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1.
Taxonomic Sufficiency (TS) is a promising analysis technique, particularly in light of the current need for rapid and reliable procedures in marine impact assessment and monitoring. However, generalizations are still difficult and there are few studies comparing the effectiveness of TS under different environmental settings. The present study investigates whether reduced taxonomy can be used to detect natural and human-driven patterns of variation in mollusk and polychaete assemblages from subtidal soft and hard bottoms in the Mediterranean. Results showed that, unlike in polychaetes, mollusk families represent effective taxonomic surrogates across a range of environmental contexts. These findings suggest that the mechanisms behind TS in mollusks could act homogeneously across habitats and environmental conditions. In contrast, multiple factors could interact to determine the robustness of polychaetes to taxonomic aggregation. This study highlights the need to go beyond the current pragmatism in this field of work and focus on the reasons underlying TS effectiveness in order to provide a general framework on the application of taxonomic surrogates in marine systems.  相似文献   

2.
Several biotic indices have been proposed for the assessment of the ecological status of benthic macroinvertebrates in marine waters, although none have been generally accepted. When it comes to assessing highly stressed natural environments, such as estuaries, the controversy and uncertainty is much higher than for any given normal index. In this article, we test the behavior and suitability of different biotic indices proposed under the perspective of the Water Framework Directive (S, H, AMBI, M-AMBI, BQI, W-statistic, Taxonomic distinctness) for the assessment of estuaries in northern Spain. The low species richness and dominance of a few tolerant species in the characteristic community of these estuaries presented a challenge to the application of the biotic indices tested. Combined approaches that integrate different aspects of water quality and ecosystem functionality could increase the reliability of the ecological assessment of these transitional waters.  相似文献   

3.
Taxonomic sufficiency (TS) involves the identification of taxa only to a level of taxonomic resolution sufficient to permit the detection of changes in stressed assemblages. Recently, however, TS has been proposed also for conservation issues as a tool to estimate biodiversity over large areas and in poorly known environments. This paper briefly reviews the use of TS in environmental impact studies and the effects of TS on sampling procedures and data analyses. The risk of possible loss of information depending on TS and the studied environment are discussed. Concluding remarks deal with the dangers of loss of taxonomic expertise in marine biological studies and assess critically the proposal of TS as a tool to describe biodiversity at a taxonomic level higher than species.  相似文献   

4.
生态系统地震灾害及其深层机制   总被引：9，自引：0，他引：9  
所有地震时空、强度对人及人类破坏的复杂性可以贯穿到各个层次的生态系统中体现出来,这样地震给人类带来的空间和时间的全面灾害即可用生态系统地震灾害来进行描述。以人类为核心,按照构成生态系统的主体和环境因子的不同,可将生态系统由内向外、逐层包容地划分成社会生态系统、环境生态系统和自然生态系统三个层次类型。在社会生态系统震害中,人类的能动作用居于主导的地位,在环境生态系统震害中,人类的能动作用居于协调的位置,在自然生态系统震害中,人类的能动作用处于服从的地位。整体上来看,生态系统震害具有四个一般特征,即连发性、群发性、长程关联性和影响长期性。蕴震体及地球岩石部分本身就具有自组织、自适应和自相似即自复制类生命体特征,因而具有网络性。因而从生态系统角度研究可以发现,地震灾害与多种灾害之间构成了一个整体的联系,这就是生态系统震害的深层机制,称之为网络性机制。地震灾害的宏观过程是地震作用于人类生存的生态环境(天然生态环境和人工生态环境)从而危及人与社会并形成灾害,震害是由多种相互关联的要素所构成的复杂系统。  相似文献   

5.
Taxonomic problems have hindered the widespread use of meiobenthos for the purpose of pollution monitoring despite its potential usefulness. The question whether it is necessary to go down to species level in order to distinguish assemblages and stations was studied using data on meiofauna densities available from a GEEP-workshop held in Norway, August 1986.

Using the complete species list of harpacticoid copepod and nematode species, the six stations could be clearly separated by different multivariate techniques (TWINSPAN, DCA, MDS, Clustering). The abundance data of the genera, the families and even the orders (in the case of nematodes) still allowed a more or less clear separation of the stations, although their relative relationships were sometimes distorted. Thus, from a practical point of view, it may be sufficient to identify the animals to genus or family level.

It is proven that this result is not due to ecological similarities between congeneric or confamiliar species. The species groups typifying the stations in the TWINSPAN analysis did not contain more confamiliar species pairs than expected from random sorting. Randomly assembled ‘families’ allowed a separation of the stations as clear as that based on taxonomic groups.

We conclude that the information contained in species abundances was preserved, at least partially, when the species are grouped, even at random. The grouping in higher taxonomic categories was as good as any, and more convenient than all the others. However, within the (limited) range of habitats studied, ecological adaptation is achieved nearly exclusively on the species level.  相似文献   


6.
Establishment of a benchmark against which deleterious changes to an estuary can be evaluated requires validating that it has not been subjected to detrimental anthropogenic perturbations and then identifying the biological features which are indicative of a pristine condition and can thus be employed as indicators for detecting and monitoring departures from the natural state. The characteristics of the benthic macroinvertebrate fauna of an essentially pristine, seasonally-open estuary in Western Australia (Broke Inlet) have been determined and compared with those previously recorded for a nearby eutrophic, seasonally-open estuary (Wilson Inlet). Density was far lower in Broke than Wilson. Compositions differed radically at all taxonomic levels, with polychaetes contributing less, and crustaceans more, to the abundance in Broke. Average taxonomic distinctness was greater for Broke than both Wilson and 16 other temperate southern hemisphere estuaries, whereas the reverse was true for variation in taxonomic distinctness, emphasizing that Broke Inlet is pristine.  相似文献   

7.
Assessing the ecological status, a concept implemented in the European Water Framework Directive [EC, 2000. Directive of the European Parliament and of the Council 2000/60/EC establishing a framework for community action in the field of water policy PE-CONS 3639/1/00, p. 72], requires the application of methods capable of distinguishing different levels of ecological quality. The Average Taxonomic Distinctness has been used as tool in this context, and we tested the robustness of Taxonomic Distinctness measures applying it in different scenarios (estuarine eutrophication, organic pollution, and re-colonisation after physical disturbance), analysing simultaneously its compliance to other types of ecological indicators. Results show that, in most of the case studies, only Total Taxonomic Distinctness was relatively satisfactory in discriminating between disturbed situations. Other Taxonomic Distinctness measures have not proved to be more sensitive than other ecological indicators (Shannon-Wiener, Margalef, and Eco-Exergy indices). Therefore, this approach does not seem to be particularly helpful in assessing systems' ecological status with regard to the WFD implementation.  相似文献   

8.
Assessing the ecological status, a concept implemented in the European Water Framework Directive [Directive of the European Parliament and of the Council 2000/60/EC establishing a framework for community action in the field of water policy PE-CONS 3639/1/00, 72 p.], requires the application of methods capable of distinguishing different levels of ecological quality. Somerfield and Clarke [Marine Environmental Research 43 (2003) 145-156] proposed Average Taxonomic Distinctness to be used as tool in this context. We tested the robustness of Taxonomic Distinctness measures applying it in different scenarios (estuarine eutrophication, organic pollution, and re-colonisation after physical disturbance), analysing simultaneously its compliance to other types of ecological indicators. Results show that, in most of the case studies, only Total Taxonomic Distinctness was relatively satisfactory in discriminating between disturbed situations. Other Taxonomic Distinctness measures have not proved to be more sensitive than other ecological indicators (Shannon-Wiener, Margalef, and Eco-Exergy indices). Therefore, this approach does not seem to be particularly helpful in assessing systems' ecological status with regard to the WFD implementation.  相似文献   

9.
Taxonomic composition, the presence of disturbance-sensitive species and abundance are attributes for monitoring the status of marine angiosperms; a biological quality element required for assessment of environmental condition under the Water Framework Directive (WFD). Their relevance for defining the ecological status of UK water bodies and the establishment of reference conditions for these attributes are described. Founded on quantitative measurements of these attributes, a set of metrics has been developed for monitoring and assessment of the only truly marine angiosperms, seagrass. The proposed metrics are presented and tested against a variety of littoral and sublittoral UK seagrass beds. In combination they express the cumulative response of marine angiosperms to different levels of anthropogenic disturbance.  相似文献   

10.
We examined the influence of land-use, habitat, and water quality on the spatial distribution of aquatic macroinvertebrates in two human-dominated catchments in the Swiss Plateau (Gürbe, Mönchaltorfer Aa). Land-use in the Gürbe catchment was dominated by agriculture, whereas urban land-use was more common in the Mönchaltorfer Aa. Study sites in each catchment were characterized using measures of local habitat conditions, water quality parameters including water temperature, and organic matter resources. A strong longitudinal gradient in temperature, conductivity and nitrogen was evident among sites in the Gürbe catchment, although sites on a main tributary had a strong agricultural signature and deviated from this pattern. Percentage agricultural land-use in the Gürbe was strongly correlated with algal biomass and the water quality PCA axes associated with conductivity, nitrogen (axis-1) and temperature (axis-3). Spatial grouping of sites by water quality was less evident in the Mönchaltorfer Aa, except for a strong signal by wastewater treatment plant effluents and partial differences between upper and lower basin sites. Percentage forest and agricultural land-use in the Mönchaltorfer Aa were correlated with water quality PCA axis-2, being associated with phosphorus and temperature. Macroinvertebrate densities, taxonomic richness, and axis-1 from a non-metric multidimensional scaling analysis (NMDS) of taxonomic composition were significantly correlated with water quality PCA axis-1 in the Gürbe catchment. Here, macroinvertebrate densities and NMDS axis-1 scores based on taxon relative abundances and densities were correlated with land-use features. Spatial distances between sites also were related to site differences in macroinvertebrates, reflecting the strong longitudinal environmental gradient in the Gürbe. Taxonomic differences between water quality PCA site groups were less pronounced in the Mönchaltorfer Aa, although differences were significant for trichopterans, ephemeropterans, chironomids, gastropods and coleopterans. Here, NMDS axis-1 based on taxon relative abundances and densities was correlated with forest land-use. Spatial distances between sites were not evident in macroinvertebrate site differences, reflecting the less pronounced spatial and longitudinal patterns in environmental attributes in this catchment. Our results support the hypothesis that spatial distributions of macroinvertebrates are related to spatial relationships among environmental attributes like land-use, habitat, and water quality in human-dominated catchments that depend on river network complexity, a habitat-filtering template in line with ecological niche theory.  相似文献   

11.
Niphargus puteanus is the oldest described species of its genus and, in the past, was used as a taxonomic annotation for any subterranean amphipod record. For that reason, no clear knowledge exists about its actual range size and habitat preferences. We here applied a molecular taxonomic and phylogeographical approach based on mitochondrial and nuclear DNA to shed light on its distribution and to infer its demographic history. Furthermore, we analysed aquifer types and water flow regimes to provide a clearer picture of the species’ ecological requirements.Our results indicate that N. puteanus is widely distributed north of the Alps, having its core range in the geomorphological natural region of the ‘South German Scarplands’ (SGS). Additionally, isolated satellite populations exist in the Taunus and the Sauerland, and two single individuals were collected in Luxembourg and in Austria, respectively. The species’ maximal distribution range reaches 756 km between the two single-specimen records and 371 km within the SGS. A very high haplotype diversity was observed, revealing the presence of seven haplotype groups. All the haplogroups were present in the SGS and exhibited distinct spatial-genetic patterns. We thus inferred a high degree of population isolation, with the SGS being a potential long-term refugium for N. puteanus. Historical drift of specimens along major riverine networks (Rhine, Danube) may provide an evolutionary dispersal mechanism explaining the formation of satellite populations.From an ecological perspective, populations of N. puteanus were found to be closely associated with fast-flowing spring environments within fissured aquifers. This species should therefore be classified as both crenophile and stygophile, effectively exploiting resources of surface as well as subsurface spring waters.  相似文献   

12.
Multiple stressors like alterations of water quality, hydrology and hydromorphology impact riverine ecosystems. To counteract its consequences, restoration measures are required, e.g. demanded by the EU Water Framework Directive. However, small-scale hydromorphological restoration measures often show little success. Besides overriding stressors, recolonization potential and insufficient time for development are often discussed as reasons for this lack of success. Over a period of 17 years a hydromorphological restoration measure in a German lowland stream reach was evaluated, excluding most of these confounding factors. The restoration measure was left to its self-dynamic development, i.e. there was no further intervention by water management, apart from some large wood installations after 8 years. In the accompanying studies, changes in hydromorphology and the organism groups macroinvertebrates (including both structural and functional diversities), fish and macrophytes were investigated.We proved a rapid and stable enhancement of ecological functions as indicated by a diverse and resilient macroinvertebrate biocoenosis. Both taxonomic and functional richness of macroinvertebrates significantly increased, but varied over time. Since the restoration measure allowed self-dynamic development, a taxonomic and functional endpoint was not achieved even after 17 years, even though near-reference conditions were attained after only 4 years. Deficits in fish communities were most probably due to their low recolonization potential.Our results underscore that small scale hydromorphological restoration can be successful if overriding stressors are absent. Furthermore, we proved the importance of self-dynamics in restoration measures, allowing hydromorphological and biological development.  相似文献   

13.
Benthic faunal data is regularly collected worldwide to assess the ecological quality of marine environments. Recently, there has been renewed interest in developing biological indices able to identify environmental status and potential anthropogenic impacts. In this paper we evaluate the performance of a general polychaete/amphipod ratio along the Norwegian continental shelf as an environmental indicator for offshore oil and gas impacts. Two main trends are apparent: first, a contamination gradient is discernible from where production takes place compared to stations 10,000 m away. Second, the quality of the marine environment has improved over time. These results are consistent with monitoring reports employing a combination of uni- and multi-variate statistics. Thus, we consider this ratio as a relatively simple, useful and potentially cost-effective complement to other more demanding assessment techniques. Because of its strong theoretical basis, it may also be useful for detecting ecological change as a result of other activities.  相似文献   

14.
Environmental impact assessment (EIA) is a procedural tool for environmental management that identifies, predicts, evaluates and mitigates the environmental impact of development proposals. In the process of EIA, EIA reports, prepared by developers, are expected to delineate the environmental impact, but in practice they usually determine whether the amounts or concentrations of pollutants comply with the relevant standards. Actually, many analytical tools can improve the analysis of environmental impact in EIA reports, such as life cycle assessment (LCA) and environmental risk assessment (ERA). Life cycle impact assessment (LCIA) is one of steps in LCA that takes account of the causal relationships between environmental hazards and damage. Incorporating the concept of LCIA into an ERA as an integrated tool for the preparation of EIA reports extends the focus of the reports from the regulatory compliance of the environmental impact, to determine the significance of the environmental impact. Sometimes, when using integrated tools, it is necessary to consider fuzzy situations, because of a lack of sufficient information; therefore, so ERA should be generalized to a fuzzy risk assessment (FRA). Therefore, this paper proposes the integration of a LCIA and a FRA as an assessment tool for the preparation of EIA reports, whereby the LCIA clearly identifies the causal linkage for hazard–pathway–receptor–damage and then better explain the significance of the impact; furthermore, a FRA copes with fuzzy and probabilistic situations in the assessment of pollution severity and the estimation of exposure probability. Finally, the use of the proposed methodology is demonstrated in a case study of the expansion plan for the world’s largest plastics processing factory.  相似文献   

15.
Differing arrangements exist for water resources regulation in the four nations of the UK. This account is largely concerned with England and Wales where a unitary regulation of water resources permits a coherent view of developments, although some reference is made to Scotland and Northern Ireland.Following a review in 1987 of compensation flows from UK reservoirs attention has more recently been focused on a broader range of water resource developments. The more obscured impacts of groundwater developments is now attracting the greater attention. Measures of environmental impact are confused by a wide number of environmental variables and the lack of consistent observation of these through the period of disturbance. Uncertainties have been compounded during studies by the coincidence of a major drought period with consequent accentuation of seasons with prolonged river lowflows.Historically water resource developments have been aimed by Engineers to maximise the production of usable water. The value of the resource in situ to the natural or previous managed environment will have had its defenders but that value could be degraded in pursuit of the primary goal. Recent convention and now statutory requirement for environmental impact assessment demands the involvement of inter-disciplinary study teams. This welcome practice remains bedeviled by the lack of sound quantitative criteria for water resource engineering design.There is no absence of general scientific understanding of environmental impacts but the need remains for the establishment of criteria and regular analytical procedures with which to link hydrological regimes with ecological success. Much work is being done in the UK to address this matter and there is increasing collaboration between Hydrologists and Biologists to seek constructive remedies.  相似文献   

16.
为了解向家坝水电工程对金沙江下游鱼类多样性的影响,基于2016—2018年邵女坪(库首)、绥江(库中)和桧溪(库尾)3个江段的鱼类群落调查数据,分析了向家坝库区鱼类物种、分类和功能多样性空间格局,结合蓄水前(2011年)和蓄水初期(2015年)的资料,探讨了蓄水后向家坝库区不同维度鱼类多样性的变化趋势。向家坝库区各江段以广适性的瓦氏黄颡鱼(Pelteobagrus vachelli)和静水性的(Hemiculter leucisculus)占优势,两者的数量百分比分别为30.15%±14.82%和13.91%±11.16%。非度量多维尺度分析显示,蓄水后向家坝库区库首邵女坪和库中绥江鱼类群落差异最小,库首邵女坪和库尾桧溪鱼类群落差异最大;库中绥江在蓄水前、蓄水初期和2016—2018年3个时期的鱼类群落差异均较大,表明蓄水后绥江江段鱼类群落经历了剧烈变化。库区不同江段鱼类Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数均表现为:桧溪>邵女坪>绥江,鱼类分类多样性指数和分类差异指数均表现为:桧溪>绥江>邵女坪。库区鱼类摄食、运动和繁殖等不同维度的功能多样性(功能丰富度、功能均匀度、功能离散度)空间格局不同,但总体上库中绥江鱼类功能丰富度最高,功能均匀度最低。与蓄水前相比,绥江江段鱼类物种、分类多样性呈下降趋势,鱼类功能丰富度和均匀度也有下降趋势。蓄水后绥江江段鱼类群落主要功能性状发生了明显变化,如蓄水前以下位口、纺锤形体型鱼类占优势,蓄水后以端位口、侧扁形体型鱼类占优势。不同维度多样性指数侧重于鱼类多样性的不同方面,结合多种指数分析有利于更全面地了解鱼类群落对环境变化和外界干扰的响应。研究结果有助于深入了解水电工程建设对金沙江下游鱼类多样性的影响,为鱼类多样性保护提供依据,也可为长江“十年禁渔”效果评估提供本底资料。  相似文献   

17.
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18.
This study tested the hypothesis that, during recent years, the benthic macroinvertebrate fauna of the large basin of the Swan-Canning Estuary has changed in ways consistent with deteriorating environmental conditions in that estuary. Between 1986/7 and 2003/4, the compositions of that fauna altered markedly at the species and even family levels. Thus, the densities and number of species of molluscs, and especially of crustaceans, which are particularly susceptible to environmental stress, declined, while those of the more tolerant polychaetes increased. However, taxonomic distinctness declined consistently only at one of the four widely-spaced sampling sites and the dispersion of samples did not differ markedly between periods, indicating that the benthic fauna has not undergone such extreme changes as in the nearby Peel-Harvey Estuary. It is thus proposed that benthic macroinvertebrates can act as important indicators of the severity of environmental degradation in microtidal estuaries in regions where such perturbations are increasing.  相似文献   

19.
Environmental monitoring is performed on seafloor communities since these organisms are relatively stationary and integrate the environmental conditions over many years. Standard practices involve sampling by grab. Epifaunal taxa, often missed by grab sampling, are likely to have different ecological functions. We investigate how current environmental assessments represent the benthic community as a whole by comparing taxonomic and functional components sampled by grabs and epibenthic trawls. Faunal communities sampled by trawl (filtrating or predator, epifauna) and grab (infaunal, detrivore) differs widely by sampling distinct functional components, and these may be expected to respond to different human-induced stressors. Neither component appears to be a good surrogate for the community as a whole. We suggest a benthic monitoring by combining both techniques. Sustainable ecosystem functioning is intimately tied to the health of both components of the benthic community, and is recognized as an important goal by signatories of the Convention on Biological Diversity.  相似文献   

20.
A fuzzy parameterized probabilistic analysis (FPPA) method was developed in this study to assess risks associated with environmental pollution-control problems. FPPA integrated environmental transport modeling, fuzzy transformation, probabilistic risk assessment, fuzzy risk quantification into a general risk assessment framework, and was capable of handling uncertainties expressed as fuzzy-parameterized stochastic distributions. The proposed method was applied to two environmental pollution problems, with one being about the point-source pollution in a river system with uncertain water quality parameters and the other being concerned with groundwater contaminant plume from waste landfill site with poorly known contaminant physical properties. The study results indicated that the complex uncertain features had significant impacts on modeling and risk-assessment outputs; the degree of impacts of modeling parameters were highly dependent on the level of imprecision of these parameters. The results also implied that FPPA was capable of addressing vagueness or imprecision associated with probabilistic risk evaluation, and help generate risk outputs that could be elucidated under different possibilistic levels. The proposed method could be used by environmental managers to evaluate trade-offs involving risks and costs, as well as identify management solutions that sufficiently hedge against dual uncertainties.  相似文献   

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