par Garnier, Josette;Mourelatos, Spyridon 
Référence Freshwater biology, 25, 3, page (515-523)
Publication Publié, 1991-06
Référence Freshwater biology, 25, 3, page (515-523)
Publication Publié, 1991-06
Article révisé par les pairs
| Résumé : | Based on data for 14C-primary production and biomass changes in the small, shallow Creteil Lake, overall phytoplankton losses were calculated through an annual cycle (November 1985-October 1986). Summer 1986 is compared with summer periods in 1985 and 1980, these two years corresponding to extreme levels of algal biomass. Independent from the trophic state of the lake, phytoplankton populations were dominated by small-sized species (<20 μm); their high growth rate (maximal in May and June: 0.8 day-1) was characteristic of nanoplanktonic natural populations. The positive correlation between phytoplankton losses and production indicates a close coupling between growth and loss processes. With a high filtering rate (0.22 day-1 as an annual average), zooplankton impact is considerable at any time of the year but especially in late summer, when grazing losses exceeded primary production. The persistence of small algae throughout the year implies that a great part of the phytoplankton production was harvested by grazers which led to a recycling of organic matter within the water column. -from Authors |
