment. Because ostracodes contribute to both extant and fossil lacustrine diversity, they can be used to track evolution in water quality. Living ostracode communities in a variety of aquatic habitats of western Mongolia were analyzed in relation to environmental and hydrochemical variables of those habitats, based on presence/absence data from net samples. The sampled water bodies represent broad gradients in ionic concentration and composition. Ostracode community composition of springs differed from all other sampled habitats, which was also reflected in CCA analyses. Our data indicated that the ostracode fauna of western Mongolia shows a high response to calcium content, alkalinity, salinity, temperature, nutrients, and altitude. Species composition and diversity seem to be determined by solute evolution dominated by Ca-depletion. In general, this seems to be an important regulator of lacustrine ostracode species composition in several semi-arid regions. Binary logistic regression was used to predict the occurrence of the most common species with a minimal set of environmental variables. The resulting models showed on average low performance, and mainly demonstrated the potential of such modeling to predict the distribution of typical bio-indicator species.     

Regional-scale analysis of subtidal rocky shore community

The French monitoring network, REseau BENThique (REBENT), was launched by the Ministry of the Environment in 2003 following the 1999 Erika oil spill. REBENT aimed to acquire baseline knowledge of coastal benthic habitat distributions with a special focus on biological diversity. This study analyzed data from 38 subtidal rocky reef sites collected by a single diving team of marine biologists along the coast of Brittany from 2004 to 2010. At each site, the depth limits of the algal belts were determined between 0 and ?40 m Chart Datum (CD); the flora and fauna compositions and abundances were sampled at ?3 and ?8 m CD. A total of 364 taxa (156 flora and 208 fauna), belonging to 12 phyla, were identified. The results showed that the depth limit and density of kelp beds increased as water turbidity decreased; moreover, several changes in community structure could be related to water turbidity and temperature. Thus, northern and southern Brittany showed strong differences in diversity and structure of the dominant kelp species (Laminaria hyperborea and Saccorhiza polyschides). The results from this kelp habitat composition survey (dominant kelp species and indicator species) provided important information for local pressure assessments, like increases in turbidity. The data also provided a reference that could be useful for detecting changes in coastal water temperatures due to global warming.     

Diversity as a measure of benthic macroinvertebrate community response to water pollution

The assumption that water pollution causes a depression in the diversity of benthic macroinvertebrates as measured by the Shannon index and similar diversity indices is questioned. An interpretation of the community response of benthic macroinvertebrates to pollution in the Millers River, Massachusetts is developed from species presence-absence and abundance data in conjunction with published information on the species' environmental tolerances as compared to chemical water quality data. This interpretation is compared with one derived solely from diversity index values. The interpretations are quite different; the differences may be attributed to other environmental factors such as impoundments and flow reductions which influence the fauna and thus the diversity index value, but which are not related to pollution. In addition, several intrinsic features of the diversity indices increase their bias.Contribution No. 47 of the Massachusetts Cooperative Fishery Unit jointly supported by the U.S. Bureau of Sport Fisheries and Wildlife, the Massachusetts Division of Fisheries and Game, the Massachusetts Division of Marine Fisheries, and the University of Massachusetts.     

Defining past ecological status and in situ reference conditions using benthic foraminifera: A case study from the Oslofjord,Norway

Characterizing marine water bodies and defining ecological status, both present and past (pre-impacted), has become an important task for EU's Member States and their associates during the last decade due to the implementation of the Water Framework Directive (WFD). However, none of the methods used to define Ecological Quality Status (EcoQS) are able to accurately define the status for both the present-day and reference conditions at a given site (i.e., in situ). Recent studies have revealed a significant correlation between the diversity of living (stained) fossilizable benthic foraminifera (protists) and associated environmental parameters (e.g., dissolved oxygen concentration). The present study takes this relationship a step further by applying methods used to define present-day EcoQS on fossil benthic foraminiferal assemblages and, thereby, defining past EcoQS (PaleoEcoQS). This is particularly useful for defining reference condition in areas where biological- and instrumental time-series are limited or lacking. Our case study from the Oslofjord, Norway, shows that (1) the “Foraminiferal method” can define temporal developments in in situ EcoQS from reference to present-day conditions, (2) results of the “Foraminiferal method” reflect available historical biological records and hydrographic time series, (3) data (1993 and 2009) on macrofauna (traditional bio-monitoring tool) and benthic foraminifera from the same sites define the same EcoQS, and (4) the changes in foraminiferal diversity through time are due to human activity (pollution), rather than climate change. Using in situ data to define ecological reference conditions is preferable compared to modeling or comparisons with present-day supposedly similar reference conditions.     

Patterns of diversity and habitat relationships in terrestrial mollusc communities of the Pukeamaru Ecological District, northeastern New Zealand

Aim The New Zealand terrestrial mollusc fauna is among the most speciose in the world, with often remarkably high richness at lowland forest sites. We sought to elucidate general explanations for patterns of richness in terrestrial mollusc communities by analysis of species coexistence and habitat relationships within a New Zealand district fauna. Location Pukeamaru Ecological District, eastern North Island, New Zealand. Methods We sampled molluscs using qualitative methods at twenty-three sites and quantitatively by frame sampling of scrubland-forest floor litter at sixteen of these sites and analysed patterns of species richness and turnover in relation to regional species pools and local habitat attributes. We then tested for nonrandom assemblage of taxa along diversity and habitat gradients. Results Ninety-four indigenous mollusc species were recorded from a district fauna estimated at 102 indigenous species: only two species were endemic. From the presumptive geological history of the district, the low endemism, and Brooks parsimony and indicator species analyses of faunal relationships, the communities were indicated to have resulted by accumulation of colonists from other New Zealand districts since the Miocene. Richness ranged from two or three indigenous species in dune habitats to fifty-nine species in a floristically rich forest. Beta diversity was high and site occupancy per species was low, indicating communities structured by successive replacement of ecological equivalents. Sites differing in vegetation had characteristic species assemblages, indicating a degree of habitat specialization. Canonical correspondence analysis indicated that canopy tree species, canopy height, floristic diversity, altitude, litter mass, and litter pH were important determinants of species assemblage in scrubland and forest. Richness was strongly associated with site floristic diversity and, for litter-dwelling species, the pH of litter substrate. High richness occurred at those sites supporting molluscs in high abundance. Shell-shape distributions were essentially Cainian unimodal, with communities dominated by snail species with subglobose to discoidal shells. Mean and variance of shell size increased with mollusc species richness and floristic diversity at sites, indicating dominance of communities by small-shelled species at early successional or floristically poor sites, and increased richness resulting from addition of larger snails into vacant niches. Shifts in shell form were associated with sympatry in several congeneric taxa. Main conclusions The underdispersion of shell shape, relative to faunas elsewhere in the world, indicates that community structure in New Zealand land snail faunas has been constrained by limited phylogenetic diversity and/or by convergence upon successful adaptations. The remarkably high richness that characterizes these communities indicates special conditions allow coexistence of numerous species. The relationship between floristic diversity at sites and the richness, diversity, and shell-size distributions of the molluscs suggests assemblages structured around niche partitioning among competing species. While there is an element of congruence between vegetation and mollusc pattern, this study indicates that assembly rules will be defined, and spatial pattern predicted, only through a better understanding of the linkage between regional species pool, organism traits, environment, and local community assemblage.     

Effects of copper, cadmium and contaminated harbour sediments on recolonisation of soft-bottom communities

An extensive field experiment on benthic colonisation on polluted sediments was carried out at 50 m depth at three locations representative of the pollution gradient in the inner Oslofjord. The aim of the study was to investigate the effect of copper, cadmium and polluted harbour sediment on recolonisation of benthic fauna, and whether the response varied with a varying degree of background pollution. Copper and cadmium were added to the local sediments at the three locations, while the contaminated harbour sediment was taken from the hypoxic Oslo harbour and transplanted to well-oxygenated and less-polluted locations. Oslo harbour has a poor macrofauna, the sediments are heavily contaminated and the oxygen levels in the bottom waters are low. One of the aims of this experiment was to separate effects of contamination from effects of low oxygen. Sediments with high levels of copper (∼400-1500 mg/kg) clearly had a negative effect on colonisation by several taxa. This negative response was more pronounced at the relatively pristine location in the outer fjord compared to the more polluted sites, probably as a result of an increased bioavailability of the metals in sediments with lower concentrations of organic carbon. Sediments with high levels of cadmium (∼9-23 mg/kg), on the other hand, did not have negative effects on colonisation of any taxa. In the boxes with polluted harbour sediments, only the polychaete Raricirrus beryli showed reduced abundance. This lack of community response clearly indicates that hypoxia is more critical than high concentrations of contaminants for the establishment of a normal benthic fauna in the Oslo harbour area. The experiment only lasted for 6 months and the recolonising fauna was dominated by opportunistic and r-selected species. Long-term toxic effects may therefore have occurred if the experiment had lasted longer. The experiment also showed that the time for the development of a community resembling the ambient community was faster on the polluted than on the more pristine location.     

Temporal and Spatial Diversity and Distribution of Arboreal Carabidae (Coleoptera) in a Western Amazonian Rain Forest1

Diversity of arboreal carabid beetles was sampled by fumigation in 100 3 × 3 m stations within a 100 × 1000 m terra firme forest plot in Ecuadorian Amazonia. Nine sampling dates from January 1994 to October 1996 yielded 2329 individuals belonging to 318 species of which more than 50 percent were undescribed species. A high percentage of the species sampled were rare; the proportion that occurred once per sampling date (singletons) ranged from 50.0 to 62.5 percent. Estimates of species richness were from 82 to 282 species of arboreal carabids in the study plot on a given sampling date. Most richness values were greater than 173 species. Species accumulation curves attained asymptotes for all but one sampling date, indicating that an adequate level of sampling effort was used to characterize the diversity of carabid fauna. Total accumulation curves based on pooled data failed to reach asymptotes. There was a high turnover in species composition between sampling dates; less than 50 percent of the species between the majority of sampling dates were shared, suggesting that the total species pool may be extremely large. Although species composition changed seasonally, species richness varied little. Spatial autocorrelation analysis revealed that the structure of this species assemblage was significantly patterned at distances below 280 m. Taken together, the large percentage of undescribed species, die failure of the overall species accumulation curves to level off, and the high turnover in species composition indicate that the species diversity of carabid beetles is far higher than previously thought.     

Chemical criteria for marine eutrophication with special reference to the Oslofjord,Norway

Results of a chemical and geochemical study of the Oslofjord system are presented to explore the possibility of qualitatively identifying a eutrophication gradient. Nutrient concentration and dissolved oxygen may indicate such a gradient in areas of similar hydrographies. Uncertainties due to minor differences in hydrography may be resolved by considering sedimentary organic carbon, C:N ratios and the accumulation of mineralisation products in the sediment pore water. The reliability of the sedimentary organic matter and the pore water composition as gradient indicators can be impaired by input of terrestrial organics, dispersal of mineralisation products by the benthic fauna or the apparent high levels of organic carbon and pore water nutrients in the absence of the benthic fauna under anoxic conditions.     

Sewage pollution and the infaunal benthos of Victoria Harbour,Hong Kong

Victoria Harbour, Hong Kong, receives 800 million litres · day^?1 of untreated sewage from 3.6 million people, but is flushed by tidal currents at velocities up to 1.1 m · s^?1. Two replicate Smith-McIntyre grab samples were collected at 66 stations in August 1979, yielding a total of 5797 animals belonging to 68 species. Agglomerative hierarchical classification was used to delineate five station groups; a sixth group contained four stations where no fauna were found. All but one of the groups inhabited fine sediments (> 70% silt-clay) and could be placed along a gradient conforming to the typical pattern of organic pollution effects found in boreal and temperate waters. Abiotic areas, found in enclosed typhoon shelters, were successively replaced by a very poor fauna, a peak of opportunists, an ecotone point and a transition to normal fauna. The peak of opportunists was dominated by the oligochaete Thalassodrilidesgurwitschi (Hrabe); the polychaetes Capitella capitata (Fabricius) and Minuspio cirrifera (Wiren) were also numerous. Overall abundance was low (784 individuals · m^?2) compared with opportunists in boreal and temperate waters. The remaining station group was found in coarser sediments (<40% silt-clay) and an inflexion was observed in the log-normal distribution of individuals per species. Dominant species included the bivalve Tapes philippinarum (Adams & Reeve) and the polychaete Minuspio cirrifera; overall abundance was high (1103 individuals · m^?2). In general, pollution was assessed by the pattern of changes in number of species, abundance, biomass, diversity and evenness, by log-normal distributions of individuals per species, and by the indicator species M. cirrifera. When compared with earlier (1976) data, community conditions were generally similar but the abundance of individual species varied greatly and M. cirrifera was absent. The severely polluted area was ≈ 15 km²; this is similar in extent to offshore discharge sites and indicates the importance of tidal flushing in this inshore channel.     

Meiofauna of the profundal zone of the northern part of Lake Ladoga as an indicator of pollution

Benthic meiofauna was sampled at 19 stations, mainly in the northern part of Lake Ladoga, from depths between 13 and 199 m and from types of environment ranging from sheltered areas near pollution sources to less polluted open areas. About 80 taxa were identified, of these 70 to the species level. The greatest numbers of species were oligochaetes (24 species) and harpacticoids (8 species). Certain quantitative ratios of meiofauna were shown to be correlated with environmental data. The species of the oligochaete families Lumbriculidae and Aeolosomatidae and the harpacticoids as a collective group, excluding Canthocamptus staphylinus, were most clearly confined to the less eutrophied environments. The oligochaete species Amphichaeta leydigii, Dero digitata and Tubifex tubifex, the resting stages of Cyclopinae, and Eucyclops serrulatus among the Eucyclopinae were most clearly concentrated in the eutrophicated or polluted environments. The groups of Naididae, Cladocera and Eucyclopinae did not have much value as indicators. Shannon diversity index correlated positively with the total phosphorus content of the water, and number of species decreased with increasing depth. In general, it seems that the pollution tolerance of the meiofauna in a very large lake such as Lake Ladoga is high, presumably due to the effective mixing of water masses.     

Ground beetles (Coleoptera, Carabidae)on set-aside fields in the Campine region and their importance for nature conservation in Flanders (Belgium)

Three set-aside fields of arable land on sandy soil in the Campine region of Flanders (Belgium), differently managed for nature conservation purposes, were sampled for their carabid beetle fauna during a complete year cycle by means of pitfall traps. About 3650 ground beetles belonging to 53 species were obtained. Besides this remarkably high diversity, no less than 11 Red data book species for Flanders were found. These species include three rare, two near- threatened, three vulnerable, two endangered and one critically endangered species. The most notable species were Amara tricuspidata and Harpalus froelichi. Although the results are based on a limited data set, we can conclude that, at least for ground beetles, conversion of agricultural fields to set- aside poor fields or dry grasslands has great potential with respect to regional conservation biology in the Campine region. Ordination of the data shows that each field can be characterized by a somewhat different carabid beetle community. The restricted data do not allow us to conclude which management measures seem most appropriate. The safest recommendation at this stage is to use a variety of practices on different fields, in order to enhance general diversity, and, above all, to avoid afforestation. Traditionally managed arable land thus can have a distinctive and comparatively species-rich carabid fauna, which recently has become endangered to a high degree.     

An assessment of macroinvertebrate functional feeding groups as water quality indicators in the Buffalo River, eastern Cape Province, South Africa

The aim of this paper was to investigate the potential for using functional feeding groups (FFGs) as indicators of water quality conditions in rivers, using the Buffalo River, South Africa, as a specific example. Multivariate classification and ordination techniques were used to investigate species and FFG distributions in relation to a number of physico-chemical variables at 16 sites from the headwaters to the estuary of the Buffalo River.Two-way indicator species analysis (TWINSPAN) of species composition ranked most of the sites sequentially down the river, irrespective of water quality conditions. Ordination of FFGs from a set of riffle samples collected in mid-late summer showed only weak relationships between FFG distribution and water quality changes, except where variables changed sequentially down the river (e.g. pH and temperature). Individual species responses to water quality gradients were examined for nine riffle-dwelling species representing diverse FFGs. Following correspondence analysis of a matrix of environmental variables and species frequencies, some species showed strong associations with defined ranges of some variables. In particular, Adenophlebia auriculata (Leptophlebiidae, Ephemeroptera) from the headwater sampling site, was associated with low pH and low temperature. Simulium damnosum occurred under conditions of high turbidity, while Afronurus harrisoni was found under high concentrations of potassium, ammonium and nitrite ions.We conclude that although there was a distinct headwaters fauna in the Buffalo River, and sequential downstream changes in species composition, most FFGs (apart from shredders) were represented down the whole length of the river. FFG classifications are therefore unlikely to provide useful indications of water quality conditions in the Buffalo River.Using a categorical approach to classifying water quality variables, and by applying correspondence analysis to the resulting matrix, we recognised nine species that could be used to define water quality. These indicator species can be used to define tolerance ranges of the fauna for water quality conditions in different parts of the Buffalo river.     

Faunal relationships to abiotic factors along the River Dan in northern Israel

A 4.5 km section of the River Dan in northern Israel was sampled at intervals of 6 weeks, between April 1983–March 1984, using standardized mesh bags. The river is characterized by extremely stable temperature and other physical and chemical conditions. The effects of a water diversion project 2400 m from the spring were investigated.The relationships between fauna and depth, current velocity and distance from the spring sources were evaluated. Of 48 common taxa analyzed, 27 showed relativity to the distance from the sources, 18 to current velocity and 12 to depth. The lowest density of invertebrates, but the highest number of taxa and highest variety of species were found at the spring sources. The sampling site immediately downstream from the water diversion project was characterized by intermediate densities, lowest varieties of species and highest evenness of distribution.Results are compared with the predictions of the Intermediate Disturbance Hypothesis; but the influence of invertebrate drift caused this hypothesis to be inapplicable to lotic waters. Invertebrate drift is in addition suggested as an important factor governing the structure of the fauna at the spring sources.     

Groundwater Macrocrustaceans as Natural Indicators of the Ariège Alluvial Aquifer

The macrocrustacean fauna from an alluvial aquifer in the French Pyrénées was investigated using 15 wells scattered over the floodplain. Wells were sampled at three contrasting periods for faunal, phy‐sical and chemical variables to investigate relationships between amphipod, isopod distributions and environmental factors. The assemblages, dominated by stygobite amphipod species, showed an overall persistence between the sampling dates. Groundwater quality exhibited between‐site variations related to agriculturally‐induced pollution. Low correlations existed between water quality and fauna distribution patterns. At the scale of the aquifer, groundwater contamination did not influence the macrocrustacean distribution. The spatial distribution of amphipods and isopods was clearly related to hydrogeology and hydrodynamics: strong relationships were found between the assemblages composition and the hydrological context of the stations (wells from the alluvial plain and from the alluvial terrace). With respect to spatial and temporal scales and providing adequate sampling methods, macrocrustaceans then constitute natural indicators of groundwater hydrodynamics in the Ariège aquifer.     

New Caledonia has a depauperate subterranean ant fauna, despite spectacular radiations above ground

Ants are often a target of tropical biodiversity assessment because of their ecological dominance and value as indicators of ecosystem health, but high microhabitat specificity, patchy distribution and cryptic habits of many species make effective sampling problematic. Although tropical ant faunas have long been known to show strong vertical stratification, only recently has it been recognised that this can include a high diversity of subterranean species that are poorly sampled using traditional methods. Global diversity patterns of subterranean ants and their responses to above-ground disturbance remain largely unknown. We describe ants collected in 360 subterranean traps distributed across 15 sites representing contrasting soil types (volcano-sedimentary and ultramafic) in New Caledonia, a recognised Global Biodiversity hotspot. New Caledonia has a diverse above-ground ant fauna that includes spectacular radiations of both Gondwanan and Indo-Malayan genera from all above-ground layers (litter, epigaeic and arboreal), and so it might be expected also to harbour a subterranean ant fauna of high biogeographic and conservation significance. We show that New Caledonia supports an extremely depauperate subterranean ant fauna, especially on ultramafic soils, with only two cryptobiotic species recorded in subterranean traps, and a trap success rate up to an order of magnitude lower than in comparable Australian studies. Our results show that there is an uncoupling of ant diversity above- and below- ground, such that a high diversity and conservation significance of ants above ground is not necessarily matched below.     

Regional species richness in an obligate subterranean dwelling fauna – epikarst copepods

Aim  The diversity of the obligate cave-dwelling fauna has proved difficult to measure because of the highly localized distributions of most species. We investigated: (1) the local and regional diversity patterns of a major component of the obligate cave-dwelling fauna living in the epikarst zone, the karst layer closest to the surface; (2) variations in local and regional patterns of species richness; and (3) sampling sufficiency at multiple scales.
Location  Caves in the Dinaric Mountains of Slovenia.
Methods  We sampled continuously the abundance of 37 species of copepods dislodged from the epikarst from 35 ceiling drips in six caves for a period of one year. Copepods were collected in a specially designed net that allowed continuous collection.
Results  Based on species accumulation curves and Chao estimates of total diversity, we determined that 3–4 months of continuous sampling were sufficient to find 90% of the species in a drip, that five drips were sufficient to find 90% of the species in a cave, and that five caves were sufficient to find 90% of the species in a region.
Main conclusions  The epikarst copepod fauna is a significant part of the aquatic cave fauna, contributing about 20% at the regional level. Because of the scale of variation, much of which occurs within a cave, and because of the availability of continuous sampling devices, the epikarst component of subterranean diversity seems to be more thoroughly and accurately measured than do other components.