A separate study showed that the Warrambungle fire in 2013 resulted in annual soil losses of about 25 tonnes per hectare, which matches the government’s projected national park losses of 19.4 tonnes per hectare for the parks. national. Likewise, the fires of the early 1980s in the Royal National Park resulted in annual soil losses of 46 tonnes per hectare.
Professor Eldridge said erosion from fires has many negative environmental effects, ranging from loss of soil carbon and nutrients such as nitrogen and phosphorus, to clogged waterways and a reduced habitat.
“Soils take a long time to recover after a fire because the formation rates are extremely slow,” he said. “A typical rate for NSW is about one centimeter every thousand years. Repeated high intensity fires will slow this rate of soil formation.”
A spokeswoman for the Planning Department said the combination of fires and follow-up rains could “trigger major erosion events as the ability of landscapes to maintain soil stability changes due to the temporary loss of soil. plant cover “.
“Erosion events can drown out plant recovery and deplete seed banks in the soil,” she added.
Losses from erosion also extend to cultural heritage, such as in the Blue Mountains near Lake Burragorang.
A sacred waterhole on Reedy Creek – which the traditional owners of Gundungurra believe to be linked to Gurangatch, a Dreamtime spirit who was part fish and part reptile – has been practically filled with silt after the 2019-20 fires.
“We believe [Gurangatch] rested here, ”said Kazan Brown, a traditional owner. “It used to be about six feet deep, but now it’s only ankle deep.”
The report noted that 123 plant species currently designated as non-threatened had more than 80% of their sightings recorded in the 2019-2020 fire, raising questions as to whether their status should be changed. Likewise, 18 animal species now listed as non-threatened have had more than half of their sightings recorded in areas that have been burned.
“These numbers should sound the alarm bells on how NSW is able to deal with endangered species,” said Penny Sharpe, Labor Party spokesperson for the environment. “Losing so much soil and registering so much environmental degradation puts our fragile endangered species even more at risk.”
Despite such a report, the Berejiklian government cut spending on endangered species by a quarter in the budget released last month.
“Given the damage documented by the fires, there should be more money in programs like Saving Our Species, not less,” Ms. Sharpe said.
The Morning Edition newsletter is our guide to the most important and interesting stories, analysis and ideas of the day. register here.