Multiscale patterns of spatial variation in stream macroinvertebrate communities

Our ability to detect patterns of variation of communities depends on the spatial scale of observation. I examined the spatial variation of macroinvertebrate community structure: abundance, richness, evenness, percentage of Ephemeroptera, Plecoptera and Trichoptera (EPT), and taxonomic composition across a wide range of spatial scales in two mountain streams. In a nested design, three segments were selected within each basin, three riffles within each segment, three sections within each riffle, and three samples within each section. Significant variation of communities occurred mainly at sample and riffle scales, although different community characteristics may vary at different scales. Environmental factors were strongly related to communities, but these relationships depended on spatial scale in many cases, suggesting that the influence of the environment is ultimately regulated by the grain and extent of organisms. This study highlights the importance of multiscale studies to obtain a complete understanding of the spatial variation of macroinvertebrate communities and their relationship with the environment.     

Eulittoral macroinvertebrate communities of lowland lakes: discrimination among trophic states

1. Nutrient inputs from urban and agricultural land use often result in shifts in species composition of pelagic and profundal invertebrate communities. Here, we test if nutrient enrichment affects the composition of eulittoral macroinvertebrate communities, and, if so, if macroinvertebrate communities of five different habitat types reflect differences in trophic state. 2. Macroinvertebrate community composition of 36 lakes was significantly correlated with total phosphorus (TP) concentration, the proportion of coarse woody debris (CWD) and root habitats and the proportion of grassland. 3. However, macroinvertebrate communities of five major habitat types from eight lakes were more dissimilar among habitats than among trophic states. Community composition of reed and stone habitats was significantly correlated with wind exposure but not TP concentration, while macroinvertebrate composition of sand habitats was related to TP concentration and coarse sediments. In CWD and root habitats, both TP concentration and a predominance of invasive species covaried, which made it difficult to relate the observed compositional differences to either trophic state or to the effects of competition between native and invasive species. 4. Trophic state influenced the composition of eulittoral macroinvertebrate communities but to a lesser extent than has been previously reported for profundal habitats. Moreover, the effects of trophic state were nested within habitat type and were partially superseded by biotic interactions and small‐scaled habitat complexity. Although eulittoral macroinvertebrate communities were not strong indicators of the trophic state of lowland lakes, they may be used to assess other anthropogenic impacts on lakeshores.     

Relationship of fish and macroinvertebrate communities in the mid-Atlantic uplands: Implications for integrated assessments

Indices developed for stream bioassessment are typically based on either fish or macroinvertebrate assemblages. These indices consist of metrics which subsume attributes of various species into aggregate measures reflecting community-level ecological responses to disturbance. However, little is known about the relationship between fish and macroinvertebrate metrics, or about how ecological health assessments are affected by assemblage-specific responses to disturbance. We used principal component analysis (PCA) and regression analysis of existing fish (n = 371) and macroinvertebrate (n = 442) stream bioassessment data from a multi-source dataset to determine broad scale, within-assemblage metric patterns, and to examine the intercorrelation of fish and macroinvertebrate metrics (n = 246) and their response to watershed area and land use/land cover gradients. Fish and macroinvertebrate metrics expressed as principal components (PCs) accounted for 72.4 and 85.4% of dataset variance, respectively, with PC-metric patterns reflecting aspects of stream impairment including water and habitat quality. Model components predicting fish metric response differed among fish PCs, with watershed area and macroinvertebrate metric response strongly correlated with the first fish PC, and remaining fish PC models consisting of watershed area, land use, and macroinvertebrate PCs. Correlation between fish and macroinvertebrate PCs, and models relating fish and macroinvertebrate PCs generally explained less variation (13–27%) than metric response models of fish (25–34%) and macroinvertebrates (8–38%) to watershed area and land use/land cover variables. Best-response models integrating fish and macroinvertebrate PCs, watershed area, and land use/land cover variables accounted for the greatest variation in fish PCs (32–50%) across sites. Because fish and macroinvertebrate metrics provide different information on ecological condition, integrated use of information from multiple groups may be appropriate when developing monitoring programs.     

Spatial scale and ecological relationships between the macroinvertebrate communities of stony habitats of streams and lakes

1. Comparative studies of distinct, but not ecologically isolated, systems such as lakes and streams may improve our understanding of the importance of ecological linkages in aquatic ecosystems. 2. In this study we compared the macroinvertebrate benthos of stony habitats in Swedish lakes and streams. Community composition was used to evaluate zoogeographic patterns and functional feeding guilds were used to identify mechanisms potentially affecting such patterns. 3. Stream communities were generally more diverse and species‐rich and had a higher proportion of grazers, shredders and passive‐filter feeders than lakes. Lake communities had a higher proportion of predators and collector‐gatherers. Of the 10 most common taxa, only Leptophlebia mayflies, clams (Sphaeriidae) and the isopod Asellus aquaticus were recorded in both lakes and streams. 4. Among‐site variance in macroinvertebrate communities accounted for by regional‐scale variables was low (6.4% for lakes and 10.1% for streams), compared with that by local‐scale variables (21% for lakes and 37.6% for streams). For lakes, the among‐site variance in macroinvertebrate communities was best explained by habitat‐scale characteristics followed by ecosystem, riparian, catchment, geographic position and ecoregion. For streams, the variance in macroinvertebrate communities was best explained by ecosystem characteristics followed by habitat, catchment, riparian, ecoregion and geographic position. 5. Conspicuous differences in spatial pattern were revealed between lakes and streams. For lakes, the most unequivocal differences in community composition and function occurred at the transition zone between the mixed forests in the south and the boreal coniferous forests in the north. Surprisingly, streams did not respond as strongly to profound landscape‐level differences in climate and vegetation cover. 6. The spatial differences noted between macroinvertebrate communities of lakes and streams may be because of differences in retention of detrital matter. Our findings imply that detrital inputs are qualitatively similar, but that the retention and processing of coarse particulate organic matter was presumably higher in lake littoral regions than in stream riffle habitats. 7. Although our findings support the conjecture that species distribution is determined fundamentally by conditions prevailing at the local‐scale, regional factors such as land use/type and the role of history were important and seemingly act as strong determinants of large‐scale patterns in biodiversity.     

Spatial and temporal variability of macroinvertebrate communities in two farmed Mediterranean rice fields

The spatial and temporal variation of macroinvertebrate assemblages was studied in two Portuguese commercial rice agroecosystems under the effect of field management involving the application of pesticides and fertilizers. A faunal succession of organisms was observed on both fields. Grazers were the first to colonize the paddies after a dry period when pesticides were applied, followed by development into nymphs and by an increase in the abundance of the species after the application of fertilizers. At the end of the season when no pesticides or fertilizers were applied, the communities changed with the presence of adult predators as a result of an increase in prey. Insecticide application revealed specific taxa increase due to the lack of competition with the target organism. Macroinvertebrates tended to prefer infested field margins with aquatic, submerged vegetation, revealing a spatial distribution along the paddies. Two different sampling devices were used and proved necessary in documenting the macroinvertebrate communities (grab for benthic and hand-net for pelagic organisms).     

Effects of Mediterranean climate annual variability on stream biological quality assessment using macroinvertebrate communities

Data on macroinvertebrates of selected reference sites were compiled from a long-term monitoring programme carried out in the Mediterranean Catalan Basins (NE Spain) that permitted analysis for nine years, from 1996 to 2004, using a homogeneous data collection procedure. This study aims to analyse the differences in composition and structure of macroinvertebrate communities at family level in five Mediterranean river types, and the values of biological quality metrics (IBMWP and IASPT indices, taxon richness and EPT) in reference conditions. Also differences between seasons (spring vs. summer) and between dry and wet periods were analysed. The dry and wet periods were determined using the Standardised Precipitation Index (SPI). A total of 29 reference sites were selected out of 184 sampling sites analysed, and 171 reference samples were available (from 1996 to 2004), of which 88 were sampled in dry periods, whereas 83 correspond to wet periods. Differences on community composition at family level were appreciated, clustering the rivers in three different groups: (1) rivers with a continuous flow regime located in siliceous zones; (2) rivers with a continuous flow regime located in calcareous zones; and (3) temporary rivers regardless of geology. Moreover, our results explain that the characteristics of hydrological periods (dry and wet) characterize the differences between communities better than just the season. The analysis of four biological quality metrics reveals clear differences between values obtained from dry and wet periods concerning taxon richness, EPT values and IBMWP biological indices, whereas the IASPT index does not show significant differences. The median taxonomic richness in wet periods is 32 macroinvertebrate families per sample while in dry periods this value falls to 22. Reference values of IBMWP index, the total number of taxa, and EPT metric are different between dry and wet periods in spring samples, while these differences are not relevant for IASPT index except for temporary streams. Hydrological specific conditions should additionally be considered in order to better calculate biological reference conditions, and to properly apply biological quality metrics used to establish the ecological status in Mediterranean rivers, especially in temporary ones. The use of the dry–wet period classification according to the climate characteristic results is a more accurate application of the Water Framework Directive in Mediterranean rivers. Implications of future climate change should be also considered from our results.     

Influences of catchment and corridor imperviousness on urban stream macroinvertebrate communities at multiple spatial scales

Resolving land cover hierarchy relationships in urban settings is important for defining the scale and type of management required to enhance stream health. We investigated associations between macroinvertebrate assemblages in urban streams of Hamilton, New Zealand, and environmental variables measured at multiple spatial scales comprising (i) local-scale physicochemical conditions, (ii) impervious area in multiple stream corridor widths (30, 50 and 100 m) along segments (sections of stream between tributary nodes) and for entire upstream networks, and (iii) total impervious area in stream segment sub-catchments and upstream catchments. Imperviousness was higher for stream segment sub-catchments than for entire catchments because of the agricultural headwaters of some urban streams. Imperviousness declined as corridor width declined at both segment and catchment scales reflecting the vegetated cover along most urban stream gullies. Upstream catchment imperviousness was strongly and inversely correlated with dissolved organic carbon concentration, whereas segment and upstream corridor scales were correlated with water temperature and pH. Corridor imperviousness appeared to be a stronger predictor than catchment imperviousness of Ephemeroptera, Plecoptera and Trichoptera taxa richness and the Quantitative Urban Community Index specifically developed to assess impacts of urbanisation. In contrast, imperviousness at all measured scales added only marginal improvement in assemblage-based models over that provided by the local-scale physicochemical variables of reach width, habitat quality, macrophyte cover, pH and dissolved oxygen concentration. These findings infer variable scales of influence affecting macroinvertebrate communities in urban streams and suggest that it may be important to consider local and corridor factors when determining mechanisms of urbanisation impacts and potential management options.     

High spatial variability biases the space-for-time approach in environmental monitoring

The space-for-time approach is widely used in fundamental and applied ecology but assemblages from some habitats are highly variable. For example, streams may show marked spatio-temporal changes in the taxonomic composition of the macroinvertebrate assemblages. We exemplify the effect of the temporal component ‘season’ on some assemblage-derived stream quality assessment metrics under the assumptions of the space-for-time and the replicated samples approaches. Benthic macroinvertebrates were sampled in spring, summer, and fall from two stream types, namely streams in the Pleistocene sediments of the alpine foothills and small fine substrate dominated siliceous highland rivers in southern and central Germany. As exemplified for ASPT and the German multimetric index (MMI), the data showed no effect of season when samples were regarded as independent, whereas stream quality decreased between spring and fall in the replicated samples approach. The transformation of MMI to rank-ordered stream quality classes depicted a decrease in perceived stream quality in 29% and 54% of the sites by summer and early fall, respectively, when compared to spring samples. We thus suggest (1) to test seemingly robust metrics in a repetitive measures approach for other stream types and regions, and (2) to standardize the sampling season for ecological quality assessment. Based on this example, we assume that many subtle, but significant, environmental trends are still to be detected in highly heterogeneous habitats from various ecosystems.     

Temporal and spatial variability in nearshore bacterioplankton communities of Lake Michigan

The spatial and temporal variability of bacterial communities were determined for the nearshore waters of Lake Michigan, an oligotrophic freshwater inland sea. A freshwater estuary and nearshore sites were compared six times during 2006 using denaturing gradient gel electrophoresis (DGGE). Bacterial composition clustered by individual site and date rather than by depth. Seven 16S rRNA gene clone libraries were constructed, yielding 2717 bacterial sequences. Spatial variability was detected among the DGGE banding patterns and supported by clone library composition. The clone libraries from deep waters and the estuary environment revealed highest overall bacterial diversity. Betaproteobacteria sequence types were the most dominant taxa, comprising 40.2–67.7% of the clone libraries. BAL 47 was the most abundant freshwater cluster of Betaproteobacteria , indicating widespread distribution of this cluster in the nearshore waters of Lake Michigan. Incertae sedis 5 and Oxalobacteraceae sequence types were prevalent in each clone library, displaying more diversity than previously described in other freshwater environments. Among the Oxalobacteraceae sequences, a globally distributed freshwater cluster was determined. The nearshore waters of Lake Michigan are a dynamic environment that experience forces similar to the coastal ocean environment and share common bacterial diversity with other freshwater habitats.     

Responses of macroinvertebrate communities to long‐term flow variability in a Sonoran Desert stream

Current global models predict a hotter and drier climate in the southwestern United States with anticipated increases in drought frequency and severity coupled with changes in flash flood regimes. Such changes would likely have important ecological consequences, particularly for stream and riparian ecosystems already subject to frequent hydrologic disturbance. This study assessed the potential response of aquatic macroinvertebrates to interannual variation in hydrology in a spatially intermittent desert stream (Sycamore Creek, AZ). We compiled data on the recovery of macroinvertebrate communities following spring floods, with successional sequences captured 11 times over a 16‐year period (1983–1999). This period encompassed a transition from perennial to intermittent flow in this system, and included a record drought in 1989–1990. Results show that while the size of floods initiating sequences had little explanatory power, changes in macroinvertebrate community structure during postflood succession were closely associated with antecedent flooding and drought. Year‐to‐year differences in benthic communities integrated taxon‐specific responses to antecedent disturbance, including differential resistance to channel drying, use of hyporheic refugia, and variable rates of recovery once stream flow resumed. The long‐term consequences of drying on community structure were only evident during later stages of postflood succession, illustrating an interaction between flood and drought recovery processes in this system. Our observations highlight the potential for predicted climate changes in this region to have marked and long‐lasting consequences for benthic communities in desert streams.     

Classification and ordination of profundal macroinvertebrate communities in nutrient poor, oligo-mesohumic lakes in relation to environmental data

SUMMARY. 1. Profundal macroinvertebrates and water chemistry of sixty-eight nutrient poor, poorly buffered lakes were sampled in 1983 or 1986. Assemblages of profundal zoobenthos were classified using two-way indicator species analysis (TWINSPAN), ordinated by canonical correspondence analysis (CCA), and related to physico-chemical factors using CCA. discriminant analysis, and regression.
2. 90% of zoobenthos (TWINSPAN) groups were classified correctly using discriminant analysis. Depth (Function 1), soluble reactive Si(OH)₄ and HCO₃, -(2), and phytoplankton biovolume and pH (3) were the strongest correlates with the three discriminant functions.
3. Regression analysis showed that depth, KmnO₄, consumption, and phytoplankton biovolume were the best estimators of zoobenthos biomass in the profundal.
4. Multivariate analyses showed species assemblages amongst the profundal zoobenthos to be good indicators of lake type, particularly depth, pH, and phytoplankton biovolume.     

An experimental model for the spatial structuring and selection of bacterial communities

Community-level selection is an important concept in evolutionary biology and has been predicted to arise in systems that are spatially structured. Here we develop an experimental model for spatially-structured bacterial communities based on coaggregating strains and test their relative fitness under a defined selection pressure. As selection we apply protozoan grazing in a defined, continuous culturing system. We demonstrate that a slow-growing bacterial strain Blastomonas natatoria 2.1, which forms coaggregates with Micrococcus luteus, can outcompete a fast-growing, closely related strain Blastomonas natatoria 2.8 under conditions of protozoan grazing. The competitive benefit provided by spatial structuring has implications for the evolution of natural bacterial communities in the environment.     

Rotifer communities from some Araucanian lakes of southern Chile

During the last decade much information has been produced about the zooplankton communities in southern Chile; however, most of this is related to the crustacean assemblages. The present communication examines the spatial and temporal distribution of rotifer assemblages and their relation to the environmental variables during one-year period in four Araucanian lakes. A total of 19 species was found in these oligotrophic lakes. Keratella cochlearis, Synchaeta stylata, Trichocerca porcellus, Conochilus unicornis and Collotheca pelagica were widespread, and seven species exhibited a more restricted distribution among the lakes. Species richness varied from 6 to 12; similarly, one or two dominant species usually accounted for more than 80% of the total annual abundance. Similar dominant species occurred in two lakes, but their maximum peaks of abundance differed in time; in the remaining lakes the most important species were different. Calculated rotifer diversity showed a fluctuating pattern, with low values during the year in three lakes, and high ones in Lake Llanquihue. Species diversity was significantly related to species richness in all lakes. Discriminant analysis based on the occurrence and abundances of species throughout the year revealed that the rotifer assemblage in Lake Llanquihue was different from that in the rest of the Araucanian lakes. Furthermore, the same analysis using environmental variables showed that this lake is clearly discriminated from the others on the basis of the ionic composition of the water (i.e. Cl^–, Na⁺, Mg²⁺). Rotifer abundances in these lakes were significantly influenced by a number of abiotic variables, including those related to water ionic composition. These relationships may imply that the small differences in chemical characteristics of these lakes influence the structure of the rotifer community.     

Persistence and stability of macroinvertebrate communities in streams of Denali National Park, Alaska: implications for biological monitoring

1. Macroinvertebrate communities were studied from 1994 to 2001/2002 (except 1997) in six streams in Denali National Park, interior Alaska. All six streams were potential reference streams with no known impairment. 2. Abundance of individual taxa varied markedly from year to year. Overall, abundance decreased over the study period, particularly with respect to mayflies. Stonefly taxa showed lower persistence and were sometimes absent from a stream in any particular year. 3. Mean community persistence for the six streams, as measured by Jaccard's similarity coefficients between years, varied from 0.48 in the year pair 1999–2000 to 0.78 in 1998–99. Tattler Creek (a small stable stream) supported the most persistent macroinvertebrate community and Highway Pass Creek (a small, unstable creek) the least. Mean community persistence showed a significant relationship with mean winter snowfall (November to March) for the six streams. 4. The highest community compositional stability was found in Tattler Creek and the lowest in Highway Pass Creek, but stability varied markedly over time for the six streams, peaking in 1994–95 and reaching a minimum in 2000–01. Compositional stability was significantly related to the Pfankuch Index of channel stability. 5. The composition metrics % Chironomidae, % dominant taxa, %EPT, % Ephemeroptera and % Plecoptera, employed as part of the Alaska Stream Condition Index, varied over almost their entire range in these pristine streams across the 9 years of the study. 6. This study demonstrates the wide range of natural variation that occurs in benthic macroinvertebrate communities in these pristine central Alaskan streams, potentially limiting the applicability of composition metrics for the biological monitoring of water quality in these systems.     

Seasonal and spatial variability of sediment bacterial communities inhabiting the large shallow Lake Balaton

Seasonal studies of surface sediment bacterial communities, from two basins with differing trophic states within Lake Balaton (Hungary), were carried out using molecular (denaturing gradient gel electrophoresis, DGGE) and cultivation-based techniques. The presence of polyphosphate accumulates was tested using Neisser staining, and phosphatase activity was investigated on organic phosphorus (P) compound. Aerobic viable cell counts were significantly higher in the eutrophic than mesotrophic basin in each season. The lowest viable counts were observed in the autumn and the highest in spring and summer month in both basins. The DGGE fingerprints of the samples reflected that the composition of sediment bacterial communities in the two basins were distinct in spring and summer, and similar in autumn, but similarly diverse in all seasons. On the basis of partial 16S rDNA sequences, the 216 strains were affiliated with six major bacterial lineages: Firmicutes; Actinobacteria, Bacteroidetes, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. Common species characterized from both basins constituted up to 66% of all identified phylotypes. Strains related to Bacillus sp. were dominant in all but one sample. Isolates affiliated with Aeromonas sp. prevailed in the sample taken from the mesotrophic basin in spring. The majority of the strains showed excess poly-P accumulation. Association of Neisser staining and phosphatase activity test results suggested that excess poly-P accumulation serves as P storage for sediment bacteria. Our study implied the importance of Firmicutes, Actinobacteria, Alphaproteobacteria, and Aeromonas species in benthic bacterial P retention.     

Marked seasonality and high spatial variability of protist communities in shallow freshwater systems

Small eukaryotes have key roles in aquatic ecosystems, influencing their local environment, global biogeochemical cycles and climate. Their impact depends on community structure, which varies along time. However, very few studies take into account temporal variation. This is especially true for small, shallow freshwater systems, which remain largely understudied despite their wide variety, global surface and intense microbial activity. We have monthly followed changes in the community structure of small microbial eukaryotes (0.2–5 μm cell diameter) for 2 years in four ponds and one brook located in North-Western France based on massive 18S rDNA amplicon 454 pyrosequencing. We detected a total of 3742 stringently defined operational taxonomic units (OTUs) encompassing all recognized eukaryotic supergroups and lineages of uncertain affiliation. Although geographically close, protist communities in the five ecosystems were contrasting, with very few shared OTUs, suggesting that environmental selection mainly drives community structure. The temporal dynamics of different high-rank taxa appeared complex and rapid at monthly scales. Despite this, a clear and reproducible seasonality was observed. As expected, low-abundance OTUs dominated the community. Although some of them appeared sporadically or remained at low frequencies during the survey, others occasionally reached relatively high abundances, sometimes recurrently. This shows that at least a fraction of low-abundance eukaryotes constitutes a seed bank. The annual proportion of primary producers, free-living heterotrophs and parasites appeared remarkably constant among the different ecosystems, suggesting underlying trends of ecosystem carrying capacity for these functional groups.     

Benthic macroinvertebrate biomass and wildfires: evidence for enrichment of boreal subarctic lakes

1 We quantified the effects of forest fire on littoral benthic macroinvertebrate biomass on a boreal subarctic plateau in Alberta, Canada. Water chemistry and benthos were collected from six lakes, 1 and 2 years following a 1995 fire which burned about 91% of their catchments (i.e. recently burnt lakes), and from four other lakes whose catchments burned between 1961 and 1985 (i.e. previously burnt lakes). Seven lakes whose catchments had not burned since at least 1957 served as reference systems.
2 Total benthic macroinvertebrate biomass and biomass of Chironomidae were 1.5‐ and 2‐fold (P<0.05) greater within recently burnt lakes than in reference systems, whereas the biomass of Oligochaeta (P=0.06) and Amphipoda (P=0.07) were marginally higher in burnt than reference lakes. Burnt lakes had greater colour (P<0.05) and marginally (P=0.06) higher concentrations of soluble reactive phosphorus than reference lakes.
3 Nutrient diffusing substrata deployed in a previously and a recently burnt lake indicated that littoral epilithic communities were co‐limited by the availability of phosphorus (P) and nitrogen (N), although co‐limitation was stronger in the previously burnt than the recently burnt lake. Epilithic chlorophyll a on natural stone surfaces in the recently burnt lake was also 3.5 times higher (P<0.05) than that from the previously burnt lake.
4 Among all 17 lakes, total benthic biomass and biomass of Chironomidae, Amphipoda and Nematoda, were significantly (P<0.05) or marginally (P=0.06) related to soluble reactive phosphorus (SRP) but not dissolved inorganic nitrogen or colour. These regressions explained between 11% and 64% of variation in benthic biomasses.
5 Linear regressions and second‐order polynomials explained 18% and 24% of the variation in concentrations of SRP and water colour with time since fire, respectively, and between 22% and 70% of variation in total biomass and biomass of the five dominant invertebrate groups. These analyses suggest that benthic biomasses continue to be elevated for about 15–20 years following fire before declining to pre‐disturbance levels.     

Palaeoecological significance of calcimicrobial communities during ramp evolution: An example from the Lower Cambrian of Germany

Summary The palaeoecology of calcimicrobial communities from the only Gondwana-related Lower Cambrian in Central Europe (eastern Germany, carbonates and siliciclastics) has been studied. Six morphological groups of calcimicrobes are described. Some of them show a significant ability for sediment stabilization and construction of biohermal reef mounds. Other types of calcimicrobes were more common in biostromal thickets. Some of them were capable of populating different environments, growing in different modes and on different substrates. AnEpiphyton-archaeocyathan reef mound is described, illustrating the importance of calcimicrobes for mound formation. The fossil communities together with a complex of sedimentary features allow a reconstruction of the depositional history of the environment. Based on comparison with similar Gondwanan Lower Cambrian successions (Sardinia/Italy, Spain) and facies development a model is proposed describing the sedimentary history. Three depositional stages are distinguished: (1) deep subtidal ramp, (2) shallow subtidal ramp, (3) shallow subtidal to intertidal mixed siliciclastic-carbonate ramp with migrating oolitic shoals. In spite of similarities with the deposits in southern Europe, some distinct differences exist with respect to the succession of facies, the completeness of the sections, the fossil spectrum, and the nature of the siliciclastic sediments. For the German Lower Cambrian, a facies development from a low energy deep environment to a high energy shallow environment (partly restricted and with some evaporites) can be reconstructed. As compared with Sardinia and Spain, the depositional environment of the eastern German Lower Cambrian successions was predominantly characterized by low-energy conditions.