Acta Botanica Croatica, Vol. 74 No. 2, 2015.
Original scientific paper
https://doi.org/10.1515/botcro-2015-0025
Halophilic diatom taxa are sensitive indicators of even short term changes in lowland lotic systems
Zsuzsanna Kókai
; Environmental Protection and Nature Conservation Authority, Trans-Tisza Region, Debrecen, Hatvan u. 16, H-4025 Hungary
István Bácsi
; University of Debrecen, Department of Hydrobiology, Debrecen, Egyetem tér 1, H-4032 Hungary
Péter Török
; MTA-DE Biodiversity and Ecosystem Services Research Group, Debrecen, Egyetem tér 1, H-4032 Hungary
Krisztina Buczkó
; Hungarian Natural History Museum, Budapest, Könyves Kálmán krt. 40. H-1476 Hungary
Enikő T-Krasznai
; Environmental Protection and Nature Conservation Authority, Trans-Tisza Region, Debrecen, Hatvan u. 16, H-4025 Hungary
Csaba Balogh
; Environmental Protection and Nature Conservation Authority, Trans-Tisza Region, Debrecen, Hatvan u. 16, H-4025 Hungary
Béla Tóthmérész
; MTA-DE Biodiversity and Ecosystem Services Research Group, Debrecen, Egyetem tér 1, H-4032 Hungary
Viktória B-Béres
; Environmental Protection and Nature Conservation Authority, Trans-Tisza Region, Debrecen, Hatvan u. 16, H-4025 Hungary
Abstract
The occurrence and spread of halophilic diatom taxa in freshwater lotic ecosystems are influenced both by natural processes and anthropogenic pollution. Diatom assemblages were regularly monitored in lowland lotic systems in Hungary (Central Europe) during the unusually dry year of 2012. Highly pronounced changes in diatom composition were observed from spring to autumn. Halophilic taxa (especially Nitzschia sensu lato species) appeared in the dry autumn. In addition, the total relative abundances of halophilic species also increased up to autumn. Abundance of Nitzschia cf. lorenziana and Nitzschia tryblionella showed a positive correlation with chloride and phosphate concentration, while that of other taxa like Tryblionella apiculata or Tryblionella calida showed a positive correlation with the concentration of nitrate. Our fi ndings clearly demonstrated that these halophilic and mesohalophilic diatom taxa were sensitive indicators of even short-term changes in lowland lotic ecosystems, such as the increasing salt concentration from spring to autumn caused by the lack of rainfall and/or environmental loads.
Keywords
cell size; dry year; freshwater river; nutrient load; salt concentration; taxa number; temporal dynamics
Hrčak ID:
146029
URI
Publication date:
1.10.2015.
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