Funded via ArbNet

Project Completed: 2023

Institution: Inala Jurassic Garden

Partnership between Royal Botanic Gardens Kew (Wakehurst) and Inala Jurassic Garden
(Australia) to survey and monitor an in situ population of Nothofagus cunninghamii (Myrtle
Beech) on Bruny Island, Tasmania, Australia for Myrtle Wilt disease.

Nothofagus cunninghamii (Myrtle Beech) has been globally assessed as Vulnerable (Baldwin et al, 2018. The Red List of Nothofagus). The objective of this project was to survey and monitor the same areas of forest at regular intervals for a one year period, to detect signs of myrtle wilt attack in Nothofagus cunninghamii forest, in the South Bruny Ranges.

Three 20m wide x 200m long transects were established and all N. cunninghamii within the transects were numbered and monitored over one year.

Three surveys were conducted: in March 2023, September 2023 and February-March 2024. Data collected included: the plant ID number; geopoint; morphometrics (DBH and form); health of each specimen; distance from road/walking tracks; evidence of logging, and taking various photographs of the tree, trunk, canopy, surrounding forest, and evidence of myrtle wilt/other disease.

Data from 448 trees were analysed, 24 of which were recorded as dead or dying in the first survey. Over the course of the 12 month period, two dying trees died, and two additional originally healthy trees were recorded as dying (each over a 6 month period).

Seed was collected from 11 N. cunninghamii from the Mount Mangana Conservation Area and lodged at the Tasmanian Seed Conservation Centre, Royal Tasmanian Botanical Gardens for long-term storage. Leaf material was collected from six individuals of N. cunninghamii in two separate locations on Mount Mangana, together with one pressed herbarium specimen from each population as a reference voucher.

To increase community awareness of the threats to N. cunninghamii, several information sessions were conducted and contributions were made to articles, newsletters from relevant organisations and on the Inala Jurassic Garden and GCC Nothofagus websites.

Six volunteers who surveyed the three Bruny Island transects are committed to further long-term monitoring in this location. Residents of other communities near N. cunninghamii forests have also expressed support and future assistance with monitoring. The methodology has been reviewed and adapted over the three surveys and will be available for other volunteer-led teams to implement.

The baseline data collected for Myrtle Wilt on Bruny Island can be used to inform potential conservation interventions for the species. The data will be shared with contacts at the Department for Parks and Wildlife, Tasmania, so it can be used to inform wider conservation initiatives. An important part of the project was to develop a methodology that could be largely implemented by volunteers. This will enable it to be continued locally with minimal funding, and to give it potential to be upscaled and implemented more widely in Tasmania.