Scheda di dettaglio – i prodotti della ricerca
| Dato | Valore |
|---|---|
| Title | Long-term trends of epilimnetic and hypolimnetic bacteria and organic carbon in a deep holo-oligomictic lake |
| Abstract | We analysed the long-term dynamics (1980-2007) of hypolimnetic and epilimnetic bacterial abundances and organic carbon concentrations, both dissolved (DOC) and particulate (POC), in the deep holo-oligomictic Lake Maggiore, included in the Southern Alpine Lakes Long-Term Ecological Research (LTER) site. During the 28 years of investigation, bacterial abundance and POC concentrations did not decrease with declining phosphorus concentrations, while DOC concentrations showed a pronounced decrease in the epi- and hypolimnion. We used the annual mean total lake heat content and total annual precipitation as climate-related variables, and in-lake total phosphorus as a proxy for trophic state. The model (forward stepwise regression, FSR) showed that reduced anthropogenic pressure was more significant than climate change in driving the trend in DOC concentrations. Bacterial dynamics in the hypolimnion mirrored the fluctuations observed in the epilimnion, but average cell abundance was three times lower. The FSR model indicates that bacterial number variability was dependent on POC in the epilimnion and DOC in the hypolimnion. In the hypolimnion, cell biovolumes for rod and coccal morphotypes were significantly larger than in the epilimnion. |
| Source | Hydrobiologia (The Hague. Print) 644 (1), pp. 279–287 |
| Keywords | Long-term dynamicsDOC and POCBacteriaCell biovolumeChlorophyll aHolo-oligomictic Lake Maggiore |
| Journal | Hydrobiologia (The Hague. Print) |
| Editor | Kluwer Academic Publishers, Boston, Paesi Bassi |
| Year | 2010 |
| Type | Articolo in rivista |
| DOI | 10.1007/s10750-010-0150-x |
| Authors | Bertoni, Roberto; Callieri, Cristiana; Corno, Gianluca; Rasconi, Serena; Caravati, Emanuele; Contesini, Mario |
| Text | 407738 2010 10.1007/s10750 010 0150 x ISI Web of Science WOS 000276071600019 Long term dynamics DOC and POC Bacteria Cell biovolume Chlorophyll a Holo oligomictic Lake Maggiore Long term trends of epilimnetic and hypolimnetic bacteria and organic carbon in a deep holo oligomictic lake Bertoni, Roberto; Callieri, Cristiana; Corno, Gianluca; Rasconi, Serena; Caravati, Emanuele; Contesini, Mario CNR; Univ Zurich; Univ B Pascal We analysed the long term dynamics 1980 2007 of hypolimnetic and epilimnetic bacterial abundances and organic carbon concentrations, both dissolved DOC and particulate POC , in the deep holo oligomictic Lake Maggiore, included in the Southern Alpine Lakes Long Term Ecological Research LTER site. During the 28 years of investigation, bacterial abundance and POC concentrations did not decrease with declining phosphorus concentrations, while DOC concentrations showed a pronounced decrease in the epi and hypolimnion. We used the annual mean total lake heat content and total annual precipitation as climate related variables, and in lake total phosphorus as a proxy for trophic state. The model forward stepwise regression, FSR showed that reduced anthropogenic pressure was more significant than climate change in driving the trend in DOC concentrations. Bacterial dynamics in the hypolimnion mirrored the fluctuations observed in the epilimnion, but average cell abundance was three times lower. The FSR model indicates that bacterial number variability was dependent on POC in the epilimnion and DOC in the hypolimnion. In the hypolimnion, cell biovolumes for rod and coccal morphotypes were significantly larger than in the epilimnion. 644 Published version Articolo in rivista Kluwer Academic Publishers 0018 8158 Hydrobiologia The Hague. Print Hydrobiologia The Hague. Print Hydrobiologia The Hague. Print Hydrobiologia. The Hague. Print Hydrobiologia Dordrecht The Hague. Print Hydrobiologia Boston The Hague. Print Hydrobiologia London The Hague. Print roberto.bertoni BERTONI ROBERTO cristiana.callieri CALLIERI CRISTIANA gianluca.corno CORNO GIANLUCA |