Microbial plankton assemblages, composition and biomass, during two ice-free periods in a deep high mountain lake (Estany Redó, Pyrenees)

Abstract

Microbial plankton composition and biomass were monitored for two ice-free periods in a deep oligotrophic high-mountain lake (Redó, Pyrenees). Phytoplankton dominated microbial biomass, while the relationship between total water-column-integrated autotrophic and heterotrophic biomass ranged from 1.5 to 6.5 (an average of 4.4). Heterotrophic biomass was dominated by bacteria (an average of 47 %), but heterotrophic nanoflagellates and, to a lesser degree, ciliates occasionally constituted a sizeable proportion. In general, the microbial biomass ratios were 10:2:2:1 for PHY:BAC:HNF:CIL. About one hundred eukaryotic species were found, although most of them in low abundance and frequency. Phytoplankton biomass was dominated by flagellated chrysophytes and dinoflagellates (an average of 40 and 32% respectively); occasionally cryptophytes (in deep layers) and chlorococcal chlorophytes (during the autumn mixing period) were also significant. In the two years sampled, the maximum phytoplankton diversity was observed during the autumn mixing period. Heterotrophic flagellate biomass was dominated by chrysophytes (78% on average), but sporadically a non-identified species reached high abundances. Oligotrichs, (an average of 43% of total ciliate biomass) dominated the ciliate community, still other groups (gymnostomatida and prostomatida) were also significant. Bacteria biomass was largely homogeneous throughout the two periods, but size segregation was observed especially when the lake was stratified, with larger bacteria appearing in the upper layers. The highest planktonic microbial biomass occurred during the mixing periods, mainly during spring. But no clear relationships were found between the temporal distribution of bacteria, phytoplankton, heterotrophic flagellate and ciliate biomass.

Downloads

Download data is not yet available.
Published
1999-08-01
Section
Original Articles
Keywords:
phytoplankton, bacteria, heterotrophic flagellate, ciliate, oligotrophic lakes
Statistics
Abstract views: 1583

PDF: 448
Share it

PlumX Metrics

PlumX Metrics provide insights into the ways people interact with individual pieces of research output (articles, conference proceedings, book chapters, and many more) in the online environment. Examples include, when research is mentioned in the news or is tweeted about. Collectively known as PlumX Metrics, these metrics are divided into five categories to help make sense of the huge amounts of data involved and to enable analysis by comparing like with like.

How to Cite
1.
FELIP M, BARTUMEUS F, HALAC S, CATALAN J. Microbial plankton assemblages, composition and biomass, during two ice-free periods in a deep high mountain lake (Estany Redó, Pyrenees). jlimnol [Internet]. 1Aug.1999 [cited 23Jan.2020];58(2):193-02. Available from: https://jlimnol.it/index.php/jlimnol/article/view/jlimnol.1999.193