Immediately before human settlement, dense tall podocarp- angiosperm forest dominated the moist Southland and southern coastal Otago districts. Open, discontinuous podocarp-angiosperm forest bordered the central Otago dry interior, extending along the north Otago coast. Grassland was mostly patchy within these woody ecosystems, occurring on limited areas of droughty or low-nutrient soils and wetlands, or temporarily after infrequent fire or other disturbance.
Pollen analysis of a high altitude bog (Winterton Bog) and an alluvial soil sequence in the upper Awatere catchment on the western flanks of the Inland Kaikoura Range, and radiocarbon dates on wood and charcoal from the Marlborough region, have established a Holocene, (post 10 000 years B.P.) vegetation history for this area.