Abstracts of Published papers in peer-reviewed books
Norton, D.A. 1991(b). Scientific basis for the conservation management of New Zealand plant communities. In: I.F. Spellerberg, B. Goldsmith and M.G. Morris (eds), The Scientific Management of Temperate Communities for Conservation, Blacwell Scientific Publications, Oxford, pp 349-381
Introduction
The conservation management of animal communities, especially birds, in New Zealand has received considerable attention and is generally well known and respected. In contrast, the conservation management of plant communities has in the past been poorly resourced and is less well known. Frequently in New Zealand, legal protection and subsequent fencing has been seen as the end-point of the conservation effort for plant species. However, it is now becoming clear that legal protection is only the first step in the on-going management of plant communities for conservation. Furthermore, to be effective this management needs a sound scientific base.
New Zealand, an archipelago consisting of three main islands and numerous off-shore islands, has been separated from other land masses for some 60-80 million years. Mainland New Zealand lies at a latitude (34-37°S) comparable to that of Spain and southern France but the New Zealand biogeographical region extends from 29°S to 55°S. Considerable climatic diversity occurs in the New Zealand region ranging from subtropical in the far north to subsntarctic in the far south. Mainland New Zealand, however, experiences a cool, moist, temperate climate that is strongly influenced by its oceanic location and prevailing westerly airflow.
Changes in the shape of the New Zealand archipelago throughout its history have had a major influence on the evolution of the modern biota, encouraging speciation, with successive invasion, isolation, reinvasion and back-invasion of populations from one island to another. This, together with its long isolation, a mixture of southern (Palaeoaustral), Australian and Malayo-Pacific biogeographic elements, and the relatively recent settlement by humans, means that many of the issues relevant to plant conservation management in New Zealand differ substantially from those in northern temperate regions. However, similarities do occur with other islands (e.g. the Hawaiian and Galapagos Islands).
Westhoff (1971) proposed four landscape categories for Europe: natural, subnatural, semi-natural and cultivated. Three of these are recognizable in New Zealand.
Natural landscapes account for about 28% of the land area and are predominantly upland and forested. Although the original vegetation is structurally and floristically intact, and direct human impact minimal, more subtle changes are taking place such as browsing and predation by introduced mammals, and it is probable that there are now few areas, if any, that are truly 'natural'. Much of New Zealand's natural landscapes are protected in national parks, conservation parks and other conservation areas.
Semi-natural landscapes are widespread, covering about one-third of New Zealand. While being modified in various ways by human activities, these areas still have a large indigenous component. In many areas of New Zealand, semi-natural landscapes are all that remain of formerly widespread natural landscapes and therefore have important conservation values. Semi-natural landscapes frequently require much more intensive conservation management than is needed in natural landscapes, often just in order to maintain the status quo. However, only a small proportion of these landscapes are formally protected.
Cultivated landscapes include agricultural, h orticultural and forestry landscapes, together with urban areas, and are dominated by plant species alien to New Zealand. These areas have little value for biological conservation, except where small pockets of residual indigenous biota p ersist.
In recent years New Zealand nature conservation has focused on the identification and protection of remaining areas with important conservation values. Although about 19% of New Zealand is now formally protected, considerable deficiencies still occur in the reserve system, especially in lowland areas and areas with semi-natural landscapes. There is now a legislative commitment in New Zealand to protect representative examples of the biota. Based on the division of New Zealand up into ecological districts and regions, the Protected Natural Areas Programme is surveying the remaining unprotected areas of New Zealand in order to identify representative areas that should be protected. This represents an attempt to define, largely on a scientific basis, geographical units with a relatively homogeneous and distinctive ecological character. Current progress has been reviewed by Ogle (1989). Conservation in cultivated landscapes, particularly urban areas, is also receiving more attention, especially where there is potential for restoring rare examples of h ighly modified indigenous communities.
In this chapter I discuss some key features of the New Zealand vegetation that are critical in the conservation management of New Zealand plant communities and species. The main issues involved are overviewed and their relevance to management discussed. Issues associated with reserve design and location are not discussed, unless they pertain directly to management.
References omitted from the Introduction (web developer).