Tradescantia fluminensisin a Manawatu (New Zealand) forest: I. Growth and effects on regeneration

Abstract

Tradescantia fluminensis Vell. is an adventive plant which has established in many lowland native forest remnants in New Zealand, where it forms a dense ground cover up to 60 cm thick. In one remnant in Manawatu its standing crop was lowest in areas of reduced light intensity, as was its regrowth over one year in cleared plots, suggesting that Tradescantia would not flourish m undisturbed forest remnants where forest floor light levels remain low. There was a significant negative relationship between presence of Tradescantia and presence of native tree seedlings, indicating that regeneration of natives may be inhibited by the dense ground cover of Tradescantia. In a glasshouse experiment segments of Tradescantia stem which were at least 1 cm long readily sprouted. Seed set was never observed so reproduction at this site was wholly vegetative.