Palmer, J. (2022, February). Charlesworth Reserve invertebrate survey, Christchurch: Summer 2021 – 2022. Avon-Heathcote Estuary Ihutai Trust.

Funded by the Avon-Heathcote Estuary Ihutai Trust as a 2021-2022 summer scholarship project, the purpose of this study was to survey the flying, ground-dwelling, and arboreal invertebrate species present in Charlesworth Reserve. To achieve this, five different survey methods were used, including scrape and search surveys and pitfall trapping as methods previously used in 2017 and 2021 Charlesworth studies, as well as active surveys, beating sheets, and malaise traps which were not previously used in Charlesworth. Species richness, diversity, and distribution were then analysed and compared across sites and previous studies.

The study recorded 175 different invertebrate taxa across a range of endemic and exotic vegetation habitats. 40 of the taxa found were considered common, while 135 were rare. Grassland and leaf litter habitats also tended to have greater species richness. Overall, the study concluded that the diverse presence of pollinators, dispersers, detritivores, and predators demonstrated that Charlesworth Reserve was a working ecosystem, indicating restoration effort success. Consequently, it was predicted that further establishment of native vegetation would likely lead to further increases in native and endemic invertebrate species.

Following this study, the author recommended that future studies should investigate indicator species of ecosystem health and underlying environmental factors which could explain the diversity and distribution of invertebrates found across Charlesworth Reserve. They also recommended that exotic grasslands should be recognised as valuable habitats for invertebrates, and therefore not mown frequently.