MEDIA REPORT |  Small in size, big in impact, scientists fear end for microscopic species

Richard Medd says Mount Canobolas is one of the state’s most rich and diverse ecosystems. (ABC Central West: Hamish Cole )

An increase in the number of threatened tiny plant species in country New South Wales is putting rare ecosystems at risk, according to scientists. 

Key points:

  • Scientists say a decline in microorganisms is putting rare ecosystems under increased strain 
  • Mount Canobolas is home to more than 1,000 species, 18 of which are deemed threatened 
  • At least three new species were found on the mountain during a survey at the weekend

Mount Canobolas, near Orange in the state’s central-west, is home to more than 1,000 species, making it one of the most densely populated habitats in the country. 

But there have been 18 species deemed threatened and four endangered in the area in the past decade.

Many of them are tiny organisms that can only be seen with a microscope. 

Macquarie University honorary postdoctoral associate Alison Downing said microorganisms such as lichens and mosses played a vital role in the ecosystem. 

“They act to trap moisture and soil and by doing this they actually stabilise the whole environment,” she said. 

“They make it easier for other flowering plants to grow in that area, in turn, assisting wildlife.” 

Alison Downing says introduced species, such as cattle, have contributed to a decline of microorganisms. (ABC Central West: Hamish Cole 

Dr Downing said the microorganisms were previously found across the state but mismanagement of livestock had resulted in only small, isolated communities remaining. 

“One of the problems is with stock cattle in particular, they are really hard-hoofed animals so as they go through, they effectively cut up these soil crusts and convert them to dust,” Dr Downing said. 

“If you have a bad sandstorm or a windy day, they [microorganisms] will just be blown away along with the topsoil.” 

Mount Canobolas is part of a 1,672-hectare state conservation area.

A volcanic eruption 11 million years ago gave the region its rich, fertile soil and altitude. 

According to the NSW Farmers Association, this has made the region one of the state’s prime agricultural regions, contributing almost $2 billion to the economy each year. 

Growing issue across the country 

Orange Field Naturalist Society member Richard Medd said losing the microorganisms, such as mosses and lichens, created a chain reaction. 

“All of those species interact with each other,” he said.

He said taking one or two out would affect several others.

“They won’t survive,” he said.

“As soon as you break them up it plays havoc.” 

The Canobolas candlebark tree is one of 10 species endemic to the mountain, meaning it doesn’t occur anywhere else.(Supplied

Dr Medd said Mount Canobolas was a rare oasis for tiny species.

“If the communities are fragmented then they lose their integrity and those ecosystems start to break down,” Dr Medd said.

“We are seeing that in major habitats throughout Australia in the deserts, in the Great Barrier Reef, in the alpine areas.” 

New species found 

He said if was not all doom and gloom for the Mount Canobolas ecosystem though after researchers found at least 15 new species for the region. 

This type of moss is one of 15 species previously not found on Mount Canobolas. (Supplied: Rosemary Stapleton)

Polyrichum commune is a species of moss that is typically found in the alpine regions of Tasmania and the Snowy Mountains. 

Dr Downing and DrMedd stumbled across the bryophyte organism while conducting a survey on Mount Canobolas.

“It is really quite exciting, it is not particularly a rare species, but we haven’t ever recorded it here,” Dr Downing said. 

About 70 per cent of Mount Canobolas was destroyed by a bushfire that required more than 100 firefighters to put out in 2018. 

Dr Meddsaid the fire most likely allowed microorganisms that had previously been lying dormant in the soil, such as the polyrichum commune, to sprout. 

Report by Hamish Cole in ABC News Central West, 23 May 2022