0000000000273802
AUTHOR
M. J. Dasí
Summer phytoplankton assemblages across trophic gradients in hard-water reservoirs
Summer phytoplankton assemblages are described and characterised according to their prevalence in a series of hard-water reservoirs of eastern Spain that had been classified in trophic categories on OECD criteria. Distribution patterns of phytoplankton species were ordinated statistically by principal components analysis (PCA). The first component was strongly related to trophic gradient and it particularly discriminated the eutrophic and hypertrophic reservoirs. The second component segregated life-forms, so that (1), on the oligo-mesotrophic side, large dinoflagellates were separated from small centric diatoms, unicellular chrysophytes and filamentous ullotrichales and, on the eu-hypertro…
Environmental Variables and Planktonic Communities in Two Ponds of El Hondo Wetland (SE Spain)
The annual cycle of physical and chemical variables and plankton dynamics was studied in two shallow ponds (East and West Ponds) of the El Hondo wetland, an ecosystem of international importance. Water conductivity increased up to 31-49 mS cm -1 as water level decreased due to high evaporation and minimal water inputs. Initially considered mesohaline, the waters were reclassified as polyhaline during the hot season. EP was subject to successive desiccation-flooding cycles, and flooding of the dried sediment caused the release of high concentrations of nitrogen and phosphorus compounds, which quickly depleted. The algal species composition was typical of eutrophic ecosystems, and the chlorop…