The role of allelopathy in the invasion of the Chinese tallow tree (Sapiumsebiferum)

The rapid transition from grassland to Chinese tallow tree (Sapium sebiferu m) woodland may be partly due to allelopathic effects on native plants. A b ioassay was performed using aqueous extracts of Sapium or little bluestem ( Schizachyrium scoparium) and Schizachyrium seeds. Schizachyrium germination rates and germination timing were unaffected by watering treatments. Growt h of Schizachyrium seedlings was significantly facilitated by watering with Sapium extracts versus watering with water. These results suggest that all elopathic effects are not responsible for the competitive success of Sapium in coastal prairies.