Introduction

To date, nearly all vegetation studies in New Zealand have been carried out in pristine to semi-natural systems. Thus, urban ecology in New Zealand is in its infancy as compared with the centuries of observation, documentation and mapping of vegetation, biotopes and natural history in urban areas of Europe (Gilbert,1989; Breuste et al., 1998; Sukopp, 2002; Breuste, Chapter 21; Florgård, Chapter 22; Wittig, Chapter 30) and 30-plus years of study in North America (Zipperer and Guntenspergen, Chapter 17). The relatively few studies of urban vegetation in the New World have typically focused on remnant natural systems enveloped by residential and commercial dwellings (Airola and Buchholz, 1984; Rudnicky and McDonnell, 1989; Kuschel, 1990; Molloy, 1995; McDonnell et al., 1997). Accordingly, there is a distinction to be made between the ecology of remnant primary ecosystems (those that retain at least some thread of biological and pedological continuity with the primeval system) and the ecology of synthetic or spontaneous recombinant systems on anthropogenic substrates (i.e. most vegetation in cities and towns). In New Zealand, we know quite a lot about natural forest, wetland and grassland vegetation, whether in National Parks or as remnants in cities (Wardle, 1991); but little about recombinant communities of cultural landscapes (that is, human-inhabited landscapes in the sense of Nassauer (1997)). They have been traditionally shunned in New Zealand because they almost totally comprise exotic, planted and/or weedy species.