Ecosystem shifts and Cladocera responses in a freshwater lake in semi-arid regions: The successional synergistic effects of natural and human factors in the past 170 years
Data files
May 12, 2025 version files 6.95 KB
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README.md
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Supporting_information-data_of_cladocera_subfossil_.csv
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Abstract
The data of cladocera subfossils in the sediment core of Hulun Lake, the largest freshwater lake in northern China's semi-arid region (48.55°~49.33°N, 116.97°~117.81°E). The results indicate that both internal factors (such as lake sedimentary environment, fish catches, lake water level, organic matter, and nutrients) within the lake and external factors (including population, urbanization rate, and livestock husbandry) in the surrounding basin have been key drivers influencing the structure of Cladocera in Hulun Lake over the past 170 years. The originally predominant littoral Cladocera species (Chydorus sphaericus. sl.) were replaced by planktonic (Bosminidae) since 1980s accompanied by a decline in diversity, which corresponds with the process of eutrophication and pollution in the lake.
Dataset DOI: 10.5061/dryad.dv41ns299
Description of the data and file structure
The data of Cladocera subfossils in the sediment core of Hulun Lake, the largest freshwater lake in northern China’s semi-arid region (48.55°~49.33°N, 116.97°~117.81°E). This is the raw data file of Cladocera community succession in Hulun Lake over the past 170 years.
The column header 'Age (yr/AD)' represents the time series. The column headers from B to R (in %) refer to the species name of zooplankton Cladocera. The column header in S, 'Intotal individual (ind./g)', represents the absolute abundance of Cladocera.
Experimental procedures:
Approximately 1.5 g of dry sediment from each subsample of the HLH-9-1 core and surface sediment samples were used for the analysis of Cladocera subfossils. Cladocera remains were counted and identified based on their shells, headshields, postabdomens, and claws, following the identification methods outlined in Jiang and Du (1979), Szeroczyńska and Sarmaja-Korjonen (2007), and Xiang et al. (2015)). A minimum of 100 individuals were counted from each sample (Szeroczyńska and Sarmaja-Korjonen, 2007).
References
Jiang, X., Du, N., 1979. Fauna of China-Arthropod Phylum-Crustacean-Freshwater Cladocera. Beijing: Science Press, pp: 41-42. (In Chinese)
Szeroczyńska, K., Sarmaja-Korjonen, K., 2007. Atlas of subfossil Cladocera from central and northern Europe. Swiecie: Friends of the Lower Vistula Society.
Xiang, X.F., Ji, G.H., Chen, S.Z., Yu, G.L., Xu, L., Han, B.P., Dumont, H.J., 2015. Annotated Checklist of Chinese Cladocera (Crustacea: Branchiopoda). Part I. Haplopoda, Ctenopoda, Onychopoda and Anomopoda (families Daphniidae, Moinidae, Bosminidae, Ilyocryptidae). Zootaxa 3904(1): 1-27.
Results:
A total of 14 Cladocera taxa from the families Bosminidae, Chydoridae, and Daphniidae, were identified in the HLH-9-1 core. The most abundant and widespread species in the sediments included the littoral species Chydorus sphaericus. sl*.* (mean relative abundance, 41%) and* Alona* spp. (mean relative abundance, 26%), as well as the planktonic species Bosminidae (including Bosmina spp., Bosmina (E.) longispina and B. longirostris with mean relative abundance of 24%) (Fig. 2). The meso-oligotrophic species of Bosmina (E.) longispina made up the largest proportion (6%) of the identified Bosminidae. Additionally, the* littoral species of Alona guttata* had a mean relative abundance of 6%.
Code/software
This dataset can be used with various software tools, such as Tilia program, to perform cluster analysis and visually illustrate the patterns of Cladocera community structure changes in Hulun Lake over the past 170 years.