The regeneration gap of New Zealand gymnosperms

Abstract

The majority of stands of Dacrydium cupressinum, Podocarpus spicatus and Libo cedrus bidwillii at six localities in the South Island and Stewart Island show a “regeneration gap”, i.e., a paucity of seedlings, saplings, and young trees. This is most evident to the east of the Main Divide and least evident in Stewart Island. Increment borings indicate that the lowest rate of regeneration occurred between 1600 and l800 A.D., if it is assumed that the growth rings are annual. It is suggested that during this time. the area supporting regeneration contracted into the coolest, moistest, and least drought prone parts of the country, and that more recently, it has been expanding again. This is in fair agreement with Holloway's hypothesis concern ing the effects of climatic change on South Island forests. © Taylor & Francis Group, LLC.