Aquatic macrophytes of the mountain lake Krnsko jezero, Slovenia

Abstract

The macrophyte vegetation in the mountain lake Kmsko jezero has been monitored since I 991. Five species of aquatic macrophytes,occupying different depths, were present in the lake. Changes in depth distribution were detected due to accelerated eutrophication caused by inputs of nutrients from the watershed. In the period between 1997 and 1998 repeated earthquakes additionally influenced the processes in the lake Kmsko jezero, by increased input of matter. The occasional phytoplankton blooms reduced water transparency and consequently disturbance to growth, development and distribution of anchored macrophytes occurred. In 1998 macrophytes spread down to 7.0 m, reaching the maximum at 5.8 kg DW m2 at 2 m depth. The total primary production in the lake was estimated at 4991 kg organic matter per year out of which Chara and Potamogeton species presented 95.5 % and 0.6 %, respectively.