AME - Vol. 55, No. 1 - Feature article

Mekkojärvi, in southern Finland, is one of countless small, humic lakes around the boreal zone; inset: sampling the brown water rich in DOC. Photos: Sami Taipale

Taipale S, Jones RI, Tiirola M

 

Vertical diversity of bacteria in an oxygen-stratified humic lake, evaluated using DNA and phospholipid analyses

 

Pronounced seasonal stratification and low light penetration promote the frequent occurrence of oxygen deficiency in boreal humic lakes. During the mid-summer period of water column stratification, the microbial biomass of the polyhumic Mekkojärvi in southern Finland shifts from a diverse array of heterotrophic bacteria in the upper water column to dominance of abundant photo- or chemoautotrophic bacteria in the deeper, anaerobic layers of the lake. When the water column is mixed in spring and autumn, the dying obligate anaerobic bacteria may provide an important additional burst of carbon and nutrients, offering a highly labile substrate source in stratified humic lakes.

 

Inter-Research Science Publisher is pleased to make this Feature Article openly available for viewing by our readers.

 

Abstract   Back to contents page   Link to full PDF