Sun/shade Acclimation and Nitrogen Nutrition of Tradescantia Fluminensis, a Problem Weed in New Zealand Native Forest Remnants

Tradescantia fluminensis Vell. is a perennial, herbaceous species native to tropical regions of Brazil and Argentina which has become established in many lowland native forest remnants of the North Island and northern South Island of New Zealand. Under certain conditions, T. fluminensis spreads rapidly to form a dense mat up to 60 cm in depth which can ‘smother’ ground cover species and prevent seedlings of canopy species from establishing, thus blocking the regeneration cycle (Esler, 1962, 1988; Kelly and Skipworth, 1984; Timmins and Williams, 1987; Ogle and Lovelock, 1989). Tradescantia fluminensis is capable of growth under a wide range of irradiance levels. It can grow under a forest canopy at irradiance levels around 1% that of open ground (Kelly and Skipworth, 1984) H.G. MAULE, M. ANDREWS, J.D MORTON, A.V. JONES and G.T. DALY 1 Department of Plant Science, Lincoln University, Canterbury, New Zealand. 2 Present Address: Ecology Centre, University of Sunderland, Sunderland, SR1 3SD, United Kingdom. 3 Department of Animal and Veterinary Science, Lincoln University, Canterbury, New Zealand.