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1.
The concept of spatial scale is at the research frontier in ecology, and although focus has been placed on trying to determine the role of spatial scale in structuring communities, there still is a further need to standardize which organism groups are to be used at which scale and under which circumstances in environmental assessment. This paper contributes to the understanding of the variability at different spatial scales (reach, stream, river basin) of metrics characterizing communities of different biological quality elements (macrophytes, fishes, macroinvertebrates and benthic diatoms) as defined by the Water Framework Directive. For this purpose, high-quality reaches from medium-sized lowland streams of Latvia, Ecoregion 15 (Baltic) were sampled using a nested hierarchical sampling design: (river basin → stream → reach). The variability of metrics within the different groups of biological quality elements confirmed that large-bodied organisms (macrophytes and fish) were less variable than small-bodied organisms (macroinvertebrates and benthic diatoms) at reach, stream and river basin scales. Single metrics of biological quality elements had the largest variation at the reach scale compared with stream and basin scales. There were no significant correlations between biodiversity indices of the different organism groups. The correlation between diversity indices (Shannon’s and Simpson’s) of the biological quality elements (macrophytes, fish, benthic macroinvertebrates and benthic diatoms) and a number of measured environmental variables varied among the different organism groups. Relationships between diversity indices and environmental factors were established for all groups of biological quality elements. Our results showed that metrics of macrophytes and fish could be used for assessing ecological quality at the river basin scale, whereas metrics of macroinvertebrates and benthic diatoms were most appropriate at a smaller scale.  相似文献   

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Abstract This paper describes a simple and inexpensive procedure for the rapid biological assessment of water quality in rivers and streams in eastern Australia. The procedure involves the standardized collection of samples of 100 macroinvertebrates from defined habitat types within a water body. Specimens are identified to family level only and a biotic index is calculated. Proposed future testing and evaluation are described, and the limitations of the rapid approach are discussed.  相似文献   

4.
Models are developed which predict changes in macrofloral and macroinvertebrate assemblages in response to surface water acidification. Empirical relationships between assemblage type and water chemistry are used to predict the probabilities of species occurrences during acidification, as recreated by the hydrochemical model, MAGIC. The water chemistry of two streams is simulated between 1844 and 2124. From 1958, alternative scenarios involved either moorland or conifer forest. From 1984, sulphate deposition was either constant or reduced by 50%. Alternative ecological models driven by pH or total hardness are compared. The floral model showed minor differences between scenarios, probabilities of species occurrence changing gradually and reaching stable values by around 1964. For certain invertebrate species the occurrence probabilities changed rapidly over relatively short periods, for example in the late 20 h century under moorland with constant deposition. Reduced sulphate deposition prevented decrease of acid sensitive species in moorland scenarios but not under forest, which greatly accelerated faunal changes irrespective of deposition pattern. Differences between the pH and hardness models indicated that the effects of these parameters should be separated in future studies. Where an earlier model showed only step changes in invertebrate assemblage type, this new approach can model more precise taxonomic shifts occurring with acidification. Such changes could be important to conservation, or as early indicators of response to pollution. The tentative simulations here suggest that large taxonomic changes may occur over relatively short periods during acidification.  相似文献   

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The objective of this synthesis is to present the key messages and draw the main conclusions from the work on lakes in the REBECCA project, pointing out their links to theoretical ecology and their applicability for the WFD implementation. Type-specific results were obtained from analyses of large pan-European datasets for phytoplankton, macrophytes, macroinvertebrates and fish, and indicators and relationships showing the impact of eutrophication or acidification on these biological elements were constructed. The thresholds identified in many of the response curves are well suited for setting ecological status class boundaries and can be applied in the intercalibration of classification systems. Good indicators for phytoplankton (chrysophytes, cyanobacteria) and macrophytes (isoetids and charaphytes) responses to eutrophication were identified, and the level of eutrophication pressure needed to reach the thresholds for these indicators was quantified. Several existing metrics developed for macrophytes had low comparability and need further harmonisation to be useful for intercalibration of classification systems. For macroinvertebrates, a number of metrics developed for rivers turned out to be less useful to describe lake responses to eutrophication and acidification, whereas other species based indicators were more promising. All the biological elements showed different responses in different lake types according to alkalinity and humic substances, and also partly according to depth. Better harmonisation of monitoring methods is needed to achieve better precision in the dose–response curves. Future research should include impacts of hydromorphological pressures and climate change, as well as predictions of timelags involved in responses to reduction of pressures.  相似文献   

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The aim of the intercalibration exercise presently performed by the EU is to identify and resolve significant inconsistencies between the ecological quality classifications of EU Member States and the normative definitions of the EU Water Framework Directive. Based on benthic macroinvertebrate data of two European stream types (small siliceous mountain streams and medium-sized lowland streams in Central and Western Europe) we correlated the indices of 10 river quality assessment methods (ASPT, BMWP, DSFI, German Multimetric Index, Saprobic Indices) applied in Austria, Czech Republic, Denmark, Germany, Poland, Slovak Republic, Sweden and United Kingdom. National class boundaries were compared via regression analysis. Assessment methods of the same type (Saprobic Indices, BMWP/ASPT scores) showed best correlation results (R2>0.7). The good quality status boundaries of the national methods deviated up to 25%; thus indicating the necessity to harmonize the national classification schemes. Prerequisites of the presented intercalibration approach are (1) a sufficiently large and consistent dataset representative of the respective common intercalibration types and (2) agreement on common type specific reference conditions.  相似文献   

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Abstract Two sets of data were used to evaluate the procedure for rapid assessment of rivers described by Chessman (1995): (i) 72 samples from four habitats at 27 sites on the Nepean River and tributaries; and (ii) 41 riffle samples from the Blue Mountains. In the Nepean system all the sites had moderate anthropogenic disturbance but none had gross organic pollution. There were, however, conductivity differences related to mixed sandstone and shale lithology. The sites differed widely in natural physical attributes such as stream order (2–6) and altitude (40–600 m). The Blue Mountains data included sites with little or no anthropogenic disturbance and sites greatly affected by organic pollution. There was again a wide range of altitudes (15–1000 m) but stream orders were more restricted (1–4). The occurrence of macroinvertebrate families was analysed using cluster analysis (TWINSPAN) and ordination (semi-strong hybrid multidimensional scaling). Relationships between the patterns observed, the SIGNAL biotic index, and physical and chemical data were investigated. The Nepean data showed that the sample size of 100 animals used in the rapid procedure was sufficient to reveal natural distribution patterns in the communities, and that SIGNAL was essentially independent of these patterns. In the Blue Mountains, water pollution had a greater effect on macroinvertebrate communities than the physical habitat, and SIGNAL distinguished sites with differing levels of pollution.  相似文献   

11.
A device for quantitatively sampling the macroinvertebrates of large stones in streams is described. In comparison to the usual method for sampling the fauna of large stones, (the lifting of stones upstream of a hand net), the present method accurately samples stonedwelling animals that are good swimmers. Details are given of a reliable method to measure the surface area of stream stones using thin plastic sheeting.  相似文献   

12.
Sutton  M.A.  Milford  C.  Nemitz  E.  Theobald  M.R.  Hill  P.W.  Fowler  D.  Schjoerring  J.K.  Mattsson  M.E.  Nielsen  K.H.  Husted  S.  Erisman  J.W.  Otjes  R.  Hensen  A.  Mosquera  J.  Cellier  P.  Loubet  B.  David  M.  Genermont  S.  Neftel  A.  Blatter  A.  Herrmann  B.  Jones  S.K.  Horvath  L.  Führer  E.C.  Mantzanas  K.  Koukoura  Z.  Gallagher  M.  Williams  P.  Flynn  M.  Riedo  M. 《Plant and Soil》2001,228(1):131-145
A new study to address the biosphere-atmosphere exchange of ammonia (NH3) with grasslands is applying a European transect to interpret NH3 fluxes in relation to atmospheric conditions, grassland management and soil chemistry. Micrometeorological measurements using the aerodynamic gradient method (AGM) with continuous NH3 detectors are supported by bioassays of the NH3 `stomatal compensation point' (s). Relaxed eddy accumulation (REA) is also applied to enable flux measurements at one height; this is relevant to help address flux divergence due to gas-particle inter-conversion or the presence of local sources in a landscape.Continuous measurements that contrast intensively managed grasslands with semi-natural grasslands allow a scaling up from 15 min values to seasonal means. The measurements demonstrate the bi-directional nature of NH3 fluxes, with typically daytime emission and small nocturnal deposition. They confirm the existence of enhanced NH3 emissions (e.g. 30 g N ha–1 d–1) following cutting of intensively managed swards. Further increased emissions follow fertilization with NH4NO3 (typically 70 g N ha–1 d–1). Measurements using REA support these patterns, but require a greater analytical precision than with the AGM.The results are being used to develop models of NH3 exchange. `Canopy compensation point' resistance models reproduce bi-directional diurnal patterns, but currently lack a mechanistic basis to predict changes in relation to grassland phenology. An advance proposal here is the coupling of s to dynamic models of grassland C–N cycling, and a relationship with modelled plant substrate-N is shown. Applications of the work include incorporation of the resistance models in NH3 dispersion modelling and assessment of global change scenarios.  相似文献   

13.
Fifty-five macroinvertebrate metrics were tested for their response to pond condition in 41 ponds of northwest Spain to develop a preliminary multimetric index for ecological assessment of Mediterranean flatland ponds. Stressor specific response of individual attributes to eutrophication and habitat alteration was also investigated to identify differences in the responses of metrics to single stressors and elucidate how this might affect the performance of the final index. Several combinations were tested using discrimination efficiency (25th percentile of slightly impaired sites for metrics decreasing with perturbation and 75th percentile of slightly impaired sites for metrics increasing with perturbation) and Mann–Whitney U-test with Bonferroni adjustment (P < 0.001). The final index comprised five measures (generic richness of Chironominae, generic richness of Dytiscidae + Odonata + Tanypodinae, relative richness of Chironomidae, % Macropelopini and Shannon index) and discriminated between acceptable (good) and unacceptable (moderate) conditions with more than 86% efficiency. Moreover, all the five measures included in the final index showed unidirectional responses to eutrophication, decreasing as eutrophication increased. In contrast, the effect of habitat alteration was less clear, especially in ponds in best available conditions where a vegetation belt of shrubs and trees prevented growing of macrophitic vegetation on shores and consequently associated fauna. Interestingly, none of the functional groups (e.g. % predators and % collector–gatherers) were sensitive to degradation. Handling editor: K. Martens  相似文献   

14.
This paper describes the usage and the performance evaluation of the completeness index method in the ‘Surveillance of Rare Cancers in Europe project’ (RARECARE) for estimating rare cancer prevalence in Europe. The 15-year prevalence at 1st January 2003 for 255 cancers is obtained from a pool of 22 RARECARE cancer registries (CRs). Incidence and survival models are applied to the RARECARE database to estimate the parameters from which the completeness indices are calculated. Complete prevalence is obtained adjusting the observed 15-year prevalence by the completeness index, to account for those cancer survivors diagnosed before the CR activity started. Main factors influencing the performance of the completeness index method for rare cancers are the same as for common cancers: age distribution of incidence and lethality of the cancer. For cancers occurring in the elderly, with low survival rates and consequently a restricted number of long-term survivors we obtained completeness indices higher than 0.9. Values lower than 0.7 correspond to those cancers with good prognosis and/or incidence more concentrated at the younger ages, indicating that 15 years of follow up are insufficient to detect all prevalent cases. Validation analysis shows that for a restricted subgroup of rare cancers with very low incidence and low survival, the completeness indices were not able to adequately correct the observed prevalence even considering a registration period of 20 years. On average, sensitivity analyses show a slight overestimation of complete prevalence for rare and common cancers whose increasing incidence is known in literature. RARECARE is the largest project on rare cancers conducted to date. Improving health care programs for cancer survivors is a public health priority and prevalence data which provides important information in this field should be regularly asked to Member States and included in the EU health statistics.  相似文献   

15.

Background

The first European Perinatal Health Report showed wide variability between European countries in fetal (2.6–9.1‰) and neonatal (1.6–5.7‰) mortality rates in 2004. We investigated gestational age patterns of fetal and neonatal mortality to improve our understanding of the differences between countries with low and high mortality.

Methodology/Principal Findings

Data on 29 countries/regions participating in the Euro-Peristat project were analyzed. Most European countries had no limits for the registration of live births, but substantial variations in limits for registration of stillbirths before 28 weeks of gestation existed. Country rankings changed markedly after excluding deaths most likely to be affected by registration differences (22–23 weeks for neonatal mortality and 22–27 weeks for fetal mortality). Countries with high fetal mortality ≥28 weeks had on average higher proportions of fetal deaths at and near term (≥37 weeks), while proportions of fetal deaths at earlier gestational ages (28–31 and 32–36 weeks) were higher in low fetal mortality countries. Countries with high neonatal mortality rates ≥24 weeks, all new member states of the European Union, had high gestational age-specific neonatal mortality rates for all gestational-age subgroups; they also had high fetal mortality, as well as high early and late neonatal mortality. In contrast, other countries with similar levels of neonatal mortality had varying levels of fetal mortality, and among these countries early and late neonatal mortality were negatively correlated.

Conclusions

For valid European comparisons, all countries should register births and deaths from at least 22 weeks of gestation and should be able to distinguish late terminations of pregnancy from stillbirths. After excluding deaths most likely to be influenced by existing registration differences, important variations in both levels and patterns of fetal and neonatal mortality rates were found. These disparities raise questions for future research about the effectiveness of medical policies and care in European countries.  相似文献   

16.
While the risk of ovarian cancer clearly reduces with each full-term pregnancy, the effect of incomplete pregnancies is unclear. We investigated whether incomplete pregnancies (miscarriages and induced abortions) are associated with risk of epithelial ovarian cancer. This observational study was carried out in female participants of the European Prospective Investigation into Cancer and Nutrition (EPIC). A total of 274,442 women were followed from 1992 until 2010. The baseline questionnaire elicited information on miscarriages and induced abortions, reproductive history, and lifestyle-related factors. During a median follow-up of 11.5 years, 1,035 women were diagnosed with incident epithelial ovarian cancer. Despite the lack of an overall association (ever vs. never), risk of ovarian cancer was higher among women with multiple incomplete pregnancies (HR(≥4vs.0): 1.74, 95% CI: 1.20-2.70; number of cases in this category: n?=?23). This association was particularly evident for multiple miscarriages (HR(≥4vs.0): 1.99, 95% CI: 1.06-3.73; number of cases in this category: n?=?10), with no significant association for multiple induced abortions (HR(≥4vs.0): 1.46, 95% CI: 0.68-3.14; number of cases in this category: n?=?7). Our findings suggest that multiple miscarriages are associated with an increased risk of epithelial ovarian cancer, possibly through a shared cluster of etiological factors or a common underlying pathology. These findings should be interpreted with caution as this is the first study to show this association and given the small number of cases in the highest exposure categories.  相似文献   

17.

Background  

Because of the subjective nature of Restless Legs Syndrome (RLS) symptoms and the impact of these symptoms on sleep, patient-reported outcomes (PROs) play a prominent role as study endpoints in clinical trials investigating RLS treatments. The objective of this study was to validate a new measure, the Post Sleep Questionnaire (PSQ), to assess sleep dysfunction in subjects with moderate-to-severe RLS symptoms.  相似文献   

18.
Demand for flexible work hours (FWH) is increasing in Europe aimed at increasing the number of production hours on one hand, and, on the other, reducing individual working hours and/or increasing autonomy and control on them. In view of the lack of knowledge of the effects of FWH on health and safety, we started a pilot project, funded by the Joint Programme for Working Life Research in Europe (SALTSA), aimed at: a) comparing the most relevant national legislation and how the EU Directive 93/104 "concerning certain aspects of working time" has been implemented in the member States; b) reporting prevalence and trend of FWH in Europe according to the three EU Surveys on Working Conditions carried out in the last decade; c) collecting practical examples of innovative FWH; d) evaluating their impact on health and safety in relation to work sectors, job demands, social life, aging and gender. Consequent actions are going to include information and consultancy for pertinent authorities and social parties involved, as well as training programmes for Union officials and similar groups concerning the organisation of FWH according to ergonomic principles.  相似文献   

19.
Homocysteine (Hcy) plasma level is an independent risk marker for venous thrombosis, myocardial infarction, stroke, congestive heart failure, osteoporotic fractures, and Alzheimer disease. Hcy levels are determined by the interaction of genetic and environmental factors. The genetic basis is still poorly understood, since only the MTHFR 677 C-->T polymorphism has been consistently associated with plasma Hcy levels. We conducted a genomewide linkage scan for genes affecting variation in plasma Hcy levels in 398 subjects from 21 extended Spanish families. A variance-components linkage method was used to analyze the data. The strongest linkage signal (LOD score of 3.01; genomewide P = .035) was found on chromosome 11q23, near marker D11S908, where a candidate gene involved in the metabolism of Hcy (the nicotinamide N-methyltransferase gene [NNMT]) is mapped. Haplotype analyses of 10 single-nucleotide polymorphisms within this gene found one haplotype associated with plasma Hcy levels (P = .0003). Our results, to our knowledge, represent the first genomic scan for quantitative variation in Hcy plasma levels. They strongly suggest that the NNMT gene could be a major genetic determinant of plasma Hcy levels in Spanish families. Since this gene encodes an enzyme involved in Hcy synthesis, this finding would be consistent with known biochemical pathways. These data could be relevant in determining the relationships between Hcy level, cardiovascular disease, osteoporosis, and Alzheimer disease.  相似文献   

20.
Global pharmaceutical consumption is rising with the growing and ageing human population and more intensive food production. Recent studies have revealed pharmaceutical residues in a wide range of ecosystems and organisms. Environmental concentrations are often low, but pharmaceuticals typically are designed to have biological effects at low doses, acting on physiological systems that can be evolutionarily conserved across taxa. This Theme Issue introduces the latest research investigating the risks of environmentally relevant concentrations of pharmaceuticals to vertebrate wildlife. We take a holistic, global view of environmental exposure to pharmaceuticals encompassing terrestrial, freshwater and marine ecosystems in high- and low-income countries. Based on both field and laboratory data, the evidence for and relevance of changes to physiology and behaviour, in addition to mortality and reproductive effects, are examined in terms of the population- and community-level consequences of pharmaceutical exposure on wildlife. Studies on uptake, trophic transfer and indirect effects of pharmaceuticals acting via food webs are presented. Given the logistical and ethical complexities of research in this area, several papers focus on techniques for prioritizing which compounds are most likely to harm wildlife and how modelling approaches can make predictions about the bioavailability, metabolism and toxicity of pharmaceuticals in non-target species. This Theme Issue aims to help clarify the uncertainties, highlight opportunities and inform ongoing scientific and policy debates on the impacts of pharmaceuticals in the environment.  相似文献   

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