Publication details
Hydromorphological degradation modifies long-term macroinvertebrate responses to multiple stressors in Czech lowland rivers
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| Year of publication | 2024 |
| Type | Conference abstract |
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| Description | European lowland rivers have been exposed to extensive anthropogenic stress for almost a century. Despite substantial improvement in water quality, novel stressors, mainly climate change, continuously endanger them. Their long-term development has often been studied, yet the impact of hydromorphological degradation on these changes was rarely considered, even though its effect on riverine biota is known to be substantial. To elucidate how such a degradation modifies macroinvertebrate response in multiplestressor environment, we evaluated water quality, hydroclimatic and biological changes in nine Czech lowland rivers over some 20 years, regarding their hydromorphological degradation degree. We divided our sites into highly degraded and less degraded sites and found that despite comparable development in all studied environmental variables, the two site groups exhibit distinct biotic changes. Highly degraded sites experienced decreased evenness, increased proportion of non-native taxa and functional reorganisation, changes congruent with continuous deterioration. In contrast, less degraded sites displayed several favourable changes, such as increased total and potamal indicator richness, as well as assemblage stabilisation with few functional changes. Increased abundance and upsurge in non-native taxa abundance and richness was found in both site groups. Despite these changes, no significant trends in wellestablished biotic indices were found. Our study shows that hydromorphological degradation modifies macroinvertebrate response to changing environmental conditions, such as reduced pollution, but also rising thermal and hydrological consequences of climate change, that are expected to amplify in the near future. |