Loss of Transverse Continuity and Terrestrialization of Shoreline Vegetation by the Human Disturbance in a Reservoir

초록

The Reservoir Uiam located in the central part of Korea was constructed for the purpose of the hydroelectric power generation. The shoreline vegetation has been well developed because its annual water level fluctuation is as small as 1 m and the slope of waterfront is gentle. Recently, habitats of the shoreline vegetation have been limited because of human-induced disturbances such as construction of bike road and riprap protection structure. To understand the changes of shoreline vegetation in the Reservoir Uiam, we investigated changes in hydrology and water quality from 2004 to 2013 and flora, structure and distribution of shoreline vegetation in 2006, 2010 and 2013. Among water quality factors, only total nitrogen had a significant tendency of increase. But other factors did not show a significant change from 2004 to 2013. Changes in the species number of hydrophytes and hygrophytes were not significant but that of mesophytes increased from 2006 to 2013 in the shoreline of the Reservoir Uiam. The results of detrended correspondence analysis (DCA) using vegetation structure data showed a tendency of decrease in hydrophytic communities and increase in hygrophytic and mesophytic communities from 2006 to 2013 in the Reservoir Uiam. The distribution area of shoreline vegetation in the Reservoir Uiam decreased from 2010 to 2013. In particular, the distribution area of hydrophytic vegetation decreased but that of hygrophytic and mesophytic vegetation increased. In conclusion, limitation and terrestrialization of habitats of shoreline vegetation by riprap construction and shoreline development in the Reservoir Uiam caused the loss of transverse continuity from waterbody to upland, and it led to the increase in terrestrialized vegetation. This research was supported by a grant (12-TI-C02) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.