Biodiversity of indigenous tussock grassland sites in Otago, Canterbury and the central North Island of New Zealand I. The macro-invertebrate fauna

This contribution introduces a short series of papers on biodiversity of indigenous tussock grassland at four sites in New Zealand. A survey of invertebrates of tussock grassland sites was carried out in summer of 3 successive years, 2001-03. The sites included two in Otago in snow tussock grassland at Deep Stream and Mt Benger, a site at Cass in inland Canterbury, and one at Tukino in the central North Island. Sampling was carried out by taking turf samples from each site, and extracting the invertebrates with heat extractors. The invertebrates were divided into 30 major groups. This quantitative sampling method allowed the densities of invertebrate groups to be calculated. Total macro-invertebrate density for all sites ranged between c. 1600 and 5600 m(-2). Total invertebrate abundance was highest at the central North Island site, but this was very much dominated by Formicidae. Across all sites, Formicidae, Coleoptera, and Pseudococcidae were consistently the most abundant groups represented.