2011 Volume 5 Pages 13-19
In a pond located around Lake Izunuma-Uchinuma in Miyagi Pref., Japan, aquatic plants were monitored during the month of August from 2006 to 2010. Vallisneria denseserrulata grew well (60-80 cm in leaf length) in the pond from 2006 to 2009. After lotus, Nelumbo nucifera, was first observed at the pond in 2008, the lotus community spread and covered more than 80% of the water surface by 2010. Once the distributional area of V. denseserrulata was covered by the lotus, the V. denseserrulata community disappeared in 2010. At that time, three stunted and uprooted V. denseserrulata floated on the water surface. The stunted plants had short roots which may have allowed them to be easily uprooted by fish or wave action. These results indicated that limited light conditions caused by the lotus community caused the growth suppression and subsequent disappearance of V. denseserrulata.
