Welcome to Gum Tree Guardians!
What is Gum Tree Guardians?
Gum Tree Guardians is a project on the iNaturalist platform to monitor the spread of myrtle rust in Australia. This project has been generously funded by Eucalypt Australia through a Dahl Fellowship and can be viewed here: https://inaturalist.ala.org.au/projects/gum-tree-guardians
What is myrtle rust?
Myrtle rust is a disease caused by the fungal pathogen Austropuccinia psidii, affecting trees within the family Myrtaceae. This family includes over 330 genera, including our iconic Eucalyptus and Melaleuca just to name a couple! The disease is typified by the appearance of yellow spores on susceptible plants with symptoms appearing on young plant tissue such as leaves, stems, flowers, and fruit. Multiple infections can lead to severe defoliation and plant death. The spores produced by the pathogen, are easily spread to other plants through the wind or by human movement on clothes or transportation of infected material. Examples of symptoms on a range of plants can be viewed here: https://agriculture.vic.gov.au/biosecurity/plant-diseases/shrub-and-tree-diseases/myrtle-rust/myrtle-rust-host-plants-and-symptoms
Where did it come from?
The threat to Australian Eucalyptus and Myrtaceae was realised when A. psidii began causing major damage in Eucalyptus plantations in Brazil. Although strict biosecurity measures were put in place to keep A. psidii out of Australia, the pathogen was discovered in Australia in 2010. First detected in New South Wales, it has since been spread to Queensland, Victoria, the Australian Capital Territory, Tasmania, the Northern Territory, and Western Australia.
Why do we need your help?
A particular challenge for myrtle rust research is monitoring the spread of the pathogen and detecting new incursions. Myrtaceae are one of the top species rich families in Australia, widely distributed throughout Australia. To predict where an incursion may occur, climatic modelling has been developed to determine the climatic suitability of A. psidii across Australia. These models can be overlapped with Myrtaceae species distribution maps to narrow down areas of high risk of an incursion. Of particular concern is climatic suitability within the Eucalyptus rich biodiversity hotspot of South-West Western Australia. With Myrtaceae in this region already under threat by soil-borne pathogens such as Phytophthora cinnamomi, monitoring of plants within such regions is imperative to ensure the pathogen is acted upon swiftly in the event of an incursion to ensure the survival of the species.
How will the data be used?
The data obtained from the project will provide valuable data for both researchers and conservationists alike. This data can serve myrtle rust research in many ways. Firstly, it can used to identify new species of Myrtaceae susceptible to the pathogen that have not already been identified. Further, if myrtle rust is detected in a new location (on any species), it will allow for Myrtaceae species in those areas to be tested for their response to the pathogen and seed collected for conservation. The identification of myrtle rust in a new locations will also inform researchers of the spread of the pathogen, also aiding conservation efforts.
How do you add an observation?
Contributing to the Gum Tree Guardians project is easy! Once you have created an account on iNaturalist Australia (https://inaturalist.ala.org.au/signup), you’re ready to start uploading your observations. Please remember, myrtle rust spores spread very easily. If you observe myrtle rust on any Myrtaceae species, it is important that you DO NOT TOUCH IT to avoid spreading it to other trees or areas.
- Take several close up image of symptoms. This is usually yellow spores which can appear on leaves, stems, flowers, or fruit
- Take an image on the whole plant if possible to assist with identification and to show the surrounding environment
- Upload observation to the iNaturalist platform using your phone or web browser. If possible, include the plant it was identified on in the comments section.
Myrtle rust observations will automatically be added to the Gum Tree Guardians project. You can view the project and become a member here: https://inaturalist.ala.org.au/projects/gum-tree-guardians and a guide is available to make uploading as easy as possible: https://inaturalist.ala.org.au/pages/getting+started
Happy observing,
Alyssa (project administrator)
