Mike Peters
Mike is the founder and National President of NZERN, inventor of PIPI4, and President of the Addington Bush Society. Lives in Christchurch after a lifetime working as a welder.
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| 25 April 2003 11:28 AM | # 3 |
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| off the top of my head - these were devised by ecologists in the early 1980s. geof park, set up a quango-like group called the biological resource centre (BRC) which was eventually subsumed by the setting up of DOC. one of the tasks that the BRC set for itself was to provide a basis for biological data recording in coherent land units that shared common characteristics of geology, landform, landscape, soils, climate, vegetation, wildlife and human/cultural activity or land use. these units were developed at 2 scales - ecological districts (there are about 250 of them), grouped together into ecological regions of which there are about 70. Thus the banks ecological region (banks peninsula) comprises 3 ecological districts - akaroa (or is it wairewa), herbert and port hills which are distinguished by lower rainfall (from east to west) and greater degree of modification or intensity of development and habitation.
one of the prime purposes of the maps was to fulfil another intent of the BRC - to facilitate a biological survey of the country that could be the basis for conservation - ensuring a representative cross-section of remaining ecosystem types in each ecological district. there was no comprehensive knowledge of the extent and distribution of natural remnants outside of national parks and given the rate of development and elimination of nature in our cultural landscapes it was regarded as urgent to get relatively objective information to be able to argue the case for protection. these surveys were indeed funded by government (they were called protected natural area surveys (PNA), although 'unprotected natural area survey' may have been more appropriate! Furthermore, it was hoped that the ecological districts would engender a 'sense of place' among the resident community. only about a half of the eco districts have been surveyed to date and the attrition is still continuing. [the success of using the surveys to promote protection depends on ascribing a rather philosophically difficult concept of signficance to remnant habitats. there are differences of opinion amongst ecologists about how this information should be applied. one could argue that unless a site is accorded the highest degree of significance (which is often recognised in district plans) then it is tantamount to a death warrant for the lower ranked sites. given the decimation of natural values in our cultural landscapes one could argue that we can't afford to lose any more. we are already below critical mass.]
i digress; back to the topic - the districts and regions were generated by local groups of ecologists operating in different parts of the country under some general guiding principles laid down by the BRC. expert meetings were held in the regions and lines drawn on maps (based on the collective experience of those present) until some local consensus was reached and some coherent definition for the boundaries could be written.
BRC then collated this information from around the country and attempted to achieve some uniformity of criteria and produced the maps and descriptions which are now used with some minor modifications arising from some of the PNA surveys.
but there wasn't complete consistency across the land - the expert intuitive outcome would vary according to the particular strengths of each regional group of ecologists. some would emphasise soils, others climate, others vegetation or rare animals; but they have been used now for over 15 years and are a convenient shorthand for places around the country.
there are other more sophisticated (objective?) systems for classifying the land according to similarities of environment and character. these are called environmental domains - largely developed in nz by john leathwick. they are based on climatic and land data from across the country. all the information is analysed by computer to group places that are similar in all the parameters assessed and to separate them from places that are different. perhaps we will eventually shift to them as a basis for plant selection in planterguide. but the domains may still need some massaging into more 'friendly' groupings.
colin meurk |
