HEATHLAND VEGETATION OF THE SPIRITS BAY AREA, FAR NORTHERN NEW-ZEALAND

The heathland vegetation of northern New Zealand is usually regarded as a "derived" vegetation type resulting from forest destruction during the Maori and European periods of settlement. Plant species cover-abundance data from sample quadrats in the Far North are analysed using Detrended Correspondence Analysis (DCA) and Two-way Indicator Species Analysis (TWINSPAN) and are then correlated with soil nutrient data. Variations in species composition of heaths appear to be related primarily to soil type. Age since last fire is also important but was not examined in detail in this study. Heaths on volcanic soils were commonly dominated by Kunzea ericoides and will follow a succession to forest in the absence of recurrent fire. Heaths on podzolised earths and sands were characterised by low nutrient status and dominance of Leptospermum scoparium and a number of cyperaceous species. Slow growth rates, probably due to nutrient limitation and seasonal waterlogging of soils, in combination with occasional fires are likely to maintain a heathland vegetation type.