Coleoptera species in bush remnants at a closed coal mine in southeast Otago

Abstract

Rehabilitation earthworks and site reconstruction radically changed the abandoned nature of a closed coal mine in southeast Otago. Around 90% of natural vegetation was cleared for replacement mass planting of indigenous shrubs. A small network of mānuka and kānuka bush patches (40+ years old) was retained as remnant ‘islands’ in a matrix of cleared, bare ground. Coleoptera were sampled in three size classes of bush remnants and a mature forest remnant in 2003 to identify which indigenous species had persisted in the modified setting. From 72 samples, 1155 individuals were recorded from 81 species and 24 families. Indigenous species dominated the sampled fauna and, except for the absence of large predatory species, were found to represent a typical southern Otago forest-associated assemblage. Significant multivariate differences in species composition based on relative abundance existed between different remnant size groups. Only 6% of species were distributed throughout all of the bush remnants. A later sample taken in 2010 from 7-year-old plantings on waste rock indicated few shared species with the nearby mānuka–kānuka remnants. Over rehabilitation time, a finely structured Coleoptera community is developing in revegetated habitats at the coal mine.