Studies on the sediments of lakes with varying trophic status are of particular importance when considering changes in the natural environment. In this study, our objective was to examine subfossil remains of Cladocera species and the relationship between the sedimental Cladocera assemblages and geochemical variables during 11 years of sediment records from northern Hungarian lakes. To achieve this, we compared sedimental cladoceran communities and the geochemistry of the sediment layers among lakes. Among the studied lakes, one was an intermittent lake (KMT: the Kis-Morotva Lake) which dried out in 2012 but was subsequently naturally refilled in 2013 by groundwater affected by the high-water level of the River Tisza. The other type consisted of permanent lakes (SZA: the Szabolcs oxbow lake, TI: the Timár Morotva Lake) that never dried out. The results of the beta diversity analysis show that the deposition of Cladocera communities was similar among the sediment layers of lakes, while the abundance differences contributed significantly to replacement. Subsequently, core sediment samples of the three lakes were compared based on the remains of Cladocera communities and geochemical variables using Adonis (PERMANOVA). The core sediment samples indicate variations in Cladocera communities alongside disparities in geochemical variables across the same lakes. In conclusion, the significance of sediment cores containing the remains of the Cladocera community has grown significantly in the reconstruction of historical ecological and climatic changes.

Cladocera communities in surface sediments from 31 lakes in Hungary were analysed to assess the impacts of land use on the aquatic systems. We evaluated the alpha and beta diversity metrics, with land use classification types based on the Corine Land Cover. Physical and water chemistry parameters were analysed using standardised procedures. Using redundancy analysis (RDA), total phosphorus (TP) was identified as the key driver of Cladocera composition and distribution. End-member mixing analysis (EMMA) revealed distinctive ecological patterns in Cladocera assemblages across land use types. Our results demonstrate that agriculture and urbanisation contribute to the associated degradation of the lakes and changes in trophic states. Wetlands, forests, and open waters play a critical role as buffer zones in mitigating anthropogenic effects, with Cladocera community composition mirroring the nutrient conditions of the lakes.

Climate change and global warming are increasingly affecting freshwater bodies both locally and globally, resulting in fluctuating water levels. Understanding how Cladocera communities are organized across different water body types is important for ecological assessment and conservation. In this study, we compared Cladocera assemblages between different wetland types with different water body types and evaluated the role of physicochemical characteristics and spatial structuring in shaping the community distribution patterns. Six water bodies were selected for our study; each contained three sampling points spaced at least 75–100 m apart. Cladocera specimens in the filtrate samples were identified at the species level. Homogeneity of multivariate dispersions (PERMDISP) and PCA analysis of site-related spatial effects were used to test differences in community composition. Based on previous studies and results, we concluded that the water body type significantly influenced the composition of Cladocera communities among the wetlands investigated.