A new method to measure the health of Antarctic moss

Like most plants, moss relies on water to survive. However, in Antarctica, where water is mostly locked up in ice the moss have had to adapt.

For them, meltwater over summer is critical to their survival. As the Antarctic region faces more climate pressures, including heatwaves, the availability of meltwater is changing. 

“From our past work, we know that the amount of water in the ecosystem is critical to determining both the health of moss, if it is green and lush or grey and dormant, and also, which moss species grow where,” explains Distinguished Professor Sharon Robinson. 

So developing the ability to monitor water content, alongside other health indicators like “greenness”, within the moss beds is key to their conservation. 

To address this issue a team of SAEF scientists from the University of Wollongong, together with scientists at the University of Tasmania, have collaborated on a new method to measure moss bed water content, using drones fitted with short-wave infrared sensors. 

In February 2022, the team travelled to Casey Station in Antarctica with the Australian Antarctic Program to test out the method. They mapped three moss sites surrounding the station, including two within Antarctic Specially Protected Areas (ASPAs), by shining short-wave light across the environment and collecting measurements of the reflected light (or spectral indices). 


Once back in Australia, the team ran experiments to characterise the relationship between the reflected light and its association with moss water content using artificial intelligence. Combining this data with imagery, they were able to create high-resolution maps of the moss beds and their water content. 

Each map shows how the water content is high around the obvious sources of water such as ponds, streams and melting snowbanks. They also showed patches of unhealthy moss in areas that are not close enough to snow melt.


SAEF Deputy Director, Professor Sharon Robinson, explains often in remote sensing, scientists can use a “greenness” index as a simple measure of health but for moss, this isn’t an accurate indicator of its health. 

“This is because most plants lose chlorophyll, and their green colour when they are unhealthy. Think about autumn leaves which turn yellow or red as they lose chlorophyll before they are shed.” 

“But mosses have a superpower, they can dry out and remain dormant for years or even decades. Unusually when they dry out they stay green, maintaining the chlorophyll so that when the water arrives they can rehydrate and start photosynthesising again really quickly.”

“But this means a moss greenness index does not tell us if they are functioning optimally. We need a greenness and a water index to really understand moss healthiness.”

This new method paves the way for developing a monitoring system that uses greenness and water content to measure moss health in an effective and non-destructive way.  The study has also provided baseline data that will enable scientists to track moss health as snow and ice banks retreat and evidence base to help make conservation decisionssuch as whether to create artificial snowbanksto protect the moss into the future. 

Read more

Turner, D., Cimoli, E., Lucieer, A., Haynes, R.S., Randall, K., Waterman, M.J., Lucieer, V. and Robinson, S.A. (2023), Mapping water content in drying Antarctic moss communities using UAS-borne SWIR imaging spectroscopy. Remote Sens Ecol Conserv. https://doi.org/10.1002/rse2.371