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1.
Zhongqiang Li Dan Yu Wen Xiong Qiang Wang Manghui Tu 《Biodiversity and Conservation》2006,15(11):3401-3416
Assessments of biodiversity are time-consuming and require a high level of expert knowledge. A reduced set of taxonomic ranks
other than species has been proved to be useful for rapid and cost-effective assessment of biodiversity. However, few studies
have examined how well this method performs for aquatic plant group that of enormous ecological importance. We studied the
aquatic plant flora in the arid zone of China and examined whether the distribution of species α- and β-diversity could be
predicted well from genus-, and family-levels. Analyses of 3 years field data showed that significant and positive relations
exist between α-diversity of species and α-diversity of genera and family in both entire arid zone and five sub-zones. In
contrast, β-diversity at species level is difficult to predict from β-diversity indexes at higher taxonomic level. The results
indicate that higher-taxon α-diversity, especially at the generic level in our research, can be useful surrogates of species
α-diversity for aquatic plants conservation. 相似文献
2.
Lucia Sekulová Michal Hájek Petra Hájková Eva Mikulášková Alexandre Buttler Vít Syrovátka Zuzana Rozbrojová 《Plant Ecology》2012,213(2):237-249
The diversity of spring habitats can be determined not only by local environmental conditions, but also by large-scale biogeographical
effects. The effects can differ across various groups of organisms. We compared α-, β- and γ-diversity patterns of bryophytes
and vascular plants of (sub)alpine springs in three contrasting mountain ranges: Alps (Switzerland), Balkans (Bulgaria), Western
Carpathians (Slovakia, Poland). We used univariate and multivariate statistics to test for the effects of pH, conductivity,
altitude, slope, mean annual temperature and annual precipitation on diversity patterns of both taxonomic groups and compared
diversity patterns among the regions for particular pH and conductivity classes. We identified acidophyte and basiphyte, calcifuge
and calcicole species using species response modelling. All regions displayed significant relationship between conductivity
and α-diversity of vascular plants. Bulgaria showed the highest α-diversity of vascular plants for the middle part of the
conductivity gradient. For both taxonomic groups, the β-diversity in the middle part of gradient was highest in Swiss Alps.
The total species pool was lowest in Bulgaria. The percentage of basiphyte and calcicole species was highest in the Alps.
In (sub)alpine springs, mineral richness was a better determinant of vascular plant α-diversity than pH, and the extent of
the alpine area did not coincide with α-diversity. Observed inter-regional differences in diversity patterns could be explained
by the different proportion of limestone bedrock and different biogeographic history. The differences in α-diversity between
both taxonomic groups are presumably result of the different rates of adaptation processes. 相似文献
3.
We examined the effects of the presence of bird's nest ferns on the species diversity of oribatid mites in the whole forest
in terms of the three categories of species diversity (α-, β-, and γ-diversity) in a subtropical forest in south-western Japan.
The species diversity (1 − D) of oribatid communities in the ferns was significantly lower than those in bark of trees and the forest-floor litter and
soil, and was similar to that in the branches. The oribatid faunas in the litter in and the roots of the fern were more similar
to those in both the forest-floor litter and soil than to the faunas in the other arboreal habitats. However, the ferns can
be colonized by endemic oribatid species specialized to such environments. The number of oribatid species estimated for a
hypothetical stand with no ferns was about 180 species from 80 samples; this value did not differ significantly from that
in another hypothetical stand with ferns (ca. 190 species). Thus, the species richness of oribatid communities estimated for
the whole forest (the γ-diversity) was not affected by the presence or absence of bird's nest ferns. The α- and β-diversities
of oribatid communities on bird's nest ferns were lower than those in other habitats, and they might not dramatically raise
the overall γ-diversity of invertebrate communities in the whole forest. The bird's nest ferns, however, can generate a unique
habitat for specialized species, and this would help to maintain species diversities of invertebrates at the whole-forest
scale in subtropical forests. 相似文献
4.
Ecologists have traditionally viewed the total species diversity within a set of communities as the product of the average diversity within a community (alpha) and the diversity among the communities (beta). This multiplicative concept of species diversity contrasts with the lesser known idea that α- and β-diversities sum to give the total diversity. This additive partitioning of species diversity is nearly as old as the multiplicative concept, yet ecologists are just now beginning to use additive partitioning to examine patterns of species diversity. In this review we discuss why additive partitioning remained "hidden" until just a few years ago. The rediscovery of additive partitioning has expanded the way in which ecologists define and measure β-diversity. Beta diversity is no longer relegated to describing change only along an environmental gradient. Through additive partitioning, β-diversity is explicitly an average amount of diversity just as is α-diversity. We believe that the additive partitioning of diversity into α and β components will continue to become more widely used because it allows for a direct comparison of α- and β-diversities. It also has particular relevance for testing ecological theory concerned with the determinants of species diversity at multiple spatial scales and potential applications in conservation biology. 相似文献
5.
Claudia Melis Maria Sundby Reidar Andersen Arne Moksnes Bård Pedersen Eivin Røskaft 《Biodiversity and Conservation》2007,16(5):1321-1335
The indirect effect of moose Alces alces browsing on ground beetle's abundance and diversity was investigated by pitfall trapping in a mixed coniferous forest in
Vestfold County (59°19′ N, 9°50′ E, Norway), during the summer of 2002. Three areas with different browsing pressures, ranging
from non- to medium- and heavily browsed were chosen and dry weight of bilberry Vaccinium myrtillus and humidity at ground level were measured in the three locations. As predicted, the gradient analyses showed that browsing
by moose influenced the composition of carabid fauna, and that browsing intensity and humidity covaried with the most important
gradient in carabid species composition found across the three locations. Species that live in light stands with rather dry
soil, were more often captured in the browsed areas, whereas shade tolerant and hygrophilous species were more abundant in
the non-browsed area. The carabid abundance increased significantly with increasing browsing pressure. According to our predictions,
the diversity at trap level (α-diversity) was higher in the highly browsed area. Conversely, species turnover (β-diversity)
decreased with browsing intensity. On the other hand, the rarefaction analysis showed that the regional species richness (γ-diversity)
was considerably higher in the medium browsed area than in the heavily browsed one, which is consistent with the intermediate
disturbance hypothesis. This study indicates that moose, by reducing the bilberry that constitutes the field layer in summer,
affect carabid species composition and might be capable to reshape the whole ecosystem in our study area by a cascade effect. 相似文献
6.
In this study α and β diversity patterns of five leaf litter arthropod groups (ants, predatory ants, oribatid mites, spiders
and other arachnids) were described and compared in 39 sampling patches of a transformed landscape in southwestern Colombia,
that represented five vegetation types: secondary forest, riparian forest, giant bamboo forest, pasture and sugarcane crop.
It was also assessed whether some taxa could be used as diversity surrogates. A total of 6,765 individuals grouped in 290
morphospecies were collected. Species richness in all groups was lower in highly transformed vegetation types (pasture, sugarcane
crop) than in native ones (forests). In contrast, there were no clear tendencies of β diversity among vegetation types. Considering
sampling patches, 0.1–42% of the variation in α diversity of one taxonomic group could be explained from the α diversity of
another, and 0.2–33% of the variation of β diversity of a given taxon was explained by that in other groups. Contrary to recent
findings, we concluded that patterns of α diversity are more congruent than patterns of β diversity. This fact could be attributed
to a sampling effect that promotes congruence in α diversity and to a lack of a clear regional ecological gradient that could
promote congruent patterns of β diversity. We did not find evidence for an ideal diversity surrogate although diversity patterns
of predatory ants had the greatest congruencies. These results support earlier multi-taxon evaluations in that conservation
planning should not be based on only one leaf litter arthropod group. 相似文献
7.
Increasing loss of biodiversity in agricultural landscapes is often debated in the bioenergy context, especially with respect to non-traditional crops that can be grown for energy production in the future. As promising renewable energy source and additional landscape element, the potential role of short rotation coppice (SRC) plantations to biodiversity is of great interest. We studied plant species richness in eight landscapes (225 km2) containing willow and poplar SRC plantations (1,600 m2) in Sweden and Germany, and the related SRC α-diversity to species richness in the landscapes (γ-diversity). Using matrix variables, spatial analyses of SRC plantations and landscapes were performed to explain the contribution of SRC α-diversity to γ-diversity. In accordance with the mosaic concept, multiple regression analyses revealed number of habitat types as a significant predictor for species richness: the higher the habitat type number, the higher the γ-diversity and the lower the proportion of SRC plantation α-diversity to γ-diversity. SRC plantation α-diversity was 6.9 % (±1.7 % SD) of species richness on the landscape scale. The contribution of SRC plantations increased with decreasing γ-diversity. SRC plantations were dominated more by species adapted to frequent disturbances and anthropo-zoogenic impacts than surrounding landscapes. We conclude that by providing habitats for plants with different requirements, SRC α-diversity has a significant share on γ-diversity in rural areas and can promote diversity in landscapes with low habitat heterogeneity and low species pools. However, plant diversity enrichment is mainly due to additional species typically present in disturbed and anthropogenic environments. 相似文献
8.
The large-scale deep-sea biodiversity distribution of the benthic fauna was explored in the Mediterranean Sea, which can be seen as a miniature model of the oceans of the world. Within the framework of the BIOFUN project (“Biodiversity and Ecosystem Functioning in Contrasting Southern European Deep-sea Environments: from viruses to megafauna”), we investigated the large spatial scale variability (over >1,000 km) of the bathyal macrofauna communities that inhabit the Mediterranean basin, and their relationships with the environmental variables. The macrofauna abundance, biomass, community structure and functional diversity were analysed and the α-diversity and β-diversity were estimated across six selected slope areas at different longitudes and along three main depths. The macrobenthic standing stock and α-diversity were lower in the deep-sea sediments of the eastern Mediterranean basin, compared to the western and central basins. The macrofaunal standing stock and diversity decreased significantly from the upper bathyal to the lower bathyal slope stations. The major changes in the community composition of the higher taxa and in the trophic (functional) structure occurred at different longitudes, rather than at increasing water depth. For the β-diversity, very high dissimilarities emerged at all levels: (i) between basins; (ii) between slopes within the same basin; and (iii) between stations at different depths; this therefore demonstrates the high macrofaunal diversity of the Mediterranean basins at large spatial scales. Overall, the food sources (i.e., quantity and quality) that characterised the west, central and eastern Mediterranean basins, as well as sediment grain size, appear to influence the macrobenthic standing stock and the biodiversity along the different slope areas. 相似文献
9.
Ecological Diversity and Biodiversity as Concepts for Conservation Planning: Comments on Ricotta 总被引:3,自引:0,他引:3
Sarkar S 《Acta biotheoretica》2006,54(2):133-140
Ricotta argues against the existence of a unique measure of biodiversity by pointing out that no known measure of α-diversity
satisfies all the adequacy conditions that have traditionally been set for it. While that technical claim is correct, it is
not relevant in the context of defining biodiversity which is most usefully measured by β-diversity. The concept of complementarity provides a closely related family of measures of biodiversity which can be used
for systematic conservation planning. Moreover, these measures cannot be replaced by summary statistics but must rely on inventories
of biodiversity surrogates at candidate sites for conservation. 相似文献
10.
Ecologists have traditionally viewed β-diversity as the ratio between γ-diversity and average α-diversity. More recently, an alternative way of partitioning diversity has been proposed for which β-diversity is obtained as the difference between γ-diversity and average α-diversity. Although this additive model of diversity decomposition is generally considered superior to its multiplicative counterpart, in both models β-diversity is a formally derived quantity without any self-contained ecological meaning; it simply quantifies the diversity excess of γ-diversity with respect to average α-diversity. Taking this excess as an index of β-diversity is a questionable operation. In this paper, we show that a particular family of α-diversity measures, the most celebrated of which is Rao's quadratic entropy, can be adequately used for summarizing β-diversity. Our proposal naturally leads to a new additive model of diversity for which, given two or more sets of plots, overall plot-to-plot species variability can be additively partitioned into two non-negative components: average variability in species composition within each set of plots and the species variability between the set of plots. For conservation purposes, the suggested change of perspective in the summarization of β-diversity allows for a flexible analysis of spatial heterogeneity in ecological diversity so that different hierarchical levels of biotic relevance (i.e. from the genetic to the landscape level) can be expressed in a significant and consistent way. 相似文献
11.
Biologists seek an understanding of the processes underlying spatial biodiversity patterns. Neutral theory links those patterns to dispersal, speciation and community drift. Here, we advance the spatially explicit neutral model by representing the metacommunity as a network of smaller communities. Analytic theory is presented for a set of equilibrium diversity patterns in networks of communities, facilitating the exploration of parameter space not accessible by simulation. We use this theory to evaluate how the basic properties of a metacommunity – connectivity, size, and speciation rate – determine overall metacommunity γ -diversity, and how that is partitioned into α - and β -components. We find spatial structure can increase γ -diversity relative to a well-mixed model, even when θ is held constant. The magnitude of deviations from the well-mixed model and the partitioning into α - and β -diversity is related to the ratio of migration and speciation rates. γ -diversity scales linearly with metacommunity size even as α - and β -diversity scale nonlinearly with size. 相似文献
12.
Takehiro Sasaki Masatoshi Katabuchi Chiho Kamiyama Masaya Shimazaki Tohru Nakashizuka Kouki Hikosaka 《Biodiversity and Conservation》2012,21(6):1577-1588
Understanding of the scaling of diversity is critical to enhance conservation strategies for subalpine moorland ecosystems
vulnerable to future environmental changes. However, a paucity of quantitative data strongly limits such attempts. In this
study, we used an additive diversity partitioning framework and quantified diversity patterns of moorland plant communities
across hierarchical spatial scales, within- and between-sample transects, and between sites (corresponding to α and two levels
of β diversity). Moorland sites markedly differed in size (range 1,000–160,000 m2) and were isolated from each other to varying extents within an inhospitable matrix (i.e., forests). We found that β diversity
components were consistently higher, whereas the local α diversity component was consistently lower than expected by chance.
We observed substantial contribution at the between-site scale to total species richness. By focusing on diversity patterns
of moorland plant communities across multiple hierarchical spatial scales, we could thus identify the scale at which regional
diversity is maximized. Our results suggest that protection of as many moorland sites as possible, to ensure beta diversity
between sites, will effectively conserve total diversity. The use of additive diversity partitioning is a major step forward
in providing strategies for the biological conservation of subalpine moorland ecosystems vulnerable to future environmental
changes. 相似文献
13.
We examined temporal changes in macrofaunal α- and β-diversity over several spatial scales (within patches, among patches, across landscapes and across regions) in Long Island Sound on the northeast USA coast. Regional ε-diversity was estimated at 144 taxa, however γ-diversity fluctuated over time as did α- and β-diversity components. Based on additive partitioning, patch- and region-scale β-diversity components generally had the highest contributions to γ-diversity; lower percentages were found at within-patch and landscape scales. Multiplicative diversity partitioning indicated highest species turnover at within- and among patch scales. For all partition results, within-patch and patch-scale β-diversity increased sharply when hypoxia impacted benthic communities. Spatial variation in diversity components can be attributed to the collection of different patch types at varying spatial scales and their associated habitats across the benthic landscapes, as well as gradients in depth and other estuarine-scale characteristics. Temporal variation in diversity components across spatial scales may be related to seasonal changes in habitat heterogeneity, species population dynamics, and seasonal disturbances. Rare species were significant and temporally consistent components of macrofaunal diversity patterns over different spatial scales. Our findings agree with other marine and terrestrial studies that show diversity components vary significantly over different spatial scales and the importance of habitat/landscape heterogeneity in supporting diversity. However, our results indicate that the relative contributions of scale-specific β-diversity components can also change significantly over time. Thus, studies of diversity patterns across patches and landscapes based on data collected at one time, or assembled into a single data set from different times, may not capture the full suite of diversity patterns that occur over varying spatial scales and any time-specific determinants of those patterns. Many factors that shape and maintain sedimentary communities vary temporally, and appear to play an important role in determining and maintaining macrofaunal diversity over different spatial scales. 相似文献
14.
Steinar Engen Bernt‐Erik Sæther Anne Sverdrup‐Thygeson Vidar Grøtan Frode Ødegaard 《Oikos》2008,117(5):738-748
We show how the spatial structure of species diversity can be analyzed using the correlation between the log abundances of the species in the communities, assuming that two communities at different localities can be described by a bivariate lognormal species abundance distribution. A useful property of this approach is that the log abundances of the species at two localities can be considered as samples from a bivariate normal distribution defined by only five parameters. The variances and the correlation can be estimated by maximum likelihood methods even if there is no information about the sampling intensity and the number of unobserved species. This method also enables estimation of over-dispersion in the sampling relative to a Poisson distribution that allows sampling adjustment of the estimate of β-diversity. Furthermore, we also obtain a partitioning of species diversity into additive components of α-, β- and γ-diversity. For instance, if the correlation between the log abundances of the species is close to one, the same species will be common and rare in the two communities and the β-diversity will be low. We illustrate this approach by analysing similarities of communities of rare and endangered species of oak-living beetles in south-eastern Norway. The number of recorded species was estimated to be only 48.1% of the total number of species actually present in these communities. The correlations among communities dropped rather quickly with distance with a scaling of order 200 km. This illustrates large spatial heterogeneity in species composition, which should be accounted for in the design of schemes of such devices for assessing species diversity in these habitat-types. 相似文献
15.
Baoshan Cui Xinsheng Zhao Zhifeng Yang Bin Chen Na Tang Xuejie Tan 《Frontiers of Biology in China》2008,3(2):194-202
We investigated and monitored a reed community in the fields. Data on the bio-ecological characteristics and β-diversity of reed communities in different environmental gradients (mainly based on water depth) of the Yellow River Delta
were collected through multianalysis, extremum analysis and β-diversity index analysis. In accordance with the square sum of deviations (Ward) cluster analysis, 10 sampling plots were
divided into six types with the dominant plants in different plots varying according to the change in environmental gradients.
The dominant plants in these plots varied from aquatic plants to xerophytes and salt tolerant plants as water depth decreased.
The average height and diameter of the reeds at breast level were significantly correlated with the average water depth. The
fitness curves of average density and coverage with average water depth were nonlinear. When the average water depth was 0.3
m, the average density and coverage of reeds reached the apex value, while the height and diameter of the reeds at breast
level increased with the water depth. There were obvious changes to the environmental gradient in the Yellow River Delta.
The transitional communities were also found to exist in the Yellow River Delta by β-diversity analysis. Vicarious species appeared with the change in water depth. The occurrence of substitute species is determined
by the function of common species between adjacent belts. The different functions of common species led to differences in
community structure and function and differences in dominant plants. The result reflects the variations of species present
in different habitats and directly reflects environmental heterogeneity. The values of β-diversity indices of adjacent plots were higher than those of nonadjacent plots. There are transition zones between the xerophytes
and aquatic plants in the Yellow River Delta. In an aquatic environment, the similarity of reed community is higher than that
of xeromorphic plants. The β-diversity index can reflect plant succession trends caused by the change in environmental gradients in the Yellow River Delta.
The β-diversity index reveals plant responses to changes in environmental gradient and is helpful in observing changes in patterns
of species diversity in relation to environmental gradient change and evolving trends in the future, which in turn plays a
prominent role when environmental water requirements of wetland are discussed.
__________
Translated from Acta Ecologica Sinica, 2006, 26(5): 1533–1541 [译自: 生态学报] 相似文献
16.
Carlo Ricotta 《Acta biotheoretica》2006,54(2):141-146
This reply paper includes two brief remarks in rejoinder to the commentary papers of Myers and Patil, Podani, and Sarkar.
The first observation concerns the fundamental nature of ecological diversity measures, while the second one specifically
addresses some interesting mathematical connections between α- and β-diversity. 相似文献
17.
Soft bottom communities were sampled quantitatively in Tahiti lagoon (French Polynesia) at 18 stations in five zones around
the island over 1 year. In addition, various environmental parameters (silt/clay fractions, organic content, chlorophyll and
phaeopigment content) were sampled at the same stations over 2 years. The temporal and spatial variabilities of the macrobenthic
communities are described and related to these environmental parameters. Each zone ran from the fringing reef to the inner
flat of the barrier reef. The macrofauna exhibited a high richness (392 taxa) with an average mean biomass of 1.8 g AFDW m−2 (grams ash-free dry weight per square metre). These communities exhibited temporal but not seasonal fluctuations. The biomass
of the macrofauna increased from the fringing to the barrier reefs, and the density of individuals was significantly higher
on the fringing reefs. Ordination techniques highlighted four groups of stations characterised by distinctive species composition,
density and biomass. The first group included stations located on the inner flat of the barrier reef and in the shallow lagoon
area and was characterised by highly diverse communities dominated by polychaetes. The second group primarily included stations
from the industrial and hotel zones. This group had the lowest diversity and was also dominated by polychaetes, especially
the capitellid Dasybranchus sp. 1. The third group was dominated by gastropods and bivalves. The final group of stations was represented only by station
51, in zone 5, which was characterised by mobile soft sediments and wave action and was dominated by the decapod Hippa cf. pacifica. Presumably, these mobile sediments facilitate the development of this benthic community, which does not occur elsewhere
in the lagoon. The diversity and biomass of these benthic communities are low compared with most other areas in the South
Pacific.
Accepted: 10 May 2000 相似文献
18.
Species diversity in vertical, horizontal, and temporal dimensions of a fruit-feeding butterfly community in an Ecuadorian rainforest 总被引:11,自引:0,他引:11
Philip J. Devries Debra Murray Russell Lande 《Biological journal of the Linnean Society. Linnean Society of London》1997,62(3):343-364
To test the hypotheses that fruit-feeding nymphalid butterflies are randomly distributed in space and time, a community of fruit-feeding nymphalid butterflies was sampled at monthly intervals for one year by trapping 6690 individuals of 130 species in the canopy and understory of four forest habitats: primary, higraded, secondary, and edge. The overall species abundance distribution was well described by a lognormal distribution. Total species diversity (γ-diversity) was partitioned into additive components within and among community subdivisions (α-diversity and β-diversity) in vertical, horizontal and temporal dimensions. Although community subdivisions showed high similarity (1 —β-diversity/γ-diversity), significant β-diversity existed in each dimension. Individual abundance and observed species richness was lower in the canopy than in the understory. However, rarefaction analysis and species accumulation curves revealed that canopy had higher species richness than understory. Observed species richness was roughly equal in all habitats, but individual abundance was much greater in edge, largely due to a single, specialist species. Rarefaction analysis and species accumulation curves showed that edge had significantly lower species richness than all other habitats. Samples from a single habitat, height and time contained only a small fraction of the total community species richness. This study demonstrates the feasibility, and necessity, of large-scale, long-term sampling in multiple dimensions for accurately measuring species richness and diversity in tropical forest communities. We discuss the importance of such studies in conservation biology. 相似文献
19.
Nikos Katsimanis Michalis Dretakis Triantaphyllos Akriotis Moysis Mylonas 《Journal of Ornithology》2006,147(3):419-427
The patterns of α-diversity and the structure and organisation of breeding bird assemblages were studied in four vegetation stages (characteristic of Mediterranean shrublands) on an eastern Mediterranean island (Crete, Greece): low phrygana, tall phrygana, low maquis and tall maquis. Phrygana differed significantly from maquis, in regard to the community metrics, composition and the homogeneity of bird assemblages. Moreover, detrended correspondence analysis ordered the census plots along a continuum of increasing vegetation height. On the other hand, within-maquis differences were few, while no significant differences were found within phrygana stages. Based upon the observed patterns, we recognise three vegetation groups: (1) phrygana, with low α-diversity and abundance and homogenous bird assemblages; (2) low maquis with relatively high α-diversity and heterogenous bird assemblages; and (3) tall maquis with relatively high α-diversity and heterogenous assemblages in which “woodland” bird species contribution is prominent. 相似文献
20.
Based on data, collected in 1980–1990, the intertidal benthic macrofauna of the Schelde and Ems estuaries was compared. The spatial occurrence of the benthic macrofauna along the salinity gradient, including the freshwater tidal area was emphasized. Both estuaries appeared to have a very similar species composition, especially at genus level. The higher number of species observed in the Schelde estuary was probably due to a greater habitat diversity. In both estuaries species diversity decreased with distance upstream. The total density did not vary along the estuarine gradient, whereas biomass is highest in the polyhaline zone.In both estuaries distinct intertidal benthic communities were observed along the salinity gradient: a marine community in the polyhaline zone, a brackish community in the mesohaline zone, and a third community in the oligohaline and freshwater tidal zones of the estuary. These three communities were very similar between both estuaries. Their main characteristics were discussed together with the occurrence and distribution of the dominant species.For the Schelde estuary and to a lesser extent also for the Ems estuary, there was evidence that anthropogenic stress had a negative effect on the intertidal macrobenthic communities of the oligohaline/freshwater tidal zone. Only Oligochaeta were dominating, whereas the very euryhaline and/or true limnetic species were missing. In the mesohaline zone, the Schelde estuary was dominated by large numbers of short-living, opportunistic species, whereas in the Ems estuary relatively more stable macrobenthic communities were observed. A comparison with some other European estuaries showed in general similar trends as those observed for the Schelde and Ems estuaries. 相似文献