Saving the Marri

Talk on ‘The decline in health of marri’ by Dr Sarah Sapsford

First time I noticed the Marri tree while walking at Kings Park. There was a small information board near the tree mentioning its name and species. Then I saw the poster of the talk “Saving the Marri” at the City of Perth Library and I decided to attend it.

Dr Sarah Sapsford talking about Marri. Click on the image for a larger preview.

Dr Sarah Sapsford from Harry Butler InstituteMurdoch University, took this session as part of the science talk series for young adults. I attended this talk with my father. Marri is a species of flowering plant found in the southwest regions of Western Australia. The flowers are red/pink or white in color.

Dr Sarah talked about how stem cankers, caused by a fungal pathogen, harm the marri. The earliest record is from 1920 in the Kings Park region. Marri were destroyed by the same disease during 1939 and the 1990s as well.

Different stages of cankers leading to the death of the branch (Image Source).

A team of researchers observed the Marri, particularly how the stem canker affects the tree, and photo documented for 13 years. Dr Sarah started her research based on these incredible studies.

It can be generalized that wetter climate leads to more cankers; while higher temperature reduces the occurrence of cankers. They found that the trees along the side of roads referred as ‘disturbed edge’ are more susceptible to cankers.

Roadside Marri trees on the disturbed edge (Image Source).

This is because the concentration of Potassium Nitrate (traditional fertilizer) is higher on the disturbed edge. Mycorrhizal fungi help Marri to absorb all these nutrients leading to the scarcity of other plants at the disturbed edge. Thicker leaf litter locks in moisture of the soil. All these lead to cankers causing pathogens to be found along the disturbed edge. Marri thrives well in the forest as the plant diversity there is better.

To save and preserve the Marri species, Dr Sarah and team collected around 4000 seedlings from the areas where the Marri species is naturally immune to cankers-causing-pathogens. They then planted these 4000 seedlings in three sites and are being monitored regularly. This exercise will last for many years.

A meme I created 🙂

It was really amazing to know that people like Dr Sarah are trying to take care of these plant species by undertaking one of the longest research studies. Hats off to them!

Leave a Reply

Your email address will not be published. Required fields are marked *