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太湖流域城市湖泊富营养化问题严重,研究不同营养水平城市湖泊底栖动物群落的差异及成因,可为丰富底栖动物生态学研究和城市湖泊生态系统恢复提供参考。本研究于2018年12月、2019年3月、6月、9月在太湖流域15个城市湖泊开展了四个季度的调查,结果显示,重度、中度、轻度富营养和中营养水体分别占10.03%、36.89%、42.07%和11.00%。随水体营养下降,透明度显著上升,浊度、总磷和叶绿素a浓度显著下降,大型底栖动物总生物量、蚌类密度和生物量上升,寡毛类密度和生物量下降。在重度富营养水体中,底栖动物总生物量显著小于其他类型水体（P<0.01）;在轻度富营养和中营养水体中,蚌类密度和生物量显著大于重度和中度富营养水体（P<0.01）,寡毛类密度则显著小于重度和中度富营养水体（P<0.01）。Shannon-Wiener、Simpson和Pielou指数随水体营养水平下降,先上升再下降,在轻度富营养水体中最高。结构方程模型分析发现,在轻度富营养和中营养湖泊中,水温、总磷和叶绿素a浓度是影响底栖动物群落的关键环境因子。总磷浓度升高会显著促进软体动物增长（P<0.01）,对螺、蚌的路径系数分别高达0.414和0.440。总磷浓度与水温上升都能显著促进多毛类种群增长（P<0.01）,抑制水生昆虫种群（P<0.01）,路径系数分别为0.376和-0.423。本研究认为,城市湖泊水体中总磷和叶绿素a浓度对大型底栖动物群落结构有重要影响,对磷和藻类的控制,对城市湖泊底栖动物群落恢复和水生态系统修复有重要参考价值。 相似文献
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- 1. Classification is a useful tool for researchers and managers wishing to group functionally similar sites or to identify unique or threatened habitats. A process‐based river classification scheme that successfully integrates physical and biological aspects of lotic form and function would enhance conservation and restoration efforts by allowing more meaningful comparisons among sites, and improving functional understanding of lotic ecosystems.
- 2. The River Styles framework provides a geomorphological river characterization scheme in which assemblages of geomorphic units vary for differing River Styles, presenting differing arrays of aquatic habitat diversity for each style.
- 3. The ecological significance of the River Styles framework is tested by comparing the macroinvertebrate assemblages and habitat characteristics of pool and run geomorphic units for three different River Styles on the north coast of New South Wales, Australia.
- 4. Multivariate ordinations and analysis of similarity (ANOSIM) revealed that macroinvertebrate community structure differed between Bedrock‐Controlled Discontinuous Floodplain rivers and Gorge rivers, and between Bedrock‐Controlled Discontinuous Floodplain and Meandering Gravel Bed rivers, especially in pools. Differences between Gorge and Meandering Gravel Bed rivers were less apparent, largely due to variations within the Meandering Gravel Bed rivers group.
- 5. The variability in macroinvertebrate assemblage structure among geomorphic units was most strongly related to variability in substrate and hydraulic variables. Substrate composition differed significantly among all River Styles and geomorphic units, but other habitat variables showed few consistent differences among River Style groups.
- 6. These results suggest that the ecological similarity of macroinvertebrate communities within River Styles may presently be limited because some important large‐scale drivers of local habitat conditions are not included in River Styles designations. Integrating River Styles classification with other large‐scale variables reflecting stream size, temperature and hydrological regime may produce a process‐based physical classification capable of identifying river reaches with similar ecological structure and function.
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- 1. The imminent damming of the Odelouca River, an intermittent Mediterranean river situated in the south‐west Algarve region of Portugal with valuable stands of riparian vegetation, has called for the compulsory implementation of compensatory measures.
- 2. In order to assess the primary environmental and human factors that drive change in the benthic macroinvertebrate assemblages of the Odelouca, and the spatial scale at which they occur, 30 sites were sampled for benthic macroinvertebrates and extensively surveyed using River Habitat Survey (RHS) in spring 2005.
- 3. A hierarchical cluster analysis of selected physical and RHS variables clearly indicated gradients of habitat quality (instream and riparian corridor) along both main channel and tributaries. Analysis of macroinvertebrate metrics by parametric and non‐parametric ANOVA showed the derived clusters of groups to be biologically distinct.
- 4. From a total of 64 variables, divided into two explanatory variable groups (environmental or pressure) over three spatial scales (habitat, reach and basin), just 20, predominantly environmental, variables were retained for subsequent analyses.
- 5. Partial canonical correspondence analyses of the selected environmental and pressure variables over the defined spatial scales showed that environmental variables contributed most significantly over all of the spatial scales and that pressure variables related to land‐use only contributed significantly at the level of the river basin.
- 6. Variables recorded by RHS contribute successfully to the detection of habitat quality gradients in a Mediterranean river system and the strongest drivers of macroinvertebrate change are primarily, but not exclusively, environmental factors occurring at middle and higher spatial scales.
- 7. Compensatory measures must therefore be implemented across a range of spatial scales, taking into account abiotic and biotic processes characteristic of disturbance‐driven Mediterranean systems that contribute to habitat heterogeneity and quality and confer functional and trophic diversity to the macroinvertebrate assemblages.
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- 1. Lake Habitat Survey (LHS) provides a standard method for characterizing the physical habitat of lakes and reservoirs, but has not been tested for its relevance to the composition and abundance of macroinvertebrates. This study investigated the relationship between the metrics used in LHS and components of macroinvertebrate communities found in the littoral zone of a shallow calcareous lake in the west of Ireland.
- 2. A scoring system, the Habitat Quality Assessment (HabQA), developed from the Lake Habitat Quality Assessment (LHQA) of the LHS, was used to assess the relationship between habitat quality based on physical structure within 10 LHS ‘habplots’ and metrics of the macroinvertebrate community.
- 3. Macroinvertebrate taxon richness, both of adults found in the riparian zone and larvae found in the littoral zone, correlated positively with the HabQA score. Macrophytes within the littoral zone, and complexity of riparian vegetation within the riparian zone, were particularly important in driving the HabQA score. While overall abundance of macroinvertebrates did not vary with HabQA score, that of particular genera did.
- 4. The HabQA score was a useful surrogate of taxon richness for adult and larval aquatic macroinvertebrates, suggesting that, in general, LHS provides a useful conservation assessment tool relevant for macroinvertebrates. However, in some circumstances, such as wave‐washed stony substrates devoid of macrophytes, the HabQA score may not capture the quality of a site for macroinvertebrates, and the importance of natural but low diversity sites should not be neglected in conservation assessment of lakes. Similarly, while the LHS method notes the presence of alien species, further work on how these could be incorporated into the method would be useful.
- 5. Reliance on a single, or overall combined, metric score across quality elements, whether based on biotic or structural assessment, has some potential limitations. It is clear that for conservation management a holistic assessment of naturalness, representativeness and species rarity needs to be made in conjunction with scoring systems.
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We examined the utility of using genera and families as surrogates of species-level assemblage patterns. We assessed cross-taxonomic level congruence, as well as taxonomic structure-environment and taxon richness-environment relationships in stream macroinvertebrate and diatom data surveyed across Finland. A number of interesting and important findings emerged from our analyses. For both macroinvertebrates and diatoms, species richness was strongly correlated with genus and family richness, and similarities in assemblage structure between species-, genus- and family-level matrices were also significant and relatively strong. For macroinvertebrates, the key environmental variables for assemblage structure and taxon richness remained the same irrespective of taxonomic level. For diatoms, however, the environmental variables related to variation in diatom taxon richness varied between taxonomic data sets, while determinants of assemblage structure remained largely the same. For macroinvertebrates, relatively similar amounts of variation in assemblage structure and taxon richness for species-, genus-, and family-level data were accounted for by the environmental variables, shared environmental and spatial variables, spatial variables, and total variation explained. By contrast, for diatoms, these components of variability differed somewhat between taxonomic levels. Our results suggest that, for macroinvertebrates, even family-level data could be used in rapid biodiversity assessments, where the objective is to examine biodiversity patterns and rank sites according to their conservation value in our study region. Families might also perform well in this task in other regions that are characterized by low faunal species diversity, but the situation is likely to be different for regions with higher species diversity. Although weaker than the relationships in macroinvertebrate data, species-level data for diatoms also showed rather similar patterns to genus- and family-level data. However, due to the low number of diatom families, it is likely that families do not provide enough variability in biodiversity patterns. Thus, for diatoms, genus-level data could perhaps be more efficient than family-level data in correlating with species-level data and portraying assemblage patterns for conservation purposes. 相似文献
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- 1. Ponds are a valuable resource for the conservation of freshwater biodiversity, but are often extremely numerous in a given area, making assessment of the conservation value of individual sites potentially time consuming.
- 2. The use of indicator taxa, the species richness of which is representative of total site species richness, may provide one way to improve the efficiency of survey work. However, such indicators are poorly developed for freshwater systems.
- 3. A data set was used describing the occurrence of macroinvertebrate taxa in ponds in Oxfordshire, UK, to assess the extent to which variation in the species richness of selected taxa most consistently represented variation in all other taxa.
- 4. Coenagriidae (Odonata) and Limnephilidae (Trichoptera) reflected the variation in species richness of other taxa most consistently, with Coenagriidae showing the best overall performance as an indicator taxon.
- 5. For both suggested indicator taxa, selection of sites based solely on the presence of at least one species of indicator would represent over 95% of all species recorded across all sites.
- 6. Further investigation in different geographical regions is necessary to establish whether these relationships are consistent over a wider area.
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Maria J. M. Ganassin Augusto Frota Carolina M. Muniz Matheus T. Baumgartner Norma S. Hahn 《Ecology of Freshwater Fish》2020,29(2):252-265
The process of urbanisation is increasing the frequency and magnitude of fluctuations in the availability of food resources for fish. In this study, we investigated whether the diet and prey selected by the guppy Poecilia reticulata reflect the different levels of urbanisation using the total area of impervious surface soil as the metric. Rural streams (low percentage of urbanisation—LPU) and urban streams (high percentage of urbanisation—HPU) were sampled during both the rainy and dry seasons. The hypothesis tested was that the diet and selective behaviour differ spatially and seasonally between LPU and HPU streams. Among the analysed items, seasonal significant differences were only observed in HPU streams. In LPU streams, the trophic spectrum was wider, and a higher diversity of prey was selected. In HPU streams, the diet richness was lower with a dominance of Chironomidae, and there was also less variability in selected prey. Ephemeroptera and Trichoptera were always avoided, but Coleoptera were avoided only in LPU, while Oligochaeta were avoided in HPU streams. Thus, the diet and prey selected by P. reticulata were different between LPU and HPU streams, and this species has potential to compete for food with the native fauna in a wide variety of environmental conditions and available resources. Therefore, this dietary flexibility probably offers competitive advantages when colonising and establishing in a new habitat. 相似文献