Flow velocity and primary production influences carbon utilization in nascent epilithic stream biofilms |
| |
| Authors: | Clemens Augspurger Kirsten Küsel |
| |
| Institution: | (1) Limnology Research Group, Institute of Ecology, Friedrich Schiller University Jena, Dornburger-Str. 159, 07743 Jena, Germany;(2) Department of Freshwater Ecology, University of Vienna, c/o WasserKluster Lunz, Biologische Station GmbH, Dr. Carl Kupelwieser Promenade 5, 3293 Lunz am See, Austria |
| |
| Abstract: | In small streams, the majority of carbon turnover is due to microbial activity in biofilms. Flow velocity is a key factor
influencing biofilm function, and nascent biofilms with high energy need for growth might be especially sensitive to hydrodynamics.
The major part of carbon supply is allochthonous but algae can provide easily available exudates for biofilm bacteria. In
this study, epilithic biofilms were grown for 2 weeks in a third order stream in Thuringia, Germany, and then incubated in
replicate flow channels in climate-controlled chambers. Glucose and arbinose were added immediately to all channels, and the
effects of flow velocity and light availability on rates of sugar removal were examined. Phosphate addition did not influence
sugar decrease rates. Flow velocities of either 0.3 m s−1 or 0.7 m s−1 resulted in 1.3 to 3.1 times higher decrease rates under the higher flow velocity. Light exclusion resulted in a 2.2 to 2.6
times faster sugar decrease but only a 0.5 times dissolved organic carbon increase compared to channels with light input,
suggesting a strong internal coupling of primary producers and heterotrophs. Our results indicate that carbon uptake from
the water column is fostered at higher flow velocities and that primary production is an important internal carbon source
in nascent epilithic biofilms. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
