Evidence for ecologically significant changes in climate during the post-glacial period in New Zealand: Chairman's address
- New Zealand Geological Survey, Lower Hutt
Compared with the vast changes in geography, topography, climate, and biota during the rest of geological time, the changes of the post-glacial period are so slight that a geologist may perhaps be forgiven if he writes them off as negligible. But in fact, a universal human weakness offsets this reaction: man views the past through spectacles that exaggerate the perspective. We look back down a logarithmic time scale so that objects and events close to us have a significance far exceeding their order of importance when viewed on a linear time scale. The post-glacial period of some 15,000 years saw the spread of Neolithic and modern man and is thus infinitely more important to us than any previous period of equal duration. Moreover, the latter part of the post-glacial, the last two millenia (on which this symposium has been concentrated), overlaps the life-span of some organisms still living, to wit the slow-growing conifers, so that the botanist and ecologist must add the parameter of time to their data and think dynamically and historically, not just descriptively. The post-glacial, in consequence, becomes a notable field of overlap of disciplines.