| 1. |
- Mastrantuono, Luciana, et al.
(author)
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Response of littoral macroinvertebrates to morphological disturbances in Mediterranean lakes : the case of Lake Piediluco (central Italy)
- 2015
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In: Fundamental and Applied Limnology. - : Publishing Technology. - 1863-9135. ; 186:4, s. 297-310
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Journal article (peer-reviewed)abstract
- The assessment of the impacts of human morphological alterations on lake ecological condition based on littoral benthic fauna is still in its infancy, especially in the Mediterranean area of Europe. Lake Piediluco is a riverine lake, sited in Central Italy, whose water level is strictly regulated for hydroelectric reasons and hence can be classified as a Heavily Modified Water Body (HMWB) according to the E.U. Water Framework Directive (WDF). Here, we aim at comparing the invertebrate assemblages among sites with a different degree of morphological alterations by identifying potential indicator species and metrics sensitive to morphological alterations, and by comparing the fauna composition collected using two sampling procedures (composite vs habitat-specific samples) with different processing times. Our results show that the invertebrate assemblages of Lake Piediluco differed according to the three types of shoreline alteration (natural, soft- and hard-altered sites) and this was more evident when we analyzed the habitat-specific samples. Several taxa, diversity and metrics based on the number of Ephemeroptera, Trichoptera, Odonata and Mollusca taxa (ETO and ETOM) are found to be sensitive to shoreline alterations and are candidates for inclusion in assessment metrics for WDF compliant monitoring of the ecological status of this lake. While habitat-specific sampling provided a more detailed picture of the assemblages, composite samples provided consistent results and could be used when processing cost is an issue.
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| 2. |
- Miler, Oliver, et al.
(author)
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An index of human alteration of lake shore morphology
- 2015
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In: Aquatic conservation. - : John Wiley & Sons. - 1052-7613 .- 1099-0755. ; 25:3, s. 353-364
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Journal article (peer-reviewed)abstract
- Morphological degradation constitutes one of the most severe threats to the ecological integrity of lakes. The development of biotic assessment methods for human lake shore alterations using littoral macroinvertebrates requires quantification of the degree of degradation by a stressor index and is complicated through simultaneous physical pressures that alter natural habitat structure. The Lake Habitat Survey (LHS) method and macroinvertebrate sampling were used to produce a pan-European dataset of morphological lake shore degradation and macroinvertebrate densities covering 51 lakes in seven countries and across four geographical regions – northern, western, southern and central Europe. Lake Habitat Survey parameters that differed significantly among three categories of morphological pressure were combined to develop the stressor index components ‘Number of habitats’, ‘Habitat diversity’, ‘Total percentage volume inhabited by macrophytes’, ‘Sum of macrophyte types’, ‘Sum of vegetation cover types’, ‘Sum of coarse woody debris/roots/overhanging vegetation’, ‘Pressure index’ (number of human disturbance sources) and ‘Natural/artificial dominant land cover type’. Stressor index components were tested for cross-correlations and for differences among pressure levels. The final composition of the stressor index was optimized for the four studied geographical regions in Europe. The resulting stressor index correlated more strongly with macroinvertebrate metrics than simpler site-specific LHS parameters or the HabQA index developed previously in one lake in north-western Europe. The stressor index developed provides deeper insight into the morphological pressures that affect littoral invertebrate communities. The results also support the use of LHS to quantify morphological stressors at sampling site level, which can ease developing other multimetric bioassessment methods. The stressor index offers the possibility for wide and regional specific application to assess hydromorphological pressures on lakes to assist conservation planning and management and further global efforts to develop and test biotic assessment methods for lakes.
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| 3. |
- Pilotto, Francesca, et al.
(author)
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Relative impacts of morphological alteration to shorelines and eutrophication on littoral macroinvertebrates in Mediterranean lakes
- 2015
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In: Freshwater Science. - : University of Chicago Press. - 2161-9549 .- 2161-9565. ; 34:2, s. 410-422
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Journal article (peer-reviewed)abstract
- Development of effective methods for assessing the ecological status of lakes based on littoral benthic fauna has been hampered by the lack of quantitative data on the relative impacts of key pressures on the benthic community. We used variance partitioning at 126 sites belonging to 14 natural Mediterranean lakes to analyze the pure and shared effects of eutrophication, morphological alterations, microhabitat type, lake morphometry and geographic position on the littoral macroinvertebrate community. The spatial arrangement of the sampling sites was responsible for 9.1% of the total variance in littoral benthic community composition, lake morphometry accounted for 4.3% of variation, and microhabitat type accounted for 3.9%. Communities appeared to be affected primarily by morphological alterations to lake shorelines, and their impact was 2.5 times as important as that of eutrophication. The structure of littoral benthic communities was governed by processes acting at several spatial scales from region to lake scale. Thus, several pressures and the various spatial scales at which these act should be taken into account when implementing methods of assessing lake ecological condition based on littoral benthic invertebrates. Region-specific methods for subalpine and volcanic lakes might enhance the validity of assessment of results of morphological alterations and improve management of those water resources.
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