Patterns of beetle diversity in kauri forest

Abstract

Kauri forest represents a major ecosystem in northern New Zealand; however, the invertebrate fauna and their ecological diversity in these forests is very poorly known. This article investigates the composition and diversity of beetle communities in two kauri forest remnants, sampled by pitfall traps each month for one year. In total 4777 beetles were caught, representing 28 families, 84 genera and 107 species. Estimates of species richness indicate there were 173 species at both sites combined. The five most abundant species contributed 71%, and the top 10 species contributed 88% of all beetles caught. The abundance, richness and composition of the beetle community were consistent throughout the year. Patterns of niche overlap also show that the same set of species co-occur throughout the year, rather than temporal partitioning of the environment on an annual time scale. This data suggests that seasonality plays a limited role in explaining the composition and diversity of beetle communities in kauri forest.

Keywords:

• Coleoptera
• pitfall traps
• seasonality
• temporal niche
• turnover

Acknowledgements

Thanks to Stephen Thorpe for identification of beetles and Guy Forrester for statistical advice and climatic analyses. This work was supported by the Entomological Society of New Zealand (21st Anniversary Award), the University of Auckland Summer Student programme to KB and MY, and the Foundation for Research, Science and Technology through funding of the Defining New Zealand's Land Biota programme.