INTRODUCTION OF NATIVE PLANTS BENEATH EXOTIC TREES PLANTED TO STABILISE PASTORAL LAND

Native plants offer a medium- to long-term vegetation option for pastoral hill country requiring on-going protection from soil slippage and other forms of erosion. Two trials were conducted to determine the establishment of transplanted native plants beneath variously pruned, spaced, willow (Salix spp.) and poplar (Populus spp.) trees, planted for site stabilisation. Fifteen months after planting, height of lemonwood (Pittosporum eugenioides) plants beneath willows was 72 cm beneath full canopies (global radiation in summer = 3 MJ m -2 d -1 ) and 76 cm where the entire canopy was removed (14 MJ m -2 d -1 ). Height of kohuhu (P. tenuifolium) plants under poplars was 98 cm beneath full canopies (12 MJ/m 2 /d), which was less (P < 0.05) than mean plant height of 107 cm attained beneath pruned poplars with 10-15% less leaf area (11 MJ m -2 d -1 ). Results are preliminary but show that the selected natives can be established satisfactorily beneath exotic deciduous trees, thereby offering a practical approach for facilitating vegetation succession and long-term land protection. Additional Keywords: poplar, willow, succession, plant interactions