From oxbow to mire: Chironomidae and Cladocera as habitat palaeoindicators

Abstract

Chironomidae and Cladocera are useful palaeoindicators to describe long-term dynamics in biodiversity of freshwater aquatic communities. However, palaeoecological studies relying on these aquatic invertebrates have generally focused on post-glacial lakes, with relatively few applications to floodplain water bodies such as palaeo-oxbow lakes. In this study, zone-level (stratigraphic) trends in Chironomidae and Cladocera assemblage composition were analysed from a small palaeo-oxbow lake in a Central European river valley of Poland. Summer air temperature and hydrological conditions were found to be the main drivers of Cladocera and Chironomidae populations, causing a cascade effect in assemblage composition. At the local habitat scale, there were autecological differences in both taxonomic groups reflecting different responses to abiotic and biotic factors. Specifically, Cladocera responded distinctly to plant vegetation and fish predation during the Late Glacial lake phase, whereas Chironomidae were more sensitive to paludification processes and disappeared in the Northgrippian dry phase of the mire. Both groups indicated fluvial activity of the River Grabia, although the response was different. Also, species richness was higher in the more taxonomically diverse Chironomidae compared to Cladocera. As both groups responded to the same factors in a different way, it is recommended that they should be used in parallel in palaeoecological research studies.

Middle Holocene Climate Oscillations Recorded in the Western Dvina Lakeland

“…Although water level fluctuations are regarded as the primary factor influencing Cladocera communities in the long term [28], the DCA (Figure 5) results were consistent with the CL-I summer temperature reconstruction, indicating it as the primary driver of cladoceran communities. The values of temperature are lower than CH-I T Jul because midges are more linked to air temperature while water fleas are linked to water temperature [6,24,140,141]. Thus, the lower values of CL-I temperature are not surprising; however, the decrease of CL-I T Jul also differs from CH-I.…”

“…The effective long-term precipitation may be estimated from changes in lake level [22]. Alongside chironomids, small crustaceans of the order Cladocera are very sensitive to lake level fluctuations, as many of the Cladocera taxa are planktonic [23,24]. Therefore, cladocerans can be successfully used for water level reconstructions [25,26].…”

Peatland Development, Vegetation History, Climate Change and Human Activity in the Valdai Uplands (Central European Russia) during the Holocene: A Multi-Proxy Palaeoecological Study

“…Cladocera remains were abundant and formed mainly by Acroperus harpae and Chydorus sphaericus, which indicate the presence of developed littoral vegetation and Bosmina longirostris that reflect a pelagic environment [95]. Testate amoebae remains were few and represented mostly by aquatic species (Centropyxis aculeata and Difflugia globulosa) and those living in acidic wetlands (Hyalosphenia papilio and Archerella flavum), which is probably explained by unfavorable conditions for shell preservation.…”

“…Cladocera remains became less abundant ( Figure 7) and were dominated by macrophyte/sediment-associated Alona rectangula and macrophyte associated Alonella excisa, whereas pelagic species disappeared. Changes in the ratio of pelagic/macrophyte-associated Cladocera is known as an indicator of lake water level, macrophyte development and nutrients availability [95,100]. Testate amoeba assemblages represent a mixture of aquatic (Centropyxis aculeata) and moss-dwelling (Hyalosphenia papilio, Nebela collaris and Archerella flavum) taxa with gradual declining of aquatic forms during this period (Figure 8).…”

Chironomidae Morphological Types and Functional Feeding Groups as a Habitat Complexity Vestige

“…A variety of environmental variables affects Chironomidae larvae both in a direct and indirect way. Among local-scale abiotic factors, some of the most important for chironomids are pH, lake depth and water nutrient status (Walker, 2001;Brooks et al, 2007;Płóciennik et al, 2020). As there are some truly rheophile taxa, chironomid subfossils can indicate a connection of peripheral river valley water bodies to the main stream during overbank episodes (Gandouin et al, 2006;Howard et al, 2010;Kittel et al, 2016).…”