The Vegetation Map

To eliminate complications introduced by European settlement it has been necessary to decide what territory was occupied by each of the principal types of vegetation about the year 1850 (Map 2). Fortunately, the main boundaries between forest and grassland lie above 1,500ft, where the poor quality of the forest and of the pasture that can be established in its place have discouraged exploitation. Accordingly, the present forest edge has been accepted as valid in most places for 1850. The only large area of upland forest destroyed since this date is on Mt. Cargill. Here, the many dead trees that are still standing, the large proportion that are of non-durable kaikawaka (Libocedrus bidwillii), and the absence of snow-tussock all contrast with the situation at similar elevations on Swampy Hill and Maungatua, where well-established snow-tussock (Danthonia flavescens) contains fragments only of durable totara (mainly Podocarpus hallii) and pink pine (Dacrydium biforme) testifying to a much earlier deforestation.

The extent of these forests, which disappeared some time prior to European settlement, is indicated on Map 2 by showing the distribution in grassland areas of ancient log remains and of forest dimples, but the latter have been mapped only on gently rolling country on Maungatua, since on steeper slopes there is danger of confusing them with the effects of soil slumping.

The accuracy of this map has been checked by a study of early records in the Hocken Library, particularly those of Shortland (1843), Monro (1844), Tuckett