The Influence of Lateral Connectivity in Floodplain Landscape on Riparian Vegetation

초록

In the stream-floodplain ecosystems, flood pulses help to enhance productivity and biodiversity by supplying water, sediment, nutrients and seeds. Lateral connectivity in most floodplain of Korean streams has been disrupted by the levee construction for the purpose of the flood control and land use. There has been an increasing awareness of the riparian zone as a critical transition zone between streams and their catchments in restoring lateral connectivity. To compare the characteristics of floodplain vegetation along the gradient of lateral connectivity of streams, we investigated the environment factor and plant community structures at the floodplain connected and isolated by levee to the channel in Cheongmi Stream, Seom River and Hwangguji Stream, Korea. Floodplains hydrologically connected to main channel were dominated by various hygrophytic and mesophytic communities such as Misccmthus sacchciriflorus. Phcilaris anmdwacea, Artemisia princeps and so on. In the disconnected floodplains to stream channel, we found the diverse wetland vegetations dominated by hydrophytes such as Zizanio latifolia, Alisma plcwfago-aquafica, Salvinia natans and so on. The results of detrended correspondence analysis using the vegetation data showed that the plant communities were ordinated along the gradients of hydroperiod and soil wetness in the floodplains. In conclusion, the disruption of lateral connectivity by the levee construction caused the changes in vegetation structure and distribution due to alternation of hydraulic environments in the riverine floodplains. 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.