Phytoplankton of turloughs (seasonal karstic Irish lakes)

Author： Cunha Pereira Helder Allott Norman Coxon Catherine Naughton Owen Johnston Paul Gill Laurence

ISSN： 1464-3774

Source： Journal of Plankton Research, Vol.33, Iss.3, 2011-03, pp. : 385-403

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

The seasonal succession of phytoplankton communities in turloughs (seasonal karstic Irish lakes) is described for the first time. R-selected species dominated throughout the duration of flooding and a clear succession of communities, with three distinct phases, was found in most turloughs: prevalence of Chlamydomonas, cryptophytes, pennate diatoms and Tribonema in the first few months of flooding followed by dominance in winter by cryptophytes, pennate diatoms and centric diatoms. A final stage in late spring was characterized by filamentous greens and chrysophytes. Algal communities in turloughs resemble those of ponds, lakes or even slow-flowing rivers, depending on the time of the year. Multivariate analysis showed that the variables significantly affecting phytoplankton composition in turloughs were total phosphorus (TP), season and mean depth/colour. Turloughs with higher TP tended to have a higher prevalence of green algae, particularly filamentous forms. Tychoplanktonic algae were also important in turloughs (up to 82 of total biovolume), probably owing to their shallow nature and to the presence of terrestrial vegetation on the bottom of the basins. The results are discussed in relation to Reynolds functional groups and other studies and, in general, it is shown that there is good accordance between the algae found in turloughs and what is presently known of their ecologies.