Iwitahi Orchid Reserve Research Project 2020-21

During 2020 a research project was developed by OCNZ and Waikato University, to update material already held by Council on the species present in the Reserve and their location, and to discuss issues relevant to the reserve’s long-term conservation and sustainability. As a result Ms Georgia Steel obtained this scholarship, which was funded by the university, The George Mason Charitable Trust, and with Timberlands Ltd funding her travel and accommodation. The OCNZ and the Orchid Foundation Trust Board (NZ) indicated they could contribute to costs if required. The research was successfully carried out over the 2020/21 summer. Georgia and her supervisor Mike Clearwater also enjoyed meeting and working with members of Council and other native orchid enthusiasts at the summer camp in early December.

As the pines have aged, the forest canopy has thinned, increasing light levels and ultimately competition between orchids and other species. To inform the conservation and potential relocation of the orchids to a new reserve, their locations were GPS-mapped, and permanent survey plots were set up for long-term monitoring of the forest’s dynamics. A total of 1,060 orchids and 20 species were found in the reserve, fewer than the 29 species previously recorded. The most abundant species were Pterostylis patens with 282 plants and Thelymitra nervosa with 181 plants. Rare species  Calochilus robertsonii were also found. However fewer species were found than had previously been reported, which may suggest the orchid populations are declining due to increased understory growth. The vegetative survey plots were established for continual follow-up to provide guidance as to whether current management strategies were adequate.

A subject identified as possibly worthy of future research into the reserve’s sustainability was the importance of mycorrhizae and pines to orchids. While there exist some descriptions of this, and is no strong proof as yet about a direct interaction. This kind of information would be relevant if it is decided that the reserve should be moved as transplanting would have to take place eventually. Since this research would involve the removal of limited orchid tissue from the reserve to a laboratory, Timberlands Ltd, on behalf of Council, approached the Iwi landowners for permission. They have granted this permission and are happy to support the research and the taking of specimens from the reserve.  They request that the results of any research be made available to them.

Georgia Steel and Mike Clearwater have summarised their research results in the 2021 Yearbook, and the full report will be made available to Council.

Allan Rae, Vice-President OCNZ