[Effects of water level fluctuation on the inter- and intra-specific relationships between Wedelia trilobata and W. chinensis].

A controlled greenhouse experiment was designed with the invasive Wedelia trilobata and native W. chinensis. Three water level fluctuation treatments (no fluctuation, change pattern by 15 cm-0 cm-15 cm, change pattern by 0 cm-15 cm-0 cm) were crossed with five plant arrangement treatments (an individual invasive plant per pot, an individual native plant per pot, 6 invasive plants per pot, 6 native plants per pot, six plants per pot with three invasive and three native plants) to explore the effects of water level fluctuation on inter- and intra-specific relationships between W. trilobata and W. chinensis. The results showed that water level fluctuation decreased signifi-cantly the total biomass, stem biomass, leaf biomass, root biomass, stem length, number of nodes, number of leaves and leaf area of W. trilobata and W. chinensis. Meantime it had significant effects on the inter- and intra-specific competition between W. trilobata and W. chinensis. Water level fluctuation changed the inter- and intra-specific competition of W. trilobata. It indicated that W. trilobata was more sensitive to water level fluctuation with stronger adaptability.